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Environmental, land cover and land use constraints on the distributional patterns of anurans: Leptodacylus species (Anura, Leptodactylidae) from Dry Chaco
PeerJ
Regina Gabriela Medina1, Maria Laura Ponssa1, Ezequiel Aráoz2
1Unidad Ejecutora Lillo (UEL), CONICET-Fundación Miguel Lillo, San Miguel de Tucumán, Tucumán, Argentina
2IER (Instituto de Ecología Regional), Universidad Nacional de Tucumán, Yerba Buena, Tucuman, Argentina
10.7717/peerj.2605
Academic Editor
Scott Edwards
Biogeography, Biosphere Interactions, Conservation Biology, Spatial and Geographic Information Science, Zoology
Conservation, Chaco, Anura, Ecological Niche Model, Land cover, Leptodactylus, Distribution
© 2016 Medina et al.
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
Medina RG, Ponssa ML, Aráoz E. 2016. Environmental, land cover and land use constraints on the distributional patterns of anurans: Leptodacylus species (Anura, Leptodactylidae) from Dry Chaco. PeerJ 4:e2605 https://doi.org/10.7717/peerj.2605
Subtropical dry forests are among the most vulnerable biomes to land transformation at a global scale. Among them, the Dry Chaco suffers an accelerated change due to agriculture expansion and intensification. The Dry Chaco ecoregion is characterized by high levels of endemisms and species diversity, which are the result of a variety of climates and reliefs, allowing a wide variety of environments. The amphibian group exhibits a high richness in the Dry Chaco, which has been barely studied in relation to land cover changes. We used ecological niche models (ENMs) to assess the potential geographic distribution of 10 Leptodactylus species (Anura, Leptodactylidae), which are mainly distributed within the Dry Chaco. We characterized these distributions environmentally, analyzed their overlap with land cover classes, and assessed their diversity of ecoregions. Also, we evaluated how these species potential distribution is affected by the transformation of land, and quantified the proportional area of the potential distribution in protected areas. We found that temperature seasonality is the main constraint to the occurrence of the species studied, whose main habitats are savannas, grasslands and croplands. The main threats to these species are the effects of climate change over spatial patterns of seasonality, which could affect their breeding and reproduction mode; the loss of their natural habitat; the exposure to contaminants used by intensive agriculture and their underrepresentation in protected areas.
Habitat destruction and fragmentation produced by changes in land use and land cover (LULC), and climate change are major factors influencing the global decline of populations and species (Bennett & Saunders, 2010). The humid tropics and amazon basin were the main focus of research and debate in relation to the effects of land transformation over biodiversity (Aide et al., 2013). Nevertheless, in Latin America, dry forests and savanna/shrub biomes are experiencing the second highest rate of absolute deforestation, behind rainforests (Aide et al., 2013). The Great American Chaco–distributed across Argentina, Paraguay, Bolivia and small areas of Brazil–and particularly the Dry Chaco, is the only subtropical dry forest in the planet (sensu Olson et al., 2001). Since the early 1900s, the Dry Chaco has experienced extensive livestock ranching (Bucher & Huszar, 1999). At present, land use patterns are quite different across countries. The greatest annual rates of landscape transformation were registered in Paraguay, reaching 4% in 2010 (the highest historical values in the entire region), followed by Argentina (Vallejos et al., 2014). In Argentina, since the 1970s, the Dry Chaco suffered an accelerated change due to agriculture expansion and intensification, especially of soybean and implanted pastures (Zak, Cabido & Hodgson, 2004; Boletta et al., 2006; Grau, Gasparri & Aide, 2008). Both in Argentina and Paraguay, chacoan habitats destruction has been identified as one of the worst environmental disasters in South America (Taber, Navarro & Arribas, 1997; Vallejos et al., 2014). While deforestation for intensive agriculture is also occurring in Bolivia, most of the Bolivian Chaco is still forested (especially when compared to Argentina and Paraguay) (Taber, Navarro & Arribas, 1997). Today, the predominant natural vegetation of the Chaco corresponds to open woodlands of thorny forest, interspersed with grasslands (Morello et al., 2012). The subtropical Dry Chaco constitutes the second largest continuous forest, behind the Amazon rainforest (Eva et al., 2004) and it is the less fragmented dry forest ecosystem in the world (Portillo-Quintero & Sánchez-Azofeifa, 2010; Caldas et al., 2013). Consequently, it represents a major asset for continental-scale biodiversity conservation, which is highly threatened by LULC changes. Despite the current rate of habitat destruction and the ecosystem value of the Dry Chaco, the system of protected areas is scarce and inefficient in most of its extension, e.g. only 2% of the Argentinean Dry Chaco is protected under some type of legislation (Brown et al., 2006).
The Dry Chaco ecoregion is characterized by high levels of endemism and diversity of species, which are the result of a variety of climates and reliefs, deriving in a wide variety of environments (The Nature Conservancy et al., 2005). Thus, analyses assessing the impacts of LULC on the geographic patterns of distribution of taxonomic groups are of major importance, since different taxa are affected in different ways by land use and by its changes (Schulze et al., 2004; Leroux et al., 2010; Dallimer et al., 2012). Amphibians exhibit high richness in the Dry Chaco, which has been scarcely studied in association to land cover changes (Torres et al., 2014). This fact is worrying since amphibians have become a high-priority group for conservation efforts (de Pous et al., 2010; Urbina-Cardona & Flores-Villela, 2010; Trindade-Filho et al., 2012; Nori et al., 2013; Nori et al., 2015) due to the concern about declines in their populations, and amphibian species extinctions around the world (Young et al., 2001).
Anuran species of Leptodactylus inhabit both open (croplands, grasslands, and shrublands) and closed vegetation (forest) areas; thus, the environmental heterogeneity of the Dry Chaco can be explored through the distribution of the genus (de Sá et al., 2014). The genus is the most diverse in the Dry Chaco, representing 25% of the anuran species of the ecoregion (Cruz, Perotti & Fitzgerald, 1992; Brusquetti & Lavilla, 2006; Vaira et al., 2012), and at least one species of Leptodactylus has been declared as near threatened by the International Union for Conservation of Nature (2016). The genus shows the highest diversity of reproductive modes within Leptodactylidae family, the most diverse family of Neotropical anurans (200 spp). Conservation priorities of a certain taxonomic group may also inform about the conservation requirements of other groups (Rodrigues & Brooks, 2007). Under this assumption and taking into account that the most diverse group may be representative of a wide group of taxa, the genus Leptodactylus might be a good indicator to assess the responses of sensitive species to changes in LULC in the Dry Chaco ecoregion.
Current techniques of ecological niche models (ENMs) allow relating species distribution data (species occurrence at known locations) with information about the environmental and/or spatial characteristics of the locations (abiotic factors). The environmental conditions of the localities where a species occur provide of just a partial image of the niche which can be represented in the geographic space; thus, they may be informative about the potential distribution of the species (Lobo, 2015). This association leads to confusion between the concepts of Species Distribution Models (SDM) and ENM, since it is natural to talk about SDM when inferences from the occupied area are involved. However, if we try to model potential areas, which essentially involves geographic localities with favorable conditions for the occurrence of a species (i.e. conditions contained in its existing fundamental or realized niche, but which may be present in other unoccupied regions), we must use ENM concept (Peterson & Soberón, 2012). ENM is a robust method to characterize regional species distributions (Seoane et al., 2006; Ficetola et al., 2010), offering reliable information regarding environmental constraints. These spatial analyses are the basis for assessing the effects of LULC changes over the potential distribution of species, and for proposing conservation strategies.
In this study, we estimated the potential geographic distribution of 10 Leptodactylus species, which are mainly distributed within the Dry Chaco; and we characterized them environmentally, i.e. by assessing which environment variables are the most relevant to determine the occurrence of these species. To spatially characterize the distributions of Leptodactylus species, we analyzed the proportion of the ecoregions and the different land cover types in the full range of the potential geographic distributions. We used existing maps of cultivated areas from 1976 to 2013 to evaluate how the potential distributions of these species have been affected by the expansion of the agricultural frontier. To evaluate the state of protection of Leptodactylus chacoan species, we quantified the proportion of the potential distribution of these species included within protected areas, focusing on species included in International Union for Conservation of Nature (IUCN) conservation categories.
Selected species
We selected ten species of the genus Leptodactylus, whose main distribution area is in the Dry Chaco ecoregion: Leptodactylus bufonius, L. chaquensis, L. elenae, L. fuscus, L. gracilis, L. laticeps, L. latinasus, L. latrans, L. mystacinus and L. podicipinus. Among these species, Leptodactylus laticeps is the only one considered as near threatened by IUCN assessments (Cortez et al., 2004); and vulnerable by the categorization of Argentinean amphibians (Schaefer & Céspedez, 2012).
Occurrence data
Presence points databases were constructed based on revised specimens of collections, databases of herpetological collections, bibliography and free databases. The material revised proceeded from the following herpetological collections: Argentina: Fundación Miguel Lillo (FML), Museo Argentino de Ciencias Naturales (MACN), Museo de la Plata (MLP), private collections of Dr. María Laura Ponssa (L) and Dr. Julián Lescano (JL); Brazil: Museu Nacional de Rio de Janeiro (MNRJ), Museu de Zoologia de São Paulo (MZUSP), and Paraguay: Instituto de Investigaciones Biológicas del Paraguay (IIBP), Museo Nacional de Historia Natural de Paraguay (MNHNP). The database of Laboratorio de Genética Evolutiva (LGE, Instituto de Biología Subtropical, Misiones, Argentina) was also considered in the analysis. One hundred thirty five scientific articles were analyzed to extract presence points. When presence points were scarce, we completed species records with data obtained from Global Biodiversity Facility Information GBIF (accessed in March 2016). We cleaned this information to avoid mistakes from outdated taxonomic arrangements. All presence records are available in Supplemental Information 1.
We confirmed the species identifications when it was possible to avoid primary source of error in niche modeling. We identified the species recognizing external morphology features proposed in literature as descriptions of species, taxonomic and phylogenetic revisions (e.g. Heyer, 1970; Heyer, 1978; Heyer, 2014; de Sá et al., 2014). We used a binocular stereoscope when it was necessary.
We used the geographic coordinates of each specimen to georeference species occurrences, using Google Earth whenever these coordinates were missing. We estimated the uncertainties of these locations by considering the extent of the locality: each locality was defined as a circle, with a point marking the most likely position (the geographic center of the named place), and a radius representing the maximum distance from the point within which the locality is expected to occur (Wieczorek, Guo & Hijmans, 2004). The database was cleaned of records which were outside the known altitudinal range of each species and whose uncertainty was higher than 10,000 m. Sampling bias in geographic space (i.e. localities which are overrepresented in the collections) may lead to biases in the inferences about the environmental requirements of the species. To avoid this spatial bias and its consequent autocorrelation, we disaggregated occurrences of each species at 10,000 m with 'ecospat' package (Broenniman et al., 2014; Boria et al., 2014) implemented in R software. The conserved occurrence points were plotted in maps to check the consistency with the known ranges of the species. We analyzed a total of 2,306 localities, and the number of occurrences per species varied between 33 for L. laticeps and 467 for L. latrans (Table 1).
Table 1:
Compiled records: number of compiled records from different sources (herpetological collections, private anuran collections, bibliographic records and Global Biodiversity Information data base) with geographic coordinates.
Unique records: number of unique locality records. Checked records: number of locality records whose specimens were checked from the total number of unique records. Records not checked: locality records whose specimens were not checked from the total number of unique records. Collections: not checked specimens of scientific collections. GBIF: locality records obtained from Global Biodiversity Information Facility, Bibliographic records: locality records obtained from literature. Disaggregate records: number of disaggregate records to 10,000 m.
Compiled records
Unique records
Checked records
Records not checked
Disaggregate records
L. bufonius 1,562 334 198 93 – 43 271
L. chaquensis 1,099 463 237 111 – 115 383
L. elenae 354 136 81 2 – 53 122
L. fuscus 1,562 1,056 476 83 303 194 772
L. gracilis 422 200 89 38 – 73 178
L. laticeps 93 43 30 11 – 2 33
L. latinasus 1,716 488 246 106 – 136 416
L. latrans 2,138 514 264 228 – 22 467
L. mystacinus 641 335 169 70 – 96 292
L. podicipinus 824 273 117 37 15 104 214
Total 10,411 3,842 1,907 779 318 838 3,148
DOI: 10.7717/peerj.2605/table-1
Ecological niche model and environmental characterization
To model the presence of a species, we used the theoretical Biotic-Abiotic-Mobility approach (BAM) of Soberon & Peterson (2005), which captures and links the geographic and environmental dimensions of species distributions (Peterson & Soberón, 2012). The BAM model is composed of three components: 1) "B" components are the biotic conditions, i.e. the appropriate suite of both present species (e.g. food) and certain absent species (e.g. strong competitors, diseases). In general, this component is not included in the modeling process due to the fact that it is very difficult to make accurate spatial quantification of this kind of data (Barve et al., 2011). According to this and considering that Leptodactylus species exhibit a broad food spectrum, for which considering the component B becomes much more difficult, we do not included it in the present work. 2) The "A" components represent the abiotic conditions, e.g. bioclimatic variables; and 3) The "M" component is the region of the world which has been accessible to the species via dispersal over relevant periods of time. This heuristic scheme assumes that stable populations of a species will be found only in the intersection of the B, A, and M components, (B∩A∩M) (Soberon & Peterson, 2005).
To delineate the "A" component, we selected environmental variables (i.e. climate and soil variables) matching the temporal and geographic resolution of the studied species occurrences. Climate variables refer to temperature and precipitation. Since anurans are ectotherms, they are more vulnerable to environmental changes than other tetrapods (Duellman & Trueb, 1994). Temperature is the most pervasive factor affecting the rate of biological reactions and physiological processes of amphibians (Rome, Don Stevens & John Alder, 1992); while precipitation is the most important extrinsic factor controlling the seasonality of reproduction in anurans (Duellman & Trueb, 1994). As a matter fact, in most of the species of temperate latitudes, reproductive activity depends on temperature and precipitation (Duellman & Trueb, 1994). Soil was hypothesized to be an important predictor of the distribution of arid-adapted anurans, since it can affect water loss rates during aestivation (Schalk, Montaña & Springer, 2015). Soil pH influences hatching success in Pseudophryne bibronii (Chambers, Wilson & Williamson, 2006), thus, soil characteristics could affect the success of the survival rate of terrestrial egg-laying species, such as most Leptodactylus species. Climate information was obtained from WorldClim database (Hijmans et al., 2005), which includes 19 variables of temperature and precipitation. Soil information was obtained from SoilGrids1km database (Hengl et al., 2014, through ISRIC–WDC Soils), which includes eight global soil variables that summarize different aspects of soil at six depths. Most of these variables are not independent; consequently, Pearson correlations were used to detect and exclude highly correlated variables (r ≥ 0.8). For soil variables, correlation analyses were made within each depth and between depths (2.5, 22.5 and 45 cm depth). When high correlations were detected, we kept the variables that most likely affect the ecology of anurans. Eight bioclimatic variables were retained: BIO1 = Annual Mean Temperature, BIO2 = Mean Diurnal Range (Mean of monthly (max temp − min temp)), BIO4 = Temperature Seasonality (standard deviation of mean month temperature × 100), BIO5 = Maximum Temperature of Warmest Month, BIO6 = Minimum Temperature of Coldest Month, BIO12 = Annual Precipitation, BIO13 = Precipitation of Wettest Month, BIO14 = Precipitation of Driest Month. Because the correlations of each soil variable between depths were high (r > 0.9), only the variables of the most superficial depth (2.5 cm) were kept. Six soils variables were retained: 1) Sand content, 2) Coarse Fragments, 3) Soil organic carbon, 4) pH index, 5) Bulk density, and 6) Cation-exchange capacity. The environmental databases used presented a spatial resolution of 2.5′ (approx. 5 × 5 km per pixel at the equator).
A critical step for calibration, validation and comparison of ENMs is the definition of the "M" component; i.e. the extent of the region where the model calibration will be performed. The "M" component must be customized for each species and must be related to an explicit a priori hypothesis (Barve et al., 2011). It is reasonable to take the set of biotic regions within which a species is known to occur as the hypothesis of the M region (Barve et al., 2011). Here, the M region was defined for each species by identifying the ecoregions (sensu Olson et al., 2001) with known presences and by buffering the resulting region to generate a soft edge. The buffer size was between 0.1° and 0.5°, depending on each species data. A buffer of 0.5° was applied when the points were located marginally in one ecoregion, and a smaller buffer (less than 0.5°), when the points were located more uniformly in the ecoregions. This prevents from including areas where the species had no access. We pruned the selected areas when they included some regions where species obviously did not occur. For example, since Leptodactylus species are mainly distributed in the lowlands, we excluded higher altitudes from the "M" regions according to the altitudinal range known for each species.
ENMs were calibrated using a maximum entropy method, MAXENT v3.3.3K (Phillips, Anderson & Schapire, 2006) in batch mode implemented in R-package "ENMGadgets" (Barve & Barve, 2016). Maxent fits models based on the probability distributions that show maximum entropy (i.e. closest to uniform), subject to the correlations of known presences of species with the environmental conditions across the study area (Phillips, Anderson & Schapire, 2006). Most default settings were kept but we defined five bootstrap replications and raw outputs (i.e. continuous probability values). We randomly partitioned occurrence data in two subsets: 50% of the occurrences were used to calibrate the model, and the remaining 50% were used for model evaluation. Given the observed limitations of the Receiver Operating Characteristics Curve (ROC) approach we used a partial ROC area under the curve (AUC) to evaluate the performance of the model (Lobo, Jiménez-Valverde & Real, 2008). Partial ROC allows for differential weighting of omission and commission errors and focuses on meaningful predictions for model evaluation (Peterson, Papeş & Soberón, 2008). We restricted ROC space to predictions corresponding to omission error ≤ 5%, and we then randomly sub-sampled 50% of the available evaluation data 1,000 times and estimated the ratios of simulated AUCs and null expectations of AUC (Peterson, Papeş & Soberón, 2008) using Partial-ROC software (Barve & Barve, 2016). Probabilities were determined by direct count of null replicate frequencies of AUC ratios falling below the observed value.
To identify the variables which contributed the most to the model, we used a jackknife test on the original environmental variables. This test removes one environmental variable from the full list at a time and recalculates the model to quantify the contribution of each variable to the overall model performance.
Spatial analyses
The resulting ENM can be projected in the geographic space, thereby depicting the potential distribution area of each species (Araújo & Peterson, 2012). We assumed that the species analyzed are in ecological equilibrium (i.e. their populations are not migrating) and that the potential distribution obtained corresponds to their historical distribution. The assumption of equilibrium of a population within its ecological niche (or single environment) implies ignoring mutation pressures from the environment and migration processes (Levene, 1953). State of stable equilibrium should not be viewed as a primary property of ecological systems, but it is a feature that can emerge from extrapolation to large spatial scales (DeAngelis & Waterhouse, 1987). The estimates of the geographic range extent obtained by ENM techniques have proved to be more representative than those obtained by traditional methods (e.g. minimum convex polygon (MCP)), particularly when data are scarce or when species are rare (Marcer et al., 2013; Pena et al., 2014; Syfert et al., 2014); and also avoid potential subjective bias of experts (Fourcade et al., 2013). We used a minimum threshold (Anderson, Lew & Peterson, 2003) to convert raw model outputs (i.e. continuous probability values) to distribution estimates (i.e. a binary representation). We modified this threshold–which, by default, includes 100% of the training data–to consider the potential error in the occurrence data, by choosing the highest threshold which included (100–E)% of the training data, assuming E = 5% (Table 2). E is an estimate of the proportion of the occurrence data that is likely to include the georeferenciation error (Peterson, Papeş & Soberón, 2008). This is a conservative method that minimizes the commission rate. This threshold defines that 95% of the observed presences are predicted as such, representing, in other words, the sensitivity of the model (Allouche, Tsoar & Kadmon, 2006). We then projected the distributional estimates of the ENM in space to obtain a quantitative potential geographic distribution. The spatial reference used for the analyses was Lambert Azimuthal Equal Area (LAEA) projection at a spatial resolution of approximately 5 × 5 km per pixel at the equator. The analyses and maps were developed with QGis software v. 2.16.2 (QGIS Development Team, 2016).
Threshold: conversion threshold values to convert raw model outputs (i.e. continuous probability values) to distribution estimates (i.e. a binary representation).
Percentages of relative contributions of the environmental variables to each one species model.
Percentage of contributions of environmental variables
Annual mean temperature
Mean diurnal range
Temperature seasonality
Max temperature of warmest month
Min temperature of coldest month
Precipitation of wettest month
Precipitation of driest month
PH index
Cation exchange capacity
Soil organic carbon
Coarse fragments
Sand content
L. bufonius 0.20 5.91 2.19 10.82* 10.43* 1.17 5.54 6.07 10.07* 29.61* 2.92 2.75 6.23 3.43 2.85
L. chaquensis 0.12 8.10 1.67 43.34* 3.74 1.09 0.89 3.72 3.65 20.33* 2.11 4.11 0.69 1.35 5.21
L. elenae 0.12 3.70 4.44 34.50* 9.72 1.75 1.50 6.44 2.11 12.07* 3.66 11.57* 2.81 3.90 1.83
L. fuscus 0.19 5.08 3.89 19.69* 2.31 0.93 6.16 6.26 6.44 30.44* 1.47 9.48 2.84 4.44 0.57
L. gracilis 0.06 4.59 4.25 18.55* 5.16 2.16 3.99 2.82 3.08 12.15* 8.60 10.40* 17.22* 5.04 1.98
L. laticeps 0.21 2.37 0.85 5.56 33.63* 3.01 3.36 6.39 8.36 2.38 2.38 0.41 7.26 16.71* 7.32
L. latinasus 0.13 9.09 6.84 23.24* 2.36 4.62 8.77 9.85 3.41 6.86 1.90 12.03* 2.46 5.02 3.55
L. latrans 0.09 7.47 5.21 47.79* 1.00 1.23 6.21 4.12 3.19 7.63 2.96 9.24 1.25 1.03 1.67
L. mystacinus 0.12 5.51 2.43 24.05* 2.03 26.99* 3.46 8.54 3.77 7.39 6.19 2.85 2.31 2.42 2.06
L. podicipinus 0.11 2.97 3.10 18.96* 9.83 5.69 8.07 1.26 21.04* 16.59* 2.41 2.54 1.71 3.19 2.62
* Values show percentages of relative contributions of the environmental variables higher than 10%.
Land cover and ecoregion characterization
To spatially characterize the potential distribution of each Leptodactylus chacoan species, we quantified the proportion of their extent which overlapped with ecoregions (sensu Olson et al., 2001) and with the different categories of land cover for Latin America produced by Blanco et al. (2013). The 24 land cover categories (e.g. broadleaf forests, needle leaf forests, mixed forests, shrublands, grasslands, water bodies, urban areas and croplands) are based on the FAO/UNEP Land Cover Classification System (LCCS). We also assessed the relationship between Leptodactylus occurrences and major habitat types, by assigning land cover categories in two groups "Forest habitats" (e.g. Subtropical broadleaf deciduous and evergreen forests, Tropical broadleaf deciduous and evergreen forests) and "open habitats" (e.g. Croplands, Tropical, Subtropical and Temperate shrublands, Tropical, Subtropical and temperate grasslands).
Land transformation in the Dry Chaco
We assessed whether the potential distribution of Leptodactylus frogs matches that of chacoan cultivable areas, i.e. suitable agriculture areas which are likely to be transformed to either pastures or croplands. In order to evaluate this, we estimated the proportion of each species distribution area affected by agriculture expansion, taking into account cultivated plots of the entire Dry Chaco region from 1976 to 2013 (Vallejos et al., 2014).
To explore the degree of protection of Leptodactylus species, we quantified the proportional protected area within the full range of the potential geographic extent of each species, taking into account the protected areas categories I to VI assigned by the IUCN (Dudley, 2008) (Ia: Strict Nature Reserve; Ib: Wilderness Area; II: National Park; III: Natural Monument or Feature; IV: Habitat/Species Management Area; V: Protected Landscape/Seascape; VI: Protected area with sustainable use of natural resources) and National Parks, even those that were not included in any IUCN category. Shape files of the protected areas were obtained from the World Database of Protected Areas (IUCN & UNEP-WCMC, 2016).
The partial ROC tests indicated significant predictive ability of the models (p < 0.001). For all species, bioclimatic variables (temperature and precipitation) were the most important predictors. The temperature variables (temperature seasonality, the maximum temperature of warmest month and the minimum temperature of coldest month) were the most important variables for seven out of 10 species. Only for one species' potential distribution (L. podicipinus) the precipitation (precipitation of wettest month) was important. For two species' potential distribution a soil variable (PH index) was the most important (Table 2).
The potential distribution areas ranged from less than 40,000 km2 for L. laticeps to 7.5 million km2 for L. fuscus, with values between 1 and 3.5 million km2 for most species (Fig. 1). Leptodactylus fuscus and L. latrans were the species with the largest potential distribution ranges (above 5 million km2) (Fig. 1).
Figure 1: Distribution area (in MMKm2) of Leptodactylus chacoan species.
DOI: 10.7717/peerj.2605/fig-1
The level of overlaps of the potential distribution areas of Leptodactylus species ranged from 30 to 72% with "forest habitats" and from 29 to 71% with "open habitats" (Table 3). Among forest habitats categories, the highest overlaps were found in Subtropical broadleaf deciduous forests, Tropical broadleaf evergreen forests and Subtropical broadleaf evergreen forests. Among open habitat categories, the highest overlap occurred with croplands.
Percentages of overlap of the distributions models of chacoan species of Leptodactylus with land cover categories from Blanco et al. (2013).
L. bufonius
L. chaquensis
L. elenae
L. fuscus
L. gracilis
L. laticeps
L. latinasus
L. latrans
L. mystacinus
L. podicipinus
Forest habitats Tropical broadleaf evergreen forest 7.46 18.06* 28.21* 36.18* 0.36 1.93 0.30 21.12* 11.22* 34.70*
Tropical broadleaf deciduous forest 0.55 0.27 0.47 0.15 0.00 0.06 0.00 0.08 0.09 0.29
Sub-tropical broadleaf evergreen forest 5.87 8.56 9.79 6.37 23.38 0.68 6.65 9.34 11.28* 6.62
Sub-tropical broadleaf deciduous forest 41.73* 14.95* 22.70* 5.03 5.00 69.12** 22.36* 6.73 10.99* 9.14
Temperate broadleaf evergreen forest 0.00 0.00 0.00 0.01 0.03 0.00 0.01 0.03 0.02 0.00
Temperate broadleaf deciduous forest 0.00 0.03 0.00 0.01 0.09 0.00 0.01 0.02 0.03 0.00
Total 55.62** 41.87* 61.18** 47.74** 28.86** 71.80** 29.33** 37.32** 33.63** 50.75**
Open habitats Tropical shrubland 0.09 6.70 6.86 15.09** 0.01 0.04 0.00 12.46** 7.70 9.55
Tropical grassland 0.00 0.00 0.01 7.60 0.00 0.00 0.00 0.18 0.00 0.19
Sub-tropical shrubland 17.32** 8.38 5.57 1.52 11.61** 10.07** 14.69** 4.69 7.28 4.61
Sub-tropical grassland 0.30 1.80 0.01 0.36 10.29 0.00 10.61 2.60 3.80 0.36
Temperate shrubland 0.00 0.11 0.00 0.00 0.83 0.00 0.03 1.90 1.17 0.00
Temperate grassland 0.00 0.00 0.00 0.03 0.24 0.00 0.22 0.26 0.03 0.00
Cropland 22.87** 36.25** 21.24** 24.99** 41.08** 15.17** 38.69** 36.27** 42.98** 29.24**
Others 3.80 4.89 5.13 2.66 7.08 2.93 6.43 4.32 3.42 5.30
Total 44.38** 58.13** 38.82** 52.26** 71.14** 28.20** 70.67** 62.68** 66.37** 49.25**
* Values show overlap percentages higher than 10%.
** Values show overlap percentages higher than 50%.
All the species considered in this study distributed beyond the Dry Chaco ecoregion (Fig. 2). Leptodactylus laticeps, L. bufonius, L. latinasus, L. elenae and L. chaquensis are mostly Dry chacoan species, with at least 25% of their geographic range occurring in the Dry Chaco. These species potentially inhabit less ecoregions than the other species (Supplemental Information 2). On the other hand, the remaining five species (L. latrans, L. fuscus, L. podicipinus, L. mystacinus, L. gracilis) potentially inhabit in a greater number of ecoregions (Supplemental Information 2).
Figure 2: Maps for each Leptodactylus chacoan species, showing: distribution models, in grey; calibration area of the distribution model, (i.e. "M" region), in black line; presence data, in purple points.
The different colors correspond to the ecoregions proposed by Olson et al. (2001); and illustrate that all the species considered are distributed beyond the Dry Chaco ecoregion. (A) Leptodactylus bufonius (B) L. chaquensis (C) L. elenae (D) L. fuscus (E) L. gracilis (F) L. laticeps (G) L. latinasus (H) L. latrans (I) L. mystacinus (J) L. podicipinus.
Land transformation in Dry Chaco
By the end of 2013, 1.8 million km2 of Dry Chaco (19% of the natural area in the entire ecoregion) were transformed to agriculture (Vallejos et al., 2014). The percentage of remaining natural areas inhabited by Leptodactylus chacoan species in the Dry Chaco decreased every year from 1976 to 2013 due to agricultural expansion, although the greatest transformation occurred after 1996 (Fig. 3). The largest percentage of potential chacoan area loss was 16% (L. mystacinus and L. podicipinus), while for seven species the loss of chacoan area were between 15% (L. bufonius, L. gracilis, L. latinasus and L. latrans) and 14% (L. chaquensis, L. fuscus and L. laticeps). The minimum loss of potential chacoan area was 13% (L. elenae) (Fig. 3).
Figure 3: Percentage of transformation of natural area to cultivated plots in the Dry Chaco from 1976 to 2013, for each Leptodactylus chacoan species.
The highest proportion of the potential distribution area in protected areas was found in Leptodactylus fuscus, L. latrans and L. mystacinus (between 6 and 11%), while the remaining species (L. bufonius, L. chaquensis, L. elenae, L. gracilis, L. latinasus, L. laticeps and L. podicipinus) exhibited between 3.5 and 5% of their potential distribution in protected areas (Fig. 4). The near threatened (Cortez et al., 2004) and vulnerable (Vaira et al., 2012) species Leptodactylus laticeps showed only 3.6% of its potential distribution in protected areas (Fig. 5).
Figure 4: Percentage of protected area within the potential distribution range of Leptodactylus chacoan species.
Figure 5: Map showing the potential distribution of Leptodactylus laticeps, in grey.
Protected areas overlaying the potential distributions of Leptodactylus laticeps are filled polygons in green.
We found that the main constraining variable of the potential distribution of Leptodactylus chacoan species is temperature (temperature seasonality, maximum temperature of warmest month and minimum temperature of coldest month), and that these species are found in both forest and open areas. In the Dry Chaco ecoregion, they inhabit cultivable areas which are being transformed from natural vegetation to pastures and croplands. Leptodactylus species are underrepresented under the current system of protected areas. This combination of features suggests that Leptodactylus chacoan species are vulnerable to both climate change and habitat transformation. This situation is especially critical for L. laticeps, which besides being already threatened is distributed mainly in the Dry Chaco and is poorly represented in the system of protected areas.
Our results show that the most important bioclimatic variable explaining species occurrence (in 70% of the studied species) was temperature. Other studies have also shown that climate (especially temperature and rainfall) is a determinant factor for amphibians (e.g. Parris, 2004; Urbina-Cardona, Olivares-Pérez & Reynoso, 2006). Since amphibians are ectothermic organisms, environmental temperature is probably a major constraint to their ecophysiological traits; for example, their mobility and their energy balance may be affected by temperature (Bennett, 1990). Physiological traits turn amphibians strongly sensitive to environmental conditions (Ferder & Burrgren, 1992), and consequently to climatic change (Pounds, Fogden & Campbell, 1999; Pounds et al., 2006). Projected climate changes over the 21st century include rises in surface temperature, and in the frequency and duration of heat waves and the occurrence of extreme precipitation events (IPCC, 2014). Also, seasonality will be affected by more frequent hot temperature extremes and fewer cold temperature extremes over most land areas (IPCC, 2014). Particularly, in south-eastern South America, which includes Dry Chaco ecoregion, changes in precipitation produce wetter conditions (Christensen et al., 2007). Under these scenarios, it is expected that populations change their geographic ranges to coldest areas, i.e. to higher altitudes or latitudes (Harsch et al., 2009; Thomas, 2010; Chen et al., 2011), although in the case of amphibians, this is unlikely due to their low dispersal ability. Measurements of the home range size of amphibians show a mean home range size of 40 m2 (Wells, 2007). Moreover, the capacity for amphibian behavioral thermoregulation is limited because the cooling effect of evaporative water loss from skin counteracts heat gain by basking (Hutchinson & Dupe, 1992). Studies revealed that the effects of climate change over amphibians involve changes in the timing of breeding of some species (Blaustein et al., 2010; Carey & Alexander, 2003), instead of changes in their distributions (Corn, 2005). For example, no colonization of higher altitude areas associated with declines of Anaxyrus boreas has been found (Livo & Yeakley, 1997). In subtropical areas, the period of activity of amphibians and their population dynamics are strongly influenced by climate seasonality, e.g. reproduction behavior of most species occurs in the warm season of the year (Conte & Machado, 2005). For many species of Leptodactylus genus, the reproductive season matches with wet and/or warm season, e.g. L. latinasus, (Gallardo, 1964; Canavero et al., 2008), L. bufonius (Cei, 1980), L. gracilis, (Canavero et al., 2008; Ximenez & Tozetti, 2015), L. mystacinus, (Gallardo, 1964), L. fuscus, (Martins, 1988; Prado, Uetanabaro & Haddad, 2005; Lucas et al., 2008), L. elenae (Prado, Uetanabaro & Haddad, 2005), L. chaquensis (Gallardo, 1987; Prado, Uetanabaro & Haddad, 2005; Canavero et al., 2008) and L. podicipinus (Cei, 1980; Vizotto, 1967; Rossa-Feres & Jim, 1994); although it was reported that populations of L. podicipinus from the Brazilian pantanal exhibit a continuous reproductive cycle throughout the year (de Almeida Prado, Uetanabaro & Lopes, 2000; Prado, Uetanabaro & Haddad, 2005). The Dry Chaco presents a monsoonal climate, in which rains are concentrated in the warm season. Since the reproduction of most amphibians is associated to water, modifications in water balance in the area could have significant effects on their breeding timing and behavior. Thus, our results suggest that climate change could affect Leptodactylus chacoan species in different and unpredictable ways.
In general, the Leptodactylus species studied inhabit both forest and open areas in similar proportions, with even a greater proportion in open areas. This result matches that of Torres et al. (2014), who found that the response of the probability of presence of all the analyzed amphibian species in Argentinean northwestern Dry Chaco to woody biomass was negative. The importance of open habitats for Leptodactylus species suggests that these species evolved in landscapes which were more similar to open habitats than to forests, a scenario proposed for the pre-European landscape of the Chaco (Morello & Saravia Toledo, 1959a; Morello & Saravia Toledo, 1959b; Adámoli et al., 1972; Adámoli et al., 1990; Bucher & Huszar, 1999), in which the substantial contemporary woodland advance has been a result of domestic livestock overgrazing (Morello & Saravia Toledo, 1959a; Morello & Saravia Toledo, 1959b; Adámoli et al., 1990). Thus, savannas might have been an important cover type where part of the chacoan biota evolved (Torres et al., 2014).
Among the open habitat categories, "croplands" was the most important for all species, which is also consistent with observational field data (e.g. Peltzer et al., 2006; Ponssa & Barrionuevo, 2008; Attademo et al., 2014; Prado & Rossa-Feres, 2014; Guerra & Aráoz, 2015). The IUCN categorization (2016) mentions that L. bufonius, L. chaquensis, L. elenae, L. fuscus, L. latinasus, L. latrans, L. mystacinus and L. podicipinus are or appear to be well adapted to anthropogenic disturbances, while Leptodactylus gracilis is found in anthropic areas only in southern Brazil (Heyer et al., 2004). The present study also shows that L. gracilis may inhabit anthropogenic areas, since 71% of their potential geographic range is covered by open habitats, from which 41% is covered by croplands. Moreover, L. gracilis, L. latinasus and L. mystacinus have been suggested to be invading species, due to their abundance in agricultural ponds, and their ability to constitute stable populations in these environments (Sanchez et al., 2013).
The dynamics of land cover transformation to agriculture shows that one half of analyzed Leptodactylus species may inhabit mainly cultivable areas. The percent loss of their potential distribution area within the Dry Chaco is near of the transformation rate of natural habitats to cultivated plots from 1976 to 2013. The largest percentages of decrease were found for L. mystacinus and L. podicipinus. This is particularly worrying for L. laticeps and L. bufonius, species which are distributed mainly in the Dry Chaco, which the loss of chacoan area represent the 14% and 10% of their entire potential distribution respectively. The entire dry diagonal region is suffering the same process of natural habitat loss described for the Dry Chaco, e.g. the Cerrado biome is being transformed for soybean production (Fearnside, 2001; Warnken, 1999). The Caatinga and the Cerrado (Beuchle et al., 2015), are also experiencing a continuous net loss of natural vegetation, and an expansion of sugarcane crops in the ''dry diagonal'' (Manzatto et al., 2009). This scenario represents potential threats to species with high percent loss in the Dry Chaco (mentioned above) and to those inhabiting the "Dry Diagonal," such as L. latrans and L. podicipinus. The projected increase in annual rainfall may accelerate deforestation rates due to agriculture expansion, which would have a significant effect in the conservation of Leptodactylus chacoan species. It has been observed that deforestation in the Chaco is to some extent controlled by annual rainfall (Grau, Gasparri & Aide, 2005). This may be especially relevant for the conservation of L. laticeps. At least 20% of the potential distribution area of this species, which is already threatened, has already been transformed to agriculture in the last 40 years. Additionally to habitat loss and/or fragmentation in the Dry Chaco, the fact that Leptodactylus anurans potential geographic range currently corresponds to croplands and cultivable areas raises concern about the potential threats to which they may be exposed, e.g. contamination. It has been shown that anuran species breeding within or around agricultural areas are usually exposed to pesticides (Peltzer, Lajmanovich & Beltzer, 2003; Peltzer et al., 2006), which produce teratogenic effects, growth and development retardation, and consequently, decreasing survivorship (Hayes et al., 2006). This could be a serious risk for these well adapted to anthropogenic disturbances Leptodactylus species, and particularly for Leptodactylus latinasus, L. chaquensis, L. latrans, L. mystacinus, L. gracilis and L. fuscus, whose reproduction habits involve the exploitation of soil depressions in cultivated areas (Vasconcelos & Rossa-Feres, 2008; Silva & Rossa-Feres, 2007; Guerra & Aráoz, 2015; Peltzer et al., 2006).
Most of the anuran species undergo ontogenetic niche shifts (aquatic larvae and terrestrial adults); which is the case of Leptodactylus anurans, whose clutch deposition mode involves aquatic or terrestrial foam nests, aquatic larvae, and terrestrial adults. Thus, anthropic landscape transformation may produce a "habitat-split" (Becker et al., 2007), i.e. a spatial separation between remnants of terrestrial habitat and breeding sites (Dunning, Danielson & Pulliam, 1992). Habitat split presents a strong negative effect on anuran species with aquatic larvae, and is a determinant factor of population size, structure, and distribution, acting within a single generation (Becker et al., 2007).
We found that the percentages of Leptodactylus species distributions represented in protected areas are scarce (11% or less). Consequently, most of their geographical ranges (i.e. approximately 90%) may be vulnerable to human disturbance. A similar pattern was found for threatened anurans of Northeastern Brazil (Adelophryne baturitensis, Adelophryne maranguapensis, Allobates olfersioides and Agalychnis granulosa) (Campos, Brito & Solé, 2013). Added to the underrepresentation of chacoan species of Leptodactylus in protected areas, it has been found that the current assignment of protected areas to IUCN categories does not correspond to the expected gradient of naturalness (Leroux et al., 2010; Bishop et al., 2004; Chape et al., 2005; Dudley, 2008). Leroux et al. (2010) showed that the global protected areas network lacks of strictly-protected areas with low human influence.
Leptodactylus laticeps is under Near Threatened and Vulnerable conservation categories by Cortez et al. (2004) and the Argentinian assessment (Vaira et al., 2012), respectively. Our results show that L. laticeps inhabits the Dry Chaco ecoregion almost exclusively, mainly the Subtropical broadleaf deciduous forest (a typical natural land cover of Dry Chaco). The land transformation analysis showed that this species inhabits cultivable lands inside the Dry Chaco ecoregion, which, in combination with the underrepresentation of L. laticeps in protected areas and the expansion of agriculture around chacoan protected areas, increases the risk of ecological isolation (Matteucci & Camino, 2012). In Copo National Park, an Argentinean protected area of Dry Chaco, the increase in human corridors (e.g. roads) between 1976 and 1988 has been followed by an increase of the surrounding parceled land between 1988 and 2007 (Matteucci & Camino, 2012). Furthermore, habitat connectivity is severely compromised in the Argentinean Dry Chaco, where there are no ecological corridors connecting protected areas (Burkart, 2007). In Paraguay, actions to keep habitat connections have been limited to proposals such as the Biodiversity Corridor of the Dry Chaco (Comisión Mundial de Áreas Protegidas Paraguay, 2007). This proposal includes protected areas located at the northern end of the potential distribution range of L. laticeps: Teniente Agripino Enciso, Médanos del Chaco and Defensores del Chaco National Parks, the Natural Monument Cerro Timane Cabrera, Guasú Natural Reserve; and the Kaa Illa National Park in Bolivia. Also, the protected area systems in Latin America are deficient in the administration of economic resources, equipment, human resources and legal and regulatory frameworks (Brown et al., 2006; Castaño-Uribe, 2008). For instance, in Latin America and the Caribbean region: 1) Paraguay presents the lowest number of human resources per unit of protected area and the lowest rate of investment resources of the nation by protected hectare; 2) in Argentina, the staff has no specialized functions, lacking of own equipment; and 3) from 2001 to 2006, both in Argentina and in Paraguay, the amount of money allocated to protected areas decreased (Castaño-Uribe, 2008). In addition to these global concerns, it has been reported that L. laticeps species suffer of international commercial exploitation for pet trade (Schaefer & Céspedez, 2012; Cortez et al., 2004).
To conclude, the main constraint to the potential distribution range of Leptodactylus chacoan species is temperature. Consequently, climate change associated to modifications of seasonality patterns could affect the breeding time and reproductive mode of these anurans. Land transformation for agriculture activities in the Dry Chaco exhibits an increasing trend in natural habitats rate of loss, where Leptodactylus chacoan species inhabit. This implies three potential adverse effects on amphibians: 1) habitat loss; 2) "habitat split," produced by landscape fragmentation; and 3) exposure to contaminants used by intensive agriculture activities. The state of Leptodactylus protection is deficient, due to the scarcity of protected natural habitats in the region, and the underrepresentation of the potential distribution range of Leptodactylus species within protected areas (on average, around 5% of their potential distributions). This situation implies a strong concern about L. laticeps populations, whose main threats are agriculture activities and hunting pressure. In the Dry Chaco, open areas, such as savannas, grasslands and croplands, are the main habitat of Leptodactylus species. However, the current conservation focus in the Dry Chaco is on forest habitats, for which conservation planning should be redesigned to take into account the natural savannas and grasslands, in order to more comprehensively protect and account for habitat heterogeneity.
Locality data information of all unique records compiled for Leptodactylus bufonius, L. chaquensis, L. elenae, L. fuscus, L. gracilis, L. laticeps, L. latinasus, L. latrans, L. mystacinus and [i]L. podi.
Locality data information includes collection number whenever available, museum acronym following Sabaj Perez (2010), locality data description, latitude and longitude in decimal degrees, and the bibliographical reference from which the information was obtained.
DOI: 10.7717/peerj.2605/supp-1
Percentages of potential distribution of Leptodactylus spp.
Percentages of potential distribution of Leptodactylus bufonius, L. chaquensis, L. elenae, L. fuscus, L. gracilis, L. laticeps, L. latinasus, L. latrans, L. mystacinus and L podicipinus on each ecoregion (sensu Olson et al., 2001). Values with asterisk show overlap percentages higher than 10%.
The authors thank the following people for providing specimens or working space in their collections: J. Faivovich, S. Nenda, E. Lavilla, S. Kretchsmann, M. Canepa, D. Baldo, T. Grant, C. Haddad, N.C. Pupin, J. Pombal Jr., M. K. Cardoso, L. Lescano, A. Braga, J. Williams, F. Netto, F. Brusquetti, A. Weiler, K. Airaldi, N. Marínez.
Additional Information and Declarations
Regina Gabriela Medina performed the experiments, analyzed the data, contributed reagents/materials/analysis tools, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.
Maria Laura Ponssa conceived and designed the experiments, wrote the paper, prepared figures and/or tables, reviewed drafts of the paper.
Ezequiel Aráoz conceived and designed the experiments, performed the experiments, analyzed the data, reviewed drafts of the paper.
Data Deposition
The following information was supplied regarding data availability:
The raw data are included in the manuscript and as Supplemental Dataset Files.
This study was supported by the Universidad Nacional de Tucuman G519. CONICET PIP0284. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
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Lobo JM, Jiménez-Valverde A, Real R. 2008. AUC: a misleading measure of the performance of predictive distribution models. Global Ecology and Biogeography 17(2):145-151
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HOME / NEWS & MEDIA / NEWS /
Unique Research Study Identifies Benefits of 'Return Migration' for Native Workers
Doug Gavel - HKS News
Large influxes of migrants into foreign labor forces can often harm the fortunes of native workers, particularly those in low-skilled positions. A 2015 study, for instance, documented the wage losses suffered by native-born Americans in Miami as a result of the Mariel boatlift in 1980, during which as many as 125,000 Cubans immigrated to south Florida. But a new research study focusing on an entirely different set of migrants during a more recent period suggests there may be benefits to local workers when previous migrants return to work at home.
This study, co-authored by Harvard Kennedy School Professor Ricardo Hausmann and Ljubica Nedelkoska at the Center for International Development, closely examines the impacts from the return of more than 100,000 Albanian migrants to their home country in the five years following the Greek economic crisis, which began in 2009. "The suddenness and the size of the migration created conditions for studying the impact of return migration on the home labor market in a natural experiment setting," the authors report.
Using data obtained from both Albania and Greece's Quarterly Labor Force Surveys, the researchers concluded that the return migration did not reduce the wages of local workers; in fact, it was more beneficial than expected for those workers who never left their home country.
"We find that most migrants return to the district of birth where they seem to mobilize their savings in entrepreneurship; the return migrants are significantly more likely than non-migrants to employ others, work as managers and be self-employed. About half of them are active in the agricultural sector, where our findings suggest that they pull non-migrants out of non-participation, unemployment and subsistence agriculture and towards commercial farming," the authors concluded. "The effects are large enough to partially offset the negative shock of lower inflow of remittances during the post-crisis period."
Shkodra, Albania. 2014. Agim Dini has opened a farm with the help of a financial aid project (Oxfam Italia onlus) for migrants who returned to Albania. Credit: Laura Aggio Caldon.
Hausmann and Nedelkoska admit that their findings were more optimistic than they had anticipated, raising a number of important questions.
"An important question is whether migration mainly helped returnees set up firms through enabling financial savings, or through the accumulation of knowhow. While we do not have the right data to answer this question, anecdotal evidence and the timing of developments suggests that, although both played a role, the latter must have played a larger one." They cite the example of a spike in vegetable exports that took place after 2009.
The study may also hold some important lessons for policymakers when thinking about the value of their Diasporas relative to their native economies and workforces.
"Programs designed for active collaborations with the diasporas that help governments learn about the level of development, engagement interests, professional interests and needs of the diaspora, and which actively learn from the diasporas, seem more sensible policies for diaspora engagement to start with," Hausmann and Nedelkoska conclude.
Download Research Brief
See also: Migration & Mobility, News

redpajama_set_name: RedPajamaCommonCrawl


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text:
How to Reduce Owner Equity in an S-Corp
Finances & Taxes
By Alia Nikolakopulos
How Much Loss Can You Include With an S Corporation?
Difference Between S or C Corporation
What Are the Advantages of a Single Member LLC Compared to a Sole Proprietor?
What Is the Effect Dividend Payments Have on a Corporation's Balance Sheet?
Can I Give Out a Dividend in an LLC Partnership?
Owner's equity in an S-corporation is the owner's share of the company's assets and liabilities. The extent of each owner's equity depends on the percentage of the S-corporation that he owns. S-corporation equity is more commonly referred to as basis. Initially, an owner's basis is equal to the amount he invests in the company or its stock. Basis is increased by company profits and decreased by certain items. Owners of S-corporations must keep track of their own basis balances individually, as the corporation does not do this.
Subtract from the owner's equity any losses passed through to the owner at the end of the year. Net losses from the S-corporation's regular operating activities decrease the owner's basis in the company.
Subtract distributions made to the owner from his equity balance. Non-dividend distributions decrease the owner's basis. Distributions are tax-free to the owner and a deductible expense to the corporation.
Subtract non-capital, non-deductible and depletion amounts from the owner's equity balance, according to the percentage of the business owned. One of the most common expenses in this category is business meals. While these are a deductible expense for the corporation, the cost of business meals and entertainment also reduces the owner's basis in the company. Other expenses in this category include certain fines and penalties and expenses incurred by the corporation for producing non-taxable income.
IRS: S-corporation Stock and Debt Basis
Real Life Accounting; Understanding Equity Accounts; John W Day; 2008 (PDF)
Tax Almanac: Treasury Regulations - Subchapter A, Sec 1.1367-1
With a background in taxation and financial consulting, Alia Nikolakopulos has over a decade of experience resolving tax and finance issues. She is an IRS Enrolled Agent and has been a writer for these topics since 2010. Nikolakopulos is pursuing Bachelor of Science in accounting at the Metropolitan State University of Denver.
How to Figure Out Subchapter S Shareholder Earnings
How to Exit an S Corp
The Differences Between an S Corporation Shareholder Basis and a Partnership
How to Deduct Owner Health Insurance for S Corporations
Steps to Creating an Accounting Worksheet
S-Corporations & Partnership Interest
How Is a Shareholder Basis Affected by Tax Credits?
A Common Business Transaction That Would Not Affect Stockholders' Equity
How Are Property Distributions From an 'S' Corp Taxed?
1 How to Figure Out Subchapter S Shareholder Earnings
2 How to Exit an S Corp
3 The Differences Between an S Corporation Shareholder Basis and a Partnership
4 How to Deduct Owner Health Insurance for S Corporations


Natural Stone Gallery Displays Stone Pavers & Stone Cladding. Natural Stone Gallery Displays Stone Pavers & Stone Cladding.
Photos in the stone gallery are intended as a guide only. Stone, by its very nature of being natural, is subject to tone and shade variations which makes it truly individual to each client.
As you can see from the menus you can select the stones by type : colour : origin. Call us to discuss your shortlisted selection and the project which you plan on using these materials.
We are happy to supply full sized samples for selected stones and we are also available to discuss all aspects of suitability of use and installation procedures for the materials that are viewed in the stone gallery. Please note that not all materials are available as stock items and it may be necessary to order in certain products. Whilst the faster moving lines are already produced as pavers, stone tiles or cladding in standard size formats and finishes a number are not. We can produce nearly anything in natural stone and we are happy to discuss your requirements and project in greater detail.
Located in Windsor, Berkshire we complete architectural stone masonry features & Stone flooring in marble, granite and limestone, wall tiles plus cut to size stone items for interior and exterior projects.
We project manage commercial, civil and residential contracts for architects, stakeholders and main contractors.
Quality is not expensive. It is timeless.


text:
William John Heber-Percy1
M, #664841, b. 21 September 1965
William John Heber-Percy was born on 21 September 1965.1 He is the son of Reverend Christopher John Heber-Percy and Lyndis Elizabeth Phillips.1
Thomas Henry Heber-Percy1
M, #664842, b. 5 August 1967, d. 2014
Thomas Henry Heber-Percy was born on 5 August 1967.1 He was the son of Reverend Christopher John Heber-Percy and Lyndis Elizabeth Phillips.1 He died in 2014.2
[S8482] Anna Percy, "re: Percy Family," e-mail message to Darryl Roger Lundy, 11 February 2018. Hereinafter cited as "re: Percy Family."
Anna Heber-Percy1
F, #664843, b. 15 April 1970
Anna Heber-Percy was born on 15 April 1970.1 She is the daughter of Reverend Christopher John Heber-Percy and Lyndis Elizabeth Phillips.1 She married Brendan John Maguire in April 2000.2
Children of Anna Heber-Percy and Brendan John Maguire
Samuel Thomas Maguire2 b. 2001
Phoebe Rose Maguire2 b. 2004
Susan Elizabeth Heber-Percy1
F, #664844, b. 2 June 1943
Susan Elizabeth Heber-Percy was born on 2 June 1943.1 She is the daughter of G/Capt. John Heber-Percy and Eve Robertson.1 She married Karl John Sabbagh, son of Isa Khalil Sabbagh, on 31 July 1965.1
She was educated in 1964 at Girton College, Cambridge University, Cambridge, Cambridgeshire, England, Bachelor of Arts (B.A.)1 From 31 July 1965, her married name became Sabbagh.1 She lived in 2003 at 76 Sheen Park, Richmond, Surrey, England.1
Children of Susan Elizabeth Heber-Percy and Karl John Sabbagh
Lucy Elizabeth Sabbagh1 b. 13 Jan 1970
Isabella Mary Sabbagh1 b. 1972
Susanna Jane Sabbagh1 b. 1975
Jonathan Christopher Sabbagh1 b. 1978
Karl John Sabbagh1
Karl John Sabbagh is the son of Isa Khalil Sabbagh.1 He married Susan Elizabeth Heber-Percy, daughter of G/Capt. John Heber-Percy and Eve Robertson, on 31 July 1965.1
Children of Karl John Sabbagh and Susan Elizabeth Heber-Percy
Isa Khalil Sabbagh1
Isa Khalil Sabbagh lived at Washington, D.C., U.S.A.1
Child of Isa Khalil Sabbagh
Karl John Sabbagh+1
Jonathan Christopher Sabbagh1
Jonathan Christopher Sabbagh was born in 1978.1 He is the son of Karl John Sabbagh and Susan Elizabeth Heber-Percy.1
Lucy Elizabeth Sabbagh1
F, #664848, b. 13 January 1970
Lucy Elizabeth Sabbagh was born on 13 January 1970.1 She is the daughter of Karl John Sabbagh and Susan Elizabeth Heber-Percy.1
Isabella Mary Sabbagh1
Isabella Mary Sabbagh was born in 1972.1 She is the daughter of Karl John Sabbagh and Susan Elizabeth Heber-Percy.1
Susanna Jane Sabbagh1
Susanna Jane Sabbagh was born in 1975.1 She is the daughter of Karl John Sabbagh and Susan Elizabeth Heber-Percy.1


All riders are welcome, but pick your skill level carefully. Start conservatively.
This ride originates from the lower parking lot of the visitors center in Valley Forge National Park. The ride will be a moderate pace on varying terrain usually 3.5 to 4 hours in length, so bring a few power bars or your favorite mid ride snack. Start time is 10:00am and the ride begins the first Sunday after daylight savings time ends. Weather permitting this ride will continue through until mid March when most Sundays are race days. Questions contact: Ron Livingston and enquire if the ride is happening on any given weekend.
The ride meets at Cycles BiKyle. Ride leader Jay Kaplan (610-642-3128). Rides will continue throughout the Winter months starting at 9, weather permitting (specifically, if roads are dry one hour prior to ride start). Email Sam Grinspan for questions about this ride.
As an active cycling club our members are riding all the time, scheduling rides outside of the regularly posted rides, attending publicized tours and races throughout the Mid-Atlantic region. Many of these activities are set up on the discussion page. The discussion page is members only so you will need to be a current member to access this forum. Feel free to email any of the riders on this page for information on membership benefits, impromptu rides, and events club members will be attending.
This rides meets at the Victory Brewing parking lot, 420 Acorn Lane Downingtown PA. Rides start with the daylight savings time change until the time change in the fall. The ride has no formal leader and follows the same route through southern Chester county each night.
30 miles of racing at the Great Valley Corporate Center. Racing starts at 6:15. The format for this race is a sprint every three laps. The average speed ranges from 24 to 27 mph . This racing begins the 1st week ending daylight savings.


text:
Kelvin Hall
About the Re-opening
The Hunterian at Kelvinhall
Fostering Collaboration
Postgraduate study at Kelvin Hall
University of Glasgow Facilities
The Next Steps for Kelvin Hall
The re-opening of the Kelvin Hall in 2016 marks the first stage in its transformation as a new academic and cultural destination for Scotland and the UK.
Hunterian at the Kelvin Hall
The new Kelvin hall opened in 2016, the result of a partnership between the University of Glasgow, the National Library of Scotland and the city of Glasgow.
The refurbishment work transformed the landmark building into a centre of excellence for research, teaching, public engagement and health and wellbeing.
The new development has allowed the University's Hunterian Museum to enhance access to its collections, and provide new opportunities for training and research.
The Hunterian Collections Study Centre is the first purpose-designed facility within Higher Education to offer innovative object-based research, teaching and training for a wide educational audience.
It operates as an object laboratory, in which museum collections and objects can be studied, curated or used for teaching or training.
The Hunterian at the Kelvin Hall:
houses over one million items from the Hunterian collections
includes state-of-the-art teaching and conference suites, allowing the Hunterian to deliver collections-based postgraduate programmes
delivers an innovative public programme of open studies courses, through the Centre for Open Studies
delivers professional training and development for the cultural and heritage workforce, through the Academy for Cultural & Heritage Skills
Images © Andrew Lee
Learn more about the Hunterian at Kelvin Hall
Hunterian Collections Study Centre
Learn more about the Hunterian Collections Study Centre


What is the BRA? How does it and should it contribute value to the city of Boston?
What is the culture of the BRA?
What are the key touchpoints of the BRA? What works, doesn't work and why?
What is the outside perception of the BRA? What is driving that?
How do people think about the future of their city? How do they want to engage?
How is the world changing? And how will this effect Boston and the BRA?
In addition to speaking with internal staff, we'll be focusing the bulk of our learning on two development projects in Boston that are representative of the work the BRA does, are hot topics in the community and which will give us a tangible understanding of how all parties engage with one another. The projects are 3193 Washington Street (a proposed residential project on the border of Roxbury and Jamaica Plain in the BRA's PLAN JP/Rox study area) and the Back Bay/South End Gateway Project. Across these projects we'll be speaking with citizens, community groups, the media, architects, developers and the BRA staff who facilitate the development process.
We will round out our learning by conducting workshops in additional Boston neighborhoods, speaking with other developers and architects and tapping into thought leaders and best-in-class cities to understand trends in urban planning and civic engagement.
Throughout the project we're looking for input so please participate in the conversation.


More fun than just a barrel of monkeys would definitely be 100 Monkeys!
100 Monkeys is a five piece alterna-funk band out of Los Angeles in which musicians Jackson Rathbone, Ben Graupner, Ben Johnson, Lawrence "Uncle Larry" Abrams, and Jerad Anderson all take on vocal and instrumental duties on different songs in what they've dubbed the "switcheroo" during their live performances. Yes, they're named after the "Hundredth Monkey Effect" (pretty clever if you ask me, seeing as there is no one particular lead singer or one person playing only one instrument for a show's duration.). They've managed to amass a small-but-definitely-growing, loyal fan base due in no small part to Jackson's visibility – he's also an actor who appears in many quirky, independent films and tv shows, but his most well-known role is that of Jasper in the Twilight Saga movies.
The July 26 Atlanta show was my third time seeing them, and this time, the "third time's a charm" rule held. And thank goodness, because I was really about to give up on this band! I have to be fair in saying that the previous two times, it was no fault of the band that I had a less than awesome time. They did everything right. Their sets were tight, they sounded good, and were supported all three times by some pretty obscure, but promising new bands you might not have heard of yet.
When I saw them at the Wild Horse Saloon in Nashville in November of '09, Chicago area blues-rockers Tin Tin Can opened. They were a wonderful choice to get the rowdy crowd (of many, many, many teen & tween Twi-hards and their mamas) up and moving and ready for the Monkeys' performance. I was exceptionally irritated at this show because it took me forever to get parked, forever to get inside the venue, and forever to find a spot about ten rows back. By then, Tin Tin Can's performance was probably half over. I was also sick as a dog, and didn't even dare stick around longer than it took me to buy a t-shirt. After leaving, it took me, and this is NO JOKE, from about midnight till 3 in the morning to get out of the parking garage in Nashville. (Okay, so some of that time was spent trying to actually find the garage I'd parked in….but most of it was spent just trying to get out onto the street!) I don't know what was going on that downtown was THAT crowded, but yikes. I swore I'd never do it again.
At the end of December 2010, I did it again. Sick as a dog again. Actually, even sicker. This time, I was headed to Atlanta . The plan was to head over to Laura's place a day early so that I could attend the in-store signing/meet & greet the band was doing early the next day. On the day I was to leave, I woke up to about six or seven inches of snow, and all roads out of Huntsville closed except for emergencies. I did head on out the next day, the day of the show, and didn't run into much trouble along the way over. After cabbing it over to the venue, we watched folk/grunge outfit The Kissing Club perform. I liked them a lot, and the Monkeys seemed to be having a lot of fun during their show! But the vibe was so off for me. I also felt so bad I ended up leaving the performance hall before the show was over, and hanging at the bar in front.
Once more, I swore I'd never do it again. Obviously, I had a change of heart somewhere along the way. As I said before, it wasn't the band's fault I didn't have a good experience. I think it was just all the other factors surrounding the shows that made me unable to enjoy myself.
So the July 26 show in Atlanta rolls around. I couldn't believe the difference….it was summer, and not cold. I was not sick. The fans were a lot of fun (seriously, I met several really awesome people at this show that I still keep in touch with!). The energy was amazing; and a good time was had by all from start to finish.
The Kissing Club opened once again, this time performing a killer cover of The Stooges' "I Wanna Be Your Dog" in addition to their original material. Also along for the ride were Vancouver, BC natives and southern rockers (yes, I know how odd that sounds, but you really should hear them for yourself) The Bleeding Horse Express. Both bands got great – and well-deserved – reactions from the crowd!
The Monkeys, this time out in support of their latest, Liquid Zoo, really outdid themselves. Seems like there was a LOT more interaction with the fans, lots of comedic banter and eccentric dancing, and all the songs we loved, including "The Monkey Song," "Keep Awake," "Aim High," "Ugly Girl," "Wings on Fire," "Orson Brawl," "Reaper," and a fabulous improv, "Butter My Biscuits." And we were also treated to a dance-off between a merch guy and the tour manager between sets.
Lawrence "Uncle Larry" Abrams and Jackson Rathbone during 100 Monkeys' July 26 performance The Loft/Center Stage, Atlanta. For the rest of the photos, go here.
100 Monkeys may not be everyone's cup of tea, but if you like your music just a bit different, their indie/funk sound (not to mention, a sound that is NOT over-produced into oblivion) might be just what you're looking for. They're a young band, but they are good. And getting better with each record. And while the Twilight fanbase has definitely helped the band, it's also hurt them. I actually think more people would give them, and their music, a chance if they weren't primarly seen as an actor's side project.
I've selected a few of my favorites for a playlist. Let me know what you think in the comments!
I keep wanting to do reviews and stuff objectively. But I give up on the concerts. I don't know enough about any technicalities to review from that standpoint, so if a band I love puts on a good show, then I'm happy. I've taken to just calling these concert pieces "my experiences" instead of reviews.
I actually wanted to go more in-depth about not being so impressed with the first two shows, but left that out mainly due to space and the fact that I really didn't find fault with the performances themselves.
LOL. Most of what I like is not anyone else's cup of tea. Thanks for commenting!
Never heard of 'em. Not a 'Twlilight' fan so not sure who the dude is. But oh, those opening guitars on "Ugly Girl" are the key to my heart. Nice post!
Thanks for commenting, Mari! Now ya know, LOL!