News

Large within-population genetic diversity of the widespread conifer Pinus sylvestris at its soil fertility limit

10:39 03.12.2015

Scots pine (Pinus sylvestris) is the only pine species native to northern Europe, and it is the most common tree species in the Baltic states. In Estonia, P. sylvestris covers almost 38% of Estonian forests and it is the key dominant species, especially in nutrient-limited sites, including characteristic Estonian extremely infertile raised bogs.

In this study, the researchers at the Estonian University of Life Sciences teamed up with Brazilian, Iranian and Swiss colleagues to study genetic variability and population structure of P. sylvestris in distant naturally-seeded bog populations positioned at the fertility limit of this species. The team hypothesized that there is a high level of outbreeding and consequently a high genetic variability at the nutrient limit of the species, and further that there is a spatial gradient in genetic relatedness indicative of the genetic component of phenotypic plasticity in the organic-mineral soil continuum. These hypotheses were partly supported by data that indicated greater within- than among-population variability and a certain spatial population structuring, reflecting small-scale adaptation. This study provides important insight into the overall genetic variability and sub-population differentiation in nutrient-limited sites. This information is of crucial value in understanding species adaptability to environmental heterogeneity and has important practical applications in selecting plant sources suitable for reforestation. Especially for reforestation of nutrient-limited habitats, e.g., degraded habitats where tree growth is particularly strongly curbed by limited soil fertility. The study was published in leading forestry journal European Journal of Forest Research.

How ENVIRON has contributed to understanding adaptation to global change

11:04 30.09.2015

Ecosystems have a large capacity to adapt to environmental perturbations, but so far, most of the future projections of global change effects do not consider the adaptation responses. This is a key shortcoming of current model predictions as adaptation responses can alter global carbon and nitrogen cycle as well as vegetation capacity to emit volatile organic compounds and contribute to secondary organic aerosol formation, with potentially important implications for the extent and rate of global change.

Likewise, little is known of adaptation of vegetation-mediated emissions of greenhouse gases other than CO2 and the relationships of these emissions to soil microbiological community composition and adaptability. Thus, understanding the capacity of ecosystems to adapt to environmental modifications is the key to predict ecosystem responses to global change. The Center of Excellence on Environmental Adaptation to Global Change (ENVIRON) is a truly interdisciplinary consortium that was formed in 2011 to address the adaptation of terrestrial ecosystems to environmental alterations.

The specific foci of the work program were the effects of globally changing environmental drivers on biological activities ecosystems and the feedbacks between soil, vegetation, and biotic interactions and atmospheric processes. In the core of the proposed centre of excellence was the Estonian Science Roadmap Initiative project „Estonian Environmental Observatory“. In frames of this large infrastructure project of national significance, unique experimental facilities had become available, including establishment of a SMEAR (Station for Measuring Forest Ecosystem – Atmosphere Relations) station, and updating a FAHM (Free Air Humidity Manipulation) platform, allowing for direct monitoring of soil-vegetation-atmosphere feedbacks and assessment of the influences of a potential global change driver, air humidity, on forest ecosystems. In addition, the partners were using lab-based facilities for studying phylogenetic and functional diversity of soil micro-organisms as well as pathogens and pests.

Genetic resources such as large collection of Arabidopsis ecotypes and recombinant inbred and near isogenic lines as well as collection of wheat cultivars and introgressed lines, and Populus and Salix genotypes were used to address molecular mechanisms behind natural variation to different abiotic and biotic stresses. Biotic stress studies considered both the effects of pathogens (plant viruses, different powdery mildew genotypes, rust fungi) and the effects of herbivores. The work conducted is currently being used to scale from molecular stress response mechanisms to ecosystem adaptation by modeling effects of abiotic and biotic stress at phenotypic, physiological and molecular levels to reveal the scope and mechanisms of stressor action and determining limits of adaptation to multiple sequential an interacting stresses.

The major outcomes of ENVIRON include: (i) identification of key mechanisms controlling adaptation to abiotic and biotic stress factors and their interactions under global change, (ii) mapping molecular mechanisms of and adaptation to stress-induced events at major functional levels, (iii) prediction of the adaptation of carbon, nitrogen and water balances of terrestrial ecosystems in globally changing environmental conditions.

Ülo Niinemets

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu 51014, Estonia

Centre of Excellence in Environmental Adaptation, Estonian University of Life Sciences, Fr.R.Kreutzwaldi 1, 51014, Tartu, ESTONIA