text: The spatial arrangement of the selected plant species influences the vegetation system and the greater habitat system. Spatial planning determines interactions between plant species. These interactions can be facilitative or competitive. Planting certain species together can protect one or both from extreme temperature fluctuations, drying out in the sun, harsh winds, and predators, in addition to improving soil composition. Competition can occur within or between species, and generally weaker individuals and weaker species die out, resulting in increased plant spacing. Spatial arrangement of revegetation species also influences pollination and seed dispersal. For species whose seeds are wind-dispersed and animal-dispersed, plant diversity in seed dispersal range is important for genetic fitness. However, too much competition within the seed dispersal range can cause reproduction to be suppressed, so it is important to balance.
  On the ecosystem level, the spatial planning of revegetation species influences animal species. A more varied plant species composition is more likely to be used by a wider variety of animal species. High-density edible plants mean animals do not have to forage as far to eat, and a plant species even being in the presence of palatable species could lead to it having more interaction with animals. Abiotic aspects of the ecosystem are also altered. Higher density revegetation can reduce erosion, protect against extreme temperatures, decrease evaporative losses of water, and increase water filtration and reinfiltration. However, higher density revegetation requires the use of more soil nutrients and water, which can potentially dry out and deplete the soil. For riparian revegetation, plant roots help to increase the shear strength of bank soil, and if tree roots begin to lose their strength, the bank is susceptible to land slips. Fibrous or matted roots in particular help to prevent against soil erosion, and are typically found in reed and sedge species.