Academic literature on the topic 'Belowground biological control'

Abstract The trajectory of plant invasions - for better or for worse - can be tied to interactions between plants and the soil community. Here, we highlight five broad ways in which belowground interactions can influence the trajectory of biological invasions by non-native plant species. First, many non-native plant species in their non-native ranges can interact very differently with the resident soil community than do native species. Second, non-native plant species often interact very differently with the soil community in their non-native ranges than in their native ranges, which can result in enemy release from antagonistic interactions. Third, non-native plant species can cultivate a soil community that disproportionately harms native competitors in invaded communities. Fourth, antagonistic soil biota in invaded communities can reduce the performance of non-native plant species, resulting in meaningful biotic resistance against invasion. Fifth, besides or in addition to antagonistic interactions with soil biota, soil mutualisms can promote the success of invasive plant species (i) when mutualists co-invade with non-native plant species that require obligate specialist mutualists, (ii) when mutualists enhance the performance of non-native plant species in their non-native ranges, and (iii) when biotic interactions in the invaded community suppress the soil mutualists of native plant species. We conclude that management practices aimed at manipulating plant - soil interactions have considerable potential to help control plant invasions, but further work is needed to understand the spatial, temporal, taxonomic and biogeographic drivers of context dependence in interactions among plants and soil biota.

The trajectory of plant invasions - for better or for worse - can be tied to interactions between plants and the soil community. Here, we highlight five broad ways in which belowground interactions can influence the trajectory of biological invasions by non-native plant species. First, many non-native plant species in their non-native ranges can interact very differently with the resident soil community than do native species. Second, non-native plant species often interact very differently with the soil community in their non-native ranges than in their native ranges, which can result in enemy release from antagonistic interactions. Third, non-native plant species can cultivate a soil community that disproportionately harms native competitors in invaded communities. Fourth, antagonistic soil biota in invaded communities can reduce the performance of non-native plant species, resulting in meaningful biotic resistance against invasion. Fifth, besides or in addition to antagonistic interactions with soil biota, soil mutualisms can promote the success of invasive plant species (i) when mutualists co-invade with non-native plant species that require obligate specialist mutualists, (ii) when mutualists enhance the performance of non-native plant species in their non-native ranges, and (iii) when biotic interactions in the invaded community suppress the soil mutualists of native plant species. We conclude that management practices aimed at manipulating plant - soil interactions have considerable potential to help control plant invasions, but further work is needed to understand the spatial, temporal, taxonomic and biogeographic drivers of context dependence in interactions among plants and soil biota.

The production of biomass by plants is of central importance to energy, carbon, and nutrient fluxes in ecosystems. Knowledge of the spatial and temporal variation of production and the underlying biotic and physical controls on this variation are central themes in ecosystem science. The goals of this chapter are to present the estimates of spatial patterns in above- and belowground production associated with the major community types found on Niwot Ridge and other alpine areas of the southern Rocky Mountains and to examine the likely environmental causes and underlying mechanisms responsible for spatial and temporal variation in production as elucidated by experimental and observational studies. Rates of primary production and standing crops of plant biomass are low in alpine tundra relative to other ecosystem types (Lieth and Whittaker 1975; Zak et al. 1994). However, within communities (i.e., at the plot level), there is large variation in rates of production, the degree of biotic control over response to environmental change, and the principal environmental constraints of primary production. As a result, the alpine is one of the most dynamic ecosystems for research. For example, there is a tenfold difference in annual aboveground production between the most and least productive sites with continuous plant cover on Niwot Ridge. In addition, the high plant diversity is a source of potential variation in physiological and developmental control of plant response to the environment. Dominant species include sedges, grasses, shrubs, and forbs, among which are N2-fixing Trifolium species. Nearly all of the dominant species may be mycorrhizal. Soil moisture, a driving force for many biotic processes, may vary by an order of magnitude between wet and dry sites following prolonged periods of drought. Thus the alpine tundra of Niwot Ridge, which might appear superficially homogeneous, in fact has complex physical and biotic gradients. This spatial variation prevents simple generalizations about single limiting resources or climatic driving forces determining spatial and temporal variation in productivity. Billings (1973) defined the mesotopographic gradient as a working unit for describing the alpine landscape, as it encompasses the full range of snow accumulation and associated microclimates and thus biological diversity.

Since the days of the IBP, there has been a strong emphasis on research about the biogeochemistry of shortgrass steppe ecosystems (e.g., Clark, 1977; Woodmansee, 1978). A major theme has been seeking to understand spatial and temporal patterns and controls of biogeochemical pools and fluxes at scales that span from several centimeters to hundreds of kilometers, and from hours to millennia. The synthesis of this work has resulted in a conceptual framework regarding the biogeochemical dynamics of the shortgrass steppe, with two key components:… 1. Spatial and temporal patterns are controlled by five 1. major factors: climate, physiography, natural disturbance, human use, and biotic interactions. Plants are the most important biotic component. The interaction of these factors as they change in time and space determines the distribution and size of biogeochemical pools and the rates of biogeochemical processes. 2. Carbon (C), nitrogen (N), and other associated biologically active elements are overwhelmingly located belowground, with more than 90% found in soils (Burke et al., 1997a). This distribution determines the biogeochemical sensitivity of the shortgrass steppe to perturbations…. These ideas have been synthesized in the development of the CENTURY ecosystem simulation model, originally developed for grasslands and agroecosystems in the shortgrass steppe region of the western Great Plains (Parton et al., 1987, and chapter 15, this volume). The model represents complex interactions among the five controlling factors to simulate C and N cycling, and has served as an organizing framework for developing hypotheses and for evaluating questions that are dif. cult to address in the field (Parton et al., chapter 15, this volume). The objectives of this chapter are to describe how nutrient pools and fluxes are distributed in the shortgrass steppe, to characterize how the five controlling factors interact to create spatial and temporal patterns, and to evaluate the potential future changes to which the biogeochemistry of the shortgrass steppe may be particularly vulnerable.