Sensitivity and resistance of communities: Evaluation on the example of the influence of edaphic, vegetation and spatial factors on soil macrofauna

Abstract

Environmental stability is a multifaceted concept and includes properties such as asymptotic stability, robustness, persistence, variability, elasticity and resistance. Resistance reflects the ability of a community or population to remain in a substantially unaltered state under external influence. The reverse of resistance is sensitivity. This article suggests a way to assess the sensitivity of animal communities to factors of various character and explain sensitivity and resistance of the macrofauna community near the floodplain of the river Dnieper within the "Dnipro-Orelsky" Nature Reserve to the effects of edaphic and plant factors, as well as spatial variables. It is shown that the regulatory impact of environmental factors is refracted through the properties of ecological systems themselves, namely resistance and sensitivity. If an ecological system does not react to changing environmental factors, such a system is indifferent with respect to these factors. In the case of regulatory influence of factors, there may be resistance, sensitivity and the proportionality of the response of the ecological system. The ratio of the specific role of a factor in the variability of a community to the contribution of the main components of the total variability of the attributive space makes it possible to assess the resistance, sensitivity and proportionality of response the ecological system to the action of that factor. If the ratio is >1, then this indicates sensitivity: level of variability of a community is higher than the relative role of environmental factors in the changing of the attributive space. If <1, this indicates resistance: the level of variability of a community is lower than the relative role of environmental factors in the changing of the attributive space. If the ratio =1 (≈1), changes in the community are proportional to the level of the main components of variation in comparison with other components. Ecological factors (both external environmental and internal due to species interactions and which have a neutral nature) cause different levels of community response to their impact. These differences refracted through different aspects of stability of a community can be described using the categories resistance, sensitivity and proportionality. The proposed procedure for quantification of specified properties of sustainability has established that the floodplain soil macrofauna is endowed with resistance to factors that prevail on the level of its variation. However, macrofauna is highly sensitive to minor factors. The community of the soil inhabitants is sensitive to fine-scale variations, which have a neutral nature.

The Small-Scale Variation of Herb-Layer Community Structure in a Riparian Mixed Forest

“…In our investigation the phytoindication estimations of the certain ecological factors were formally considered as a special source of the variation of plant community structure. The phytoindication estimates are a marker of the coordinated dynamics of plant community species, which is due to the similarity of plant responses to the effect of certain environmental factors [44]. It should be noted that we are far from the idea that a formal name of the indicated factors is fully consistent with the real environmental processes occurring within the investigated polygon.…”

“…82, pp Accepted: 2021-01-27 doi:10.18052/www.scipress.com/ILNS.82. 44 Online: 2021-04-28 CC BY 4.0. Published by SciPress Ltd, Switzerland, 2021 on herbaceous plants is much more complicated and involves the impact of trees on the habitat by modulating the availability of resources to other species [4].…”

Spatial organization of the soil macrofauna community in a floodplain forest

“…The endodynamic soilforming processes that encompass the soil profile as a whole also shape the living conditions of soil animals, which causes the structuring of their community. The plants are also important in the variability of soil properties [70]. The hierarchical organization of variation of soil properties in the profile is represented by broad-, medium-, and fine-scale components.…”

Effect of recreation on the spatial variation of soil physical properties

“…The temporal and spatial dynamics of the soil moisture content are a significant cause that affects this indicator. To reduce the influence of water content on measured values, the measurement of soil penetration resistance data at soil water content close to field capacity was proposed [55], or to correct data obtained at different water content to a reference soil penetration resistance at field capacity [56][57][58]. The differences in observed soil penetration resistance values with varying water content and bulk density of different soils were attributed mainly to the influence of soil texture, organic matter and soil water retention curve [44,50,[59][60][61][62].…”