Vulnerability of moorland plant communities to environmental change: consequences of realistic species loss on functional diversity

Abstract

Summary1. Understanding the consequences of realistic species loss on the functioning and persistence of vulnerable ecosystems is key to devising conservation strategies when environmental changes are immediate threats. Yet, few studies have provided direct evidence for conservation prioritization and decision-making. 2. We incorporated the quantification of functional diversity based on the Rao index of diversity (FD rao ) into this applied context and examined the consequences of realistic species loss on functional diversity in moorland plant communities widely interspersed within a subalpine zone in northern Japan. The realistic order of species loss was derived from the nested subset pattern in the moorland communities, which was corroborated by selective species tolerance and selective extinction. We analysed the relationships between the FD rao half-life, as an index of each moorland's vulnerability to species loss, and a range of environmental variables describing the moorlands. We then mapped this index across the entire landscape. 3. At most sites, ordered species loss caused a relatively small decline in FD rao until a certain number of species was lost and an accelerating decline thereafter, suggesting relatively low initial vulnerability to species loss. At the other sites, however, ordered species loss caused an approximately proportional decrease in FD rao , suggesting relatively high vulnerability to species loss. The model indicated that sites with higher elevation, higher carrying capacities, or increasing isolation have a shorter FD rao half-life. The mapping of this index allowed us to identify the geographical distribution of sites of high conservation priority. 4. Synthesis and applications. We performed fine-scale assessments of the vulnerability of moorland plant communities to species loss, which is likely to occur under future environmental conditions, by simulating the consequences of realistic species loss for functional diversity. The methods used here can provide urgently needed information to support the prioritization and decision-making involved in conserving ecosystems in the face of global biodiversity loss.

Environmental and spatial controls of macroinvertebrate functional assemblages in seagrass ecosystems along the Pacific coast of northern Japan

“…In support of this idea, Yamada et al (2011) concluded that the functional diversity of the macrocrustacean community in seagrass ecosystems is the variable at the local patch scale, but homogeneous (i.e., occurrence of functional redundancy) at the regional scale (e.g. Matsuzaki et al, 2013;Sasaki et al, 2014).…”

“…By using groups and diversity based on ecological traits, i.e., ''functional group'' and ''functional diversity'', that is the value and range of functional traits and ecosystem function of organisms present in a community (e.g., Mouillot et al, 2013;Storkey et al, 2013), can lead to elucidate community assembly rules and/or ecosystem processes (Yamada et al, 2011;Matsuzaki et al, 2013;Sasaki et al, 2014). Functional diversity was measured based on the values and range of ecological traits of species such as microhabitat, dispersal ability, habitat type, life history, and trophic level (e.g., Schleuter and Daufresne, 2010).…”

Impacts of environmental filters on functional redundancy in riparian vegetation

“…; Matsuzaki, Sasaki & Akasaka ; Sasaki et al . ). In a changing environment, this measure provides three major advantages: (i) valuable information on how river ecosystems respond to human and natural environmental stressors, which can help managing the current increase of multiple stressors across the river network, (ii) assessment of stressors’ effects on functional features from the descriptive to the predictive (being the assessment framework of broad‐scale applicability across ecological domains) and (iii) the geographical distribution of sites that potentially could show more stability, resistance and resilience, and vice versa.…”

Trait probability density (TPD): measuring functional diversity across scales based on TPD with R

“…Each plot includes the correlation between the two distances (q), the significance of Mantel test, and a lowess regression to illustrate the relationship. Redundancy can also be used in combination with nested subset analyses to estimate the vulnerability of ecosystem function to species loss (Zavaleta and Hulvey 2004, Sasaki et al 2014). (d) Changes in functional redundancy (expressed in relative terms) for single and multiple traits along the soil water content gradient.…”