Skip to main content
Dryad

Temporal biodiversity change following disturbance varies along an environmental gradient

Data files

Oct 04, 2021 version files 861.97 KB

Abstract

Aim
The diversity and composition of natural communities are rapidly changing due to anthropogenic disturbances. Magnitude of this compositional reorganization varies across the globe, but reasons behind the variation remain largely unknown. Disturbances induce temporal turnover by stimulating species colonizations, causing local extinctions, altering dominance structure, or all of these. We test which of these processes drive temporal community changes, and whether they are constrained by natural environmental gradients. Moreover, we assess to what degree identity shifts translate to changes in dominance structure.

Location
Finland

Time period
Observations 1985-2006, disturbance history >140 years.

Major taxa studied
Vascular plants.

Methods
We investigated temporal turnover of boreal forest understory in response to disturbance, here forest management, along a soil fertility gradient. We disentangle the roles of species gains, losses and abundance changes in driving temporal turnover in response to and after disturbance by comparing turnover rates in different forest age categories along fertility gradient. We quantify temporal turnover richness-based complement of Jaccard’s similarity index and proportional-abundance based dissimilarity index. We also test whether disturbance history or fertility influence the relationship between identity shifts and dominance structure.

Results
We found that the impact of disturbance on temporal turnover depends on soil fertility. The greatest turnover occurred in most fertile forests immediately after disturbance. There, species gains and losses strongly altered dominance structure leading to high turnover, whereas undisturbed old forests and nutrient-poor habitats were characterized by stable dominant species even when the majority of species shifted their identity.

Main conclusions
Our results suggest that human impacts on temporal biodiversity change vary along environmental gradients. In boreal forests, the fertile habitats have higher probability than nutrient-poor sites to change their composition in response to anthropogenic disturbances. Resource availability and disturbance history may thus influence consequences of temporal turnover for ecosystem functioning.