Multi‐taxon inventory reveals highly consistent biodiversity responses to ecospace variation

Abstract

Amidst the global biodiversity crisis, identifying general principles for variation of biodiversity remains a key challenge. Scientific consensus is limited to a few macroecological rules, such as species richness increasing with area, which provide limited guidance for conservation. In fact, few agreed ecological principles apply at the scale of sites or reserve management, partly because most community‐level studies are restricted to single habitat types and species groups. We used the recently proposed ecospace framework and a comprehensive data set for aggregating environmental variation to predict multi‐taxon diversity. We studied richness of plants, fungi and arthropods in 130 sites representing the major terrestrial habitat types in Denmark. We found the abiotic environment (ecospace position) to be pivotal for the richness of primary producers (vascular plants, mosses and lichens) and, more surprisingly, little support for ecospace continuity as a driver. A peak in richness at intermediate productivity adds new empirical evidence to a long‐standing debate over biodiversity responses to productivity. Finally, we discovered a dominant and positive response of fungi and insect richness to organic matter accumulation and diversification (ecospace expansion). Two simple models of producer and consumer richness accounted for 77% of the variation in multi‐taxon species richness suggesting a significant potential for generalization beyond individual species responses. Our study widens the traditional conservation focus on vegetation and vertebrate populations unravelling the importance of diversification of carbon resources for diverse heterotrophs, such as fungi and insects.

Simple attributes predict the value of plants as hosts to fungal and arthropod communities

“…Our results strongly support the idea that site‐level biodiversity is an emergent property of site conditions (Brunbjerg et al 2020), within the bounds of the regional species pool. This calls for reconsidering the widespread focus on biodiversity determining ecosystem function.…”

Scrub encroachment promotes biodiversity in wetland restoration under eutrophic conditions

“…In our study, plant species richness and the number of red-listed plants were solely affected by soil fertility and the models only had limited predictive power (c. 7 % and c. 14 %, respectively). The predictive power of these models may seem low when compared to c. 60 % explained variation in plant species richness in the full Biowide data set in Brunbjerg et al (2020). Although the two studies are not directly comparable, several explanations may be suggested for this discrepancy e.g.…”

“…Sixteen equally distanced measurements were taken in each 40 × 40 m site in May 2016 (spring/wet period). To cover the temporal variation in moisture the measurements were repeated in August 2016 (summer/dry period) (Brunbjerg et al 2020).…”

“…In fact, the diversity of heterotrophic organisms, such as arthropods and fungi, is expected to increase with the structural complexity of vegetation and diversity of carbon sources in ecosystems (Elton 1966, Pihlgren and Lennartsson 2008, Brunbjerg et al 2017). In a recent large-scale study, presence of a shrub layer was the most important variable explaining variation in species richness of fungi and arthropods (Brunbjerg et al 2020). Heterotrophic organisms gain from the increased biomass following encroachment, as shrubs provide resources and habitats for a large suite of species including herbivores, pollinators, decomposers and epiphytes (Bruun et al (in press)).…”

Population ecology and dynamics of a remnant natural population of European yew Taxus baccata in a lowland temperate forest – implications for use in reforestation

“…Reforestation with Taxaceae species such as T. baccata will increase structural complexity in woodlands due to their functional traits such as evergreen foliage, longevity and fleshy seeds (Jensen et al 2021). Thus, by creating a patchily evergreen middle-story shrub layer, the use of slow-growing, understory species such as T. baccata could result in potentially increased biodiversity and ecosystem services of a newly established forest (Gamfeldt et al 2013, Alexander et al 2016, Brunbjerg et al 2020.…”