Forest biomass, soil and biodiversity relationships originate from biogeographic affinity and direct ecological effects

Abstract

Ecosystem biomass, soil conditions and the diversity of different taxa are often interrelated. These relationships could originate from biogeographic affinity (varying species pools) or from direct ecological effects within local communities. Disentangling regional and local causes is challenging as the former might mask the latter in natural ecosystems with varying habitat conditions. However, when the species pool contribution is considered in statistics, local ecological effects might be detected. In this study we disentangle the indirect effects of the species pool and direct ecological effects on the complex relationships among wood volume, soil conditions and diversities of different plant and fungal groups in 100 old‐growth forest sites (10 × 10 m) at the border of boreal and nemoral zones in northern Europe. We recorded all species for different vegetation groups: woody and herbaceous vascular plants, terricolous and epiphytic bryophytes and lichens. Fungal communities were detected by DNA‐based analyses from soil samples. Above‐ground wood volume was used as a proxy of biomass. We measured soil pH and nutrient content and obtained modelled climate parameters for each site. Species pool effect was considered by dividing sites into boreal and nemoral groups based on community composition. In order to disentangle direct and indirect effects, we applied variation partitioning, and raw and partial correlations. We found many significant positive relationships among studied variables. Many of these relationships were associated to boreal and nemoral species pools, thus indicating that biogeographic affinity of interacting plants and fungi largely defines forest diversity and functioning. At the same time, several relationships were significant also after considering biogeography: woody plant and ectomycorrhizal fungi diversities with wood volume, many plant and fungal groups with each other, or with soil conditions. These direct ecological interactions could be considered in forestry practices to achieve both economic gain and maintenance of biodiversity.

Woody encroachment in grassland elicits complex changes in the functional structure of above‐ and belowground biota

“…Our results confirm these established patterns of plant diversity and demonstrate analogous patterns among other soil biota—higher diversity of fungi and soil animals in open than wooded grassland patches. Current evidence concerning correlated patterns of richness among different taxonomic groups is inconsistent (Wolters et al 2006, Gossner et al 2016, Banerjee et al 2018, Delgado‐Baquerizo et al 2019, Noreika et al 2019). In our system, the reverse diversity pattern—higher diversity in wooded than in open grassland patches—emerged only among EcM fungi, which reflects the presence of their host plant species (Schwob et al 2017) in wooded patches.…”

Habitat Models of Focal Species Can Link Ecology and Decision-Making in Sustainable Forest Management

“…The expert-based process (including two meetings) involved lead forest biodiversity experts in the country, with knowledge of multiple taxon groups. The forest types under question are well defined by topographic and soil conditions and have diverse species pools [167,168]. In a natural state, these forests have complex uneven-aged or all-aged structure created by gap-dynamics and, depending on moisture, rare stand replacements (mostly due to storm or pathogens) [164,169,170].…”

EstSoil-EH v1.0: An eco-hydrological modelling parameters dataset derived from the Soil Mapof Estonia

“…In addition, feature importances can be extracted from the model to determine the most influential predictor variables. (Kriiska et al, 2019;Noreika et al, 2019;Suuster et al, 2011). Where necessary, the SOM values were translated into SOC via: SOC = SOM / 1.724.…”