Sparse trees and shrubs confers a high biodiversity to pastures: Case study on spiders from Transylvania

Abstract

The integration of food production and biodiversity conservation represents a key challenge for sustainability. Several studies suggest that even small structural elements in the landscape can make a substantial contribution to the overall biodiversity value of the agricultural landscapes. Pastures can have high biodiversity potential. However, their intensive and monofunctional use typically erodes its natural capital, including biodiversity. Here we address the ecological value of fine scale structural elements represented by sparsely scattered trees and shrubs for the spider communities in a moderately intensively grazed pasture in Transylvania, Eastern Europe. The pasture was grazed with sheep, cattle and buffalo (ca 1 Livestock Unit ha-1) and no chemical fertilizers were applied. Sampling sites covered the open pasture as well as the existing fine-scale heterogeneity created by scattered trees and shrub. 40 sampling locations each being represented by three 1 m2 quadrats were situated in a stratified design while assuring spatial independency of sampling locations. We identified 140 species of spiders, out of which 18 were red listed and four were new for the Romanian fauna. Spider species assemblages of open pasture, scattered trees, trees and shrubs and the forest edge were statistically distinct. Our study shows that sparsely scattered mature woody vegetation and shrubs substantially increases the ecological value of managed pastures. The structural complexity provided by scattered trees and shrubs makes possible the co-occurrence of high spider diversity with a moderately high intensity grazing possible in this wood-pasture. Our results are in line with recent empirical research showing that sparse trees and shrubs increases the biodiversity potential of pastures managed for commodity production.

Wood Pastures: A Transitional Habitat between Forests and Pastures for Dung Beetle Assemblages

“…It seems that this is the general pattern, as this was found for other taxa as well. For example, spider [37] and grounddwelling beetle assemblages [55] of open pasture habitats and scattered trees (and other habitats) were statistically distinct. Lövei et al [56] categorised carabids to the forest edge and matrix species as these habitats had distinct assemblages.…”

“…Our study compared three habitat types with different levels of woodland cover: open pastures, wood pastures, and forests. Wood pastures are acknowledged as valuable habitats for several other taxa [36,37], and we were interested in whether (i) they exhibit an outstanding diversity that harbors both forest and grassland species and thereby have their own specific species pool or if (ii) they represent a transitional situation for dung beetles.…”

Small things are important: the value of singular point elements for birds in agricultural landscapes

“…The presence of SPELs may also increase the occurrence of other phenomena such as soil fertilisation from animal droppings (Julig et al ., 2013) and the dispersal of seeds by frugivorous birds (Galindo‐González, Guevara & Sosa, 2000; Luck & Daily, 2003; Athie & Dias, 2016; Guidetti et al ., 2016). These processes associated with SPEL may then contribute to the creation of new valuable microhabitats for many different organisms (Lentini et al ., 2012; Gallé et al ., 2017; Pustkowiak et al ., 2018).…”

Monitoring ant assemblages of oak wood-pastures. A case study from Eastern Europe

“…Wood-pastures possess both cultural and ecological significance, can provide favourable micro-habitats for a highly diverse group of organisms (Moga et al 2009;Hartel et al 2013;Falk 2014;Öllerer 2014;Hartel and Plieninger 2014;Gallé et al 2017). These silvopastoral systems occur in a wide range of physiognomies, varying from park-like stands, open grassland areas with scattered trees, to near-natural forests in which grazing has a determinant role (Bergmeier et al 2010;Hartel and Plieninger 2014).…”