Impact of an invasive tree on arthropod assemblages in woodlots isolated within an intensive agricultural landscape

Abstract

Aim: Landscape simplification and the spread of invasive species are considered beyond the main threats to global biodiversity. It is well recognized that non-crop habitats bring complexity to farmland and provide refuge for a wide range of organisms, including arthropods. However, knowledge about the effects of invasive trees on arthropods in non-crop habitats in intensive agricultural landscapes is still weak. Therefore, we examined differences in the arthropod assemblages between woodlots formed by the invasive black locust (Robinia pseudoacacia L.) and by native deciduous tree species in the intensive agricultural landscape.Location: Czech Republic, Central Europe. Methods:We used a multi-taxonomic approach to record arthropod assemblages using various sampling methods. The impacts of woodlot habitat structure were investigated across 13 arthropod taxa from different trophic levels.Results: Total abundance and species richness of all arthropods and the majority of the herbivore taxa were lower in R. pseudoacacia woodlots, likely due to losses of the forest canopy specialists. The forest specialists were associated with the native woodlots with more developed canopy and shrub layers. The impoverished diversity of the forest specialists and canopy herbivores in the R. pseudoacacia woodlots was partly compensated by the higher presence of species exploiting a well developed herb layer and open-habitat specialists, including threatened species.Main conclusions: Native woodlots and those formed by R. pseudoacacia differ in vegetation structure and host different assemblages of arthropods. Therefore, parallel presence of both types of woodlots supports arthropod diversity in otherwise simplified agricultural landscapes through creating more complex mosaic of habitats. K E Y W O R D Sarthropods, biological invasion, forest fragments; habitat alternation, invasive plants, multitaxonomic approach, non-crop habitats, Robinia pseudoacacia | 1801 ŠTROBL eT aL.

Disentangling the effects of plant species invasion and urban development on arthropod community composition

“…Furthermore, this study shows that while urban development is often seen as a facilitator of species invasion (e.g., MacDougall & Turkington, 2005), plant invasion has strong effects on the community composition of higher trophic levels independent of development. This is consistent with Elleriis, Pedersen, and Toft (2015) and Štrobl et al (2019) who reported robust effects of invasive plants on paired arthropod assemblages in temperate ecosystems in Continental Europe while accounting for site‐specific environmental variation. Hence, plant invasion is not just a side effect of urban development but also an important driver of ecological change.…”

“…First, exotic plants can outcompete native flora for nutrients, space, and light, often decreasing the richness and abundance of native plant species (Castro‐Díez, Pauchard, Traveset, & Vilà, 2016; Michelan, Thomaz, Mormul, & Carvalho, 2010). Second, invasive plants can affect higher trophic levels within the local community, such as herbivorous arthropods, through changes in their food supply and quality (e.g., Štrobl et al, 2019) or modification of the local vegetation structure and microclimatic niches (Gerber et al, 2008; Litt, Cord, Fulbright, & Schuster, 2014; Valtonen, Jantunen, & Saarinen, 2006). Similar to urban development, invasive plants can drive functional homogenization of the vegetation (Castro‐Díez et al, 2016) as well as arthropod communities (Florencio, Cardoso, Lobo, Azevedo, & Borges, 2013).…”

Pitfall trap design affects the capture efficiency of harvestmen (Opiliones) and millipedes (Diplopoda)

“…Pitfall trapping was first used for the research of epigaeic fauna by Dahl (1896) and was further developed after the publication of Barber (1931) and Stammer (1948). It is now a well‐established and commonly used quantitative method of zoocoenosis surveys, including harvestman and millipede communities (Štrobl et al., 2019). Pitfall traps are simple to use, efficient, and inexpensive and allow for the continuous collection of specimens, including night foragers, thus overcoming interspecific differences in circadian activity rhythms (Koivula et al., 2003; Southwood, 1978; Törmälä, 1982; Ward et al., 2001).…”

Habitat Characteristics Supporting Bird Species Richness in Mid-Field Woodlots

“…Mid-field woodlots are small non-productive elements in agricultural landscapes that may serve as important biodiversity refuges (e.g., Tryjanowski et al, 2014;Štrobl et al, 2019;Pustkowiak et al, 2021). However, their role as distinctive landscape features has been largely overlooked (but see Gottschalk et al, 2010;Aue et al, 2014), since previous studies have included mostly all semi-natural landscape features together at the regional scale (Billeter et al, 2008;Doxa et al, 2010;Sasaki et al, 2020) or considered larger woodland patches from the perspective of forest habitat fragmentation (McCollin, 1993;Bellamy et al, 1996;Doherty and Grubb, 2000;Bennett et al, 2004;Lorenzetti and Battisti, 2006).…”