Forest edges, tree diversity and tree identity change leaf miner diversity in a temperate forest

Abstract

In forests, besides tree diversity, tree identity can determine herbivore species diversity. Herbivore species diversity can also depend on spatial factors, such as edge effects; however, empirical evidence for this remains scarce. Furthermore, patterns in herbivore diversity may differ between forest stand level and responses at individual tree species. It is therefore important to disentangle stand‐level patterns from associational responses specific to certain host species. We studied the effects of edge distance, tree diversity and tree species composition on leaf miner abundance, richness and diversity in temperate forests. We disentangled leaf miners’ responses at stand level from those of miners associated with each of three individual tree species: Quercus robur L., Quercus rubra L. and Fagus sylvatica L. We found that tree diversity increased stand‐level leaf miner richness and diversity. Fagus sylvatica and stand‐level leaf miner abundance increased closer to edges. This was suppressed at stand level in more diverse mixtures. Underlying tree diversity effects, stand‐level leaf miner metrics are strongly associated with tree species composition, due to many unique species found on F. sylvatica and Q. robur. Additionally, F. sylvatica experienced associational susceptibility to abundance in mixtures with Q. robur. Quercus robur experienced association susceptibility to miner richness in the mixture with Q. rubra. Studying the herbivore community at different spatial scales is a first step towards better understanding tree identity effects underlying tree diversity effects. Our findings emphasise context dependency of positive diversity effects on herbivores in terms of edge effects and tree species composition.

Small scale environmental variation modulates plant defence syndromes of understorey plants in deciduous forests of Europe

“…Future research addressing the inducibility of both defence and tolerance traits in response to herbivore feeding will contribute to a better understanding of the importance of induced trait responses in shaping patterns along environmental gradients. Forest edge-to-core transects can in this context act as an extremely useful study system as they are characterized by strong biotic and abiotic clines over a small spatial scale (De Frenne et al, 2019;De Smedt et al, 2019;Govaert et al, 2020;Lantman et al, 2019;Meeussen et al, 2020;Murcia, 1995;Remy et al, 2016).…”

“…The spatial scale of sampling along latitudinal or elevational gradients (partly) mismatches the spatial scale of evolutionary processes that are postulated to drive variation in defence traits (Gaston, 2000). Forest edge-to-core transects, for example, are characterized by strong abiotic clines in temperature, humidity, light and soil nutrient availability (De Frenne et al, 2019;Meeussen et al, 2020;Murcia, 1995;Remy et al, 2016), as well as biotic clines in the floral, arthropod and gastropod community composition over less than 100 m (De Smedt et al, 2019;Govaert et al, 2020;Lantman et al, 2019).…”

Factors Driving Wetland Herbs Distribution Range of Lake-Terrestrial Ecotone in Tibet, China

“…8), took 4, 6, 8, 10, 12 sampling quadrats as the window width respectively, when the window width was 10-12 sample squares, no peak appears; When the window width was 4 to 8 plots, an obvious peak occurs near quadrat 10. Due to the edge effect, the ecotone had a larger species diversity and community richness index than adjacent communities [55], so the appearance of this peak indicated that the plant community at this location had the greatest heterogeneity, and the ecological pattern of the plant community had changed here, it was the location of the ecotone. Based on the eld survey, found that the obvious peak showed the area was the BK1 wetmesophyte/xerophyte transition zone.…”

Mixing of tree species is especially beneficial for biodiversity in fragmented landscapes, without compromising forest functioning

“…Scaling up desirability scores from plot to landscape level revealed that forest multifunctioning was most strongly affected by landscape fragmentation, while overall forest multidiversity was most strongly affected by stand composition, probably due to dominant effects of tree species identity (van Schrojenstein Lantman et al, 2020). Indeed, the study area being fragmented for many decades already, remaining forests can be expected to mainly (or even exclusively) harbour species that are well-adapted to such F I G U R E 3 Desirability scores for forest functioning (a and b) and diversity (c and d) at the plot scale (a and c) for the three monocultures and for all tree species in a mixture at different levels of fragmentation and at the landscape level (b and d) for landscapes composed of tree monocultures or of three-species mixtures.…”