Yazar "Neff, Felix" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Changes in plant-herbivore network structure and robustness along land-use intensity gradients in grasslands and forests
    (Amer Assoc Advancement Science, 2021) Neff, Felix; Braendle, Martin; Ambarli, Didem; Ammer, Christian; Bauhus, Juergen; Boch, Steffen; Schaefer, Deborah
    Land-use intensification poses major threats to biodiversity, such as to insect herbivore communities. The stability of these communities depends on interactions linking herbivores and host plants. How interaction network structure begets robustness, and thus stability, in different ecosystems and how network structure and robustness are altered along land-use intensity gradients are unclear. We analyzed plant-herbivore networks based on literature-derived interactions and long-term sampling from 289 grasslands and forests in three regions of Germany. Network size and nestedness were the most important determinants of network robustness in both ecosystems. Along land-use intensity gradients, networks in moderately grazed grasslands were more robust than in those managed by frequent mowing or fertilization. In forests, changes of network robustness along land-use intensity gradients relied on changes in plant species richness. Our results expand our knowledge of the stability of plant-herbivore networks and indicate options for management aimed at stabilizing herbivore communities.
  • Küçük Resim
    Öğe
    Reduction of invertebrate herbivory by land use is only partly explained by changes in plant and insect characteristics
    (John Wiley and Sons Inc, 2023) Neff, Felix; Prati, Daniel; Achury, Rafael; Ambarlı, Didem; Bolliger, Ralph; Brändle, Martin; Freitag, Martin
    Invertebrate herbivory is a crucial process contributing to the cycling of nutrients and energy in terrestrial ecosystems. While the function of herbivory can decrease with land-use intensification, the underlying mechanisms remain unclear. We hypothesize that land-use intensification impacts invertebrate leaf herbivory rates mainly through changes in characteristics of plants and insect herbivores. We investigated herbivory rates (i.e., damaged leaf area) on the most abundant plant species in forests and grasslands and along land-use intensity gradients on 297 plots in three regions of Germany. To evaluate the contribution of shifts in plant community composition, we quantified herbivory rates at plant species level and aggregated at plant community level. We analyzed pathways linking land-use intensity, plant and insect herbivore characteristics, and herbivory rates. Herbivory rates at plant species and community level decreased with increasing land-use intensity in forests and grasslands. Path analysis revealed strong direct links between land-use intensity and herbivory rates. Particularly at the plant community level, differences in plant and herbivore composition also contributed to changes in herbivory rates along land-use intensity gradients. In forests, high land-use intensity was characterized by a larger proportion of coniferous trees, which was linked to reduced herbivory rates. In grasslands, changes in the proportion of grasses, plant fiber content, as well as the taxonomic composition of herbivore assemblages contributed to reduced herbivory rates. Our study highlights the potential of land-use intensification to impair ecosystem functioning across ecosystems via shifts in plant and herbivore characteristics. De-intensifying land use in grasslands and reducing the share of coniferous trees in temperate forests can help to restore ecosystem functionality in these systems. © 2023 The Authors. Ecological Monographs published by Wiley Periodicals LLC on behalf of The Ecological Society of America.