Synthesizing habitat fragmentation effects on plant–antagonist interactions in a phylogenetic context

Chávez‐Pesqueira, Mariana; Carmona, Diego; Suárez-Montes, Pilar; Núñez‐Farfán, Juan; Aguilar, Ramiro

doi:10.1016/j.biocon.2015.10.002

Cited by 14 publications

(18 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If patterns of herbivory are driven by top–down processes such as trophic release, then herbivory should increase in small fragments. Conversely, if small fragment size creates depauperate communities lacking plants that sustain a diversity of herbivores, then herbivory should increase with fragment size (Chávez‐Pesqueira et al ). One factor which may affect our divergent result is scale, with some researchers suggesting that top–down trophic cascades may be more important at small spatial scales such as those in our experiments (Borer et al ).…”

Section: Discussionmentioning

confidence: 99%

Fragment size affects plant herbivory via predator loss

Genua

Start

Gilbert

2017

Oikos

View full text Add to dashboard Cite

Fragmentation and resultant changes in patch size are predicted to alter species diversity and community composition, yet the consequences of these differences for species interactions are poorly understood. Theory predicts that predators are more sensitive to fragmentation than their prey, resulting in greater predator loss in small patches. Predator loss, in turn, is predicted to 1) increase herbivory rates overall, and 2) cause herbivores to shift feeding from plants that act as refugia to those that are preferred forage. We tested these predictions in an old‐field community using two experiments. The first was a large‐scale experiment that included hundreds of arthropod species in fragments of various sizes, and used goldenrod and switchgrass to assess herbivory. Our second experiment manipulated densities of a focal predator species and a focal prey species to determine if changes in densities, rather than other characteristics of fragments, were sufficient to cause the trends observed in the first experiment. We found that predator densities declined in small fragments whereas herbivore densities showed the opposite trend. Total herbivory mirrored herbivore densities by increasing in small patches, and this mean increase was driven by large increases in goldenrod herbivory but declines in switchgrass herbivory. Experimental manipulation of densities confirmed that herbivores preferentially feed on goldenrod, and that predators depress herbivory on goldenrod but have a negligible effect on switchgrass. Our results suggest that fragmentation alters trophic interactions by causing declines in predator densities and increases in herbivore densities, but that feeding preferences of herbivores may generate unequal impacts among plant species.

show abstract

Section: Discussionmentioning

confidence: 99%

Fragment size affects plant herbivory via predator loss

Genua

Start

Gilbert

2017

Oikos

View full text Add to dashboard Cite

show abstract

“…At a larger scale, evidence shows that habitat fragmentation can alter insect herbivory via a variety of direct and indirect mechanisms (Chávez‐Pesqueira et al. , Rossetti et al. ).…”

Section: Introductionmentioning

confidence: 99%

“…A number of studies have examined the variation in herbivory between and within plant individuals as a function of physical and chemical traits (Kozlov and Zvereva 2018). At a larger scale, evidence shows that habitat fragmentation can alter insect herbivory via a variety of direct and indirect mechanisms (Ch avez-Pesqueira et al 2015, Rossetti et al 2017.…”

Section: Introductionmentioning

confidence: 99%

Insect and plant traits drive local and landscape effects on herbivory in grassland fragments

et al. 2019

View full text Add to dashboard Cite

Herbivory is one of the most important antagonistic insect–plant interactions and can be influenced by factors at local and landscape scales. Landscape fragmentation may reduce herbivory directly (i.e., decreasing abundance and species richness of herbivores), but also indirectly increase herbivory (i.e., releasing herbivores from top‐down control). At a local scale, reduced plant diversity may enhance herbivory through lessened associated resistance, while resource availability (i.e., higher vegetation height and cover) may promote herbivory. Few studies have simultaneously considered the influence of local and landscape variables on insect herbivory. We evaluate effects of landscape (fragment size, connectivity, and arable land percentage) and local factors (plant cover and height and plant species richness) on insect herbivory in fragmented calcareous grasslands. Further, we ask whether these effects depend on feeding traits of herbivores (chewers vs. suckers) and habitat specialization of plants (specialists vs. generalists). Results show that herbivory was best explained by models including variables at both local and landscape scales. However, local factors were more important than landscape variables. Herbivory was in all cases positively related to height of herbs (i.e., taller and more heterogeneous food resources), whereas the effect of plant species richness varied with feeding traits of herbivores. Herbivory by chewers, which are commonly more generalist feeders, was negatively affected by plant species richness, supporting the idea of associated plant resistance. In contrast, herbivory by suckers, which tend to be more specialized, increased with plant richness. Although there was little influence of landscape scale, herbivory on specialist plants was significantly higher in smaller grasslands probably as a consequence of herbivore release from natural enemies. Functional redundancy among herbivore species would allow to maintain overall herbivory in fragmented calcareous grasslands. This study highlights the need to consider different herbivore and plant traits for a better understanding of herbivory responses to local and landscape factors.

show abstract

“…Forest fragmentation is well-known to alter patterns of species distribution and abundance, relationships between organisms and resulting ecosystem processes (Ewers and Didham, 2006;Fahrig, 2017;Haddad et al, 2015;Lindenmayer and Fisher, 2013). Among others, it exerts strong effects on trophic cascades such as plant-herbivore-predator interactions, eventually affecting rates of tree damage and health (Bagchi et al, 2018;Chávez-Pesqueira et al, 2015;Rossetti et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

“…These have documented that the size and connectivity of forest stands can shape trophic cascades very differently depending on the relative importance of the bottom-up and top-down effects involved (De La Vega et al, 2012;Rossetti et al, 2014). Thus, small and isolated forest stands provide less and possibly lower-quality resources to herbivores (Chávez-Pesqueira et al, 2015) and their colonization requires longerdistance movements that increase energetic and fitness costs (O'Rourke and Petersen, 2017), eventually resulting in lower herbivore abundance (De La Vega et al, 2012;Simonetti et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

Insect herbivory and avian insectivory in novel native oak forests: divergent effects of stand size and connectivity

Valdés‐Correcher

Halder

Barbaro

et al. 2019

Preprint

View full text Add to dashboard Cite

The value of novel native broadleaf woodlands for biodiversity conservation is important to consider for adequate forest management in rural landscapes. Passive reforestation has been proposed as a cost-efficient tool for creating networks of novel native forest stands that would help restoring biodiversity and associated ecosystem services. Yet to date the ecological functioning of such stands remains strongly understudied compared to forest remnants resulting from longer-term fragmentation. We assessed how the size and connectivity of newly established Pedunculate oak (Quercus robur L.) stands in rural landscapes of SW France affect rates of herbivory by different insect guilds as well as rates of avian insectivory and the abundance and richness of insectivorous birds. Comparing 18 novel forest stands along a gradient of size (0.04-1.15 ha) and cover of broadleaf forests in the surroundings (0-30% within a 500 radius), we found that even the smallest stands are colonised by leaf miners and chewers/skeletonizers, and that rates of herbivory are globally comparable to those reported from older and larger oak forests. The size of stands had a relatively minor effect on herbivory, whereas it increased the abundance of insectivorous bird. It also determined rates of avian insectivory as estimated by an experiment with plasticine caterpillars. These rates were however rather low and unrelated with the extent of herbivory in the stand. Overall, our study indicates that insect herbivores tend to react more rapidly to the establishment of novel native forests than their avian predators as the latter may depend on the development of larger patches of suitable habitat in the surrounding landscape. To favour a rapid build-up of diverse, and hence stable, trophic networks involving insect herbivores and their predators, woodland creation schemes should therefore primarily focus on habitat size and quality.

show abstract

Synthesizing habitat fragmentation effects on plant–antagonist interactions in a phylogenetic context

Cited by 14 publications

References 62 publications

Fragment size affects plant herbivory via predator loss

Fragment size affects plant herbivory via predator loss

Insect and plant traits drive local and landscape effects on herbivory in grassland fragments

Insect herbivory and avian insectivory in novel native oak forests: divergent effects of stand size and connectivity

Contact Info

Product

Resources

About