The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems th...

To define plant 'nutritional quality' for aphids, the causal basis of the variation in aphid performance between host plants of different developmental ages was explored using the aphids Myzus persicae and Macrosiphum euphorbiae on potato plants (Solanum tuberosum). Both aphid species performed better on developmentally young ('pre-tuber-filling') plants than on mature ('tuber-filling') plants....

Changes in land use/land cover are a major driver of biodiversity change in the Mediterranean region. Understanding how animal populations respond to these landscape changes often requires using landscape mosaics as the unit of investigation, but few previous studies have measured both response and explanatory variables at the land mosaic level. Here, we used a "whole-landscape" approach to ass...

Small scale distribution of insect root herbivores may promote plant species diversity by creating patches of different herbivore pressure. However, determinants of small scale distribution of insect root herbivores, and impact of land use intensity on their small scale distribution are largely unknown. We sampled insect root herbivores and measured vegetation parameters and soil water content ...

Desertification is often characterized by the replacement of mesophytic grasses with xerophytic shrubs. Livestock grazing is considered a key driver of shrub encroachment, although most evidence is anecdotal or confounded by other factors. Mapping of velvet mesquite (Prosopis velutina) shrubs in and out of exclosures in 1932, 1948, and 2006 in semiarid grasslands of southeastern Arizona, USA, a...

Question: How do patterns in colonization and patch expansion of an invasive woody plant (Larrea tridentata, Zygophyllaceae) differ between two grassland ecosystems at a biome transition zone? Location: Semi-arid/arid transition zone in central New Mexico. Methods: Frequency of occurrence, height, and surface area of saplings (n = 134) and patches of adult plants (n = 247) of the invasive shrub...

BACKGROUND Space-for-time substitution-that is, the assumption that spatial variations of a system can explain and predict the effect of temporal variations-is widely used in ecology. However, it is questionable whether it can validly be used to explain changes in biodiversity over time in response to land-cover changes. HYPOTHESIS Here, we hypothesize that different temporal vs spatial traje...

The distribution of flowering across the growing season is governed by each species' evolutionary history and climatic variability. However, global change factors, such as eutrophication and invasion, can alter plant community composition and thus change the distribution of flowering across the growing season. We examined three ecoregions (tall-, mixed, and short-grass prairie) across the U.S. ...