Negative or positive feedback between arbuscular mycorrhizal fungi (AMF) and host plants can contribute to plant species interactions, but how this feedback affects plant invasion or resistance to invasion is not well known. Here we tested how alterations in AMF community induced by an invasive plant species generate feedback to the invasive plant itself and affect subsequent interactions betwe...

Ca2+-binding proteins in the watery saliva of Megoura viciae counteract Ca2+-dependent occlusion of sieve plates in Vicia faba and so prevent the shut-down of food supply in response to stylet penetration. The question arises whether this interaction between aphid saliva and sieve-element proteins is a universal phenomenon as inferred by the coincidence between sieve-tube occlusion and salivati...

A basic tenet of ecology is that negative feedback on abundance plays an important part in the coexistence of species within guilds. Mutualistic interactions generate positive feedbacks on abundance and therefore are not thought to contribute to the maintenance of diversity. Here, I report evidence of negative feedback on plant growth through changes in the composition of their mutualistic fung...

Arctic plant communities are altered by climate changes. The magnitude of these alterations depends on whether species distributions are determined by macroclimatic conditions, by factors related to local topography, or by biotic interactions. Our current understanding of the relative importance of these conditions is limited due to the scarcity of studies, especially in the High Arctic. We inv...

We compared the density and spatial distribution of four small mammal species (Microtus ochrogaster, Peromyscus maniculatus, Sigmodon hispidus, and P. leucopus) along with general measures of an old field plant community across two successional phases (1984–1986 and 1994–1996) of an experimental study of fragmentation in eastern Kansas. During the early phase the plant community was characteriz...

The relationship between plant diversity and productivity in grasslands could depend, partly, on how diversity affects vertical distributions of root biomass in soil; yet, no prior study has evaluated the links among diversity, root depth distributions, and productivity in a long-term experiment. We used data from a 12-year experiment to ask how plant species richness and composition influenced...

BACKGROUND Forecasting the consequences of accelerating rates of changes in biodiversity for ecosystem functioning requires a mechanistic understanding of the relationships between the structure of biological communities and variation in plant functional characteristics. So far, experimental data of how plant species diversity influences the investment of individual plants in direct chemical de...

Human activities have resulted in increased nitrogen deposition and atmospheric CO2 concentrations in the biosphere, potentially causing signiWcant changes in many ecological processes. In addition to these ongoing perturbations of the abiotic environment, human-induced losses of biodiversity are also of major concern and may interact in important ways with biogeochemical perturbations to aVect...

Increased human land use has resulted in the increased homogenization of biodiversity between sites, yet we lack sufficient indicators to predict which species decline and the consequence of their potential loss on ecosystem services. We used comparative phylogenetic analysis to (1) characterize how increasing conversion of forest and grasslands to grazing pasturelands changes plant diversity a...

abstract the genus hymenocrater, belong to the lamiaceae family, consist of 21 species throughout the world. in iran, about 9 species are present, of which some are endemic. plants belonging to these genuses are pharmacologically active and have been used in folk medicine all around the world. the aim of the present study was to detect the essential oils composition of hymenocrater longiflorus ...