Exotic plant invasions and chronic high levels of herbivory are two of the major biotic stressors impacting temperate forest ecosystems in eastern North America, and the two problems are often linked. We used a 4-ha deer exclosure maintained since 1991 to examine the influence of a generalist herbivore, white-tailed deer (Odocoileus virginianus), on the abundance of four exotic invasive (Rosa m...

The effect of cattle grazing on the genetic structure of native grass populations has received little attention. We investigated the effect of cattle grazing on genetic variation in Idaho fescue (Festuca idahoensis Elmer) using ISSR (inter-simple sequence repeat) DNA markers. The ISSR markers are hypervariable and are generally interpreted as being selectively neutral. Idaho fescue tillers were...

introduction the complexity of natural ecosystem, as the rangelands, is caused to propose the different approaches toevaluatethe ecosystem on the basis of sustainable and systematic management. study on the interaction connectionsbetween plants and biotic and abiotic factors in the rangeland ecosystem can be achieved by relationsofmanagerial strategies in order to conduct the rangeland health. ...

Our research on the herbaceous understory vegetation in the Kluane region, Yukon, has focused on the structure and function of natural forest understory and grassland communities. The research has involved two long-term projects. The first investigated fertilizer addition and mammalian herbivore exclosure in understory vegetation over a 20-year period and showed that nutrient availability, and ...

Exclosure plots established in three separate areas of kanuka (Kunzea ericoides var. ericoides) forest on south Kaipara spit in 1983 to assess the impact of introduced fallow deer (Dama dama) were remeasured in 1993. Kanuka shared canopy dominance with mapou (Myrsine australis), houpara (Pseudopanax lessonii) and mahoe (Melicytus ramiflorus ssp. ramiflorus) in relatively old forest in Lookout B...

     Forage production of rangelands differs during different times of grazing season and in the same month of different years. In range management projects, grazing capacity calculated once during the grazing season, which coincides with the maximum production of rangeland species. This may cause more livestock entry into the rangeland during the grazing season, leading to more degradation. Th...