Lupines (Lupinus lepidus var. lobbii), the earliest plant colonists of primary successional habitats at Mount St. Helens, were expected to strongly affect successional trajectories through facilitative effects. However, their effects remain localized because initially high rates of reinvasive spread were short lived, despite widespread habitat availability. We experimentally tested whether inse...

Desert wetlands play a significant role in flood regulation, water purification, biodiversity maintenance, and regional ecological environment improvement. Vegetation is key factor affecting wetland function it important to study the features of plant community driving forces succession. The Ningxia Habahu National Nature Reserve, typical desert ecosystem, was selected communities including den...

In recent years computer models have become increasingly important in providing insights into the developmental process of plants. The study of phyllotactic patterns provides a good example of this. Despite the huge diversity of plant forms there are only a few ways in which plant organs such as leaves, florets, scales, etc. are arranged along a plant stem. The prevalence of a small number of p...

The leaves of the carnivorous pitcher plant, Sarracenia purpurea, contain a microscopic aquatic food web that is considered a model system in ecological research. The species identity of the intermediate and top trophic level of this food web, as well the detritivore midge, are highly similar across the native geographic range of S. purpurea and, in some cases, appear to have co-evolved with th...

focus on primary succession in habitats formed on May 18, 1980, to explore mechanisms that control establishment of plants on new landforms. The rate of early primary succession is generally believed to be slow (cf. Crocker & Major 1955; Shure & Ragsdale 1977; Houle & Phillips 1989), though rates can differ significantly. As conditions are ameliorated by weathering and nutrient accumulation, th...

Tall fescue and other non-native perennial cool-season grasses (such as orchardgrass, timothy, bromegrasses, and bluegrass) provide poor wildlife habitat. Native warm-season grasses (nwsg), especially big and little bluestem, indiangrass, and switchgrass, have been promoted to replace non-native cool-season grasses and enhance quality early succession habitat. Initially, problems associated wit...

Forest degradation is a global environmental issue, but its definition is problematic. Difficulties include choosing appropriate reference states, timescales, thresholds, and forest values. We dispense with many such ambiguities by interpreting forest degradation through the frame of ecological resilience, and with reference to forest dynamics. Specifically, we define forest degradation as a st...

In the past few years, the world has taken a new view to herbal remedies and their applications and many researchers in various fields of medicine are studying this subject. In our program searching for antibacterial agents we have selected an extract prepared from the Pentanema divaricata. No report on the antibacterial activity of this species has been published in literature. Pentanema divar...

(1) Ipomoea hederacea, a common weed in cultivated fields of eastern North America, disappears quickly following abandonment of farming. (2) The effects of competition and nitrogen addition on the growth and reproduction of I . hederacea were studied during the first year of abandonment. (3) Competition and fertilization had significant absolute effects on almost all biomass variables measured ...

Coastal marine systems are affected by seasonal variations in biogeochemical and physical processes, sometimes leading to alternating periods of reproductive growth limitation within an annual cycle. Transitions between these periods can be sudden or gradual. Human activities, such as reservoir construction and interbasin water transfers, influence these processes and can affect the type of tra...