The present study used overlapping burn scars from natural wildfires to examine the effects of changes in the fire-free interval on early successional plant communities in boreal forests of centralYukon Territory, Canada. Data on plant community composition and residual organic material were collected in the first decade of post-fire regeneration in two study areas with recent fire overlap. Sit...

Host-plant preferences were assessed by Þeldmeasurement of grasshopper abundance in relation to measurements of ßoral community and by laboratory host-plant preferences. Correlations between grasshoppers and plants (biomass and percentage cover) were based on data gathered at 29 study sites in Þve distinct Florida habitats (including disturbed, freshwater marsh, high pine, oak hammock, and swam...

In [HHTZ] the authors characterize the vertex cover algebras which are standard graded. In this paper we give a simple combinatorial criterion for the standard graded property of vertex cover algebras in the case of quasi-trees. We also give an example of how this criterion works and compute the maximal degree of a minimal generator in that case.

this research has been done with the aim of explaining environmental and managerial factors that affects on rangeland vegetation distribution in saral rangelands of kurdistan province. after selecting plant types as working area were done sampling from plant types and determined some of plants parameters such as kind and number of plants and cover percentage. various environmental factors such ...

A common crop rotation in the west Iran is wheat-fallow-corn. The fallow period after wheat harvest (during fall and winter) can lead to soil erosion, nutrient losses (e.g. nitrate leaching) and offsite movement of pesticides. This period is an ideal time to establish a cover crop. In order to investigate the effects of different autumn-bseeded cover crops on subsequent irrigated corn response ...

Woody plant encroachment is a worldwide phenomenon in grassland and savanna systems whose consequence is often the development of an alternate woodland state. Theoretically, an alternate state may be associated with changes in system state variables (e.g., species composition) or abiotic parameter shifts (e.g., nutrient availability). When state-variable changes are cumulative, such as in woody...

This study was conducted to assay the effects of methanol foliar application (0, 10, 20 and 30% v/v) and bed cover (control, white and black covers) on yield and some physiological traits of marigold as a factorial based on RCBD. The results revealed the significant interaction effects of bed cover and methanol foliar application on chlorophyll a content and plant height. The highest plant heig...

The accumulation of litter or thatch can affect plant community composition by affecting the temperature, nutrient availability, and light availability of the soil environment, thereby forming a potentially important linkage between recent productivity and current ecosystem processes. To investigate the importance of litter on a fen peatland plant community, we conducted a litter addition and r...

Rhazya stricta, an evergreen poisonous shrub, is invading many rangeland areas in Saudi Arabia. A field study was conducted in Raudhat AI-Khafs to assess the relationship between R. stricta and Hammada elegans, a valuable and a dominant saltbush range plant in the area. Only eight perennial species were found in the site of which H. elegans and R. stricta were almost exclusively co-dominating t...