نتایج جستجو برای: annual forbs
تعداد نتایج: 110865 فیلتر نتایج به سال:
Abstract Invasive winter annual grasses, such as cheatgrass ( Bromus tectorum L.) are considered serious threats to regional biodiversity. Pollinator populations that depend on the native flora likely be negatively impacted these species may displaced by invasive grass species. Colonization is also predicted increase risk of wildfires, dead plant parts provide fuel in already dry and arid regio...
The dominance of invasive species is often assumed to reflect their competitive superiority over displaced native species. However, invasive species may be abundant because of their greater tolerance to anthropogenic impacts accompanying their introduction. Thus, invasive species can either be the drivers or passengers of change.We distinguish between these two possibilities in California grass...
This paper shows the general perceptions of Spanish university stakeholders in relation to the university’s annual reports and the adequacy and potential of intellectual capital reporting. To this end, a questionnaire was designed and sent to every member of the Social Councils of Spanish public universities. It was thought that these participants would provide a good example of the attitude of...
Florida’s dry prairies are rare and threatened due to suppression of natural fire regimes in these fire-dependent ecosystems. Ecological restoration of dry prairies reduces the growth of shrubs resulting from lack of fire, while encouraging the growth of grasses and forbs. In addition to prescribed burning, these efforts often use mechanical disturbance such as roller-chopping. In this study we...
In perennial grasslands R. obtusifolius (broad-leaved dock) is often surrounded by certain plant species. Thus, it is hypothesized for the current study that Rumex can affect their neighbouring plant species by allelopathic interactions. To test this hypothesis, in a series of laboratory and field experiments aqueous extracts of green R. obtusifolius leaves were sprayed on seeds of 14 herbaceou...
BACKGROUND AND AIMS Rhinanthus minor is a root hemiparasitic plant that attacks a wide range of host species which are severely damaged by the parasite. Rhinanthus minor also attempts unsuccessfully to form connections to a range of non-hosts which in contrast are not damaged by the parasite; however, the underlying physiological basis of these differences is not fully understood. METHODS Bio...
• Leaf gas exchange responses to elevated CO 2 and N are presented for 13 perennial species, representing four functional groups: C 3 grasses, C 4 grasses, legumes, and nonleguminous forbs. Understanding how CO 2 and N effects interact is important to predict plant community response to global change. • Plants were field-grown in monoculture under current ambient and elevated (560 μ mol mol − 1...
Understanding potential impacts of vegetation change on caribou energetics requires information on varia¬ tions in forage quality among different plant types and over time. We synthesized data on forage quality (nitrogen, neutral detergent fiber and dry matter digestibility) for 10 plant growth forms from existing scientific literature and from field research in the Arctic National Wildlife Ref...
Uptake capacity of organic nitrogen was studied in solution experiments on eight grasses and two forbs growing in acid soils with relatively high nitrogen mineralisation in southern Sweden. Uptake of a mixture of amino acids (alanine, glutamine, glycine), that varied between 1.6 and 6.3 µmol g(-1) dw root h(-1), could not be explained by soil data from the species' field distributions (pH, tota...
Priority effects occur when species that arrive first in a habitat significantly affect the establishment, growth, or reproduction of species arriving later and thus affect functioning of communities. However, we know little about how the timing of arrival of functionally different species may alter structure and function during assembly. Even less is known about how plant density might interac...
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