نتایج جستجو برای: harvest
تعداد نتایج: 23260 فیلتر نتایج به سال:
Human harvests can unwittingly drive evolution on morphology and life history, and these selective effects may be detrimental to the management of natural resources. Although theory suggests that harvest refuges, as sources of unselected animals, could buffer the effects of human exploitation on wild populations, few studies have assessed their efficiency. We analyzed records from >7000 trophy ...
It may be considered a bit early to write or even think about harvest, with blazing sun and heat in some regions. In all parts of the world, autumn comes after summer in various guises—color of leaves, bringing in the ‘sheaves’: we are now in the midst of summer. Through good fortune and health and international cooperation, I feel extremely enthusiastic to report two bits of harvest this summe...
PREFACE The process of setting waterfowl hunting regulations is conducted annually in the United States (Blohm 1989). This process involves a number of meetings where the status of waterfowl is reviewed by the agencies responsible for setting hunting regulations. In addition, the U.S. Fish & Wildlife Service (USFWS) publishes proposed regulations in the Federal Register to allow public comment....
Wildlife managers routinely seek to establish sustainable limits of sport harvest or other regulated forms of take while confronted with considerable uncertainty. A growing body of ecological research focuses on methods to describe and account for uncertainty in management decision-making and to prioritize research and monitoring investments to reduce the most influential uncertainties. We used...
Peach harvest workers were evaluated for exposure to azinphosmethyl residues by measuring foliar residues, urinary alkyl phosphate metabolites, plasma and erythrocyte (RBC) cholinesterase (ChE), and dermal residues using clothing and skin washes. Workers entered orchards 51 days after application and worked in treated fields for ten of the next 17 days. Dislodgeable foliar residues ranged from ...
Crops are harvested by performing a series of operations with harvesting vehicles in the field. The harvest operation is performed with combines (harvesters). Supporting logistical activities of transferring and transporting harvest (grain) from the field to the farm are carried out with the help of tractors. This research focuses on detailed logistics planning of various infield harvest operat...
The stand initiation stage decisively influences future forest structure and composition, particularly in the boreal forest which is a stand replacement disturbance driven system. In boreal Alaska, the conventional forest management paradigm has focused on the production of large-dimension timber, particularly white spruce (Picea glauca). However, energy generation and heating from wood is incr...
We develop a model of CWD management by nonselective deer harvest, currently the most feasible approach available for managing CWD in wild populations. We use the model to explore the effects of 6 common harvest strategies on disease prevalence and to identify potential optimal harvest policies for reducing disease prevalence without population collapse. The model includes 4 deer categories (ju...
Excessive harvest of corn (Zea mays L.) stover for ethanol production has raised concerns regarding negative consequences on soil physical quality. Our objective was to quantify the impact of two tillage practices and three levels of corn stover harvest on near-surface soil physical quality through the Least Limiting Water Range (LLWR). We evaluated no harvest, moderate and high stover harvest ...
Understanding how quickly landowners regenerate their timberlands after harvest is critical to developing policies to improve forest productivity. Using survey data from 81 counties in Mississippi from 1996 to 2006, this study investigated the length of the time interval between harvest and reforestation. Non-parametric duration analysis was used to examine how long NIPF landowners waited to re...
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