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1.
野菜是20世纪90年代以来人们开发新的蔬菜种类的一个热点,特别是在近年来人们不断追求食品多元化、更加注重食品健康的情况下,野菜以其一些独特的品质越来越受到人们的欢迎,因此,各地都开始了对它的研究和开发,很多地方都成立专门的开发公司,对野菜进行大批量的生产和加工,并已创出了自己的名牌产品.  相似文献   

2.
Although the area disturbed by linear features in forested systems is small relative to many other human disturbances, linear features create significantly more amounts of edge per unit area. In the boreal plains of Alberta, Canada, energy sector exploration has resulted in extensive dissection of the landscape through 8 m wide seismic lines. A spatially explicit model was developed to test how bird abundance might change in response to increasing seismic line density if individuals use seismic lines as territory boundaries or actively avoid these edges. Assuming birds had fixed territory shape and size, increasing seismic line density from 0 to 8 km/km2 resulted in a 38% decline and an 82% decline in bird abundance when individuals used lines as territory boundaries or avoided edges by 50 m, respectively. We tested the assumptions of our model using the Ovenbird (Seiurus aurocapillus). Based on radio-telemetry (n = 12), all Ovenbirds crossed seismic lines at some point during the breeding season. However, male Ovenbirds showed a distinct use of one side of the seismic line, suggesting lines acted as territory boundaries. In 12.25 ha plots (n = 24) spot-mapping detected no change in Ovenbird density as linear feature density increased from 0 to 8.6 km/km2. In 4 km2 landscapes (n = 62) sampled using a grid of nine point-counts, we also detected no changes in Ovenbird numbers across the same range of seismic line densities. Ovenbirds declined with seismic line density at the level of the individual point-count station (12 ha scale), but only when a threshold seismic line density of 8.5 km/km2 was reached. Above the threshold, Ovenbirds declined 19% for each 1 km/km2 increase in seismic line density. While relatively few places in Alberta’s boreal forest have local seismic line densities of 8.5 km/km2, forest dissection could increasingly become an issue if current energy exploration practices continue.  相似文献   

3.
A cooperative project between the International Rice Research Institute in Los Baños, Philippines, and the U.S. EPA Environmental Research Laboratory in Corvallis, Oregon, was initiated to estimate how rice yield in Asia might be affected by future climate change and enhanced UV-B irradiance following stratospheric ozone depletion. A radiative transfer model was used to estimate daily UV-B irradiance levels using remotely sensed ozone and cloud cover data for 1274 meteorological stations. A rice yield model using daily climatic data and cultivar-specific coefficients was used to predict changes in yield under given climate change scenarios. This paper gives an overview of the data required to run these two models and describes how a geographical information system (GIS) was used as a data pre- or postprocessor. Problems in finding reliable datasets such as cloud cover data needed for the UV-B radiation model and radiation data needed for the rice yield model are discussed. Issues of spatial and temporal scales are also addressed. Using simulation models at large spatial scales helped identify weaknesses of GIS data overlay and interpolation capabilities. Even though we focussed our efforts on paddy rice, the database is not intended to be system specific and could also be used to analyze the response of other natural systems to climatic change.  相似文献   

4.
江苏省茶叶生产现状及发展趋势   总被引:1,自引:0,他引:1  
江苏横跨江南茶区和江北茶区,茶叶生产历史悠久。介绍了江苏省茶叶生产现状,分析了茶产业的特点与发展优势,提出了未来茶产业的发展趋势。  相似文献   

5.
Spatial development involves multi-dimensional and multi-regional objectives that might be competing, while few studies have examined these issues simultaneously. We proposed a comprehensive model to assess the green quality of urban spatial development (GQUSD), focusing on the synergy of multi-dimensional objectives and the balance of multi-regional interests. The metropolitan city of Hangzhou was taken as an example. We included land consumption, vegetation loss and infrastructure cost as the inputs and the density of production and living activities as the outputs of spatial development. We developed a categorical Data Envelope Analysis (DEA) using geospatial big data and stratified optimization to evaluate the synergy of inputs-outputs at the finer level of spatial grids.Resultsshow a “sandwich” structure of the GQUSD in Hangzhou when considering green space and vegetation loss, and characterize four spatial typologies of agglomerated development, limited development, blinded development and low-potential development through the Bivariate Local Indicator of Spatial Association (LISA) analysis. The “sandwich” structure is shaped by spatial processes of socio-economic agglomeration, industrial-driven sprawl, new-town development and suburbanization of high-end sectors. We also find green inequality in the spatial development of Hangzhou where vegetation costs were higher in manufactural industrial sites and low-income communities. We provide urban planning strategies to balance competing interests across regions, objectives, functions and communities for green growth and sustainable goals.  相似文献   

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