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A regression tree-based method for integrating land-cover and land-use data collected at multiple scales 总被引:1,自引:0,他引:1
As data sets of multiple types and scales proliferate, it will be increasingly important to be able to flexibly combine them
in ways that retain relevant information. A case in point is Amazonia, a large, data-poor region where most whole-basin data
sets are limited to understanding land cover interpreted through a variety of remote sensing techniques and sensors. A growing
body of work, however, indicates that the future state of much of Amazonia depends on the land use to which converted areas
are put, but land use in the tropics is difficult to assess from remotely sensed data alone. An earlier paper developed new
snapshots of agricultural land use in this region using a statistical fusion of satellite data and agricultural census data,
an underutilized ancillary data source available across Amazonia. The creation of these land-use maps, which have the spatial
detail of a satellite image and the attribute information of an agricultural census, required the development of a new statistical
technique for merging data sets at different scales and of fundamentally different data types. Here we describe and assess
this nonlinear technique, which reinterprets existing land cover classifications by determining what categories are most highly
related to the polygon land-use data across the study area. Although developed for this region, the technique appears to hold
broad promise for the systematic fusion of multiple data sets that are closely related but of different origins.
The figures in the printed version of this article appear in black and white. Color figures are available from the author
upon request. 相似文献
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不同碳源条件下草菇内切型纤维素酶基因(eg1)转录表达的分析 总被引:1,自引:0,他引:1
利用Northernblot方法分析了不同碳源条件下草菇切型纤维素酶基因(eg1)的表达.结果发现,在含有纤维素的液体培养基中生长10d,eg1在草菇菌丝中有高效表达;纤维二糖、α-乳糖、β-乳糖,也能诱导eg1的表达,但和纤维素相比,eg1的表达量相对较低,并且它们的诱导效应在加入这类糖12h后迅速减弱;槐糖和龙胆二糖的诱导作用非常弱.在天然稻草为基质的固体栽培料生长时,草菇eg1的表达和草菇菌丝生长与出菇相对应,在菌丝生长期(d8)可见eg1的表达,d12时菌丝已长满,表达减弱,在出菇及菇体的分化及增大期,eg1的表达量逐渐增强,在成熟期达到最高水平;表明在草菇菇体发育中需要更多碳源及能源的补充,eg1在这方面起着非常重要的作用.图4参14 相似文献
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利用Northern blot方法分析了不同碳源条件下草菇內切型纤维素酶基因(eg1)的表达.结果发现,在含有纤维素的液体培养基中生长10 d,eg1在草菇菌丝中有高效表达;纤维二糖、α-乳糖、β-乳糖,也能诱导eg1的表达,但和纤维素相比,eg1的表达量相对较低,并且它们的诱导效应在加入这类糖12 h后迅速减弱;槐糖和龙胆二糖的诱导作用非常弱.在天然稻草为基质的固体栽培料生长时,草菇eg1的表达和草菇菌丝生长与出菇相对应,在菌丝生长期(d 8)可见eg1的表达,d 12时菌丝已长满,表达减弱,在出菇及菇体的分化及增大期,eg1的表达量逐渐增强,在成熟期达到最高水平;表明在草菇菇体发育中需要更多碳源及能源的补充,eg1在这方面起着非常重要的作用. 图4 参14 相似文献
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Representative Landscapes in the Forested Area of Canada 总被引:1,自引:0,他引:1
Canada is a large nation with forested ecosystems that occupy over 60% of the national land base, and knowledge of the patterns
of Canada’s land cover is important to proper environmental management of this vast resource. To this end, a circa 2000 Landsat-derived
land cover map of the forested ecosystems of Canada has created a new window into understanding the composition and configuration
of land cover patterns in forested Canada. Strategies for summarizing such large expanses of land cover are increasingly important,
as land managers work to study and preserve distinctive areas, as well as to identify representative examples of current land-cover
and land-use assemblages. Meanwhile, the development of extremely efficient clustering algorithms has become increasingly
important in the world of computer science, in which billions of pieces of information on the internet are continually sifted
for meaning for a vast variety of applications. One recently developed clustering algorithm quickly groups large numbers of
items of any type in a given data set while simultaneously selecting a representative—or “exemplar”—from each cluster. In
this context, the availability of both advanced data processing methods and a nationally available set of landscape metrics
presents an opportunity to identify sets of representative landscapes to better understand landscape pattern, variation, and
distribution across the forested area of Canada. In this research, we first identify and provide context for a small, interpretable
set of exemplar landscapes that objectively represent land cover in each of Canada’s ten forested ecozones. Then, we demonstrate
how this approach can be used to identify flagship and satellite long-term study areas inside and outside protected areas
in the province of Ontario. These applications aid our understanding of Canada’s forest while augmenting its management toolbox,
and may signal a broad range of applications for this versatile approach. 相似文献
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