A Method for Rapid,Spatially Explicit Habitat Assessment for Forest Songbirds

Abstract

The management of forest ecosystems for sustainabil-ity requires knowledge of the abundance and distribution of all resources, including wood and wildlife, and the ability to predict the impact of management on these resources. Spatially explicit inventories for wildlife are lacking for the vast majority of species. We propose, with example, a method of rapid habitat assessment which can be conducted with available data to produce a spatially explicit inventory of habitat for a species. Information from the literature and some census data were used to construct a simple model of potential habitat for a boreal forest songbird. Available spatial data, including landcover from Landsat TM data, and a digital elevation model, were used to map the distribution of key habitat characteristics onto the landscape. We argue for the development of these preliminary wildlife habitat models using habitat characteristics that are map-pable with currently available remotely sensed data. Given the current trend toward the development of large scale databases of topography and extant land cover, spatially explicit potential habitat models can be efficiently and inexpensively developed to provide a framework for incorporating wildlife habitat into forest management. The relationships between rapid habitat assessment, long-term studies, monitoring, and population viability analysis are discussed.     

Underpricing and Overexploitation of Tropical Forests

Abstract

Forest pricing policies for tropical timber and forest concessions can play an important role in the management, conservation, and preservation of tropical forests. The paper draws on regional studies of forest revenue systems and forest concession arrangements, country case studies, and studies in individual countries of West and Central Africa and South East Asia (Grut, Gray, and Egli, 1991; Gray and Hadi, 1989; Gray and Hadi, 1990; and Gray, 1983). Forest pricing and concession management policies, problems, and experiences in individual countries are examined, common problems and experiences highlighted, and alternatives identified. From these, the elements of a forest pricing and concession management system which supports sustainable management, efficient utilization, and forest renewal are developed.     

Accuracy of sedimentgraph modeling from topography map scale and DEM mesh size

The evaluation of scale effects on modeling performance of sedimentgraphs as the ultimate outputs of the hydrological simulation is vital for adaptive watershed management. The present study therefore analyzed effectability of simulated sedimentgraphs components in association with different topographic maps with various vector scales. The whole procedure was materialized to select the critical scale and cell size for the Galazchai Watershed, Iran. To this end, the stormwise sedimentgraphs were modeled for 23 recorded events using the Clark's Instantaneous Unit Hydrograph (IUH) model stemmed for developing Instantaneous Unit Sedimentgraphs (IUSGs) incorporated with dimensionless sediment concentration distribution (DSCD) based on the vector scales of 1:25000, 1:50000, 1:100000 and 1:250000 and cell sizes of 5, 10, 20 30, 50, 100 and 200 m. Some 644 direct sedimentgraphs (DSGs) were then evaluated based on Relative Errors (REs) for sediment volume, peak sediment, time to peak, base time and the Coefficient of Efficiency (CE). The results confirmed that REs for peak sediment, time to peak and CE were sensitive to cell size. The results further verified that the cell sizes of 5, 20, 30, 50 and 100 m were critical cell sizes in viewpoint of time to peak. In addition, the vector scales of 1:50000 with cell size of 50 m, and 1:100000 with cell sizes of 5 and 10 m were critical vector scales and cell sizes based on RMSE evaluation criterion. It is concluded from the current research that the accuracy of simulation of sedimentgraph was influenced by map scales and mesh sizes.     

近50年赣西北大坑小流域径流对降雨的响应

根据赣西北大坑小流域1957—2005年逐日降雨和径流资料,采用时间序列分析法和统计回归分析法,对降雨变化及径流的响应进行了分析。结果表明:（1）大坑小流域1957—2005年平均年降雨量为1 596.3 mm,其年内变化为典型的单峰型曲线,降雨的季节差异非常明显,同时,降雨量的年际变化较大,总体呈增加趋势。（2）大坑小流域1957—2005 年平均年径流深为814.3 mm,其年内变化为单峰型曲线,径流深的季节差异较大,同时,径流深的年际变化较大,总体呈增加趋势。（3）从年径流深与年降雨量的回归分析可知,大坑小流域的降雨量与径流深之间存在密切的相关性。当水文年降雨量增加或减少10%时,年径流深会表现出增加或减少17.8%的正响应;当水文年降雨量增加20%或减少30%时,年径流深会表现出增加35.6%或减少53.4%的正响应。     

一种粘连牛乳体细胞图像的分离算法

粘连细胞的分割是细胞精确计数的关键,针对牛乳粘连体细胞的特点,首先利用k-means方法分割细胞和背景并运用数学形态学算子对图像做预处理.然后对分割后的二值图像进行距离变换和图像重构,最后用Watershed算法分离粘连细胞,以得到最终结果.实验结果表明该方法能准确、快速地分割粘连牛乳体细胞,并能有效改善分水岭(Watershed)的过分割现象.     

一种粘连谷物图像分割及杂质识别算法开发

本文提出了一种自动分割粘连谷物并识别杂质的算法。该算法首先使用基于形态学多尺度分解的分水岭算法对粘连颗粒进行分割,接着提取各个颗粒的形态特征和颜色特征,然后计算上述样本颗粒的特征值与完好谷物的特征值之间的马氏距离,并比较它们的马氏距离与设定的阈值,来识别混杂在谷物中的杂质。通过对5种谷粒(普通大米、粗米、糙米、普通大麦、糯麦)的实验,结果表明该算法取得了较好的分割与识别效果,为谷物质量分级的评定提供了一种快速有效地检测谷物产品杂质率的方法。     

渭河流域洪水灾害关键因素分析及防治对策

讨论了近50a渭河流域洪水灾害的年际变化、月际变化和潼关高程变化。对造成该流域洪水灾害的关键因素,包括降水量年内分配不均和年际变化大,滩面淤积加重,支流河口淤塞以及河势、流态的恶化等作了分析。针对这些因素并根据渭河流域洪水灾害的特点,提出了相应的防治措施,即降低下游高程,减少河道的淤积,增大河道泄洪能力;利用水库进行调水调沙,引进客水冲刷渭河下游;防洪工程的除险加固,提高防洪标准与抗洪能力;加强非工程防洪措施的研究与建设;恢复林草植被,遏止水土流失,从源头上控制泥沙入河等。     

影响三工河干沟春季融雪洪水发生的气象因素

利用三工河流域近山前倾斜平原区气象资料,对发生在1964-2001年期间三工河干沟春季洪水量进行逐步回归分析,得到2个相关性较好的三元模型方程。模型表明,冬季积雪量越大,3月1候前期气温越低,3月2候气温越高,三工河春季洪水量就越大,反之则相反。模型中的2项气象因素是制约三工河干沟发生春洪的主要条件因素,因此,三工河流域开春期前的增温作用是近年来三工河干沟春季洪水量减少的主要原因。     

Holocene sediment budgets for upland catchments: The problem of soilscape model and data availability

This study presents a Holocene sediment budget for the upland catchment of the Speyerbach in the Palatinate Forest, southwestern Germany. The influences of both, data availability and the choice of an appropriate soilscape model on the sediment budget calculations are investigated. For budget calculations the spatial distribution of soils was derived from the soil map 1:50,000. Thickness values of soil truncation and colluvial burial were extracted from two soil data sets with varying information content. Data processing contained a disaggregation of the soil map with the help of land use data. In order to model the sediment budget a reference soil thickness (a so-called soilscape model), which represents the initial conditions is necessary. As upland soils are developed in periglacial solifluction sheets, the main solifluction sheet (MSS, “Hauptlage”) showing a constant thickness and being affected by soil forming processes was chosen.