Appropriateness of inexpensive, hand-held global positioning system units for creating weed maps in a pasture

This paper describes the practical use of a global positioning system receiver (hand-held GPS) as a means of measuring and describing pasture areas invaded by weeds. The accuracy of two GPS units, a hand-held GPS with an external antenna (GPS with an antenna) and the differential global positioning system receiver (DGPS), were examined in Morioka, northern Japan. In addition, an area of weed patches and a pasture, determined using the GPS with an antenna, were compared to the measurements made with a conventional tape and a weed map was created based on the coordinate data of latitude and longitude measurements. The accuracy of the GPS with an antenna was poor (8.3 m); however, the precision of the unit was reasonable in measuring area. An area estimation error by the GPS with an antenna was 7% when practically measuring weed patches of 141 m² and 1% in a paddock of 12 566 m². From these results, it appears that the GPS with an antenna might have an acceptable error in measuring areas for weed control in a pasture. A weed map produced from the coordinate data surveyed using the GPS with an antenna enables the state of weed growth and its domination in an area of pasture to be visually understood. Therefore, GPS technologies easily can be applied to quickly obtain information on weed infestation.     

Predicting non‐native fish dispersal under conditions of climate change: case study in England of dispersal and establishment of pumpkinseed Lepomis gibbosus in a floodplain pond

Predictions of future climate change include shifts in patterns of precipitation, evapotranspiration and water run‐off, resulting in increased periods of drought as well as variability and intensity of rainfall events. In the United Kingdom, the non‐native North American sunfish, pumpkinseed Lepomis gibbosus (L.), is expected to benefit from these changes. We examine how hydrological variability induced by predicted changes in climate will affect the dispersal and spread of pumpkinseed in England by: (i) determining the relationship between discharge regime and pumpkinseed propagule pressure; (ii) examining a newly‐established pumpkinseed population following a flood event in 2007; and (iii) comparing the growth and life‐history traits of this new population with fish collected from the source population to demonstrate how the pumpkinseed's life‐history plasticity contributes to its success as a coloniser. Using Bayesian modelling, we determined that the number of pumpkinseed escapees is likely to increase with increasing discharge. The newly‐established pumpkinseed population showed fast juvenile growth, early age at maturity and small size at maturity. These traits differed significantly from the source population, specifically total length (TL) means at ages 1 and 2 were significantly greater in the new population, whereas TL at age 4 was significantly greater in the source population, and a significantly higher proportion of mature females were found at smaller size classes in the newly established pumpkinseed population. This study demonstrates the potential link between hydrological variability (current and future) and the dispersal of non‐native pumpkinseed, leading to the establishment of new populations.     

论析欧洲的环境政策

当今世界，欧洲环境治理绩效突出。究其原因，环境政策发挥了指导性作用。而这对于环境形势目最严峻的中国具有十分重要的借鉴意义。文中对欧洲环境政策发展历程、原则及挑战进行了细致分析，以供相关研究机构和学者参考。     

记忆指导模拟退火算法的研究

提出了改进模拟退火算法的记忆指导模拟退火算法。该算法能够利用已知信息对搜索过程进行指导，提高算法的搜索效率，该法对回火退火算法的计算量减少５０％。     

高对称性_d过渡金属配合物中的Jahn-Teller效应及其作用

本文从能量方面考察高对称性 d 过渡金属配合物中的 Jahn-Teller 效应;运用Jahn-Teller 效应稳定化能从理论上推测 Jahn-Teller 畸变的程度和畸变的几何性质;同时简要地讨论了 Jahn-Teller 效应对 d 过渡金属配合物的结构特性的作用。     

基于GIS、GPS建立退耕还林数据自查核查管理系统

退耕还林档案是林业生产中的重要数据资料,是组织和指导林业生产的重要依据。利用GIS技术和数据库技术进行退耕还林档案管理可以提高管理水平,避免项目之间、年度之间的重复,提高数据的精度,提高数据汇总进度,进而提高工作生产率。该系统运用地理信息为核心,建立退耕还林空间信息的查询管理,完善管理机制,实现退耕面积调查、动态监测及数据更新、数据处理、数据存储、统计分析、规划设计、制图制表等功能,保障退耕还林工程的顺利实施。     

林火在空间上的波动性及其区域化行为

应用美国阿拉斯加州1950-2000年,加利福尼亚州1895-2001年及中国黑龙江省1980-1999年林火数据,分别计算出每年火灾发生的火场质心的经纬度坐标,用波谱分析研究其质心随年份的波动现象.结果表明:3个区域的林火的火场质心分别以一定的分布中心呈波动状态,其中火场质心在阿拉斯加州的分布中心为151.11°W、64.96°N,在加利福尼亚州的分布中心为120.02°W、37.11°N,在黑龙江省的分布中心为127.07°E、49.59°N.火场质心在美国阿拉斯加州和加利福尼亚州经度方向上均具有较强的周期性,阿拉斯加州的林火火场质心在经度方向的周期为4.2 a和6.25 a;加利福尼亚州的林火火场质心在经度方向上的波动周期为6.24 a和106 a.黑龙江省的林火火场质心在经纬度方向均具有较为明显的波动性,其周期为3.3 a和6.67 a.而阿拉斯加州和加利福尼亚州的林火火场质心在纬度方向上不具有周期性,林火发生以低频率的大面积火灾为主.     

酸化处理抑制杨木APMP纸浆返黄的研究

用草酸、硫酸等对黑杨ＡＰＭＰ浆进行酸化处理，研究了酸化对黑杨ＡＰＭＰ浆的光致返黄和热致返黄的抑制作用并对其机理进行讨论。结果表明①酸化处理能提高ＡＰＭＰ浆的白度和白度稳定性。②各种酸对ＡＰＭＰ浆的返黄抑制作用不同；试验所用的酸中，草酸最优。     

肉牛场生命周期估计及环境影响评价

试验采用生命周期估计(life cycle assessment,LCA)方法对江西高安某存栏1 800头的肉牛育肥场在整个育肥期间(7个月)的污染物排放量,以及污染物在全球变暖、环境酸化、富营养化、光化学臭氧合成方面对环境的影响进行了评估。系统边界包括化肥生产、农作物种植、饲料运输、肉牛生产和粪便处理。结果表明:温室气体排放量为(以CO2当量计)为11 908t,环境酸化气体排放量(以SO2当量计)为84.6t,富营养化气体排放量为(以PO43-当量计)为14.4t,光化学臭氧合成问题气体排放量为(以C2H4当量计)为1.68t。其中饲料运输主要影响全球变暖(占总排放量的49.8%)和光化学臭氧合成问题(占总排放量的54.1%),而粪便处理主要影响环境酸化(占总排放量的70.1%)和富营养化(占总排放量的76.4%),肉牛生产对环境的影响主要是全球变暖(占总排放量的18.1%)和光化学臭氧合成问题(占总排放量的30.9%)。因此,可考虑通过降低运输距离,改善饲料配方、粪便处理方式等降低污染物排放量。     

The face of conservation responding to a dynamically changing world

In its 40‐year history, the science of conservation has faced unprecedented challenges in terms of environmental damage and rapid global change, and environmental problems are only increasing as greater demands are placed on limited natural resources. Conservation science has been adapting to keep pace with these changes. Here, we highlight contemporary and emerging trends and innovations in conservation science that we believe represent the most effective responses to biodiversity threats. We focus on specific areas where conservation science has had to adjust its approach to address emerging threats to biodiversity, including habitat destruction and degradation, climate change, declining populations and invasive species. We also document changes in attitudes, norms and practices among conservation scientists. A key component to success is engaging and maintaining public support for conservation, which can be facilitated through the use of technology. These recent trends in conservation and management are innovative and will assist in optimizing conservation strategies, increasing our leverage with the general public and tackling our current environmental challenges.