新疆塔里木马鹿沙雅种群的生境变化分析

塔里木马鹿(Cervus elaphus yarkandensis)沙雅种群主要分布在新疆维吾尔自治区沙雅县和库车县境内。为了评估该马鹿种群的生境现状、变化趋势和变化原因,通过野外实地考察,利用GIS和RS技术,分别解译了当地过去4个年份(1972～2006年)夏季的Landsat TM/ETM+遥感影像,得到了塔里木马鹿生境变化数据:①2006年的农田面积为27082.24hm2,高盖度植被面积22616.25hm2,中盖度植被面积66703.62hm2,低盖度植被面积64470.62hm2,水体面积39735.89hm2,荒漠面积63497.26hm2,沙漠面积40308.45hm2;②过去的34年间农田面积增加了89.2%(12768hm2),高盖度植被面积减少60.1%(34125hm2),中盖度植被面积增加了17.2%(9791hm2),低盖度植被面积增加了37.3%(17520hm2),水体面积减少26.6%(14429hm2),荒漠面积增加6.9%(4123hm2),沙漠面积增加12.6%(4523hm2);③高盖度植被的斑块数量增加了20.9%,平均斑块面积下降了48.3%,最大斑块指数下降了33.3%;景观丰富度并没有变化,但Shannon多样性指数和Shannon均匀度指数分别增加了2.5%;④高盖度植被面积变化分别与当地的人口数量和畜牧存栏数呈显著负相关(r=-1.000),而农田、沙漠和荒漠面积分别与当地人口数量及畜牧存栏数呈显著正相关(r=0.800,r=1.000,r=0.800)。表明塔里木马鹿沙雅种群生境的丧失及破碎化程度较为严重;生境丧失及破碎化是人类活动和自然环境变化共同作用的结果。     

重庆彭水发现务川臭蛙

2022年7月,在重庆市彭水苗族土家族自治县新田镇调查到2只臭蛙,经比较形态特征确认为臭蛙属（Odorrana）物种。基于线粒体16S rRNA基因片段构建的臭蛙属部分物种的贝叶斯和最大似然系统发育树显示,这2只臭蛙和模式产地贵州省务川仡佬族苗族自治县的务川臭蛙（O. wuchuanensis）聚为一支,具有较高的支持率,贝叶斯后验概率为0.99、最大似然超快速引导支持（2 000次重复）自展值为95%。综合形态特征和系统发育分析,确认此2只臭蛙为务川臭蛙,系重庆市首次记录。务川臭蛙分布范围较为狭窄,此前仅记录于贵州省务川县、沿河土家族自治县、荔波县以及湖北省建始县和广西壮族自治区环江毛南族自治县。务川臭蛙在重庆彭水的发现,确认了该物种在武陵山和大娄山脉重庆段的分布。彭水发现的务川臭蛙1雄1雌,雄性体长81.3 mm,大于模式标本的最大体长,大于湖北建始县种群雄蛙体长;雌性体长87.1 mm,在模式标本的体长范围内,小于建始县种群雌蛙体长。线粒体16S rRNA基因的遗传分化分析显示,重庆市彭水苗族土家族自治县的务川臭蛙样本和模式产地的样本没有遗传分化,遗传距离为0。务川臭蛙在重庆市的...     

云南澜沧县陆稻品种资源多样性和原生境保护

云南澜沧县不仅存在丰富的陆稻品种多样性和形态多样性,而且也存在陆稻生长环境和栽种管理方法的多样性,即山地民族在陆稻栽种方面的土著知识（indigenous knowledge,IK）多样性,讨论了由传统的刀耕火种生产制度过渡到现代固耕生产方式对陆稻生产及品种资源保存和保护的影响。提出了陆稻资源多样性保护的建议。     

浙江安吉主要林地类型土壤渗透性

对浙江安吉县龙王山地区主要植被类型的土壤渗透性进行了研究.结果表明,不同土地利用类型的土壤渗透性存在很大差别.根据土壤渗透能力可将8种植被类型分为4类：第1类,落叶阔叶林,土壤渗透能力极强;第2类,草地、松林、灌木林和茶园,土壤渗透能力强;第3类,毛竹林和常绿阔叶林,土壤渗透较强;第4类,裸露地,土壤较紧实,土壤结构较差,土壤通透性不佳,渗透能力弱.经主分量分析,得到表征渗透性能综合参数α和表征根系特征的综合参数β,构建了回归方程：α=0.1708e^β-0.3122.土壤理化性质、植被根系显著地影响土壤渗透性能.植被根系提高土壤入渗性能的实质是≤1 mm细根能有效地改善土壤性状.     

岷江上游汶川县耕地景观变化及空间驱动力

基于遥感影像和地理信息系统技术,应用景观指数和Kappa指数系列方法对岷江上游耕地景观变化进行研究,并引入二项Logistic逐步回归模型,选择海拔、坡度、坡向、到道路、河流和居民点距离为驱动因子对汶川县耕地景观变化的空间驱动力进行分析.结果表明: 研究期间耕地景观面积一直处于增长趋势,1974—1986年间耕地景观面积增幅最大.1986—2000年间耕地面积增加不明显,但是耕地景观与其它景观类型相互转换频繁,空间位置变化剧烈,特别是1994—2000年期间.耕地景观面积变化的驱动力主要为政策变化.耕地景观变化的空间驱动力在不同时间段内存在较大差异.     

福建平和果树冻害调查

本文分析了1999年12月福建平和出现严重冻害的气象特点,调查全县亚热带、热带果树的冻害情况及影响冻害程度的因素,并提出冻后的管理措施。     

Trade‐offs among agronomic,energetic, and environmental performance characteristics of corn and prairie bioenergy cropping systems

Cellulosic bioenergy production provides opportunities to utilize a range of cropping systems that can enhance the multifunctionality of agricultural landscapes. In a 9‐ha field experiment located on fertile land in Boone County, IA, USA, we directly compared a corn‐soybean rotation harvested for grain, continuous corn harvested for grain and stover, continuous corn harvested for grain and stover with a rye cover crop, newly reconstructed prairie harvested for biomass and fertilized with nitrogen, and unfertilized newly reconstructed prairie harvested for biomass. Comparisons were made using four performance indicators: harvestable yield, net energy balance (NEB), root production, and nutrient balances. We found trade‐offs among systems in terms of the measured performance indicators. Continuous corn systems were the highest yielding, averaging 13 Mg ha^?1 of harvested biomass (grain plus stover), whereas fertilized and unfertilized prairies produced the least harvested biomass at 8.8 and 6.5 Mg ha^?1, respectively. Mean NEBs were highest in continuous corn systems at 45.1 GJ ha^?1, intermediate in the corn‐soybean rotation at 28.6 GJ ha^?1, and lowest in fertilized and unfertilized prairies at 11.4 and 10.5 GJ ha^?1, respectively. Concomitant with the high yields of the continuous corn systems were the large nutrient requirements of these systems compared to the prairie systems. Continuous corn with rye required three times more nitrogen inputs than fertilized prairie. Root production, on the other hand, was on average seven times greater in the prairie systems than the annual crop systems. On highly fertile soils, corn‐based cropping systems are likely to play an important role in maintaining the high productivity of agricultural landscapes, but alternative cropping systems, such as prairies used for bioenergy production, can produce substantial yield, require minimal externally derived inputs, and can be incorporated into the landscape at strategic locations to maximize the production of other ecosystem services.     

Nobloedischia rasnitsyni, a new genus and species of Oedischiidae (Orthoptera) from the Lower Permian Wellington Formation of Oklahoma, USA

Nobloedischia rasnitsynigen. et sp. n. (Oedischiidae) is described from the Lower Permian Wellington Formation of Noble County, Oklahoma. The genus is similar to both Petrelcana (Oedischiidae: Mezenoedischiinae) and Oedischia (Oedischiidae: Oedischiinae) and is left unplaced at the subfamily level. The new species is the twelfth Orthoptera species and the fourth species of Oedischiidae from these deposits.