草地灾害对草地畜牧业发展的影响分析--以西藏那曲地区为例

介绍了雪灾、风害、干旱、鼠虫草害、草地退化、沙化和水土流失等六类主要的草地灾害类型,并分析了其对草地畜牧业发展造成的影响.结果表明：草地灾害给草地畜牧业发展带来极大的负面效应,具体表现在对草地生态与环境的破坏;加剧草地承载压力;制约草地畜牧业的可持续发展等三个方面.     

四环素类抗生素污染畜禽粪便的厌氧消化特征

应用间歇试验研究了外源添加四环素(TC)和金霉素(CTC)的猪粪中温(35℃)厌氧消化特征及抗生素的降解过程.结果表明,猪粪厌氧水解酸化过程中产生的挥发性脂肪酸以丙酸为主,乙酸次之;相比于CTC添加组,TC+CTC混合添加组对易降解有机物的水解酸化有明显的抑制作用;添加TC、CTC和TC+CTC组在45 d的消化期内累积产甲烷量分别为386.4、406.0和412.1 mL,与不添加TC和CTC的对照组(464.6 mL)相比,分别减少了16.8%、12.6%、11.3%.四环素和金霉素的降解过程符合一级反应动力学方程;四环素降解的半衰期为14～18 d,金霉素为10 d.经过45 d厌氧消化处理后,四环素的降解率达88.6%～91.6%,金霉素达97.7%～98.2%.因此,畜禽粪便厌氧消化处理不仅能回收生物质能源,还能降解残留的四环素类抗生素,有效地降低抗生素污染产生的生态风险.     

基于草地畜牧业生产的三江源地区承载力多情景模拟分析

三江源地区是我国生态安全的重要屏障,同时也是我国最主要的畜牧业生产基地之一,在保证草地资源可持续利用前提下,探究合理的人口容量对该区的生态保护建设和可持续发展具有重要意义。通过模型模拟草地理论载畜量以估算畜牧业产值,设定三种居民生活水平情景,模拟不同情景不同时期下的适度人口容量,分析人口承载力的空间差异性。结果表明：“十五”期间,三种情景下全区人口承载力呈富余状态;“十一五”和“十二五”期间在当前居民和小康水平情景的人口容量尚有结余;到“十三五”期间,三种情景下人口承载力总体均超载,但空间分布不同,在当前居民、小康和富裕生活水平情景下,分别有11个、8个和2个县的人口容量尚有结余,人口承载力超载地区主要分布于三江源地区东部。应根据现有资源分布和符合主体功能要求的方向进行调整和优化人口结构,将对该地区可持续发展战略具有重要意义。     

青海草原火灾环境因素分析

应用1995-2004年10 a青海草原火灾调查资料和火灾区14个具有代表性气象台站的气象资料,分析研究了草原火灾区的气候特征、牧草结构、放牧状况,及火灾时空分布、危害和与气象要素间的关系,为预防和监测草原火灾,加强草原防火管理工作提供参考依据。分析结果表明:青海草原火灾有两个高发区,分别位于青海湖的南、北部,高发区火灾次数占火灾总次数的70%。冬春季平均气温年际增温明显时,对应的年火灾次数大幅度上升,冬春季平均气温年际变化每升高1℃,年火灾次数增加1.6次。冬春季降水偏少且分布不均、气温偏高是火灾增加的主要因素。草原秋冬转换期的11月和冬春季转换期的3月是草原火灾多发期,这2个月的火灾次数占总数的54%。草原火灾发生前,气象要素中日变化明显的有降水、风、地温、相对湿度、蒸发量等,过火面积、损失程度因这些气象条件的不同而有所差异。持续性的“暖干”天气,使草原处于极干燥、易燃的状态,它在火灾个例中占65%,草原上一旦出现火源,风助火威,就能迅速燃烧,风速与过火面积成正比。     

喀斯特山地草地植物群落结构与相似性特征

选择贵州典型喀斯特山地草地植物群落为研究对象,采用标准样地调查法,对不同海拔、坡向的植物群落结构、物种分布、种群习性等展开研究,结果表明,（1）喀斯特山地草地植物群落结构随海拔的升高,多年生草本植物种类比例逐渐降低,一年生草本植物和灌木植物没有明显的变化规律;喀斯特山地草地植物群落是以多年生草本为主,一年生草本和灌木为辅的植物群落结构类型。（2）喀斯特山地草地植物群落中,斑茅（Saccharum arundinaceum）、紫茎泽兰（Eupatorium adenophorum）、扭黄茅（Heteropogon contortus）、莠竹（Microstegium nudum）种群分别为不同海拔样点的优势种群,优势种群和次优种群以多年生草本植物主要。（3）喀斯特山地草地不同海拔间的植物群落相似性系数均在0~0.25之间,属于极不相似水平,海拔梯度间群落结构差异较大。喀斯特山地草地植物群落物种多样性较高,同时坡向对于植物群落相似性的影响较小,海拔是影响群落间差异的主要因素。     

山地草地凋落物分解与凋落物水文功能

以云南马龙县退化山地草地为研究对象.在围栏封育条件下,对分解过程中不同分解状态的凋落物分解速率、最大持水率、有效截流率及自然持水率进行了分析.结果表明,随封育时间(分解时间)的推移.草地凋落物分解速率有所降低.在同栏封育条件下,草地凋落物的分解速率显著高于未围栏封育条件(F=7.647;P<0.01).随凋落物分解时间的推移,其最大持水率、有效截流率呈抛物线状.研究发现在凋落物分解过程中,凋落物最大持水率、有效截流率将会出现一个峰值,之后将随凋落物的分解,最大持水率、有效截流率呈下降趋势.在草地凋落物分解过程中,围栏封育条件与未围栏封育条件相比,凋落物最大持水率、有效截流率出现较早,而在240 d的分解试验期内,未围栏封育条件下最大持水率峰值尚未出现.凋落物分解速率与凋落物自然持水率呈正相关,在围栏封育条件下相关性达到显著水平(r=0.94;P<0.05);未围栏封育条件下相关性达到极显著水平(r=0.93;P<0.01).     

二氧化氯对水中病毒、藻类和浮游动物的失活效果

本文研究了二氧化氯对水中一些主要病毒、藻类和浮游动物的失活效果,以及在不同消毒剂投量、接触时间和pH值等条件下,二氧化氯(ClO_2)对水体中一些微生物的杀灭和失活效果.与液氯对比的结果表明:ClO_2对藻类失活效果优于或相当于液氯;ClO_2对病毒和浮游动物的失活效果显著优于液氯;ClO_2可在一广泛的pH值范围内杀灭微生物.此外,还从理论上初步探讨了ClO_2对病毒的失活机理.研究结果表明,ClO_2是一种优良的液氯替代消毒剂,这对开展ClO_2的研究及其应用有重要意义.     

Characteristics of soil micro-and macro-arthropods and soil properties in Songnen Grassland of China during different periods of freeze–thaw season

ABSTRACT

Soil properties have an important influence on soil fauna in the grassland ecosystem. However, the relationship between the structural characteristics of soil fauna and properties in the grassland ecosystem in freeze–thaw season remains unclear. Hence, the feature of soil arthropods and properties in Songnen Grassland of China were investigated in fall–winter alternating (T1), completely frozen (T2) and winter–spring alternating periods (T3) during freeze–thaw season in three years. Results showed slight differences in the community composition of soil animals with Oribatida, Prostigmata and Mesostigmata as co-dominant groups in all sampling periods. The total number of individuals of soil arthropod at low temperature was low. The pH value, electrical conductivity (EC), and moisture content had the same order of T3?>?T2?>?T1. The activities of invertase and urease increased with increasing soil temperature, whereas protease activity had no relationship with soil temperature, soil moisture, EC and soil organic matter (SOM), activities of protease and urease were principal factors affecting individual abundance of soil animals. The sequence of their effect degrees was moisture content > EC > SOM > protease activity > urease activity. The changes in the quantitative characteristics of soil animals were related to soil properties. Therefore, soil properties can affect the structural characteristics of soil arthropod in the Songnen Grassland of China in the freeze–thaw season.     

Deconstructing compassionate conservation

Compassionate conservation focuses on 4 tenets: first, do no harm; individuals matter; inclusivity of individual animals; and peaceful coexistence between humans and animals. Recently, compassionate conservation has been promoted as an alternative to conventional conservation philosophy. We believe examples presented by compassionate conservationists are deliberately or arbitrarily chosen to focus on mammals; inherently not compassionate; and offer ineffective conservation solutions. Compassionate conservation arbitrarily focuses on charismatic species, notably large predators and megaherbivores. The philosophy is not compassionate when it leaves invasive predators in the environment to cause harm to vastly more individuals of native species or uses the fear of harm by apex predators to terrorize mesopredators. Hindering the control of exotic species (megafauna, predators) in situ will not improve the conservation condition of the majority of biodiversity. The positions taken by so-called compassionate conservationists on particular species and on conservation actions could be extended to hinder other forms of conservation, including translocations, conservation fencing, and fertility control. Animal welfare is incredibly important to conservation, but ironically compassionate conservation does not offer the best welfare outcomes to animals and is often ineffective in achieving conservation goals. Consequently, compassionate conservation may threaten public and governmental support for conservation because of the limited understanding of conservation problems by the general public.