尕海湿地退化演替过程中土壤有机氮组分的变化特征

为探究尕海湿地退化演替过程中土壤有机氮各组分变化规律,采用野外采样与室内分析相结合的方法,研究尕海湿地未退化(UD)、轻度退化(LD)、中度退化(MD)和重度退化(HD)4个退化演替阶段的土壤总氮(TN)和有机氮组分[未知态氮(HUN)、酸解氨态氮(AMN)、酸解氨基酸态氮(AAN)以及氨基糖态氮(ASN)]含量及其分布特征。结果表明: 当尕海湿地退化演替到LD时,0～10 cm层土壤TN、HUN、AMN和AAN含量分别降低17.3%、19.4%、8.6%和-5.6%,MD时分别降低28.0%、19.4%和17.1%和0,HD时分别降低35.8%、28.8%、28.6%和55.6%;10～20 cm层,LD时上述氮素含量分别降低4.0%、10.3%、2.9%和9.1%;MD时分别降低21.0%、18.3%、-2.9%和-9.1%;HD时分别降低9.9%、38.9%、21.2%和51.4%;而20～40 cm无显著变化;4个退化阶段各酸解氮组分占TN比例大小顺序为HUN(25.9%～32.5%)> AMN(6.7%～11.1%)> AAN(4.8%～11.1%)> ASN(1.2%～4.4%)。冗余分析显示,土壤含水量是土壤有机氮组分变化的主要驱动因子。尕海湿地退化显著降低了0～10 cm层土壤TN及酸解氮各组分含量,减弱了土壤氮“汇”功能,AAN和ASN对湿地退化最为敏感。     

湿地保护、生态旅游与农民增收——以云南拉市海湿地为例

生态保护与经济发展之间的矛盾是发展中国家普遍存在的问题。近年来中国开展了大规模的生态保护行动,但对于这些行动的经济效应评估主要集中在森林和草地保护,而对湿地保护鲜少关注。选取云南一个典型的高原湿地,基于当地实施的退耕还湿政策,运用倾向得分匹配(PSM)和双重差分法(DID)检验了退耕还湿对农民收入和生态旅游的长期动态影响,并进一步讨论了政策效果的异质性以及补偿资金在湿地保护中的作用。研究发现：(1)退耕还湿具有显著的增收效应,使人均收入提高了约40%,并促进了生态旅游的发展;(2)随着时间推移,退耕还湿对农民收入和生态旅游的促进作用不断增强,在多重因素的综合影响下,农民通过生计转型实现长期增收;(3)退耕还湿存在明显的异质性影响。在不同收入群体中,低收入和高收入群体的增收效应最明显,而对生态旅游的影响则主要体现在高收入群体中;此外,距离湿地资源越近的地区,农民越倾向于通过开展生态旅游实现增收;(4)补偿资金在湿地保护中具有双重作用,不仅在保护行动前期作为安全网维持农民收入不降低,而且作为启动市场和吸引民间资本参与的种子资金,进一步支持了生态旅游的发展。研究结果能够为湿地保护与社会经济协...     

常熟沿江湿地物种资源现状与保护措施

为弄清常熟沿江湿地的资源现状,提供湿地保护依据,采用野外采样和室内分析方法,从区域大尺度及生境小尺度获得湿地动植物物种科属组成、分布特征和物种生物量等信息;并对物种间的相关性和浮游生物与水质间的相关性进行了分析.结果表明:观测区植被以芦苇(Phragmites australis)、菰(Zizania latifolia)、蔗草(Scirpus planiculmis)为优势种;直链藻(Melosira italica)和铜锈微囊藻(Microcystis aeruginosa)是浮游植物中的优势种;浮游生物和底栖动物多样性较低,渔业资源相对丰富;植被、浮游生物多样性指数与底栖动物栖息密度相关性显著,而长江汛期水质与浮游生物之间没有显著相关.在湿地面积逐渐减少、生物资源日益匮乏的现状下,应从恢复湿地面积、加强动态监测和建立科学开发模式3个方面保护沿江湿地.     

Degraded ecosystems in China: status, causes, and restoration efforts

The total area of China is about 9.6 million km². Among the terrestrial ecosystems, cropland area is about 1.33 billion ha, 78% of which is degraded land; forestland area is about 1.75 billion ha, 72% of which is forest deterioration; grassland area is 3.99 billion ha, 90% of which has already degraded. Derelict mining land area is about 6 million ha, which is increasing by 12,000 ha/year. So far, only 8% of the total derelict mining land area has been reclaimed. A total lake area of 1.3 million ha has been lost since 1950; 50% of the coastal wetlands has been reclaimed. The mangrove area has declined from 40,000 ha in 1957 to 18,841.7 ha in 1986. With a total of 0.18 billion ha of water area, over 50% of it has been polluted to type III–V in terms of the Chinese Water Quality Standard Classification System. Oceanic area is about 4.73 billion ha, over 1.6% of which is also polluted. Environmental pollution is very severe in China, especially the environmental problems in rural and agricultural areas. Water resource is severely lacking and most river ecosystems are facing deterioration. The oceanic environmental problem is still fearful. Water and soil eroded areas have been increasing year after year and have become the most severe environmental issue in China. In addition, land desertification, prairie deterioration, and land salination have been increasing at an accelerating rate. Forest function has weakened and the current environment in derelict mining land areas are headachy. Biodiversity has been destroyed badly. The reasons for the deterioration of China’s environment are diverse, such as the pressure of a large population, industrialization, and its markets. The deterioration of the ecological index has already affected the current economic index and prospective economic growth directly and obviously.     

Loss and degradation of wetlands in southwestern Australia: underlying causes,consequences and solutions

Many wetlands (estimated to be about 70%) have been lost in the coastal plain region of southwestern Australia since British settlement (in 1829), primarily as a result of infilling or drainage to create land for agricultural use or urban development. While further loss is almost universally acknowledged as undesirable, wetland degradation continues with little overt public recognition of the causes or consequences. Obvious and direct causes include nutrient enrichment, salinization, pollution with pesticides and heavy metals, the invasion of exotic flora and flora, loss of fringing vegetation and altered hydrological regimes occurring as a result of urbanization and agricultural practices. Underlying causes include a lack of understanding of wetland hydrology and ecology on behalf of both planning agencies and the private sector, and poor coordination of the many different agencies responsible for wetland management. Public and political awareness of wetland values continues to increase, but sectoral organization and responsibilities for wetland management lag behind. Sufficient scientific information now exists for improved management, protection and restoration of wetlands in southwestern Australia. However, this improvement cannot occur without the necessary political will and corresponding sectoral responses needed to implement coordinated wetland management policies and actions.     

若尔盖湿地高寒草甸退化过程中土壤有机碳含量变化及成因分析

土壤碳输入与输出之间的收支差决定土壤有机碳(SOC)含量。若尔盖湿地高寒草甸退化过程中, 土壤碳输入和输出哪个过程对SOC含量的影响占主导作用还不明确。该研究用空间序列代替时间序列的方法研究了若尔盖湿地高寒草甸不同退化阶段(高寒草甸(AM)、轻度退化高寒草甸(SD)和重度退化高寒草甸(HD)) SOC含量变化及原因。首先, 通过测定高寒草甸退化阶段上主要的土壤理化性状、微生物生物量、植物生物量和功能群组成的变化, 分析了退化阶段上土壤碳输入量的变化及原因; 其次, 结合室内土壤碳矿化培养实验结果和研究区的月平均气温以及土壤呼吸温度敏感性(Q₁₀)估算了该区域土壤碳输出, 并分析了其变化原因; 最后, 分析了造成SOC含量变化的主要原因和过程。结果表明: 在退化梯度上, 土壤含水量(SWC)、SOC和全氮(TN)含量、微生物生物量碳氮含量降低; 植物群落组成逐渐从莎草科、禾本科占优势过渡到杂类草占优势, 且植物生物量降低; SOC矿化量降低; 有机碳潜在积累量降低(与AM阶段相比, SD和HD阶段有机碳潜在输入量、输出量和积累量分别降低了16%、18%、15%和59%、63%、41%)。SWC降低引起土壤容重、SOC含量、TN含量、全磷含量、C:N的改变, 进而导致植物功能群分布模式和土壤微生物的变化, 最终引起SOC输入和输出量的降低。SWC降低导致的植物碳潜在输入量的降低是若尔盖湿地高寒草甸退化过程中SOC含量下降的主要原因。     

Bird interactions with utility structures: collision and electrocution, causes and mitigating measures

The causes of collision and electrocution accidents involving birds and power lines, and measures to mitigate such accidents, are reviewed. It is convenient to group the causes according to (1) biological, (2) topographical, (3) meteorological and (4) technical aspects. As regards collisions with power lines, the important biological variables are connected with the morphology, aerodynamic capability, physiology, behaviour and life-history strategies of birds. To understand the electrocution problem, the relationship between body size and electrocuting installations must be considered. Removing earth wires (and modifying earthing methods). modifying line, pole and tower design, installing underground cables and conspicuous marking of lines, poles and towers are important measures for tackling the problems. The route planning process should include careful mapping of (1) topographical features which are leading lines and flight lanes for migrating birds and/or are important for local movements of resident species, (2) topographical elements such as cliffs and rows of trees that force birds to fly over power lines, (3) primary ornithological functions or uses of the area to avoid key areas for birds and avoid separating these areas and (4) local climatic conditions (including seasonal variations) like fog frequency and prevailing wind direction. The outcome depends largely on a combination of these factors. Objective assessment of the effects of mitigating measures, in particular wire marking, is required. The mitigating efforts should be directed against species known to be potential collision victims, and their design should be the result of a careful analysis of the biology and ecology of the target species. Because of the cumulative effects of negative impacts on bird populations today and the alarming number of species with endangered or vulnerable status being killed in connection with utility structures, the problem deserves increased general awareness.     

Ferritin oxidation and proteasomal degradation: protection by antioxidants

The accumulation of oxidatively damaged proteins is a well-known hallmark of aging and several neurodegenerative diseases including Alzheimer's, Parkinson's and Huntigton's diseases. These highly oxidized protein aggregates are in general not degradable by the main intracellular proteolytic machinery, the proteasomal system. One possible strategy to reduce the accumulation of such oxidized protein aggregates is the prevention of the formation of oxidized protein derivatives or to reduce the protein oxidation to a degree that can be handled by the proteasome. To do so an antioxidative strategy might be successful. Therefore, we undertook the present study to test whether antioxidants are able to prevent the protein oxidation and to influence the proteasomal degradation of moderate oxidized proteins. As a model protein we choose ferritin. H₂O₂ induced a concentration dependent increase of protein oxidation accompanied by an increased proteolytic susceptibility. This increase of proteolytic susceptibility is limited to moderate hydrogen peroxide concentrations, whereas higher concentrations are accompanied by protein aggregate formation.

Protective effects of the vitamin E derivative Trolox, the pyridoindole derivative Stobadine and of the standardized extracts of flavonoids from bark of Pinus Pinaster Pycnogenol^® and from leaves of Ginkgo biloba (EGb 761) were studied on moderate damaged ferritin.     

山东省滨州市湿地水鸟的多样性调查

于2008年3月～2009年4月,采用路线调查法和定点观察法对滨州市区水鸟多样性情况进行了调查,共记录7目15科36属64种。其中国家Ⅰ级保护鸟类1种,国家Ⅱ级保护鸟类2种;冬候鸟10种(15.6%),夏候鸟18种(28.1%),旅鸟28种(43.8%),留鸟8种(12.5%)。区系组成包括:古北界40种(62.5%),东洋界6种(9.4%),广布种鸟类18种(28.1%)。多样性分析显示,滨州市区水鸟的Shannon-Wiener指数H′=2.5655、Pielou指数J=0.6169及G-F指数DG-F=0.6137。在市区3个水库中,北海水库的水鸟多样性指数最高。人类活动和自然环境恶化是该地区水鸟面临的主要威胁。