卡拉麦里山有蹄类自然保护区鹅喉羚的时空分布与生境选择

基于2005年以来对卡拉麦里山有蹄类自然保护区鹅喉羚分布调查和栖息地样方采集,运用GIS技术进行目视解译与图层叠加分析进行鹅喉羚分布研究,并运用选择指数与选择系数模型探讨鹅喉羚的生境选择。研究发现,保护区内鹅喉羚四季分布虽有明显差异,但主要分布区位于在保护区中部的针茅、驼绒藜、沙蒿-驼绒藜、假木贼-针茅群落中。不同季节鹅喉羚对植被类型的选择有差异,春季鹅喉羚倾向选择假木贼-针茅群落和梭梭群落;夏季鹅喉羚喜欢针茅群落、驼绒藜群落、梭梭群落;秋季鹅喉羚则倾向选择针茅群落和假木贼-针茅群落。鹅喉羚喜欢坡度平缓的地区;春季和夏季对各种坡向随机选择的,秋季不喜欢阴坡,其他坡向则几乎随机选择;春季和夏季喜欢中坡位,不喜欢上坡位,对下坡位随机选择,秋季对各种坡位随机选择。鹅喉羚的分布主要受植被类型和水源的影响,人类干扰是影响鹅喉羚冬季分布的主要因素。食物、隐蔽性和地形因素是鹅喉羚生境选择的重要影响因素

Co-regulation of rainfall amount and timing on soil carbon mineralization in a typical salt marsh of the Yellow River Delta,China

Studying the effects of rainfall regimes such as rainfall amount and timing on soil carbon mineralization is of great importance for our understanding the mechanisms underlying the stability and accumulation of soil carbon in coastal salt marshes. In this study,we examined the responses of soil carbon mineralization (CO_2 and CH_4 fluxes) from undisturbed soil columns to rainfall events in different seasons (dry and wet seasons) with filed experiments in a primary Suaeda salsa region in the Yellow River Delta salt-marsh wetland,which is far away from the coast and not affected by tides. The results showed that rainfall amount and timing had a significant interaction in affecting soil CO_2 flux rates. During the dry season,large rainfall events significantly reduced soil CO_2 flux rates but had no significant effect in the wet season,which might be closely related to the significant increase in soil water content and salinity. Rainfall amount,rainfall timing and their interactions had no significant effect on soil CH_4 efflux rates. Rainfall timing and rainfall amount did not affect CH_4 /CO_2. CH_4 /CO_2 increased with increasing soil water content and salinity. Soil water content and soil salinity showed similar increases to increasing rainfall amount. Our results suggested that the changing rainfall regime under climate change in the future would have a great impact on soil carbon mineralization and carbon sink function by regulating soil water and salt migration in this region

卡拉麦里山保护区鹅喉羚卧息地特征的季节变化

于2007年对卡拉麦里山有蹄类保护区不同季节的鹅喉羚卧息地特征进行了研究。Mann-WhitneyU检验表明:春季鹅喉羚卧息地植物高度明显高于对照地(Z=2.27,P<0.05),驼绒藜密度、灌木盖度和地上生物量极显著高于对照地(Z=2.85,Z=3.29,Z=2.98,P<0.01);夏季鹅喉羚卧息地植物高度和单位面积地上生物量明显高于对照地(Z=2.06,Z=2.97,P<0.05);秋季鹅喉羚卧息地植物种数明显高于对照地(Z=2.52,P<0.05),灌木盖度和植物高度极显著高于对照地(Z=5.22,Z=4.58,P<0.01)。主成分分析表明,春夏秋3季影响鹅喉羚卧息地选择的主要环境因子是食物、隐蔽条件和环境温度。单因素方差分析表明,鹅喉羚卧息地特征在季节间有显著差异,以春季和夏季、春季和秋季最为明显。食物资源和环境温度的变化是导致鹅喉羚卧息地特征季节性变化的主要因素。鹅喉羚卧息地选择与其自身的体温调节有一定关系

卡拉麦里山有蹄类保护区鹅喉羚的采食地选择

2006-2007年,通过野外直接观察采样的方法,研究了新疆卡拉麦里山有蹄类动物保护区内鹅喉羚的采食地特征。Mann-Whitney U检验表明,春夏秋三季鹅喉羚采食地内的植物种数、植被盖度、植被高度和可食生物量均显著高于对照地中相应成分。主成分分析表明,影响研究区内春夏秋三季鹅喉羚采食地选择的关键环境因子是食物因子(植物种数,可食生物量和各季节大宗食物密度)、警戒因子(坡位和植被盖度)、温度因子(坡向和植被高度),以及水分因子(富含水分的食物)。冬季鹅喉羚经受严重的放牧干扰,采食地呈现为生存而被迫选择局部次适宜区域栖息的特征

冬季鹅喉羚昼间行为时间分配及活动节律

2007年12月,采用目标动物取样法在卡拉麦里山有蹄类自然保护区观察鹅喉羚冬季昼间行为。将鹅喉羚的行为分为采食、警戒、休息、移动和"其他"5种类型,各类行为所占比例雌羊为68.0%、7.0%、19.6%、5.0%、0.4%,采食行为消耗的时间最多,"其他"行为消耗时间最短,雄羊为29.6%、19.2%、29.3%、20.6%、1.3%,采食行为所消耗时间仍占最多,但较雌羊已大幅减少。无论雌雄,各行为在10min观察期内所占据平均时间均存在极显著差异(P<0.01);除"其他"行为在10min观察期内所占据平均时间性别间差异不显著外,雌雄其余4类行为间差异均极显著(P<0.01)。雌羊采食行为存在3个高峰,分别在11:00—12:00、13:00—14:00和17:00—18:00;移动高峰出现在13:00—15:00和18:00—19:00;警戒最高峰出现在13:00—14:00;休息行为表现为双峰形,分别在12:00—13:00和16:00—17:00。雄羊采食行为也有3个高峰,分别在10:00—11:00、13:00—14:00和17:00—18:00,但不如雌性明显;移动行为在13:00—14:00和18:00—19:00有2个高峰;警戒行为在13:00—14:00和18:00—19:00出现小的高峰;休息在15:00—16:00达到最高峰。雌性鹅喉羚采食、移动、警戒、休息行为在各个时段差异均显著,而雄性则是采食和警戒存在显著差异

卡拉麦里山有蹄类自然保护区鹅喉羚生境适宜性评价

在卡拉麦里山保护区内选取具有代表性的研究样区约1447km2作为评价区,基于2005年以来对卡拉麦里山有蹄类自然保护区鹅喉羚野外调查和样方采集,利用模糊赋值法建立生境评价模型,结合GIS技术的空间分析功能,以植被类型、坡度、坡向和人类干扰活动为评价因子进行生境适宜性研究。结果表明:春、夏、秋、冬四季实际生境面积分别为1146.9km2、1137.1km2、991.6km2和499.8km2,分别占研究区域总面积的79.3%、78.6%、68.5%和34.5%;其中适宜生境面积分别为304.1km2、599.4km2、303.6km2和56.2km2,分别占研究区域总面积的21.0%、41.4%、21.0%和3.9%。人类活动影响下,一些潜在生境转变为不适宜生境,春、夏、秋、冬四季生境分别丧失4.0%、3.1%、4.3%和48.5%。在各种人类活动中,居民点、国道、采矿点对鹅喉羚生境具有一定的干扰作用,使其质量有所降低,但未造成严重影响;而冬季牧民的放牧行为,导致鹅喉羚的适宜生境被家畜占据,鹅喉羚生境质量大面积下降。本文基于评价结果提出了保护措施

Effects of changes in precipitation on soil respiration in coastal wetlands of the Yellow River Delta

Soil moisture fluctuation caused by changes in precipitation patterns associated with global change is an important driving force for the dynamic changes of soil respiration. However, it is unclear how coastal wetlands respond to changes in precipitation patterns, and thus cause changes in the ecosystem blue carbon function. To explore the response and mechanism of soil respiration and environmental and biological factors to precipitation changes, the soil carbon flux observation system was applied to monitor wetland soil respiration rates under different precipitation treatments relying on increased and decreased precipitation fields outside the control experiment platform of the Yellow River Delta coastal wetland in 2017. The results showed that: (1) with increased precipitation, the wetland soil temperature gradually decreased; simultaneously,both precipitation increase and decrease significantly increased wetland soil moisture (P &lt; 0.05); (2) changes in precipitation significantly affected vegetation species composition, aboveground and belowground biomass allocation, and root/shoot ratio (P &lt; 0.05). A 40% and 60% precipitation increase significantly increased the wetland plant species and vegetation root shoot ratio; however,it significantly reduced the aboveground biomass of wetland vegetation. In addition,a 40% increase and 60% decrease of precipitation significantly increased the aboveground biomass of wetland vegetation; (3) there was no significant effect of precipitation changes on annual soil respiration in wetlands. Nevertheless,a 60% and 40% precipitation increase both significantly increased the soil respiration rate in wetlands during the non-flooding season (P &lt; 0.05); (4) the wetland soil respiration and moisture showed a quadratic curve (P &lt; 0.05) with the correlation coefficient decreasing with precipitation increase. Furthermore, during the wetland non-flooding season, soil respiration and temperature were exponentially correlated (P &lt; 0.05) with soil temperature sensitivity (Q10) increasing with increasing precipitation. There was no significant correlation between soil respiration and temperature during flooding periods; (5) during the flooding period,the soil respiration rate was inversely correlated with the surface water level (P&lt; 0.001).</p

Effects of tidal action on methane emissions over a salt marsh in the Yellow River Delta, China

Salt marshes are coastal wetlands that are considered to be a potential natural source of methane ( CH_4 ). By controlling the production, oxidation, and transport of CH_4 in soils, tidal action drives the episodic and high-magnitude emissions of CH_4 from coastal wetlands. Using the eddy covariance technique, we measured the CH_4 fluxes, environmental factors,and tidal dynamics in a salt marsh in the Yellow River Delta in China. We aimed to investigate the dynamics of CH_4 emissions in the growing season and to analyze the effect of tidal action on CH_4 emission. The results showed that the mean daily methane was 0.063 mg m~(-2) h~(-1),ranging from -0.36 to 0.57 mg m~(-2) h~(-1),during the growing season. Tidal flooding and the wet stage after tides are the significant sources of CH_4. Drying and wetting cycles induced by short-term tides resulted in pulsed CH_4 emissions. Therefore, the soil drought and wetting induced by increasing temperatures and precipitation distribution under climate change will positively impact CH_4 emissions and the carbon cycle in the region.</p

Long-term Ecological Research Support Protection of Coastal Wetland Ecosystems

滨海湿地具有较高的生物多样性,是重要经济鱼类资源的产卵场、索饵场和越冬场,也为湿地鸟类提供食物和栖息环境,是地球上生态系统服务价值最高的生态系统类型。同时,滨海湿地也是人类活动最为集中的地区之一,已成为全球变化的生态脆弱带和环境变化敏感区。中国科学院黄河三角洲滨海湿地生态试验站(以下简称"黄河三角洲站")围绕我国滨海和河口湿地环境保护与生态建设国家战略科技需求,致力于滨海湿地生态环境保护与可持续发展,以陆-海相互作用过程、湿地保护与可持续利用为主线,基于长期定位监测和野外控制试验,量化了滨海湿地生态系统碳汇现状、规律及其驱动机制,明确了水文过程与水盐运移对滨海湿地碳循环过程的影响;揭示了滨海湿地生态系统结构与功能对气候变化和人类活动的响应与适应规律;构建了退化滨海湿地生态修复技术体系,提出了"健康滨海湿地"理论与技术模式,研发了滨海湿地生态修复关键技术,实现滨海湿地保护与利用的协同发展,丰富和发展具有区域特色的滨海湿地生态学。这些研究成果不仅为黄河三角洲湿地生态保护与修复提供基础数据、科学依据和关键技术,弥补了我国特别是北方河口三角洲湿地长期观测研究的不足,也使得黄河三角洲站成为国内外无可替代的滨海湿地生态系统科学研究基地,为提升我国滨海与河口湿地研究的理论水平和促进区域可持续发展提供重要科技支撑平台

开垦对滨海湿地生态系统 CO2 交换的影响

Coastal wetlands are considered as significant sink for global C and contributors to global “ blue carbon” resources, with high primary productivity, a low soil organic matter decomposition rate, a low CH4 generation rate, and the ability to trap and bury significant amounts of allochthonous carbon. Reclamation changes soil physical and chemical properties and plant community species composition, which change carbon sequestration and emission processes, and ultimately affect the carbon sink function of coastal wet land. However, it is still not clear how carbon exchange and carbon sink respond to biological and environmental factors and their inter actions caused by reclamation in coastal wetland. Overall, clarifying the influence mechanism of reclamation on ecosystem CO2 ex change is of great significance to assessment and predict carbon sink capacity of coastal wetlan