Effects of climate change and anthropogenic activity on ranges of vertebrate species endemic to the Qinghai–Tibet Plateau over 40 years

Over the past 40 years, the climate has been changing and human disturbance has increased in the vast Qinghai–Tibet Plateau (QTP). These 2 factors are expected to affect the distribution of a large number of endemic vertebrate species. However, quantitative relationships between range shifts and climate change and human disturbance of these species in the QTP have rarely been evaluated. We used occurrence records of 19 terrestrial vertebrate species (birds, mammals, amphibians, and reptiles) occurring in the QTP from 1980 to 2020 to quantify the effects of climate change and anthropogenic impacts on the distribution of these 4 taxonomic groups and estimated species range changes in each species. The trend in distribution changes differed among the taxonomic groups, although, generally, ranges shifted to central QTP. Climate change contributed more to range variation than human disturbance (the sum of the 4 climatic variables contributed more than the sum of the 4 human disturbance variables for all 4 taxonomic groups). Suitable geographic range increased for most mammals, amphibians, and reptiles (+27.6%, +18.4%, and +27.8% on average, respectively), whereas for birds range decreased on average by 0.9%. Quantitative evidence for climate change and human disturbance associations with range changes for endemic vertebrate species in the QTP can provide useful insights into biodiversity conservation under changing environments.     

人为活动干扰对纳帕海湿地环境影响的研究

纳帕海是金沙江流域云南西北高原低纬度高海拔的季节性沼泽湿地,有着若尔盖高原湿地和我国北方湿地所不具备的特点,为我国湿地的独特类型。由于其发育于生态脆弱的横断山石灰岩地区,地处长江上游,承接和调节着高原山区的冰雪融水、地表径流和河流水量,控制着土壤侵蚀,对长江下游水位和水量均衡有着重要作用,但长期以来不合理开发利用,使该区生态环境退化问题十分严重。探讨了人为活动干扰对纳帕海湿地环境的影响,结果表明：排水垦殖造田、过牧超载等人类活动的强烈干预对纳帕海湿地发生发展产生显著影响, 40年间湖面积减少了9/10,高原特有水生植物消失或减少,草场资源与牲畜放牧关系严重失调,超载率132.5%,土壤养分衰减下降,湿地严重退化。     

青藏高原SBR工艺动力学分析

提出SBR工艺在充水期、反应期底物降解的动力学方程,并将动力学方程应用于青藏高原处理啤酒废水的SBR工艺中。求出的动力学参数值与工程实际运行能很好地吻合,表明建立的动力学模型的正确性和有效性,同时证明该工程采用的适合青藏高原气候环境特点的强化措施是必要的、可行的。     

基于综合气象干旱指数（CI）的干旱时空动态格局分析——以甘肃省黄土高原区为例

借助ArcGIS9．3和SPSS数据软件平台,根据甘肃省黄土高原区33个气象站1962-2010实测气象资料,利用综合气象干旱指数（CI）对甘肃省黄土高原区近50年的干旱特征进行了时空分析。首先计算了各站历年逐日的CI指数,统计近50年各站点出现的干旱过程、各时段的干旱事件,在此基础上分析了甘肃省黄土高原区历年各地区干旱发生的覆盖范围、频率和不同等级干旱发生的多年平均天数,揭示了甘肃省黄土高原区干旱发生的时空差异和动态格局。分析结果表明,（1）甘肃省黄土高原区有大范围干旱发生的年份,夏季和秋季较多分别有13、8a,冬季最少,只有3a。（2）从空间尺度来看,甘肃省黄土高原区中兰州一榆中一靖远一带和庆阳北部属于高值区,而岷县、渭源一带属于低值区;106°E以西“临洮．通渭．天水”一带和庆阳东南部是干旱变幅最大的地方。（3）从季节尺度来看,夏季干旱频率和持续日数最多,春季、秋季次之,冬季最少。     

黄土小流域水沙输移过程对土地利用/覆被变化的响应

以甘肃定西安家沟小流域为典型研究区,基于TM、ALOS遥感影像解译和地面长期水文数据,深入分析了1997至2010年间流域土地利用变化特征及其产流产沙效应。结果显示,（1）14年间,流域林灌草面积分别增加160.23%、176.33%和80.75%;坡耕地、居民地、裸地和梯田面积分别减少25.57%、0.16%、48.45%和21.52%。以2005年为时间节点,发现前期灌草增加较多、裸地减少明显,后期则是乔木增加比例和坡耕地减少比例更为显著,彰显出不同历史阶段植被恢复的策略变化。（2）流域出口多年平均径流量和输沙量分别由前期的18 249 m3和6 383 kg锐减至后期的2 292 m3和2 267 kg,流域土地利用/覆被有效增加是其主要驱动。（3）春冬季节,由于降雨稀少、径流泥沙的本底值很低,前后两个阶段的水沙输移量差异较小,土地利用/覆被变化的影响相对尚不显著。但在夏秋季节,随着降雨事件增多,土地利用/覆被变化减水减沙的效应趋于显性化。     

利用蒸散比和气温模拟藏北高寒草甸的光能利用效率

光能利用效率(light use efficiency,LUE)是指初级生产力与植被冠层吸收的光合有效辐射(absorbed photosynthetically active radiation,APAR)之比,对LUE的准确定量化模拟是定量化模拟初级生产力的基础。研究利用一个基于通量观测的LUE模型(EC-LUE)模拟了2004-2005年藏北高寒草甸的LUE,该模型的参数只有蒸散比(Evaporative Fraction,EF)和气温(air temperature,T_a),EF和T_a分别为最大光能利用效率(maximum light use efficiency,LUE_max)的水分和温度胁迫因子,在研究中LUE_max取0.85 g C/MJ。EF和T_a对LUE_max的胁迫作用存在两种方式:连乘方式和最小限制因子方式,这两种方式模拟的光能利用效率分别记为LUE_multipEC和LUE_minEC,并与通量观测数据估算的LUE(LUE_EC)进行了比较。结果表明,LUE_minEC显著高估了LUE_EC,而LUE_EC和LUE_{multipEC差异不显著;LUEmultipEC和LUEminEC分别解释了89%以上LUEEC的季节变化;EF显著地解释了土壤表层含水量、 比湿,且在一定程度上解释了相对湿度的季节变化;相对于水分胁迫因子,温度胁迫因子更能够解释LUEEC的季节变化。因此,EC-LUE模型可以定量化高寒草甸LUE的季节变化,同时EF可以定量化高寒草甸生态系统水分状况的季节变化。}     

黄土高原草地植被与土壤固碳量研究

在黄土高原自东南向西北,采用样带多点调查与定位监测相结合的研究方法,系统分析了不同草地类型封禁初期和封禁11 a草地生物量与固碳量变化特征。结果表明:4种草地类型地上活体植物、凋落物/地下活体根系和土壤中碳密度与碳储量分布规律均为森林草原＞梁塬典型草原＞丘陵典型草原＞荒漠草原;草地封禁11 a,地上活体植物、凋落物、0~100 cm活体根系和土壤中碳密度总量,森林草原类型为63.38~97.65 t·hm^-2,梁塬典型草原类型为49.04~68.80 t·hm^-2,丘陵典型草原类型为52.33~62.11 t·hm^-2,荒漠草原类型为11.93~19.62 t·hm^-2;碳储量4种草地类型分别为230.287 7 Tg C、332.306 7 Tg C、484.055 5 Tg C和113.856 3 Tg C;黄土高原草地总固碳量为573.10 Tg C,其中:活体植物为42.89 Tg C,占总固碳量的7.48%;凋落物为80.40 Tg C,占14.03%;活体根系为108.66 Tg C,占18.96%;土壤为341.15 Tg C,占59.53%。这充分表明,封禁不仅能使草地植被快速恢复和生物量增加,而且也是提高草地固碳潜力的一条重要途径。     

Runoff water management technologies for dryland agriculture on the Loess

SUMMARY

Arid and semi-arid environments undergo periodic seasonal agricultural droughts of varying extents and duration, erratic and ineffective rainfall of high intensity and short duration, with high surface runoff. High efficiency water-harvesting agriculture has been routinely used in the Loess Plateau agricultural production of China over the past 10 years. Localized habitat effect and regional water resource enrichment are the theoretical basis of high efficient water-harvesting agriculture. Features of this agricultural system are described, including: water harvesting of surface runoff from roads and collection in concrete yards on plastic sheets; water storage cellar tanks for harvesting runoff to provide life-saving/critical irrigation, with devices for water lifting and conveying such as hand pumps and pipelines; feasible methods of water use for limited supplies such as drip, hole, subsoil, and super-sheet irrigation; agronomic measures of high water use efficiency; and field micro-catchment for water harvesting and conservation to increase fallow efficiency in rainy seasons. Using the stored runoff water to irrigate the mulched winter wheat and spring corn, as well as vegetables and fruit trees, significant yield increasing and water use efficiency improvements have been achieved. Plastic mulching for increasing fallow efficiency in rainy seasons and improving yield of the next winter wheat crop have been developed and demonstrated. These techniques have provided obvious benefits in terms of soil and water conservation on slope farmland in the hill regions and remarkable effects of storing water and reducing drought in the dryland farming regions have been obtained.     

Mountain inhabitants’ perspectives on climate change,and its impacts and adaptation based on temporal and spatial characteristics analysis: a case study of Mt. Yulong Snow,Southeastern Tibetan Plateau

Based on the results of questionnaires issued to 202 local residents in the Mount Yulong Snow region, southeastern Tibetan Plateau, this study analyzes mountain residents’ perspectives on climate change and its impacts, their strategies to adapt to climate change impacts, including their willingness or otherwise to become ecological migrants, and some of the factors that influence their perceptions. Overall, local perception of climate change and its impacts corresponds to the patterns of observed climate change revealed by climate records. The intensity of climate change perception shows a highly significant correlation with residents’ age and villages’ elevation gradient. Most respondents did not believe that climate change affected crop growing and their yields, but the number of crop insect pests was thought to be increasing slightly and the crop growth period to be extending. Nearly all respondents believed that climate change seriously affects the mountain tourism economy, and their way of life and spiritual world. Persistent drought in recent years has forced mountain dwellers to adjust industrial structure, save water in the agricultural economy, participate in mountain tourism and work outside the home in order to adapt to climate change impacts and supplement their meager farm incomes. Additionally, residents expect to receive government compensation and relief to mitigate natural disaster damage.     

人工油松林不同生长阶段深层土壤有机碳和活性碳的差异及其影响因素

研究深层土壤碳库动态对了解陆地生态系统深层碳汇潜力、应对全球CO₂升高具有重要意义。论文以黄土丘陵区人工油松林为研究对象,以撂荒地为参照,分析了不同生长阶段的人工油松林地0~200 cm土层土壤有机碳（soil organic carbon,SOC）和活性有机碳（readily oxidizable carbon,ROC）动态变化特征及其影响因素。结果表明：在0~200 cm剖面上,不同生长阶段油松林SOC含量及储量较撂荒地显著提高。浅层（0~100 cm）SOC平均含量,成熟林为撂荒地的2.03倍,提高最大;其次是中龄林,为1.85倍;最后是幼龄林,为1.59倍。深层（100~200 cm）SOC平均含量,幼龄林、中龄林和成熟林分别较撂荒地提高了1.43、1.38和1.36倍。各生长阶段油松林浅层和深层SOC储量分别占0~200 cm SOC储量的61.0%~69.8%和30.2%~39.0%,不同生长阶段间浅层SOC储量差异显著,但深层SOC储量差异不大。浅层ROC储量,幼龄林、中龄林和成熟林依次提高了54.8%、82.0%和91.6%;深层ROC储量依次提高了32.4%、40.9%和58.1%,且深层储量占0~200 cm土层的31.2%~33.3%。不仅浅层SOC和ROC含量受多个因素的影响,而且深层ROC含量也与油松高度、根系生物量以及枯落物厚度、干重呈极显著正相关。因此,人工林建设不仅显著提高浅层SOC和ROC含量,而且对深层土壤的固碳能力有一定改善。