生态保护目标体系下海河流域湿地需水研究——以河北省衡水湖湿地自然保护区为例

随着当前海河流域水资源短缺状况不断加剧,流域内湿地面积迅速减小,生态环境日趋恶化,科学分析湿地生态环境需水量对该流域生态的保护和恢复具有重要意义.以海河流域衡水湖湿地自然保护区为例,根据研究区现状及存在的问题建立了3层次生态保护目标体系,结合湿地分类分级计算,选取植被需水量等8项指标,分析计算了不同层次生态保护目标下衡水湖湿地生态环境需水量,在此基础上,对研究区最小、最优以及最大几个典型状态下生态环境需水量进行了分析评估.分析结果表明,目前衡水湖湿地供水仅能满足生态环境最小需水量,与湿地现况基本吻合.该研究结果可为海河流域洪水资源利用与湿地生态保护和恢复提供科学依据,研究方法可为干旱半干旱地区湿地生态环境需水量的计算提供借鉴.     

辽河三角洲湿地旅游资源开发与保护

辽河三角洲湿地在特殊的地理环境、自然条件和人类活动的共同作用下而形成的独特的湿地生态旅游资源景观。基于辽河三角洲湿地生态系统的脆弱性和敏感性,为了谋求区域经济的持续发展和区域生态环境的良性运行,必须缓解湿地旅游和环境保护之间的矛盾。探讨了湿地保护与旅游开发的辨证统一关系,分析了辽河三角洲湿地旅游开发的优势与不足,提出了辽河三角洲湿地生态旅游和生态保护的有效措施。     

辽河三角洲生态系统服务价值变化

生态系统服务功能的变化对于区域的生态保护及可持续发展具有重要意义。利用遥感数据分析了辽河三角洲土地利用/覆盖变化,应用Costanza等提出的生态系统服务价值系数,分析了辽河三角洲土地利用/覆盖变化及其引起的生态系统服务价值的变化。结果表明,从1986~2000年,辽河三角洲湿地、水体面积大量减少,农田、城镇用地大量增加。这造成本区域的生态系统服务价值发生明显变化,从1986年的2.79×109美元减少到2000年的2.48×109美元,减少0.31×109美元。最后根据生态系统服务价值变化,从生态保护与可持续发展的角度探讨了辽河三角洲在发展中应该注意解决的问题及措施。     

河北省现有自然湿地生态环境需水量研究

简单介绍了湿地生态环境需水量的概念及其特点,详细分析了目前常用的关于湿地基本生态环境需水量的计算方法,经过优缺点对比,选取了适当的生态环境需水量计算方法和自然湿地生态用水需求预测参数,并对河北省现有自然湿地逐一进行了近期、中期和远期的生态环境需水量测算。测算结果对今后河北省湿地水资源节约,水资源利用率提高,河流污染控制,生态环境改善具有重要的理论意义和实用价值。     

三江平原农业需水量及适宜水稻种植面积的研究

三江平原水田面积已达95.3×10⁴ hm²，占总耕地面积的28.6%。集中种植区种植比例超过50%，最大比例为90%，造成地下水位持续下降并形成集中降深。该地区内有大面积湿地分布，地表径流减少和地下水漏斗的形成将对湿地和地区整体生态环境造成极为不利的影响。该文以农业需水量和地下水可开采模数两种计算方法，计算了适宜水稻种植的面积。结论为：在现有水田比例情况下，农业需水量为464 mm；考虑一定的径流量，适宜比例为30%，若不考虑径流，最大种植比例为50%～60%     

基于遥感方法的黄河三角洲生态需水量研究

生态环境需水量是当前水资源管理等学科研究的重点和难点。对于河流生态环境需水量已形成比较系统的理论和计算方法,但对于其它生态系统则没有固定的计算模式,生态需水量项目也因具体环境而异。依据黄河三角洲自然保护区生态系统特点,其需水量项目主要有植物需水量、湿地蒸散量、土壤需水量、野生生物栖息地需水量、补给地下水需水量和防止岸线侵蚀及河口生态环境需水量等。遥感技术在区域资源环境研究方面具有极大优越性,本文利用遥感技术重点对黄河三角洲湿地生态系统需水量中的蒸散量进行了计算,其它需水量项目则用一般方法进行了计算。计算结果表明黄河三角洲自然保护区最小生态需水量为19.21亿m3,最大生态需水量为42.14亿m3。为维持自然保护区生态环境不再恶化,每年需补给的最小生态水量为12.3亿m3。     

河北省自然湿地生态需水量分析

阐述了湿地生态环境需水量的概念和计算方法,在河北省湿地现状分析的基础上,对河北省主要湿地的生态需水量进行了测算,河北省湿地的适宜生态需水量为3.60×108m3,保证率为75%的最小生态环境需水量为2.65×108m3。在此基础上提出:河北省应建立节水型农业,把湿地生态用水列入水库分水计划及南水北调供水计划,协调湿地生态用水和生产、生活用水的关系等改善湿地生态用水的保障措施。     

辽宁省中西部地区重点河流生态需水量初探

在对辽宁省中西部地区河流生态环境历史及现状调查的基础上,比较分析辽河、浑河及太子河、大凌河生态环境现状,表明生态环境用水存在严重的被挤占现象,影响辽宁省水资源可持续发展的成败。因此,通过考虑辽宁省中西部地区河流特性和水资源条件,采用Qp(p=90%)法和Tennant法分别对不同时段的辽河铁岭站、浑河邢家窝堡站,太子河唐马寨站,大凌河朝阳站进行生态需水量计算,得出各站各时段生态需水量,其中全年生态需水量为:辽河铁岭站25769.4万m^3,浑河邢家窝堡站20444.44万m^3,太子河唐马寨站26338.68万m^3,大凌河朝阳站7316.34万m^3。这将为辽宁省中西部重点河流的可持续发展管理提供重要的理论依据。     

常熟市土地利用变化对生态服务价值的影响

采用计算机自动分类和人工目视解译相结合的方法,对常熟地区1991年、2001年、2006年的三期Landsat TM影像进行了土地利用分类,获取了主要土地利用类型信息,并计算了生态服务价值。结果表明,1991-2001年,常熟市的城镇用地显著扩张,湿地和林地面积有所增加,而耕地面积大大减少,生态服务价值有所下降;2001-2006年,城镇用地进一步扩张,耕地和林地面积锐减,湿地面积显著增加,生态服务价值显著增加。分析土地利用变化对生态服务价值的影响可以为科学、合理地进行土地利用,保持生态系统的平衡,以及人口、资源、环境的可持续发展提供决策支持。敏感性分析表明,生态服务价值对生态服务价值系数的变化是缺乏弹性的,因此结果是可信的。     

扎龙国家自然湿地生态环境需水量研究

湿地生态环境需水是指维持湿地生态系统生态平衡和正常发展、保障湿地系统生态水文功能和相关环境功能正常发挥所需的水量,以扎龙国家自然湿地为例,选取植被需水量、土壤需水量、生物栖息地环境需水量及污染物净化需水量为主要指标,估算了扎龙湿地生态环境需水量。按照湿地管理的需要,划分扎龙湿地生态环境需水量为5个级别,其中最小生态环境需水量为24 588×108m3,中等需水量为40 879×108m3,最大需水量为71 934×108m3。     

滇东南峰林峰丛区主要盆地生态环境质量评估

运用Fragstats 3.4,选取生态意义比较明显的景观格局指数,运用GIS空间分析的方法,结合云南省DEM数据和美国陆地卫星影像数据,对滇东南峰林峰丛区主要盆地生态环境质量进行评估。结果表明:（1）各盆地的基质景观均为耕地,所占面积比例38.13%～77.17%。其次是灌木林地和草地,湿地和人造地表分布比较零散,有些盆地没有湿地景观分布;（2）八宝、广南和丘北生态环境质量等级最高,其灌木林地所占比例最高,分别为35.51%,30.61%和24.50%,草地次之。而蒙自、沙甸和开远盆地生态环境质量最低,其中开远盆地灌木林地所占比例最低,为2.70%;（3）主要盆地多样性指数较大,景观总体空间格局异质性较高,灌木林地和草地对生态环境质量的贡献率较高,多样性指数低,景观异质性偏低,耕地对生态环境质量的贡献率相对较低;（4）景观破碎化指数与生态环境指数呈显著负相关;（5）灌木林地和草地景观对盆地生态环境质量的贡献率与盆地生态环境质量指数呈正相关。     

Landscape-level processes and wetland conservation in the Southern Appalachian Mountains

The function of wetland ecosystems is not independent of the landscapes in which they are embedded. They have strong physical and biotic linkages to the surrounding landscape. Therefore, incorporating a broad-scale perspective in our study of wetland ecology will promote our understanding of these habitats in the Southern Appalachians. Changes in the surrounding landscape will likely affect wetlands. Broad-scale changes that are likely to affect wetlands include: 1) climate change, 2) land use and land cover change, 3) water and air-borne pollution, 4) a shift in disturbance/recovery regimes, and 5) habitat loss and fragmentation. Changes in climate and land cover can affect the hydrology of the landscape and, therefore, the water balance of wetlands. Excessive nutrients and toxin transported by air and water to wetlands can disrupt natural patterns of nutrient cycling. Periodic disturbances, like flooding in riparian zones, is required to maintain some wetlands. A change in disturbance regimes, such as an increase in fire frequency, could alter species composition and nutrient cycles in certain wetlands. Many plant and animal species that found in small, isolated wetlands have populations that are dependent on complementary habitats found in the surrounding landscape. Loss or fragmentation of these complementary habitats could result in the collapse of wetland populations.     

The effects of changes in soil moisture on nitrogen cycling in acid wetland types of the New Jersey Pinelands (USA)

Wetlands are subject to changes in soil moisture as a result of both short-term seasonal climate variations and long-term changes in regional water resource management, both of which can modify the dynamics of ground and surface water inputs. In the New Jersey Pinelands, forested wetlands that differ in both plant communities and soil structure occur along a topographic and hydrological gradient associated with an unconfined aquifer. Proposed groundwater withdrawals may affect water content of soils along this gradient. We hypothesized that prolonged changes in soil moisture would alter net nitrogen mineralization and nitrification rates in proportion to the amount of moisture change, and that these changes would be similar for the different soils along the drainage catena. Soils from two catenary sequences of wetlands, including pine-dominated (driest landscape position), hardwood-dominated, and Atlantic white-cedar-dominated (wettest landscape position) communities were used in long-term laboratory incubations (36 weeks). Production of NH₄⁺-N, NO₃⁻-N, and dissolved organic N were measured under two sets of conditions: constant moisture levels of 100%, 60% and 30% water-holding capacity (WHC), and fluctuating moisture levels (alternating 2 week periods at 100% and 30% WHC). In soils from most of the wetlands, we observed increases in net mineralization and nitrification when constant low-moisture conditions were established, but not under fluctuating conditions. Contrary to expectations, responses to the drying treatments varied between wetland types and between replicate wetlands of each type. Under constant-moisture conditions, nitrification increased more in cedar swamps than in either type of pine wetland. Under all conditions, soils from all the wetlands within one of the catenas produced more inorganic and organic soluble N than did the wetlands from the other catena, suggesting that area-wide effects are as important as wetland type in regulating production of soluble N. Within both catenas, pine-hardwood wetlands generated more soluble N under all moisture conditions than did either pine-dominated or cedar wetlands. Our results suggest that changes in soil moisture due to management of water resources will affect N cycling in wetland soils, but that the magnitude of the effects, and the potential for large releases of nitrate, will depend on the specific soil properties of affected wetlands.     

甘南尕海不同湿地类型土壤物理特性及其水源涵养功能

通过对甘南尕海4种湿地类型的土壤物理性状和水源涵养功能的研究,结果表明:不同类型湿地的土壤颗粒组成、土壤容重和土壤孔隙度差异明显,且均随土壤深度的增加呈现波动性变化。土壤平均粗砂粒含量为草本泥炭地(63.00%)>永久性沼泽湿地(46.47%)>高山湿地(37.60%);细砂粒为高山湿地(62.40%)>永久性沼泽湿地(53.53%)>草本泥炭地(37.00%)。永久性沼泽湿地(0.49g/cm3),高山湿地(0.90g/cm3)和亚高山草甸(1.29g/cm3)平均土壤容重约是草本泥炭地(0.22g/cm3)的2,4,6倍。土壤总孔隙为草本泥炭地>永久性沼泽湿地>高山湿地>亚高山草甸,土壤非毛管孔隙度为草本泥炭地>亚高山草甸>高山湿地>永久性沼泽湿地。土壤平均最大蓄水量为草本泥炭地(13 143.94t/hm2)>永久性沼泽湿地(11 640.19t/hm2)>高山湿地(9060.79t/hm2)>亚高山草甸(7 391.80t/hm2),非毛管蓄水量为草本泥炭地(937.67t/hm2)>亚高山草甸(598.50t/hm2)>高山湿地(594.67t/hm2)>永久性沼泽湿地(325.13t/hm2)。土壤排水能力的平均值为亚高山草甸(51.49mm)>永久性沼泽湿地(49.66mm)>高山湿地(43.42mm)>草本泥炭地(22.45mm)。在甘南尕海,草本泥炭地的水源涵养功能最好,而亚高山草甸排水功能最好。     

石佛寺人工湿地芦苇群落蒸散发计算与分析

根据联合国粮农组织推荐的Penman-Monteith公式及单作物系数法,以气象数据为基础计算了2009—2012年石佛寺人工湿地芦苇生育期蒸散发量及各月份蒸散发量的多年平均值。采用偏相关分析验证了芦苇蒸散发量的主要影响因子,并确定了各月气象因子存在的线性关系。结果表明,该地区芦苇实际蒸散发量呈逐年递减趋势,多年各月份芦苇实际蒸发量平均值5—9月分别为142.4,149,138.1,120.9,83.1 mm;相关性分析验证了影响芦苇蒸散发量的因子依次是净辐射,平均温度,风速,相对湿度。该文研究了芦苇全生育期的耗水规律,为该地区制定芦苇灌溉及芦苇湿地生态需水提供了依据。     

Lowered water table causes species substitution while nitrogen amendment causes species loss in alpine wetland microbial communities

Alpine wetlands are hotspots of carbon (C) storage and methane emission, and they could be key contributors to global warming. In recent years, rapid warming has lowered the water table in alpine wetlands on the Tibetan Plateau, concurrent with intensified nitrogen (N) deposition via anthropogenic activities. We carried out a field experiment to investigate the ecological impacts of these two factors on soil bacterial and functional communities, which are essential drivers of greenhouse gas emissions. Nitrogen amendment alone decreased the phylogenetic alpha-diversity of bacterial communities which could be offset by lowered water table. In contrast, microbial functional alpha-diversity, revealed by a high-throughput microarray, remained unchanged. Both bacterial and functional beta-diversity responded to lowered water table, but only bacterial community responded to N amendment. The alpha-Proteobacteria, beta-Proteobacteria, and Bacteroidetes were the major responsive bacterial lineages, and C degradation, methanogenesis, alkaline shock, and phosphorus oxidation were the major responsive functional processes. Partitioning analysis revealed that N amendment changed bacterial community structure mainly via species loss processes but did not affect bacterial functional communities, with soil pH and ammonium as the key factors influencing changes in bacterial community structure. Conversely, lowered water table altered bacterial and functional communities through species substitution processes linked to soil pH and soil moisture. According to our results, the response mechanisms of microbial communities to lowered water table and N amendment are fundamentally different in alpine wetlands.     

Impacts of fishing by dewatering on fish assemblages of tropical floodplain wetlands: A matter of frequency and context

Tropical floodplain wetlands and the fish communities they support are subject to great pressure from human demands for water and aquatic living resources. In densely populated agricultural areas where such pressures are greatest, floodplain wetlands may be dewatered for the dual purpose of crop irrigation and fish harvesting. Viewed as highly destructive to fish communities, the practice is widely discouraged but remains common. We investigated the impacts of dewatering on fish abundance and assemblage structure in permanent floodplain wetlands of the lower Mekong region. Draining was carried out only in wetlands where access for fishing and water withdrawal was exclusive to individual households or groups, and where fishing was restricted to draining events. Subsequently, the impacts of draining were found to be equivalent to those of intensive fishing, rather than entirely catastrophic. Many wetlands were drained and fished repeatedly in a single dry season, with catches declining by 72% on average between consecutive events. Species richness and mean length of fish also declined with consecutive dewatering events. Fish biomass was higher in drained wetlands prior to the first and second draining events than in open access, non-drained wetlands. These surprising results suggest that draining of floodplain wetlands is not as fundamentally destructive to fish populations as is often assumed. Where fishing pressure under open access conditions is high, allocation of exclusive rights to fish and dewater wetlands can aid fish conservation as long as dewatering is carried out only once.     

小浪底水库对黄河三角洲湿地水分条件和景观格局的影响

研究了小浪底水库对黄河河口湿地水分条件的影响,并利用遥感方法分析了黄河三角洲湿地景观格局在小浪底运行前后的的变化情况。研究表明:(1)降雨是补给湿地水分的重要因素,由于其时间分布不均,使得黄河三角洲具有生态缺水时段;黄河的侧渗补给与降雨补给时段相同,5—7月的来水量大,补给量大,是第二大淡水补给来源。河流侧向补给的增加水量对河道沿岸附近2.5km范围内湿地的水位具有较大的影响,但对整个湿地水分改善没有明显作用。(2)小浪底水库运行后湿地总面积略有增加,其中天然湿地面积减少90.29km2,人工湿地(主要是盐田)面积增加150.11km2;沿海湿地总体上仍以海水侵蚀为主,但与小浪底运行前相比,黄河现代三角洲的河流湿地面积明显增加,同时盐碱化过程受到遏制。     

新疆地区棉花和甜菜需水量的统计降尺度模型预测

气候变化情景下新疆地区作物需水量空间分布规律的研究,可作为农业用水规划的参考依据。基于新疆维吾尔自治区41个气象站1961-2010年逐日气象数据,分别采用FAO-56 Penman-Monteith公式和单作物系数法计算各站参考作物腾发量和作物系数,由两者的乘积获得棉花和甜菜需水量(crop water requirement,ETc);运用统计降尺度模型SDSM4.2软件,预测2015-2099年高排放和低排放两种气候情景下各站棉花和甜菜的日ETc时间序列。结果表明,新疆地区1961-2010年棉花和甜菜在不同生育阶段作物系数变化范围为0.58~1.08,棉花和甜菜生育期多年平均ETc的空间分布由南部向北部逐渐减小。统计降尺度预测过程中的26个预报因子中,地表平均比湿和地表平均气温与ETc在多数站点相关性较好。2015-2099年高排放和低排放情景下的ETc空间分布规律与1961-2010年的类似,但数值小的多。总体上,全疆历史和未来的棉花和甜菜ETc均以不同程度下降。该研究可为新疆地区灌溉决策及节水规划提供依据。     

湖北省鄂州市湿地净初级生产力及固碳释氧量估算

[目的] 估算湖北省鄂州市净初级生产力(net primary productivity,NPP)以及固碳释氧量,探索一种适用于中小尺度上,涉及大量水体的湿地NPP估算方法,为制定相关湿地生态保护政策提供更为准确的数据支撑。[方法] 构建湿地分类模型,将鄂州市湿地划分为浅水地表湿地与深水水体湿地。对浅水地表湿地,采用基于遥感影像的光能利用率模型进行NPP估算;对深水水体湿地,引入叶绿素a与生物量指标,构建回归模型,对湿地水体NPP进行估算。汇总两者的估算结果,得到鄂州市湿地2020年度NPP总量及其空间分布和固碳释氧量。[结果] 鄂州市湿地2020年度净初级生产力总量为2.99×10⁵ t (以C计),CO₂的固定量为4.87×10⁵ t,O₂的释放量为3.59×10⁵ t,整体上呈现南高北低的分布格局。[结论] 采用湿地分类的方法,对深水水体湿地NPP单独进行估算,弥补了基于遥感影像的模型估算方法中对湿地水体部分估算的不足,使估算结果更接近湿地真实水平,采用的模型方法可为类似涉及水体的湿地NPP估算工作提供一种新思路和方法。