森林固碳释氧服务价值与异养呼吸损失量评估

固碳释氧是森林最重要的生态系统服务之一,将森林碳收支与固碳释氧服务价值评估相结合对于准确评估生态系统服务价值具有重要意义。应用森林碳收支模型(CBM-CFS3),分别基于净初级生产力(NPP)和净生态系统生产力(NEP)评估了2009—2030年湖北省兴山县森林生态系统总、净固碳释氧服务价值的时空动态,量化了异养呼吸造成的固碳释氧服务价值损失。模拟期间兴山县森林生态系统NPP逐渐增加(0.46—0.70 Tg/a),NEP由0.12 Tg/a先增加至0.21 Tg/a,然后逐渐下降至0.18 Tg/a;所对应的森林总、净固碳释氧服务价值范围分别为7.59—11.53亿元/a和2.21—3.70亿元/a。异养呼吸逐年增加,导致固碳释氧价值每年损失平均值为7.29亿元/a或4509元hm~(-2) a~(-1),约占总价值的68.6%。兴山县东南部异养呼吸造成的森林固碳释氧服务价值损失较高,而中部及西南部森林净固碳释氧价值较高。模拟期间兴山县森林为碳汇,稳定地提供固碳释氧服务。与NPP相比,使用NEP评估固碳释氧服务价值更为合理。忽视异养呼吸将严重高估森林生态系统固碳释氧服务价值;因而必须将物质循环过程与生态系统服务评估相结合,以降低评估结果的不确定性、提高生态系统服务的评估能力。     

小叶锦鸡儿灌丛化对典型草原群落结构与生态系统功能的影响

草原灌丛化是全球干旱半干旱地区面临的重要生态问题。灌丛化对草原生态系统结构与功能的影响较为复杂, 有待于在更广泛的区域开展研究。该研究在内蒙古锡林郭勒典型草原选择轻度、中度和重度灌丛化草地, 通过群落调查, 结合植物功能性状和土壤理化性质观测, 研究了小叶锦鸡儿(Caragana microphylla)灌丛化对草原群落结构(物种多样性、功能多样性和功能群组成)和生态系统功能(初级生产力、植被和土壤养分库)的影响。结果表明: 1)不同程度灌丛化草地的物种丰富度、功能性状多样性和群落加权性状平均值差异显著, 其中, 中度灌丛化草地的物种多样性和功能多样性较高, 表明一定程度的灌丛化有利于生物多样性维持。2)重度灌丛化草地的地上净初级生产力(ANPP)显著高于轻度和中度灌丛化草地, 其原因主要是随着灌丛化程度加剧, 群落内一/二年生草本植物显著增加, 而多年生禾草和多年生杂类草显著减少。三个灌丛化草地的植被叶片和土壤碳、氮库差异均不显著。3)灌丛化对草原生态系统功能包括ANPP、植被和土壤养分库均没有直接的影响, 而是通过影响功能群组成、土壤理化性质和功能多样性, 间接地影响生态系统功能; 灌丛化导致功能群发生替代和土壤旱碱化是最重要的生物和非生物因素。     

Continental mapping of forest ecosystem functions reveals a high but unrealised potential for forest multifunctionality

Humans require multiple services from ecosystems, but it is largely unknown whether trade‐offs between ecosystem functions prevent the realisation of high ecosystem multifunctionality across spatial scales. Here, we combined a comprehensive dataset (28 ecosystem functions measured on 209 forest plots) with a forest inventory dataset (105,316 plots) to extrapolate and map relationships between various ecosystem multifunctionality measures across Europe. These multifunctionality measures reflected different management objectives, related to timber production, climate regulation and biodiversity conservation/recreation. We found that trade‐offs among them were rare across Europe, at both local and continental scales. This suggests a high potential for ‘win‐win’ forest management strategies, where overall multifunctionality is maximised. However, across sites, multifunctionality was on average 45.8‐49.8% below maximum levels and not necessarily highest in protected areas. Therefore, using one of the most comprehensive assessments so far, our study suggests a high but largely unrealised potential for management to promote multifunctional forests.     

Using the Ecological Risk Index Based on Combined Watershed and Administrative Boundaries to Assess Human Disturbances on River Ecosystems

Efforts at the restoration of river ecosystems are needed not only in local habitats but are also important in terrestrial regions. Large-scale assessment of human activities can be useful in integrated watershed management. In this study, we modified the Ecological Risk Index (ERI) by considering the spatial distribution of human activities in China's Haihe River Basin (HRB). The stressor factors of human activities included population, impervious surface, cattle, agricultural land use, industry, fertilizers, pesticides, water conservation facilities, and roads. A total of 423 assessment units in the HRB were created by combining watershed and administrative boundaries to analyze the spatial distribution of human activities. Two index options, the ERI (including all stressors) and the ERI-D (excluding reservoirs and sluices), were examined for different management objectives. All the stressors and both ecological risk indices (ERI and ERI-D) were ranked in four levels: low, moderate, high, and very high. Our study demonstrated that the ERI and ERI-D can provide an overview of the spatial pattern of human stressors related to river ecosystems across a large geographic region. The approach developed in this study is useful for prioritizing management actions in targeted areas.     

Community composition has greater impact on the functioning of marine phytoplankton communities than ocean acidification

Ecosystem functioning is simultaneously affected by changes in community composition and environmental change such as increasing atmospheric carbon dioxide (CO₂) and subsequent ocean acidification. However, it largely remains uncertain how the effects of these factors compare to each other. Addressing this question, we experimentally tested the hypothesis that initial community composition and elevated CO₂ are equally important to the regulation of phytoplankton biomass. We full‐factorially exposed three compositionally different marine phytoplankton communities to two different CO₂ levels and examined the effects and relative importance (ω²) of the two factors and their interaction on phytoplankton biomass at bloom peak. The results showed that initial community composition had a significantly greater impact than elevated CO₂ on phytoplankton biomass, which varied largely among communities. We suggest that the different initial ratios between cyanobacteria, diatoms, and dinoflagellates might be the key for the varying competitive and thus functional outcome among communities. Furthermore, the results showed that depending on initial community composition elevated CO₂ selected for larger sized diatoms, which led to increased total phytoplankton biomass. This study highlights the relevance of initial community composition, which strongly drives the functional outcome, when assessing impacts of climate change on ecosystem functioning. In particular, the increase in phytoplankton biomass driven by the gain of larger sized diatoms in response to elevated CO₂ potentially has strong implications for nutrient cycling and carbon export in future oceans.     

城市近郊型乡镇农业生态经济系统生态潜力及产业空间布局——以延安市河庄坪镇为例

生态脆弱区抗干扰能力弱，明确其系统的生态潜力，在潜力的基础上开发利用资源对区域的可持续发展具有重要的意义。研究基于生态系统服务价值视角，尝试测度农业生态经济系统生态潜力，同时以三产融合典型代表乡镇为研究对象，对其农业生态经济系统生态潜力和主导产业进行时空分析，最后对生态系统加以功能分区。结果显示：（1）气体调节、气候调节、水源涵养和土壤形成与保护是生态系统提供的主要服务功能。随退耕还林工程实施，林地面积的增加使生态系统服务价值量随之上升，在空间上呈现"中间低两翼高"的格局。（2）农业生态经济系统生态潜力受服务价值与资源开发过程影响，与生态系统服务价值在空间上相对一致，呈现出"两翼高中间低，北高南低"的分布格局，其中，退耕还林工程的推进直接导致林地的生态潜力增加，耕地的生态潜力减少。（3）研究区在退耕过程中形成以大棚种植为主的设施农业、以农林特色销售为主的商品型种植农业，以山地苹果为主的林果产业以及以酒店商贸为主的服务行业。并随城镇一体化的推进，主导产业呈现出由传统粗放型大田种植向集约型设施农业方向发展。在空间上形成了以镇区分布为主的第三产业、依托拐沟坡地的林果产业和沿川道展开的设施农业的产业布局。（4）基于生态系统服务价值，研究区农业生态经济系统功能区划分为城镇生态环境维护区（第Ⅰ类型区）、农业生态保护区（第Ⅱ类型区）、生态安全屏障区（第Ⅲ类区）3个区域。     

基于享乐价格-结构方程双模型的西宁城市湿地生态系统服务价值及影响因素研究

湿地为城市发展提供巨大的生态系统服务，但其被市场“认可”的经济价值难以准确评估。以青海省西宁市城市湿地为例，筛选房屋结构、可达性、环境、湿地等10个因子，采用享乐价格模型对110个湿地周边社区样点的因子数据(2020年)进行分析，定量分析城市湿地被市场“认可”的价值量。采用断裂点理论和加权Voronoi图模型方法等，分析了湿地生态系统服务价值的空间影响范围；构建了湿地生态系统服务价值影响因素的结构方程模型，探究了影响湿地生态系统服务价值的主要因素。结果表明：(1)2020年湟水城市湿地的总价值达到3.367亿元，约有54.3%的生态系统服务通过房产被市场转化；(2)湟水湿地单位面积的生态系统服务价值为151.916元/m~2,生态系统服务价值由大到小排列：火烧沟(1.632亿元)>海湖湿地(0.710亿元)>宁海湿地(0.629亿元)>北川湿地(0.330亿元);(3)湿地生态系统服务价值占房产总价值的比例达到2.04%,位列10个因素中的第7位；线性函数模型结果显示，购买者对湿地的边际支付意愿是0.12元/m~2,即购买者愿意为房产与湿地之间的距离每缩小1m而多支付...     

碳储存变化背景下东营市海岸带生态系统保护修复

生态修复是指在不同人为干预程度下，协助已遭受退化、损伤或破坏的生态系统恢复的过程。我国海岸带地区资源丰富、位置优越，但过度的开发建设活动严重破坏了当地的生态环境，急需对受损的海岸带生态系统进行保护和修复。以东营市海岸带地区为例，运用InVEST模型对其2005、2010、2015和2018年4个时间段的碳储存功能进行评估并分析碳储存及"碳源碳汇"的动态变化，以间接反映出区域生态系统的稳定性和健康程度。结果表明，2005-2018年东营市海岸带碳储存功能持续减弱，13年间碳储存总量减少了1.341×10⁶ t，生态系统碳储存功能受到严重破坏，其中有8.68×10⁴ hm²生态系统碳储存功能评价等级为差和极差，空间上受损最为严重的区域主要分布在岸线附近的北部、东北部和东南部。按照东营市海岸带碳损失空间差异和生态系统演替规律，从3个方面提出相应的修复方案，包括加强恢复区保护力度、稳定碳储存能力，整顿辅助区粗放模式、塑造碳储存廊道和退还重建区滨海湿地、扭转碳损失趋势，以期通过改善和恢复研究区海岸带生态系统碳储存功能，实现对受损生态系统的有效保护和修复。