纳帕海湿地黑颈鹤生境利用对人为干扰的响应机制

Habitat use is the reflection of species self-demand and the reaction to the outside stress, which concern the living condition and the spread pattern of the population. With the worldwide increasing human activities, the protection of endangered species and its habitat confront huge challenge, which means the response mechanism of species habitat use to the human disturbance become the key of that problem need to be clarified. As the main wintering area of middle population of the Black-neck crane (Grus nigricollis), which is critically endangered, the Napahai wetlands (content 85% of the population) suffered intense human disturbances in recent years. Some research showed that the core habitat of the Black-neck crane population occupied only 1.2% of the whole reserve, which means it is urgent to understand the response mechanism of the Black-neck crane habitat use to the human disturbances. This study firstly take high temporal, spatial resolution aerial photograph of Napahai wetlands underlying surface and the Black-neck crane population distribution, represent the potential habitat pattern by the unmanned aerial vehicle (UAV) in wintering period, analyze the dynamic change process of the potential habitat patterns and distinguish the suitable habitat range for the Black-neck crane. Secondly, launch field survey and monitoring of the human interferences in Napahai wetlands, for understanding the interference patterns (types, intensity, scope and time). Thirdly, the experiment and observation will be taken for determining the response distance of 3 basic interference units: human, vehicle and big livestock, and the “interference & responses” model will be built to reveal the response mechanism of the Black-neck crane habitat use to the human interference. The result will support the protection of Black-neck crane population in Napahai wetlands and the management of the human activities.

生境选择与利用是物种自身需求及应对干扰的空间表征，反映其种群整体生存状况。面对日益增强的人类活动，阐明物种生境利用对人为干扰的响应机制是建立针对性物种保护模式的基础。作为黑颈鹤中部种群（濒危种群）主要越冬地，纳帕海湿地近年来人为干扰强烈，导致黑颈鹤种群核心利用生境仅占保护区面积1.2%，亟需深入认识黑颈鹤生境利用对人为干扰的响应机制。本研究首先利用无人机遥感技术开展高时、空精度纳帕海湿地下垫面、黑颈鹤种群分布监测，表征并分析黑颈鹤潜在生境格局及其变化过程，筛选越冬期黑颈鹤种群适宜利用生境区间；其次对纳帕海湿地区人为干扰开展地面调查与监测，明确其干扰格局（类型、强度、范围及时间）；再次开展基本干扰单元抵近干扰响应距离实验，并构建“干扰——响应”模型，揭示黑颈鹤生境利用对人为干扰的响应机制，模拟不同人为干扰情景下黑颈鹤实际生境格局；从而为纳帕海黑颈鹤保护及人为干扰的管控提供支撑。

生境选择与利用是物种自身需求及应对干扰的空间表征，反映其种群整体生存状况。面对日益增强的人类活动，阐明物种生境利用对人为干扰的响应机制是建立针对性物种保护模式的基础。作为黑颈鹤中部种群（濒危种群）主要越冬地，纳帕海湿地近年来人为干扰强烈，导致黑颈鹤种群核心利用生境仅占保护区面积1.2%，亟需深入认识黑颈鹤生境利用对人为干扰的响应机制。本研究通过以下几个方面针对人类活动对黑颈鹤生境利用的干扰及相应进行了调查分析，量化了其干扰——相应机制：1）人为干扰对纳帕海湿地黑颈鹤生境压力格局表征；2）纳帕海湿地黑颈鹤生境利用对人为干扰的响应机制；3）纳帕海湿地水文情势模拟。研究得出以下结论：黑颈鹤潜在生境类型可划分为泥沼、典型沼泽、洼地、滩涂、浅明水、农田和草甸，且整个越冬期中泥沼生境都占据主导地位，黑颈鹤在迁离期对农田的利用程度显著上升。迁入期、稳定期和迁离期潜在生境面积分别为2196.8 hm2，2607.3 hm2和2989.6 hm2。随着湿地退水，黑颈鹤生境利用格局也整体向北调整。人为干扰对纳帕海黑颈鹤种群越冬生境影响较大，迁入期干扰最强时段为上午8-10时；稳定期干扰最强的时段为下午2-4时；迁离期干扰最强的时段下午2-4时。研究区北部干扰主要集中于春宗村和达拉村，南部干扰集中于从古村和布伦村。黑颈鹤在迁入期、稳定期、和迁离期的实际生境面积分别为1342.2 hm2、1447.7hm2和1745.6hm2。结合三个时期的潜在生境格局以及干扰格局来看，黑颈鹤生境利用程度较高的区域均受到不同程度干扰，受干扰生境主要为泥沼、洼地、滩涂以及典型沼泽，黑颈鹤的平均警戒距离为183±50 m。控制低复合干扰强度干扰可以快速有效地保护和恢复黑颈鹤生境，但保护工作的核心仍是恢复和调节纳帕海湿地的水文情势，做到干季漫流补水，雨季控水防洪。而且，对水文的调节不能仅仅局限在湿地区范围以内，更应该从流域尺度考虑，建立流域季节性整体调控管理机制，将整个纳帕海湿地生态系统保护纳入城市发展规划。