北京湾过渡带生态系统服务梯度效应分析及生态分区

北京湾过渡带兼具山地-平原和乡村-城市的双重过渡性,生态系统服务的供给存在显著的梯度效应。该研究在对9种典型生态系统服务评估的基础上,研究了北京湾过渡带生态系统服务随植被覆盖度和土地开发程度变化的梯度效应,进而对研究区进行了生态分区并识别各分区主导的生态系统服务类型。结果表明:生态系统服务的形成过程和影响因素各不相同,导致各生态系统服务的分布存在较大的空间差异性。除休闲游憩外,大多生态系统服务随植被覆盖度和土地开发程度呈现出明显的梯度效应。总体来说,食物供给和水质调节随植被覆盖度的提高而降低,随土地开发程度的提高而增加;其他生态系统服务则相反。各生态系统服务随植被覆盖度变化的突变点的范围为0.45～0.56,随土地开发程度的突变点的范围为15%～31%。基于植被覆盖度和土地开发程度的突变点将北京湾过渡带划为4个生态分区:自然或半自然区域、半自然区域、半人工-半自然区域和人工区域。自然区域以调节服务为主,人工区域以供给服务为主,半自然区域和半人工-半自然区域二者兼具,但各有侧重,且体现出一定过渡性。结合现有规划内容,提出不同生态分区生态系统服务的优化管理策略,以促进当地生态系统的可持续发展。

Gradient effects and ecological zoning of ecosystem services in transition zone of Beijing Bay

The transitional zone of Beijing Bay forms the mountain-plain boundary lines and rural-urban social distinctions. The balance of ecological protection and economic development dominates in the regional boundary. Therefore, there is a significant gradient effect on the supply of ecosystem service in the Beijing Bay. In this study, nine typical ecosystem services were evaluated in the Beijing Bay using grids as the research unit, according to the biophysical processes formed by ecosystem services. Vegetation coverage and land development intensity were used to characterize gradient effect of ecosystem services, further to delineate four partitions with the dominant ecosystem service. The results showed that: 1) There was remarkable spatial variation in the distribution of ecosystem services due to the different formation process and influencing factors. Some services, such as food supply, increased from the hilly mountain to plain areas, indicating that ecosystem was greatly affected by human activity. The supply of ecosystem services, such as biodiversity, showed an opposite trend, due to ecosystem types and biophysical processes increased from flat plain to mountain. Specifically, water conservation and recreation determined the supply of ecosystem services. 2) Except recreation, most ecosystem services showed obviously gradient effects with vegetation coverage and i land development intensity. Each ecosystem service can be identified 0-2 mutation points along the change of two factors. In vegetation coverage, the mutation points of ecosystem services were 0.45-0.56, whereas in the intensity of land development were 15%-31%. Food supply and water quality regulation revealed a dramatic decrease as the increase in vegetation coverage between two identified mutation points. Water retention, quality regulation of air and soil increased significantly with the increase of vegetation coverage below the one identified mutation point. Carbon storage and erosion control constantly increased as the increase in vegetation coverage. Biodiversity enhanced remarkably with the increase of vegetation coverage between two identified mutation points. Food supply and water quality regulation showed an increasing trend with the improvement of land development intensity. Other ecosystem services continuously showed a significant downward trend with the increase in the intensity of land development. There was no mutation in water retention, carbon storage, erosion control and soil quality regulation with land development intensity. 3) Using the mutation points of vegetation coverage and land development intensity, the transitional zone of Beijing Bay was divided into four ecological regions, where the vegetation coverage of 0.45 and 15% intensity of land development. Natural or near natural region was dominated by regulation services, whereas the artificial area was dominated by supply services. Both semi-natural and semi-artificial regions were dominated by regulation and supply services, with an emphasis on a certain transitional feature. An optimized strategy of ecosystem services was proposed, according to the characteristics of different ecological regions. The findings can provide a sound basis for ecological protection, ecological restoration, and compensation policies, further to promote the sustainable development of local ecosystems.