Ayesu Samuel, Agbyenyaga Olivia, Barnes Victor Rex, Gyamfi Adwoa, Asante Richard Krobea
Resource Management Support Centre, Forestry Commission, Ghana.
Department of Agroforestry, Kwame Nkrumah University of Science and Technology, Ghana.
Heliyon. 2024 Sep 10;10(18):e37499. doi: 10.1016/j.heliyon.2024.e37499. eCollection 2024 Sep 30.
Watershed ecosystems are important for the provision of multiple ecosystem services (ES) that are critical to human welfare. Few studies particularly in the tropics assess the multiple ecosystem services, economic value, and effect of land use change on economic value. This paper provides evidence of the quantitative. economic value and effect of land use change on the economic value of watershed ESs from Barekese and Owabi in Ghana. Geospatial analysis and the stated preference method were used for the study. Primary and secondary data were collected from households, institutions, and other sources to quantify and estimate ecosystem services. The geospatial analysis showed that forest degradation and deforestation have increased over the last three decades in the watershed with settlements and cropland being the major land use changes. The two watersheds provide many ecosystem services, including provisioning services (water, fuelwood, bushmeat, fish), regulating services (carbon sequestration, water supply, water purification, soil fertility), and cultural services (ecotourism). An aggregated economic value for the ESs of GH₵ 707.701 x 10 ($144.428 x 10) was estimated for the two watersheds. For the different sites, the economic value for the Barekese and Owabi watersheds were $110.645 x 10 ($6609.06/ha/yr) and $33.783 x 10 ($5857.76/ha/yr) respectively. Our analysis showed that conversion of forest to other land uses resulted in a significant reduction in the value of ecosystem services. Conversion of the watershed to Tree Crop, Food Crop, Grassland or Settlement could reduce the economic value of ESs by 4%-80 %. The study demonstrates that ecosystem services assessment could provide important information for conservation and development policies related to watershed management in the tropics. To ensure ecosystem service supply, the risks of land use change should be considered in watershed conservation strategies including land use zoning and adaptive management systems.
流域生态系统对于提供多种对人类福祉至关重要的生态系统服务（ES）具有重要意义。很少有研究，尤其是在热带地区，评估多种生态系统服务、经济价值以及土地利用变化对经济价值的影响。本文提供了关于加纳巴雷凯塞和奥瓦比流域生态系统服务的定量经济价值以及土地利用变化对其经济价值影响的证据。研究采用了地理空间分析和陈述偏好法。从家庭、机构和其他来源收集了主要和次要数据，以量化和估算生态系统服务。地理空间分析表明，在过去三十年里，该流域的森林退化和森林砍伐有所增加，定居点和农田是主要的土地利用变化类型。这两个流域提供了许多生态系统服务，包括供给服务（水、薪柴、丛林肉、鱼）、调节服务（碳固存、供水、水净化、土壤肥力）和文化服务（生态旅游）。估计这两个流域生态系统服务的总经济价值为707.701×10加纳塞地（144.428×10美元）。对于不同地点，巴雷凯塞和奥瓦比流域的经济价值分别为110.645×10美元（6609.06美元/公顷/年）和33.783×10美元（5857.76美元/公顷/年）。我们的分析表明，森林向其他土地利用类型的转变导致生态系统服务价值显著降低。将流域转变为经济作物种植、粮食作物种植、草地或定居点可能会使生态系统服务的经济价值降低4% - 80%。该研究表明，生态系统服务评估可为热带地区与流域管理相关的保护和发展政策提供重要信息。为确保生态系统服务供应，在包括土地利用分区和适应性管理系统在内的流域保护战略中应考虑土地利用变化的风险。
