以淨零觀點探討宜蘭淺山地區生態系統服務時空變遷與權衡

Abstract

宜蘭縣因其地理位置，是一個容易受到氣候變遷影響的地區，但在提供生態系統服務方面發揮著重要作用，包括農業、森林和水域生態系統。然而，有限的土地利用資源是永續發展課題下的挑戰，因為土地利用無法滿足日益增長的生態系統服務需求。在此浪潮下，2050前達成淨零目標已為世界共識，期望透過盡力達成全球碳平衡，以減緩氣候變遷對於人類福祉的負面影響。然而，區域尺度的淨零目標需要對土地利用的詳盡規劃，為了解決這一問題，有必要探討在土地利用變遷影響下，不同生態系統服務之間的權衡關係。本研究利用生態系統服務評估與權衡模型 (Integrated Valuation of Ecosystem Services and Tradeoffs, InVEST) 及地理資訊系統 (Geographic Information System, GIS) 工具，包括熱點分析 (Hot Spot Analysis, Getis-Ord Gi*)、皮爾森相關分析 (Pearson Correlation Analysis)，及雙變量空間自相關分析 (Bivariate Autocorrelation, Lee’ L) 等工具，分析了宜蘭淺山地區 (員山鄉、三星鄉、冬山鄉) 1994年至2020年村里界尺度之土地利用和生態系統服務的時空變遷狀況，及與人類淨零永續生活最相關之碳儲存、年度產水量、棲地品質與稻米生產服務間的權衡與協同關係。本研究結果主要發現：(一)宜蘭淺山地區有賴於福山試驗林區面積的穩定性，碳儲存服務在26年間大致能與該地區水稻生產的二氧化碳當量抵銷，提供了淨零目標重要的碳匯源；(二)在全研究區域尺度下，棲地品質服務與其他三種生態系統服務間皆存在權衡關係，而其餘服務間則皆為協同關係；(三)在村里尺度下，宜蘭淺山地區的生態系統服務供給具有明顯的空間分布差異，本研究認為若要實現區域上的淨零目標，可以關注那些多數生態系統服務在26年間存在協同關係的村里，顯示它們未來具有提供多功能生態系統服務的潛力；(四)依據生態系統服務在宜蘭淺山地區的空間分布特徵，可以劃分為三大功能區，並針對不同區域調整土地利用規劃與生態系統服務利用策略。本研究為淨零永續土地利用政策規劃，及面臨類似挑戰的地區提供參考。

Located in northeastern Taiwan, Yilan County is an area vulnerable to the impacts of climate change. Despite this, the county plays a crucial role in providing multiple ecosystem services, and also provides important ecosystem services to the nearby Taipei metropolitan area. However, limited land use resources pose a challenge, as land use cannot meet the increasing demand for ecosystem services. In this context, achieving net-zero emissions by 2050 has become a global consensus, aiming to achieve global carbon balance to mitigate the negative impacts of climate change on human well-being. At the regional scale, net-zero targets require detailed land use planning. To address this issue, it is necessary to explore the trade-offs among different ecosystem services under the influence of land use change.This study applied the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and Geographic Information System (GIS) tools, including Hot Spot Analysis (Getis-Ord Gi*), Pearson Correlation Analysis, and Bivariate Spatial Autocorrelation Analysis (Lee’s L), to analyze spatiotemporal changes in land use and ecosystem services at the village scale in Yilan’s foothill areas (Yuanshan, Sanxing, and Dongshan) from 1994 to 2020. The analysis focused on the trade-offs and synergies among four ecosystem services most closely related to sustainable net-zero living: carbon storage, annual water yield, habitat quality, and rice production.The main findings are as follows: (1) Thanks to the stability of the Fushan Experimental Forest area, carbon storage in Yilan’s foothill region over the 26-year period could largely offset the CO₂ equivalent of rice production in the area, providing an important carbon sink for achieving net-zero targets; (2) At the overall study area scale, habitat quality exhibited trade-off relationships with the other three ecosystem services, while the remaining services showed synergistic relationships; (3) At the village scale, the supply of ecosystem services in the study area showed spatial variation. The study suggests that villages where most ecosystem services have exhibited synergistic relationships over the 26 years may have potential for providing multifunctional ecosystem services in the future; (4) Based on the spatial distribution characteristics of ecosystem services, the area can be classified into three major functional zones, and land use and ecosystem service planning strategies can be adjusted accordingly for each zone. This study provides a reference for sustainable land use policy planning for net-zero targets, as well as for other regions facing similar challenges.