臺北市都市公園中地上與地下部交互作用與土壤生態功能運作之關係

Above-belowground interactions on soil ecosystem functioning in Taipei urban parks

謝嘉(Chia Hsieh)

指導教授 ： 李美慧

國立臺灣大學/理學院/地理環境資源學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201702934

摘要

都市綠色基礎建設所具之土壤生態系統功能，可協助減緩人為活動對於都市生態系統中土壤生物多樣性與生地化循環所造成的影響。然而目前對於綠色基礎建設中，尤其是都市公園，植被與土壤交互作用關係與其所具之生態系統作用過程尚未有完整地了解。因此，本研究於2015年12月至2017年1月間，調查了副熱帶地區台北市三個都市公園中，樹與草以及草坪等兩種棲地型態之地上─地下部特性與溶解性有機物質特性。本研究使用紫外光─可見光光譜學與三維螢光光譜學，以了解土壤溶解性有機物質的組成特性，探討其與地上─地下部特性在兩種棲地型態間的差異，及其與土壤微生物胞外酵素活性間的關係性。在相同的枯落物移除頻率、割草強度以及相近之遊憩活動強度下，植被組成、表層土壤 (0-10 cm) 物化特性與土壤生物組成於三個公園間不具顯著差異。兩種棲地型態中，地表節肢動物組成也不具有顯著差異。另一方面，草坪相對於樹與草之棲地型態，則具有較高的土壤水分含量與土壤微生物胞外水解酵素活性，以及較高比例之降解過的溶解性類腐植酸物質、氮營養物質濃度與土壤有機質含量。此外，前四者間更具有顯著正相關性。本研究結果顯示，在實際具有經營管理與民眾遊憩使用等人為活動下，透過規劃種植相似之植被型態，可使不同土地利用歷史的公園綠地具有相似的土壤食物網組成與生態系統作用速率。由於木本植物枯落物的移除，地表草本植物成為影響地表棲地結構組成、表土層之有機物質資源輸入，以及土壤含水量等重要的因子。兩個棲地型態間，相似的地表植被組成使土壤食物網組成趨於相近，而土壤中有機物質分解速率則主要受到土壤水分含量所影響。基於本研究的結果，建議未來如欲藉由規劃與經營管理公園綠地中之植被，以提升土壤生物多樣性或土壤有機物質含量時，應進一步了解植被組成多樣性與植被管理強度對於土壤生物組成的影響與其系統功能運作之情況。

關鍵字

人為活動 ； 綠色基礎建設 ； 地表節肢動物 ； 微生物胞外酵素活性 ； 溶解性有機物質 ； 三維螢光激發─發散矩陣 ； 平行因子分析方法

並列摘要

Soil ecosystem functions in urban green infrastructures (GIs) could help mitigate the impact of human activities on soil biodiversity and biochemical cycle in urban ecosystems. However, plant-soil interactions on soil ecosystem processes in GIs, especially urban parks, are unclear. In this study, the above-belowground properties and soil dissolved organic matter (SDOM) properties of two habitat types, namely tree with grass (TG) and grass (G), from three subtropical urban parks in Taipei City were investigated from December 2015 to January 2017. Ultraviolet-visible spectroscopy and three-dimensional excitation-emission matrix fluorescence spectroscopy were used to characterize SDOM. The differences between the above-belowground properties in TG and those in G were investigated. The relationships between SDOM properties and soil microbial extracellular enzyme activities were also analyzed. With identical litter removal, grass clipping intensities, and similar recreational activities intensities, there were no significant differences in plant compositions, the physicochemical properties of surface soils (0-10 cm), and soil food web compositions. Between two habitat types, ground arthropod compositions were not significantly different. In addition, G had higher soil water content, soil microbial extracellular hydrolases activities, decomposed humic acid-like substances in SDOM, nutrients levels, and SOM content than TG did. Furthermore, the former four parameters had strong positive correlations with each other. The results of this study suggest the formation of soil food web and the rate soil ecosystem processes could correspond to vegetation planting under different land use histories in the field. With the woody litter removal, ground grass cover becomes an important factor in the composition of ground habitat structure, soil organic resources input, and the soil water retention in two habitat types. Between two habitat types, the comparable composition of grass plants
could form similar soil food web compositions in two habitat types, and the rates of decomposition and mineralization could be majorly induced by soil water content. From this study, if we want to promote the soil biodiversity or the soil organic matter content by plant planning and management in GIs, the effect of plant diversity and management intensity on soil ecosystem functioning should be further investigated.

並列關鍵字

human activity ； green infrastructure ； ground arthropod ； microbial extracellular enzyme activity ； dissolved organic matter ； three-dimensional excitation-emission matrix ； parallel factor analysis

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