土壤是森林生態(tài)系統(tǒng)的主要組成部分，對(duì)氣候變化的響應(yīng)可能潛在的影響森林生態(tài)系統(tǒng)的物質(zhì)循環(huán)過(guò)程。土地利用變化深刻影響著土壤生態(tài)系統(tǒng)物理化學(xué)特征,。再造林是青藏高原東緣亞高山區(qū)域一個(gè)重要林業(yè)實(shí)踐活動(dòng),。因此,，再造林活動(dòng)不僅影響土壤物理化學(xué)特性,，而且可能進(jìn)一步影響森林土壤對(duì)未來(lái)氣候變化響應(yīng)的方式和程度。
中國(guó)科學(xué)院成都生物研究所生態(tài)研究中心劉慶研究員課題組徐振鋒等人通過(guò)開(kāi)頂式生長(zhǎng)室模擬增溫的研究方法,，比較研究了人工針葉林和天然針葉林土壤N轉(zhuǎn)化及有效性，土壤微生物特性和酶活性對(duì)一定量氣候變量的初期響應(yīng),。
研究表明：在生長(zhǎng)季節(jié)內(nèi),，模擬增溫往往能顯著增加天然林土壤的可溶性碳、氮庫(kù),，而對(duì)人工林土壤的可溶性碳,、氮庫(kù)沒(méi)有影響。短期模擬增溫顯著增加兩類(lèi)森林生態(tài)系統(tǒng)土壤凈N礦化和有效性,，但增加方式不同(人工林氨化作用占主導(dǎo)而天然林硝化作用占主導(dǎo)),。增溫初期，兩類(lèi)生態(tài)系統(tǒng)的土壤微生物生物量碳,、氮都沒(méi)有明顯變化,。與土壤氮轉(zhuǎn)化相關(guān)的組分庫(kù)對(duì)模擬增溫的響應(yīng)與生態(tài)系統(tǒng)類(lèi)型和季節(jié)變化密切相關(guān)，天然林對(duì)模擬氣候變化的響應(yīng)更為敏感,。增溫導(dǎo)致的土壤有效氮庫(kù)的增加可能在一定程度上提高森林生產(chǎn)力,，但增溫引發(fā)的天然林可溶性土壤N庫(kù)增加(可溶性有機(jī)氮和硝態(tài)氮)也可能通過(guò)淋溶方式從系統(tǒng)中大量丟失。（生物谷Bioon.com）
生物谷推薦英文摘要：
Applied Soil Ecology doi:10.1016/j.apsoil.2010.07.005
Initial soil responses to experimental warming in two contrasting forest ecosystems, Eastern Tibetan Plateau, China: Nutrient availabilities, microbial properties and enzyme activities
Zhen-feng Xua, b, Rong Hua, Pei Xionga, Chuan Wana, Gang Caoa and Qing Liu
a Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
b Graduate University of the Chinese Academy of Sciences, Beijing 100039, China
In order to understand the effects of projected global warming on soils in different land-use types, we compared the impacts of warming on soils in two contrasting forest ecosystems (a dragon spruce plantation and a natural forest) using the open-top chamber (OTC) method in the Eastern Tibetan Plateau of China. The OTC on average enhanced daily mean soil temperatures by 0.61 °C (plantation) and by 0.55 °C (natural forest) throughout the growing season, respectively. Conversely, soil volumetric moisture declined by 4.10% in the plantation and by 2.55% in the natural forest, respectively. Warming did not affect dissolved organic C (DOC) and N (DON) in the plantation but significantly increased them in the natural forest. Elevated temperature significantly increased net N mineralization rates and extractable inorganic N pools in both sites. Warming had no effects on microbial biomass C (MBC) and N (MBN) and their ratios (MBC/MBN) in the plantation and significantly increased MBC and MBN only late in the growing season in the natural forest. Warming did not affect basal respiration in the plantation but significantly increased it in the natural forest. No clear change was observed in metabolic quotient between warming regimes for both forest types. Experimental warming tended to increase invertase and urease in both forest soils. Measured pools related to N turnover generally showed significant interactions in warming, forest type and sampling date. Taken together, our results indicate that responses of soils to experimental warming depend strongly on forest managements and seasons.
