【摘要】：對川西高山樹線紅杉新鮮凋落物中有機(jī)組分于11月進(jìn)行自然條件(對照)、加氮(2g N·m~(-2))、增溫(頂開式培養(yǎng)室)、加氮+增溫4個處理的原位培養(yǎng),并監(jiān)測凋落物中有機(jī)組分的分解動態(tài).結(jié)果表明:在試驗開始后4個月內(nèi),增溫、加氮以及加氮+增溫處理比對照顯著促進(jìn)了紅杉凋落物中水溶性糖、水溶性酚和多酚的分解,但隨著培養(yǎng)時間的延長,累積分解量的差異逐漸縮小.與對照相比,增溫、加氮和增溫+加氮處理均抑制紅杉凋落物中CH_2Cl_2提取組分、酸溶碳水化合物、酸溶木質(zhì)素和非酸溶木質(zhì)素分解,其中增溫處理抑制作用最強,加氮處理抑制效果最弱,增溫+加氮處理介于二者之間;增溫處理對非酸溶木質(zhì)素和CH_2Cl_2提取組分的半分解周期延長1倍以上,熱水溶組分的半分解周期延長50%以上.在原位培養(yǎng)條件下,紅杉新鮮凋落物中水溶性糖、水溶性酚、多酚、酸溶碳水化合物、酸溶木質(zhì)素是較容易分解的有機(jī)組分,半分解周期分別為182、159、127、154和190 d;熱水溶組分、CH_2Cl_2提取組分和非酸溶木質(zhì)素是較難分解的有機(jī)組分,半分解周期分別是209、302和318 d;盡管低溫季節(jié)(11月至次年3月)極其寒冷,氣溫均低于0℃,常被認(rèn)為是微生物活性最弱、有機(jī)物分解最慢的時期,但結(jié)果顯示低溫季節(jié)期間紅杉凋落物各有機(jī)組分卻分解最快.因此,氮沉降和升溫將遲滯該區(qū)域高寒紅杉林凋落物的分解.這將有利于高寒森林生態(tài)系統(tǒng)的土壤碳固持.
[Abstract]:In November, natural conditions (control), nitrogen (2g N 路m ~ (- 2),) and nitrogen warming (in situ culture) were applied to the fresh litter of yew in the alpine tree line of western Sichuan, and the results were as follows: (1) the fresh litters were cultured in situ under the condition of natural condition (control), nitrogen (2g N 路m ~ (- 2) and nitrogen. And monitor the decomposition dynamics of components in litter. The results showed that the decomposition of water-soluble sugar, water-soluble phenol and polyphenol in litters of Taxodium lanceolata was significantly promoted by heating, nitrogen and nitrogen treatments within 4 months after the beginning of the experiment, but with the prolongation of culture time, the decomposition of water-soluble sugar, water-soluble phenol and polyphenol in litters was significantly increased. The difference in cumulative decomposition amount was gradually reduced. Compared with the control, the CH_2Cl_2 extraction components, acid-soluble carbon-water compounds, acid-soluble lignin and non-acid-soluble lignin decomposition were inhibited by the treatments of warming, nitrogen and nitrogen, among which, the temperature-increasing treatment had the strongest inhibitory effect on the decomposition of the acid-soluble carbon-water compound, the acid-soluble lignin and the non-acid-soluble lignin. The inhibition effect of nitrogen addition treatment was the weakest, and the temperature increase and nitrogen addition treatment was in the middle of the two treatments. The semi-decomposition period of non-acid-soluble lignin and CH_2Cl_2 extracts was prolonged by more than one-fold and the half-decomposition period of hot-water soluble components was prolonged by more than 50%. Under the condition of in-situ culture, water-soluble sugar, water-soluble phenol, polyphenol, acid-soluble carbon-water compound and acid-soluble lignin were easy to decompose in the fresh litters of Taxus lanceolata. The semi-decomposition periods were 182159127154 and 190 d, respectively. Hot water soluble components, CH_2Cl_2 extraction components and non-acid soluble lignin are difficult to decompose organic components, and the semi-decomposition periods are 209302 days and 318d, respectively. Although the low temperature season (November to March of the following year) is extremely cold and temperatures are below 0 鈩，

本文編號：2433581