林火干擾對興安落葉松林下植被多樣性和生物量的影響1)

石亮　周梅　王鼎　葛鵬　秦可珍　趙鵬武　　　王慶海

(內蒙古農業大學，呼和浩特，010020)　　　　　　　　　　　　　(內蒙古根河林業局)

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林火干擾對興安落葉松林下植被多樣性和生物量的影響1)

石亮周梅王鼎葛鵬秦可珍趙鵬武王慶海

(內蒙古農業大學，呼和浩特，010020)(內蒙古根河林業局)

以寒溫帶大興安嶺受林火干擾的興安落葉松林下植被為研究對象，采用植物多樣性測度方法和收獲法，分析火燒強度和自然恢復年限對林下植被物種多樣性和生物量的影響。結果表明：在不同火燒強度的影響下，林下植被物種多樣性有所降低，Shannon-Wiener指數表現為隨林火強度呈遞減趨勢，Margalef指數表現出未過火區>中度火燒跡地>輕度火燒跡地>重度火燒跡地的規律；火燒降低了林下植被的總生物量，主要降低的是灌木生物量；重度火燒和輕度火燒后草本生物量有所提升，但提升量不足以改變總生物量降低的趨勢。在自然恢復過程中，Margalef指數表現為先升高后降低的單峰變化趨勢，而Pielou指數的變化趨勢與之相反；恢復年限與植被生物量呈正相關關系，草本生物量在經過5 a恢復后逐漸達到一個穩定期，灌木生物量在1～10 a的自然恢復期內持續增長。

火燒強度；自然恢復；生物量；多樣性指數；興安落葉松

With larch boreal forest vegetation under interference of forest fire in Daxing’an Mountain, we used the plant diversity and harvesting methods to analyze the impacts of fire severity and age of spontaneous recovery on plant diversity and biomass. Understory plant diversity was reduced under different degrees of fire. However, from Shannon-Wiener index, the plant diversity had a decreasing trend with the intensity of fire. From Margalef index, the order of plant diversity from high to low was not burned area, moderate burned area, lightly burned area, and severe burned area. But Pielou index had not significant difference (P>0.05). As for biomass, fire reduced the total biomass of understory vegetation, especially shrub biomass. Although the herbaceous biomass was improved under severe burning and light burning, it was not enough to offset the decreased total biomass. During the recovery, Margalef index (1-5 a) of understory vegetation had a growth trend with the longer recovery period, while a decreased tendency in 5-10 a. However, Pielou index had a contrary trend. The vegetation biomass was positively correlated with the recovery period. There is a stable period to herbaceous biomass after 5-a gradual recovery, and shrub biomass continues to grow in 1-10-a recovery period.

火干擾是影響林下植被多樣性的重要因子[1]，火干擾被認為是生態系統的正常行為，是促進植物群落發展的驅動力[2]。大面積森林火燒后，與森林環境有關的大氣、水域和土壤等領域內的森林生態因子之間的生態平衡受到干擾，森林環境會發生急劇變化，各種物質循環、能量流動和信息傳遞遭到破壞，導致森林生態平衡的破壞[3]。