【摘要】 为了解氮沉降对神农架地区川金丝猴栖息地地衣多样性的潜在影响,本文以最大光合效率Fv/Fm、地衣细胞膜完整性(RE)和叶绿素OD435/OD415为指标,以神农架地区生物量较大、可能被川金丝猴取食的4种树生地衣(长松萝Usnea longissima、桦树松萝Usnea betulina、杯树花日本变种Ramalina calicaris var.japonica和裸缘衣Parmotrema hypoleucinum)为对象,以去离子水和不同浓度的KNO3、NH4NO3和(NH4)2SO4的溶液浸泡处理,采用MiniPAM荧光仪在氮处理前和处理后的0、24、48和72 h分别测定地衣的Fv/Fm值,在72 h后测定地衣浸出液电导率RE和叶绿素OD435/OD415值,研究4种地衣的氮敏感性。结果表明,4种地衣对72 h的高氮处理均表现出敏感性,但敏感的氮素类型和指示指标存在种间差异。其中,(1)以Fv/Fm为指标,长松萝和桦树松萝对KNO3最敏感,杯树花日本变种和裸缘衣则对(NH4)2SO4较为敏感;(2)以RE为指标时,长松萝和桦树松萝对(NH4)2SO4最敏感,而杯树花日本变种在KNO3、NH4NO3和(NH4)2SO4间无差异,裸缘衣则对(NH4)2SO4较为敏感;(3)以OD435/OD415为指标时,长松萝和裸缘衣对(NH4)2SO4较为敏感,桦树松萝对KNO3和(NH4)2SO4均敏感,杯树花日本变种则对KNO3、NH4NO3和(NH4)2SO4均敏感。上述研究结果不仅证明川金丝猴栖息地树生地衣面临氮沉降的现实威胁,还说明其氮敏感性具有种特异性和及其作用机制的复杂性。因此,进一步开展川金丝猴栖息地氮沉降特征及其对川金丝猴主食地衣影响的研究,对川金丝猴保育具有重要的意义。更多还原

【Abstract】 To explore the potential impacts of nitrogen deposition on lichen diversity in SnubNosed Monkey( Rhinopithecus roxellana) habitats in Shennongjia,an in-situ experiment was conducted in a forest in Shennongjia Nature Reserve. Four common epiphytic lichens( Usnea longissima,Usnea betulina,Ramalina calicaris var. japonica and Parmotrema hypoleucinum) were collected,then soaked in solutions of KNO3,NH4NO3,( NH4)2SO4,or deionized water three times,for half an hour each time at 0,24 and 48 h,respectively; then Fv/ Fm,cell integrity( measured as solution electrical conductivity,RE) and chlorophyll OD435/ OD415 were measured after 72 h,which are indexes indicating lichen sensitivity to nitrogen deposition. The results showed that higher nitrogen concentration led to a significant decrease of Fv/ Fmand OD435/ OD415 and a significant increase of RE. Furthermore,species-specific differences in sensitivity were found for different nitrogen types and different indications. Based on the response of Fv/ Fm,U.longissima and U. betulina were more sensitive to KNO3 than to NH4SO4 and NH4NO3,but R.calicaris var. japonica and P. hypoleucinum were more sensitive to( NH4)2SO4than to KNO3 and NH4NO3. According to RE response to nitrogen treatment,U. longissim,U. betulina and P. hypoleucinum were most sensitive to( NH4)2SO4,but there was no significant difference among responses of R. calicaris var. japonica to KNO3,NH4NO3and( NH4)2SO4. As with OD435/ OD415,U. longissim and P. hypoleucinum were more sensitive to( NH4)2SO4than to KNO3 and NH4NO3,U. betulina was more sensitive to KNO3and( NH4)2SO4than to NH4NO3,but R. calicaris var. japonica was equally sensitive to the three nitrogen types. The results suggested that more attention should be paid to negative effects of nitrate deposition on habitats of Snub-Nosed Monkey at Shennongjia Nature Reserve,and further investigation on effects of nitrogen deposition on lichen biomass accumulation and nutrition components should be conducted to a perfect conservation of Sichuan Snub-Nosed Monkey.更多还原