草业学报
草業學報
초업학보
Acta Prataculturae Sinica
2015年
11期
20-28
,共9页
金红喜%何芳兰%李昌龙%韩生慧%王强强
金紅喜%何芳蘭%李昌龍%韓生慧%王彊彊
금홍희%하방란%리창룡%한생혜%왕강강
高寒草甸%沙化%植被特征%土壤理化性质%土壤微生物数量
高寒草甸%沙化%植被特徵%土壤理化性質%土壤微生物數量
고한초전%사화%식피특정%토양이화성질%토양미생물수량
alpine meadow%desertification%vegetation characteristics%soil physical-chemical properties%soil microbial quantity
对不同沙化程度高寒草甸植被特征、土壤理化性质及土壤微生物数量进行调查分析,结果表明:1)随着沙化程度的加剧,植物多样性指数、地上/地下生物量、土壤含水量及浅层土壤有机质、全氮、速效磷含量呈逐渐下降趋势,植物优势度、pH 值呈增加趋势;深层土壤有机质、全氮、速效磷在轻度沙化样地上达到最高值。2)在不同沙化程度的土壤中,细菌数量最多,之后依次为放线菌、固氮菌、真菌;微生物在轻度沙化样地中的数量比其他3个样地都大。3)以土壤深层速效磷作为控制因子,偏相关关系分析显示,土壤微生物总量及土壤细菌数量变化与地上植物丰富度指数、植物生物量、地下生物量呈极显著负相关关系,而与植物地上/地下生物量之比呈极显著正相关关系;固氮菌数量与地上生物量呈显著相关关系,而真菌数量与地下生物量呈显著相关关系;除地上/地下生物量之比与土壤微生物数量之间呈正相关关系外,其余植被特征值与土壤微生物数量之间均呈现负相关关系。
對不同沙化程度高寒草甸植被特徵、土壤理化性質及土壤微生物數量進行調查分析,結果錶明:1)隨著沙化程度的加劇,植物多樣性指數、地上/地下生物量、土壤含水量及淺層土壤有機質、全氮、速效燐含量呈逐漸下降趨勢,植物優勢度、pH 值呈增加趨勢;深層土壤有機質、全氮、速效燐在輕度沙化樣地上達到最高值。2)在不同沙化程度的土壤中,細菌數量最多,之後依次為放線菌、固氮菌、真菌;微生物在輕度沙化樣地中的數量比其他3箇樣地都大。3)以土壤深層速效燐作為控製因子,偏相關關繫分析顯示,土壤微生物總量及土壤細菌數量變化與地上植物豐富度指數、植物生物量、地下生物量呈極顯著負相關關繫,而與植物地上/地下生物量之比呈極顯著正相關關繫;固氮菌數量與地上生物量呈顯著相關關繫,而真菌數量與地下生物量呈顯著相關關繫;除地上/地下生物量之比與土壤微生物數量之間呈正相關關繫外,其餘植被特徵值與土壤微生物數量之間均呈現負相關關繫。
대불동사화정도고한초전식피특정、토양이화성질급토양미생물수량진행조사분석,결과표명:1)수착사화정도적가극,식물다양성지수、지상/지하생물량、토양함수량급천층토양유궤질、전담、속효린함량정축점하강추세,식물우세도、pH 치정증가추세;심층토양유궤질、전담、속효린재경도사화양지상체도최고치。2)재불동사화정도적토양중,세균수량최다,지후의차위방선균、고담균、진균;미생물재경도사화양지중적수량비기타3개양지도대。3)이토양심층속효린작위공제인자,편상관관계분석현시,토양미생물총량급토양세균수량변화여지상식물봉부도지수、식물생물량、지하생물량정겁현저부상관관계,이여식물지상/지하생물량지비정겁현저정상관관계;고담균수량여지상생물량정현저상관관계,이진균수량여지하생물량정현저상관관계;제지상/지하생물량지비여토양미생물수량지간정정상관관계외,기여식피특정치여토양미생물수량지간균정현부상관관계。
In recent years,desertification has been a serious threat to the alpine meadow ecosystem in the Maqu County of Gansu Province.To evaluate the effects of desertification on alpine meadow soil and vegetation,four types of plots with different grades of desertification were established in 2012.The vegetation characteristics, soil physico-chemical properties,and abundance of soil microbes were measured and analyzed in August 2013. At the same time,the relationship between the vegetation characteristics and soil microorganisms was ana-lyzed.The results showed that the plant diversity index,soil moisture content,soil organic matter,total nitro-gen (N),and available phosphorus (P)decreased as the degree of desertification intensified,and the plant dominance index and pH value increased conversely.The deep-soil organic matter,total N,and available P showed the highest values in the lightly desertified plots.Bacteria were the most abundant soil microorganisms in all plots,followed by actinomycetes,fungi,and then nitrogen-fixing bacteria.The lightly desertified plots had the largest number of microbes.A partial correlation analysis showed that the total quantities of soil micro-organisms and bacteria were negatively related to above-ground plant richness index,plant biomass,and below-ground plant biomass,but positively related to the above-ground/below-ground biomass ratio.There were sig-nificant correlations between the abundance of nitrogen-fixing bacteria and aboveground plant biomass,and be-tween the abundance of fungi and below-ground plant biomass.The quantity of soil microorganisms was posi-tively related to the above-ground/below-ground biomass ratio,but negatively related to all of the other meas-ured vegetation characteristics.