羊草和大针茅群落的暗呼吸强度与环境条件关系的初步探讨

草原群落的干物质产量,是由光合作用和呼吸作用所决定。呼吸作用对于干物质的生产是必不可少的一环,因为任何物质的形成都需要能量,而这种能量正是由呼吸作用所提供的。#br#草原群落的生长、呼吸和光合受到光照、温度、水分和土肥等环境因子的影响。在适宜的气候条件下,生长、呼吸和光合有着严格的偶联关系,并能使群落的生长效率保持比较高的水平,然而在异常的气候条件下,如高温、干旱、低湿等,会增加群落的无效呼吸,使光合产物过量的消耗,导致偶联关系的破坏,光合效率下降,终致造成植物的死亡。#br#本文就羊草和大针茅草原群落的暗呼吸强度与环境条件的关系进行探讨,视其对草原群落光合生产效率的影响,从而为人工促进天然草原生产力的提高,提供依据。

THE PRELIMINARY STUDIES ON RELATIONSHIP BETWEEN DARK RESPIRATION RATE AND ENVIRONMENTAL FACTORS IN LEYMUS CHINENSIS AND STIPA GRANDIS COMMUNITIES

The product ion of dry plant material in steppe community is deter-mined by photosynthesis and respiration. Respiration provides the necessary energy for growth of steppe plants. While under stress environmental conditions, such as high temperature, drought or low moisture, etc., the uneffective respriation of the plant community will increase and the pho-tosynthetical products will be over consumed. Hence the efficiency of photosynthesis decreases consequently. On the other hand, under the proper environmental conditions the dark respiration of steppe community is affec-ted by air temperature. The dark respiration drops about a half with each drop of 5℃. Under dry condition, the dark respiration of community incre-ases with the increase of moisture. These concern with the growth rate of community. under good soil water condition.The growth rate of community and the production of dry material will be raised when increasing the amount of fertilizer to the soil. with that the dark respiration will beincreased relevantly.