四种短命植物若干生物学生态学特性的研究

THE ECOLOGY OF FOUR EPHEMERAL PLANTS

卷果涩芥（ＭａｌｃｐｌｍｉａｓｃｏｒｐｉｏｉｄｅＳ）、四齿芥（Ｔｅｔｒａｃｍｅｑｕａｄｒｉｃｏｒｎｉｓ）、长齿四齿芥（Ｔ．ｒｅｃｕｒｖａｔａ）和狭果鹤虱（Ｌａｐｐｕｌａｓｅｍｉｇｌｏｂｒａ）为新疆北部常见的四种短命植物。本文从种子生物学、发育节律、株形和植株寿命等方面研究它们与生存环境的协调与适应。

Malcolmia scorpioides,Tetracme quadricornis,T. recurvata and Lappula semiglabra are common ephemeral plants in the desert of the northern part of the Xinjiang Uilgur Autonomous Region,China. Their biological characteris-tics such as seed biology,morphalogy and developmental rhythm make themadapt to the temperate arid environment.(1)Low daily maximum temperature is necessary fot germination Cons-equently,the seeds avoid germinating in the hot and dry summmer,but ge rm-inate in the spring and autumn when there are suitable conditions for plants.(2)There are multiple ge rmination periods during spring and autumn,with only a portion of the seeds from the seed bank germinating each time.Therefore,these plants can survive and propagate after certain catastrophicevents,which can occur easily in the desert.(3)The shift from vegetative stage to reproductive stage is apparentlyaffected by temperature. The termination of the individual’s life span depen-ds on the soil .moistute contents.This might suggest that the growth of theseephemeral plants.Would resemble the annuals or winter annuals if the soilmoisture condition were appropriate for the growth of these plants in the sunmmer.(4)There are two groups of individuals in one population,namely spr-ing-germinated plants and autumn germinated plants.They differ from each othet in many aspects,such as morphology,biorhythm and reproduction rate. (5)with the active growth of plants,the spatial distributions of roots,assimilative organs and reproductive organs change with the changing envir-onment .