毛乌素沙地中国沙棘无性系生长格局与生物量分配

Studies on the clonal growth pattern and biomass allocation of H ippophae rhamnoides L.subsp sinensispopulation in Mu Us Sandland

根据对毛乌素沙地不同土壤水分和光照条件下中国沙棘无性系跟踪挖掘和测定 ,比较分析了无性系生长格局和生物量分配规律。结果表明 ,在较高的水分或光资源有效性条件下 ,地上生物量所占比例大 ,这些生物量的再分配主要用于分株的树干和叶片生长 ,萌蘖根分枝强度高但隔离者长度小 ,无性系生长格局倾向于集团型 ,这样有利于无性系对已占据生境的巩固和利用。在较低的水分或光资源有效性条件下 ,地下生物量所占比例大 ,这些生物量的再分配主要用于隔离者和根系的生长 ,结果形成了较长的隔离者但萌蘖根的分枝强度小 ,无性系生长格局倾向于游击型 ,从而促使无性系尽快超过不利的微生境斑块、提高分株生长于有利生境斑块的概率 。

Based on the data of following excavation and the investigation of clones,clonal growth and biomass allocation pattern of H ippophae rhamniodes L.subsp sinensis clones under different conditions of water and lightresource supply were analyzed.The results indicated thatclones under higher level ofwater orlightresource supply showed a phalanx growth pattern,and had shorterspacers,copious branching and a rapid accumulation of many single axis ramets with large leaf- area.Clones growing in water- poor or light- poor microhabitats showed a guerilla growth pattern,and had long spacers,less frequent branching and a few ramets with complex axis.The clonal growth seemed allow a foraging strategy.Under the condition of lower levels of water or light resource supply,clones produced longer spacers with higher biomass allocation in orderto capture the resource and escape from poor microhabitat,and increased the probability of ramets growing in favorable microhabitat.On the contrary,under higherlevels ofwaterorlightresource supply,clones produced shorter spacers,dry weight of biomass was mainly allocated to the growth of ramets,suggesting that water- rich or light- rich sites were exploited by a growth pattern that consolidated the clone's occupation of the area.