【作者】 刘济明；

【导师】 李俊清；

【作者基本信息】 北京林业大学 ， 生态学， 2010， 博士

【摘要】 喀斯特环境是一种脆弱的生态环境,土层浅薄,土壤容量少,岩石出露率高,水土流失严重,土壤养分含量低,生态环境恶劣。小蓬竹生活在环境恶劣的喀斯特地区,仅在贵州罗甸县、平塘县、紫云县及长顺县城关镇的喀斯特山地上有分布,生长状况良好。为了探索小蓬竹的生长适应性,分析小蓬竹的濒危机制,为小蓬竹种质资源保护与开发利用、石漠化治理过程中的物种筛选和合理搭配等提供理论基础,本文采用野外调查、比较分析和系统分析的方法,研究了小蓬竹在喀斯特小生境、构件、克隆、种群、群落等方面的适应特征,研究表明:1、小蓬竹的生境可分为土面、石面、石沟、石隙、石槽和石洞6种小生境。除石面外,其它5种小生境均有小蓬竹分布。土面小生境最适于小蓬竹生长,而石洞小生境最不适于小蓬竹生长,其它三种小生境的小蓬竹生长情况差别不大。小蓬竹分布的小生境形成石面型、石面-土面型、土面-石面型三种组合类型。利用小蓬竹造林时,主要利用的应该是石沟、石隙以及石槽小生境。2、小蓬竹的适宜叶面积指数为7.1893。小蓬竹净光合速率日变化曲线呈双峰曲线,在12:00和15:00出现了两个高峰,具有明显的“午睡”现象。对其光响应曲线的测定表明:小蓬竹的光补偿点为13.57μmol·m^-2·s^-1,光饱和点较高,达到1200μmol·m^-2·s^-1左右,说明小蓬竹属于耐阴性竹种。3、小蓬竹在孤立木生境中不管是枝构件还是叶构件都要好于林缘和林中生境;但在枝条长度方面,林缘要好于孤立木和林中。各级分枝的平均角度随竹龄的增大而呈现不同的波动趋势,但总体是趋于35°。随着年龄的进一步增加,平均分枝角度进一步增加,自然整枝高度随着年龄的增加而逐渐增高,同时茎上平均分枝数随着年龄的增加逐渐减少。小蓬竹在孤立木和林缘生境中,克隆构件类似于K-对策者;在林中生境里类似于r-对策者。4、在不同的土壤水分环境下,小蓬竹的克隆构型表现出明显的可塑性,这主要体现在间隔子长度和分枝强度上。小蓬竹克隆分株之间的分枝角度相对固定,主要是15°、40°、70°、110°四个角度。小蓬竹能通过克隆可塑性来调节其觅食行为。小蓬竹作为克隆植物具有明显的生理整合作用。5、小蓬竹在种群水平上具有一系列适应性特征。出笋数多,但退笋率也高,成竹率低,营养空间不足是小蓬竹退笋率高的主要原因。在小蓬竹分布区内,自然林中的小蓬竹种群年龄结构属增长型,但趋于稳定。小蓬竹的分布格局与研究时的取样尺度有很大关系,克隆分布格局随研究尺度的加大而由随机型变化为集群型。克隆分株分布格局一直呈集群型,但随着研究尺度的加大其集群程度也逐渐增强。小蓬竹种群调节是密度制约性的,受克隆密度以及克隆分株密度的影响。小蓬竹的环境容纳量在100株/m²左右。6、小蓬竹是其所属群落的优势种,并且是唯一的建群种。小蓬竹群落科、属组成较为分散。小蓬竹群落有较强的热带性质,并具有明显的过渡性特征。天然小蓬竹群落各层次的物种多样性指数均接近于1,天然小蓬竹群落是相对稳定的群落。小蓬竹群落土壤种子库中具有丰富的活力种子。7、小蓬竹能很好的适应所在区域的环境,并且对群落环境有明显的影响。小蓬竹能明显改善群落内土壤的物理和化学性质,并且改善作用优于相同环境中的灌木群落和草地。小蓬竹群落具有比相同环境中的喀斯特灌木群落和草地更好的水土保持功能。8、小蓬竹濒危有三个可能原因:一是人为砍伐利用过度;二是喀斯特地区狭小的土壤空间及特殊的克隆生长特性;三是小蓬竹对气候条件的要求。9、小蓬竹可以作为喀斯特生态系统恢复重建的物种用于贵州南部和西南部、云南大部、广西、重庆和湖南等省份的石漠化治理。更多还原

【Abstract】 Karst habitat is a kind of fragile ecology environment,which has followed typical characters: shallow and less soil,high rate of bare stone,serious soil erosion,low soil nutrient content and bad growth condition.Drepanostaehyum luodianense only distributes and grows well in adverse Karst regions,such as Luo Dian,Ping Tang and Chengguan of Chang Shun district in Guizhou province.To explore the growth adaptability,analyze the endangered mechanism and provide the theoretical foundation of the protection and exploitation of D.luodianense,species selection and reasonable collocation in the process of rocky desertification control.Based on the ways of field investigation, comparative analysis and system analysis,the adaptability characteristics of D.luodianense was studied in the Karst microhabitat,modular,cloning,population,community and so on.The results showed that:1 The habitat of D.luodianense can be divided into six kinds of microhabitats:soil surface,stone surface,stone ditch,stone crevice,stone slot,stone cavern.D.luodianense grows in the other 5 microhabitats except stone surface.For the growth of D.luodianense,soil surface is the optimal,stone cavern is the worst,while there is no significant difference in other three microhabitats.So,it can be divided into three types:stone surface,stone-soil combination surface and soil-stone combination surface.The main utilized microhabitats should be stone ditch,stone crevice and stone slot when D. luodianense is used to forestation.2 The optimum LAI of D.luodianense is 7.1893.The net photosynthetic rate curve of D. luodianense is bimodal,to be accompanied by significant "nap" phenomenon,and which two peaks appear at 12:00 and 15:00.The determination of light response curve shows that the light compensation point of D.luodianense is 13.57μmol·m^-2·s^-1,while the light saturation point reach up to 1200μmol·m^-2·s^-1.And all those proved that D.luodianense is a shade-tolerant bamboo species.3 The growth of branch and leaf modular of D.luodianense in isolated habitats is better than that in forest edge and inside forest.But branch length in forest edge is better than that in isolated habitats and forest habitats.With the increase of tree ages,there are different fluctuations in the average branching angle at all levels,but the average angle is about 35°.With further increase of tree ages,both the average branch angle and the height of natural pruning increases gradually,while the average number of branches in stems decreases.The clonal modular growth of D.luodianense tends to K-strategy in forest edge and isolated habitats,while it is R-strategy in inside forest habitats.4 Clonal architecture of D.luodianense appears obvious plasticity under different soil moisture circumstances,which is mainly reflected in the spacer length and branching intensity.The branch angles of the clonal ramets of D.luodianense are relatively fixed in four kinds of angles mainly:15°,40°,70° and 110°.D.luodianense can adjust foraging behavior through clonal plasticity.As a kind of clonal plant,D.luodianense has an obvious characteristic of physiological integration.5 There is a series of adaptive feature of D.luodianense in population level.It has high shoot-emergence number,high mortality and low bamboo grown-up rate.The shortage of nutrition is the main reason for the high mortality.In the distribution of D.luodianense,the age structure of the population is growing,but it tends to be stable.There is a great relationship between the distribution pattern and the sampling scale.With the increase of research scale,the clonal distribution pattern changes from random to cluster-based type,and the clonal ramets distribution pattern is an enhanced cluster-based type.The population regulation of D.luodianense belongs to density dependence type, which is affected by clonal density and clonal ramets density.The environment capacity of D. luodianense is about 100/m².6 D.luodianense is the dominant species and the only constructive species in this kind of community which families and genera composing are quite scattered and reflect significant tropical features and obvious transition characteristics.The species diversity indexes of D.luodianense community are close to 1 at all levels,thus,it is a relatively stable community.There are rich viable seeds in the community’s soil seed bank.7 D.luodianense can adapt well and influence the community environment markedly where it distributes.In the same environment,D.luodianense community not only can obviously improve the soil’s physical and chemical properties but also can effect in soil and water conservation better than the shrub community and grassland.8 There are three possible reasons that D.luodianense is an endangered species.Firstly,it has been excessive lopped and utilized.Secondly,it has special characteristics of clonal growth and the soil space is narrow in Krast region.Thirdly,it needs strict climate conditions.9 As the species for restoration and reconstruction in Karst ecosystem,D.luodianense can be used to treat rocky desertification in the south and southwest of Guizhou provinces,most parts of Yunnan provinces,Guangxi provinces,Chongqing and Hunan provinces.更多还原