【作者】 薛瑶芹；

【导师】 张文辉；

【作者基本信息】 西北农林科技大学 ， 植物学， 2008， 硕士

【摘要】 本研究通过样地调查,研究了柴松(Pinus tabulaeformis f. Shekannesis)的地理分布、生物学特征以及不同生境下柴松群落特征、种群数量结构、种群生殖生态,阐明了柴松的群落特征、种群动态及生殖特征,为制定合理的保护和管理措施以有效保护现有柴松天然林并扩大其分布范围提供理论依据。主要结论如下:1.柴松是油松的变型,分布区狭小,只集中分布在子午岭北部的富县和尚塬林场。地理位置属于油松种群分布区西北部。柴松幼苗生长较快,其胸径生长盛期在6～22 a,高度速生期在6～18 a,材积生长盛期在高、径生长盛期之后,一般从18 a开始能维持到40 a,材积成熟年龄>46年。2.柴松群落中,共有52科120属162种种子植物,可划分为12个类型和9个变型,北温带成分最多(51属),占总属数的49.51%,热带植物成分占一定比例。柴松群落可划分为5个群落类型:柴松+辽东栎-水栒子-苔草群落;柴松-虎榛子-苔草群落;柴松-水栒子-苔草群落;柴松-黄蔷薇-苔草群落;柴松-绣线菊-苔草+野棉花群落。不同群落类型的物种组成和林分结构有所不同;柴松为优势种所构建的群落环境有一定的相似性。柴松群落中20个主要物种的总体联结性不显著,82.4%的种对间没有显著的联结关系,表明柴松群落的植物种类组成和群落结构趋于稳定;随着各群落生境光照条件的增强,与柴松不相关的物种数增加,而与其正关联的物种逐渐减少。3.柴松种群的幼苗均表现为聚集分布,而随着生境的不同,幼树和大树表现为聚集分布或者表现为随机分布,幼苗和幼树聚集性最强的尺度为25 m2,大树的为100 m2。不同生境中的柴松种群,多数柴松种群年龄结构属于进展型种群,存活曲线均接近Deevey III型,在无人为干扰的情况下能得到进一步发展。海拔、坡向、土壤含水量和土壤酸碱度对种群的数量结构产生了主要影响。4.不同种群的标准株单株产种量差异不显著;柴松种子在天然条件下的发芽率很低,种群C的发芽率最高也仅有1.203‰;较低的草本层盖度、灌木层盖度和偏碱性的土壤有利于柴松种子发芽。不同生境种群的1年生幼苗数为:种群D(5.00株/100 m2) >种群C (2.00株/100 m2) >种群B(0.75株/100 m2),柴松种群在光照条件适中的生境更新最为良好,而光照条件较强的南坡不适于柴松低龄个体的生长。更多还原

【Abstract】 Starting with the geographic distribution, basic biological characteristics and the species composition, stand structure, interspecies relationship, population structure, spatial pattern, fecundity and population regeneration in different habitat, the community feature, population dynamics and reproduction characteristics of Pinus tabulaeformis f. Shekannesis were studied systematically based on the detailed plot investigation, which provided the basis of making reasonable conservation and management measures for protecting the present P. tabulae-formis f. Shekannesis natural forest effectively and expending its distribution scope. The main conclusions were as follows:1. P. tabulaeformis f. Shekannesis was an ecological forma group of P. tabulaeformis in the Loess Plateau. The concentrated distribution area of it, which belonged to Heshangyuan forest farm located in the north of Ziwuling, was narrowness. This area was located in the northwest of P. tabulaeformis distribution area. The seedling of P. tabulaeformis f. Shekan-nesis relatively grew rapid, the DBH of it grew fast in 6～22 a, height growth increased in 6～18 a, volume grew rapid in 18～40 a, and the age of volume maturation>46 a.2. There were 162 species of seed plants in P. tabulaeformis f. Shekannesis community, belonging to 120 genera, 52 families. The florae of seed plants presented a diversified and complicated composition, including 12 types and 9 variants, among which the north temper-ate distribution compositions made significant dominant and it accounted for 49.51% in total genera, and the tropic elements took some percentage. Based on the species important value, the P.tabulaeformis f. Shekannesis community in Qiaobei forest area could be divided into 5 community types: P.tabulaeformis f. Shekannesis+Quercus wutaishannica-Cotoneaster mul-tiflorus-Carex sp. Community, P.tabulaeformis f. Shekannesis-Ostryopsis davidiana-Carex sp. Community, P.tabulaeformis f. Shekannesis-Cotoneaster multiflorus-Carex sp. Commu-nity, P.tabulaeformis f. Shekannesis-Rosa hugonis - Carex sp. Community, and P.tabulaeformis f. Shekannesis- Spiraea salicifolia - Carex sp.+Anemone upehensis Commu-nity. The species composition and stand structure of different community types showed dif-ference. And the community environment, in which P.tabulaeformis f. Shekannesis was dominant species, had some similarity. The overall association among 20 main species in the community was not significant, 82.4% species-pairs showed insignificant association and low interspecific association index, which mainly indicated the species composition and commu-nity structure tended to be stable. In different community types, the numbers of species un-correlated with P.tabulaeformis f. Shekannesis increased along with the enhancement of light conditions in community, meanwhile, the numbers of in positive association with P.tabulaeformis f. Shekannesis gradually decreased.3. Seedlings of 5 P.tabulaeformis f. Shekannesis populations all showed aggregated dis-tribution pattern, the saplings and large tree in different population fitted into aggregated dis-tribution or random distribution, in addition, the aggregated intensity of these two develop-ment stage was lower than that of seedlings. The area with the highest aggregated intensity was 25 m2 in seedling and sapling, and 100 m2 in large tree. Except population A, the age structure of other populations belonged to progressive type, and the survival curve of them belonged to Deevey III, all these indicated that most population could keep stable state, and further develop without artificial destruction. The analysis of PCA showed that the main fac-tors that affecting the population structure were slope site, altitude, slope face, water content and the pH value of soil.4. The quantity of cones and seeds per individual of different population had no signifi-cant difference. The natural germination rate of P.tabulaeformis f. Shekannesis was very low, and the highest one among 5 populations was only 1.203‰(population C). Generally benefi-cial conditions for germination were higher pH soils with lower coverage of shrub and herb plants. The numbers of 1-year-old seedlings in population showed the status of population D (5.00 Ind./100 m2)> population C (2.00 Ind./100 m2) >population B (0.75 Ind./100 m2). There was no 1-year-old seedling in population A and E. The growth of basal diameter and height of aerial stem of 1～10 year old individuals in population C and D was higher than that in other population, this indicated that young individuals grew well under the habitat with mod-erate light condition, however, south slope with strong light condition was not the suitable environment for natural generation.更多还原