【作者】 何俊；

【导师】 赵秀海；

【作者基本信息】 北京林业大学 ， 生态学， 2011， 博士

【摘要】 2008年南方重大冰雪干扰导致我国800多个自然保护区严重受损,生态环境受到严重破坏。如何及时准确地获得自然保护区冰雪干扰程度,确定具有代表性的受损评价因素和评价指标,对灾后植被恢复和生物多样性保护是极其紧迫的工作。此外,作为中亚热带常绿阔叶林到南亚热带季风常绿阔叶林过渡地带,江西九连山国家级自然保护区亚热带常绿阔叶林群落特征研究对常绿阔叶林研究和生物多样性研究具有重要意义。本文选取江西九连山国家级自然保护区亚热带常绿阔叶林为研究对象,利用大面积固定样地监测技术,研究了九连山亚热带常绿阔叶林群落特征、草本季节动态；阐述了冰雪干扰对林分不同层次的影响,并研究胸径、多度、坡向、坡度等因素对受损程度的影响；比较了不同层次优势种的受损差异,揭示不同优势种的冰雪干扰抵抗能力；调查冰雪干扰后1年内树木的死亡情况,分析了冰雪干扰对群落组成和结构的影响,并提出相关恢复措施。具体研究结果简述如下：1九连山亚热带常绿阔叶林群落特征林分共调查树木(Dbh≥1cm)58科、108属、221种,物种组成丰富。林分以壳斗科栲属常绿物种占据绝对优势,伴生樟科、山茶科和柿树科常绿物种,拟赤杨、枫香和马尾松也有一定数量。林分垂直结构较明显。优势种的径级结构以稳定增长型为主。红钩栲、米槠栲、罗浮栲、丝栗栲、罗浮柿和细枝柃种群以聚集分布为主。2草本物种多样性及季节动态九连山亚热带常绿阔叶林样地共调查到草本39科、61属、75种,其中蕨类植物36种。冬季淡竹叶、求米草等物种的枯萎对物种组成产生了一定的影响,但不同季节草本物种组成变化小。狗脊和镰叶瘤足蕨在不同季节总优势度均为最高。冬季物种多样性指数最低,其他季节的物种多样性相似。草本多度分布不均,不同季节以1-16株的个体数为主。草本垂直结构以30cm以下个体数为主。下坡位和沟边生境的物种数和个体数均为最高。3冰雪干扰对不同林分层次的影响不同林分层次受损表现有差异。林分下层树木以压弯受损为主,中层树木以腰折、断梢和压弯受损为主,而上层树木以断梢受损为主。林分整体不同受损等级的受损个体数与胸径级显著负相关；翻兜率、腰折率与胸径级显著负相关；断梢率、MDI与胸径级显著正相关。在不同层次,不同受损等级的受损个体数与多度均呈显著正相关,而受损率与多度无显著相关性。林分中层树木的翻兜个体数、腰折个体数、翻兜率、腰折率、MDI值与上层树木MDI值呈显著正相关。林分下层树木的翻兜个体数、腰折个体数、压弯个体数、翻兜率、腰折率、压弯率、MDI值与中上层树木MDI值呈显著正相关。整体上,坡向对受损个体数和受损率影响显著。N-NE坡向下树木的受损最严重。除了林分中层的腰折率,坡度对其他层次不同受损等级的受损率均无显著影响。坡度对对林分中层腰折个体数、林分下层和林分整体压弯个体数、林分整体的腰折和断梢个体数有显著影响。胸径和坡向可以作为受损个体数和受损率的评价因素,多度可以作为受损个体数评价因素。MDI值是最好的受损评价指标。4不同层次优势种受损比较不同层次优势种受损均有显著差异。林分上层鸭公树、杨梅、米槠和马尾松MDI值均大于180%,而浙江新木姜和丝线吊芙蓉低于80%。林分中层米槠、木荷和红钩栲MDI值大于150%,而浙江新木姜、小叶石楠、刺毛杜鹃、厚皮香、丝线吊芙蓉、四角柃和黄丹木姜子的MDI值均低于100%。林分下层罗浮栲、米槠、列叶柃和红楠MDI值大于70%,而狗骨柴、黄绒润楠、虎皮楠、细枝柃和心叶连蕊茶MDI值均小于50%。整体上,米槠和鸭公树受损最严重,浙江新木姜和丝线吊芙蓉受损较轻。5冰雪干扰对九连山亚热带常绿阔叶林组成和结构的影响九连山亚热带常绿阔叶林冰雪干扰后1年内树木的死亡率约12%。短期内冰雪干扰对九连山亚热带常绿阔叶林物种组成、优势种组成和物种多样性影响很小。拟赤杨和马尾松的重要值减少率为19.0%和16.8%,其他优势种的重要值变化率均小于10%。0-5m高度级灾后的个体数为灾前的10.5倍,而其他高度级的个体数均有不同程度的减少。冰雪干扰导致优势种不同径级个体数减少,但优势种的径级结构没有改变。冰雪干扰对林分组成和结构影响较小,优势种演替趋势未发生改变,林分采取自然恢复。更多还原

【Abstract】 The south of China suffered heavy ice-snow disturbance in 2008, more than 800 Natural Reserve were badly damaged, and ecological environment was seriously disturbed. How to accurately obtain damage degree information, identify representative evaluation factors and indexes are urgent work to restoration of Forest Ecosystem and preservation of Biodiversity. Besides, as the transition zone, studies on community characteristics of subtropical evergreen broad-leaved Forest in Jiulianshan Mountain are important to the researches on national subtropical evergreen broad-leaved Forest and Biodiversity. Based on the large fixed monitoring plot of subtropical evergreen broad-leaved Forest in Jiulianshan Mountain, the community characteristics and herb seasonal dynamics were studied in this article. The influences of ice-snow distubance on different tree-layers was demonstrated, and then the influences of Dbh, abundance, aspect and slope on damage degree were analyzed. In order to understand the resistance to ice-snow disturbance of different dominant species, the damage degree of dominant species were compared. At last, according to the death information after one year, the effects of ice-snow disturbance on community composition and structure were researched and related restoration measures were suggested. The brief results are as follows:1 Community characteristics of subtropical evergreen broad-leaved forest in Jiulianshan MountainThere are rich species in Forest, including 58 families,108 genera and 221 species. Evergreen species of Castanopsis take the absolutely dominant position, accompanying by the evergreen species of Lauraceae, Theaceae, Ebenaceae, and Alniphyllum fortunei, Liquidambar formosana, Pinus massoniana have certain number. The vertical structure was apparently divided into 5 layers. The Dbh class structures of dominant species mostly are stable growth type. Castanopsis lamontii, C.fabri, C.carlesii, C.fargesil, D.morrisiana and Eurya loquaiana tend to have aggregated spatial distribution at different scales.2 Species diversities and seasonal dynamics of herbs There are 75 herbs in plot, including 36 ferns. Herbs respectively belong to 61 genera and 39 families. Death of Lophatherum gracile, Oplismenus undulatifolius in winter had certain influence on species composition, but the influence was not significant. Woodwardia japonica and Plagiogyria distinctissima had highest SDR in different seasons. Species diversity in winter was lowest, and other seasons were similar. Abundance structure was uneven, and the individual number of 1～16 abundance class in different seasons was the most. In vertical structure, the individual number below 30cm was the most. Areas of low-slope and near water had the most number of species and individuals.3 Influence of ice-snow disturbance on different tree layersDamage situation of plants were different among three tree-layers. Plants in under-layer were mostly in damaged modes of bending, plants in mid-layer were subjected to trunk breakage, top breakage and bending, and plants in upper-layer mostly suffered top breakage. In whole forest, Individual numbers of different damage classes were significantly negative correlation with Dbh classes; uprooting rate, trunk breakage rate were significantly negative correlation with Dbh classes; however top breakage rate, MDI were significantly positive correlation with Dbh classes. In different tree-layers, the number of damaged individuals of different damage modes were significantly positive correlation with abundance, however the damage rates were no significant correlation with abundance. Uprooting number, trunk breakage number, uprooting rate, trunk breakage rate, MDI of plants in mid-layer were significantly positive correlation with MDI of plants in upper-layer. Uprooting number, trunk breakage number, bending number, uprooting rate, trunk breakage rate, bending rate, and MDI of plants in under-layer were significantly positive correlation with MDI of plants in upper and mid-layer. Totally, aspect had significant effect on damage number and rates of different damage modes in different tree-layers. Plants under N-NE aspect suffered most serious damage. Except for trunk breakage rate of plants in mid-layer, slope had no significant effect on other damage rates in different tree-layers. Slope had significant effect on trunk breakage number in mid-layer, bending number in under-layer and whole forest, trunk breakage and top breakage number in whole forest. Dbh and aspect can be selected as valuable factors on numbers and rates of damage, abundance can be selected as valuable factors on numbers of damage. MDI value was the best valuable index on numbers and rates of damage.4 Comparison of dominant species damage degree The damage degree among dominant species (Iv≥5% ) had significant difference. In upper-layer, MDI of Neolitsea chuii, Myrica rubra, Castanopsis carlesii and Pinus massoniana were above 180%, however Neolitsea aurata var.chekiangensis and Rhododendron westlandii were below 80%. In mid-layer, MDI of C.carlesii, Schima superba and C.lamontii were above 150%, but N.aurata var.chekiangensis, Photinia parvifolia, R.championae, Ternstroemia gymnanthera, R.westlandii, E.tetragonoclada and Litsea elongate were below 100%. In under-layer, MDI of C.fabri, C.carlesii, E.distichophylla and Machilus thunbergii were above 70%, on the contrary, Tricalysia dubia, M.grijsii, Daphniphyllum oldhami, E.loquaiana and Camellia cordifolia were below 50%. In the whole, C. carlesii and N.chuii suffered more serious damage, and Neolitsea aurata var.chekiangensis and Rhododendron westlandii had strong resistence to ice-snow disaster.5 Influence of ice-snow disturbance on forest composition and structureDeath rate of plants after one year was about 12%. The influence of ice-snow disturbance on species composition, dominant composition and species diversities in short time were little. The important value of A.fortunei and P.massoniana respectively decreased 19.0% and 16.8% , but changes of other dominant species were less than 10% . Individual number in 0-5m height class increased to 11 times after one year, and number in other height classes decreased to certain extent. Number of individuals in different Dbh of dominant species decreased after one year, however the Dbh class structure have no change. Ice-snow disturbance had little influence on species composition and community structure of subtropical evergreen broad-leaved forest in Jiulianshan Mountain, and growth trend of dominant species had no change, so the natural restoration was suggested to local forest recovery.更多还原