共查询到20条相似文献，搜索用时 586 毫秒
1.
宝天曼植物群落物种多样性研究 总被引：33，自引：5，他引：33
对宝天曼保护区植物群落物种多样性进行了研究。结果表明 ,物种丰富度指数、多样性指数和均匀度指数在群落梯度上的分布趋势基本一致 ,较好地反映了不同植物群落类型在物种组成方面的差异。草本层物种丰富度指数明显高于乔木层和灌木层 ,草本层物种丰富度指数在群落梯度上的变异最大 ,灌木层次之 ,乔木层最小。乔木层物种多样性指数小于灌木层和草本层 ,草本层和乔木层物种多样性指数在群落梯度上的变异程度明显大于灌木层。灌木层物种均匀度指数大于乔木层和草本层 ,草本层和乔木层均匀度指数在群落梯度上的变异程度大于灌木层。物种丰富度指数和多样性指数的较大值出现在高海拔和低海拔群落 ,较小值多出现在中等海拔群落。物种均匀度指数的较小值多出现在中等海拔群落 ,但其较大值在各海拔群落都有分布。草本层物种丰富度指数和多样性指数的较高值多分布在低海拔群落 ,较小值多分布在中等海拔群落 ;乔木层和灌木层的各种指数以及草本层的物种均匀度指数在海拔梯度上的分布规律不明显 相似文献
2.
为了解银瓶山森林公园润楠属植物的群落组成、物种多样性及其与海拔因子的关系,对森林公园内不同海拔的12块样地进行调查研究,计算乔木层、灌木层和草本层的物种丰富度指数、Simpson优势度指数、Shannon-Wiener多样性指数和Pielou均匀度指数,分析群落物种多样性与海拔之间的相关性,结果表明:银瓶山润楠属群落中共有70种植物,隶属于41科58属.各植物群落的物种丰富度指数(S)、Simpson优势度指数(D)、Shannon-Wiener多样性指数(H')整体表现为灌木层＞草本层＞乔木层,Pielou均匀度指数(E)表现为草本层＞灌木层＞乔木层.不同群落的乔木层植物物种多样性沿海拔梯度呈先上升后下降的单峰模式,灌木层和草本层的物种丰富度指数、Shannon-Wiener多样性指数均表现为随着海拔的升高而逐渐下降的规律;Simpson优势度指数、Pielou均匀度指数未呈现明显规律. 相似文献
3.
佳木斯市杏林湖公园植物群落数量特征分析 总被引：1，自引：0，他引：1
采用分层随机抽样方法对佳木斯市杏林湖公园的植物群落进行调查,并进行群落数量特征分析。结果表明:公园内共有维管植物46科105属124种,其中蕨类植物2科2属2种,裸子植物2科3属5种,被子植物42科100属117种。多样性分析表明物种丰富度指数(S)和多样性指数(H’)表现一致,均为:草本层>乔木层>灌木层;生态优势度指数(C)表现为灌木层>乔木层>草本层;均匀度指数(J)表现相反为乔木层>草本层>灌木层。建议今后在公园维护过程中加强抚育,加大灌木种类的引进力度,促进群落物种多样性的提高。 相似文献
4.
通过对闽北地区天然常绿阔叶林中的栲树群落植物多样性进行系统调查,结果表明:闽北地区天然常绿阔叶林中的栲树群落植物物种繁多,多样性丰富。调查统计共有79种植物,其中乔木层20种,灌木层38种,草本层及层间植物21种。物种多样性指数(H)为灌木层>乔木层>草本层;均匀度指数(J)为灌木层>乔木层>草本层;优势度指数(C)为草本层>乔木层>灌木层。综合分析表明该区的栲树群落物种多样性指数高,栲树在闽北地区适生性较好。 相似文献
5.
对顺德区5种人工林群落物种多样性进行了定量研究.结果表明:窿缘桉、台湾相思与湿地松群落物种多样性指数为灌木层>草本层>乔木层,针阔混交与阔叶混交群落物种多样性指数为灌木层>乔木层≥草本层,均匀度指数(E a除外)为灌木层>草本层>乔木层;群落间乔木层差异显著,灌木层与草本层变化趋势相对较复杂,但针阔混交林群落与阔叶混交林群落之间,窿缘桉、台湾相思与湿地松群落间无显著差异;7种多样性指数中,乔木层与灌木层采用的研究指数幅度更宽广,可采用SP、SW与P指数测度物种多样性,草本层采用Jsp、P指数较好;提出了基于物种多样性的人工林群落管理措施. 相似文献
6.
依据山西灵空山国家级自然保护区油松林群落的调查结果,研究了油松群落的物种组成,计算了各层次物种重要值,分析了物种多样性。结果表明:(1)在64个样地中发现了177种植物,其中乔木28种,灌木51种,草本98种,隶属于49科110属。(2)乔木层和草本层优势种更为明显。依各层次植物重要值排序,乔木层优势种为油松,草本层优势种为披针苔草,灌木层优势种为土庄绣线菊。(3)多样性指数在各层次表现为:灌木层多样性指数和均匀度指数最高,优势度最低;草本层的丰富度指数最高;乔木层的优势度指数最高,丰富度、多样性和均匀度指数均最低。 相似文献
7.
冰砬山天然次生林群落结构与物种多样性特征 总被引：3，自引：0，他引：3
根据在辽宁冰砬山16块天然次生林样地的调查数据,对天然次生林的植物群落结构和物种多样性特征进行了研究,测定了各层次植物物种的重要值,采用多种方法计算各层次物种的丰富度指数、均匀度指数和多样性指数。结果表明:冰砬山天然次生林群落成层现象和各层次优势种比较明显,依重要值排序乔木层优势种为蒙古栎和紫椴,亚优势种为花曲柳、色木槭和怀槐;灌木层优势种为斑枝卫矛、金银忍冬、胡枝子和金刚鼠李,亚优势种为刺五加和胡榛子;草本层优势种为羊胡苔草。该地区天然次生林群落植物物种比较丰富,丰富度指数草本层最高,乔木层和灌木层较接近;均匀度指数和多样性指数灌木层最高,草本层最低,乔木层居中。 相似文献
8.
根据植物群落的特征,将黔中喀斯特地区石漠化后植被自然演替过程分成草丛阶段、草灌阶段、藤刺灌丛阶段、次生乔林阶段和常绿阔叶林阶段,应用物种丰富度指数、Simpson指数、Shannon-Wiener指数和Pielou均匀度指数分别研究各演替阶段草本层、灌木层、乔木层和群落总体的物种多样性.结果表明:在植被演替过程中,物种多样性从草丛阶段开始增加,草本层到藤刺灌丛阶段达到峰值,随后下降;灌木层、乔木层和群落总体则增长到次生乔林阶段达到峰值.草丛阶段和草灌阶段物种多样性为草本层＞灌木层;藤刺灌丛阶段乔木层物种多样性最低,草本层与灌木层物种多样性大小对比因测度方法不同而有差异;次生乔林阶段和常绿阔叶林阶段物种多样性为灌木层＞草本层＞乔木层.黔中喀斯特地区石漠化后在人为干扰较小的情况下,植物群落由草本植物占优势逐渐向灌木和乔木树种占优势转移,并最终形成喀斯特森林. 相似文献
9.
10.
采用样方调查法对永胜县云南红豆杉分布区植物群落的物种多样性及群落特征进行研究。结果表明,7个样方（共4200m^2）中,记录到维管植物104种,隶属41科75属;从物种多样性指数的平均值来看,物种丰富度（S）、多样性（H＇）、均匀度（E）、优势度（D）均表现为灌木层〉草本层〉乔木层。总体来看,7个样方相同层次的物种多样性差异较大;在调查地云南红豆杉作为伴生种出现于6种类型的群落中,群落垂直结构明显,可划分为乔木层、灌木层和草本层。其中乔木层又可划分为2～3个亚层;主要树种多变石栎和云南红豆杉种群表现为衰退型种群。建议加强对其种质资源的保护,开展云南红豆杉更新适宜环境研究,规划适宜地块进行人工繁育,扩大种群规模。 相似文献
11.
A. Lehtijärvi H. T. Doğmuş‐Lehtijärvi A. G. Aday Kaya S. Ünal S. Woodward 《Forest Pathology》2017,47(6)
Although several Armillaria species have been reported in Turkey, there is little information about their ecology in Turkish forests. In this study, we investigated five forest stands, approximately 5–74 ha in size, in Kastamonu province in the Black Sea Region of Turkey for the presence of Armillaria species in stumps and logs. The stands were mixed Abies nordmanniana ssp. bornmülleriana and Pinus sylvestris forests managed using a selective cuttings system; the proportion of fir in the total number of stems and stumps ranged from 36 to 98%. Based on sequence analysis of the internal transcribed spacer and intergenic spacer regions of the rDNA, all rhizomorphs sampled from the stumps and logs were of Armillaria ostoyae. The size of the genets was estimated with random amplified microsatellites analysis of the isolates and ranged from single stumps to approximately 450 m2. One to seven genets were found in each stand. These results indicate that the genets had arisen from spores and vegetative spread was limited on most sites. 相似文献
12.
通过对上海松江中央公园内65株特大银杏树白蚁为害情况的调查,发现该公园银杏受害率为100%,其中存在活白蚁的银杏占总量的56.9%,采用毒土处理、粉剂疗法、建立白蚁监测点等措施,经过两次灭杀,活白蚁的灭杀率达到92.3%和93.3%,从而使存在活白蚁银杏树的比例从56.9%下降到2.7%,白蚁发生情况明显降低。
相似文献
13.
14.
建平半干旱地区石质山地造林技术研究 总被引：1，自引：0，他引：1
研究了不同植物在石质山地的造林成活率、土壤化学性质随造林年限的变化和造林措施对土壤化学性质和植物胸径、树高年净生长量的影响。结果表明：不同植物在石质山地的成活率在21%～85%之间,其中白榆和沙打旺的成活率分别为81%和85%,而小叶杨、刺槐、栾树的成活率均在70%左右;植被能明显提高石质山地不同土层的有机质、全N、P2O5含量,但提高程度随土层深度、养分种类和造林年限的不同而不同;在同一土层,生物复合肥料、菌剂和保水剂均显著提高土壤有机质含量（p〈0.01）并显著降低土壤P2O5含量（p〈0.01）;只有保水剂可引起土壤全K含量的明显升高;生物复合肥料、菌剂和保水剂均显著提高白榆、小叶杨、刺槐、栾树树高和胸径的年净生长量,但保水剂的提高程度最高。 相似文献
15.
植物经常暴露在各种生物和非生物的胁迫之下,这些胁迫会影响植物的生长发育和繁殖并最终导致植物死亡。为了抵御不利的环境条件,植物已经进化出复杂而精细的网络来感知胁迫并激活防御系统。为此,植物激活许多信号转导通路,这些信号转导通路可以改变一些胁迫响应基因的表达,从而引起植物形态、生理和生化的改变以适应逆境。DNA胞嘧啶甲基化是高等真核生物的主要表观遗传机制之一,在维持基因组稳定性和调节基因表达方面起着关键作用。表观遗传变异比遗传变异更为灵活。一旦环境条件发生变化,为了适应新的环境植物都会发生表观遗传的改变。许多研究表明DNA甲基化参与植物的发育和应激反应。基于相关研究对DNA甲基化进行了综述,对植物逆境胁迫有重要意义。 相似文献
16.
17.
The study focused on the success of regeneration on patch cuts in spruce-dominated stands in terms of stocking and tree height. It was based on an experiment in the Kainuu region in northern Finland. The experimental design included 8 stands with 58 clearcut patches of variable size (0.09–0.37?ha), on which either natural regeneration without site preparation or site preparation and planting of Scots pine was applied. A regeneration survey was conducted 13–15 growing seasons after treatments. Patches without site preparation had been restocked quite well from natural seed sources. The average number of trees was about 11,000?ha?1, of which 1700?ha?1 crop trees. With site preparation and planting, the stocking levels were also very high, 25,000 and 2100?ha?1, respectively. One hundred percent of the planted patches and 75% of the naturally regenerated patches had an acceptable density. Restocking was equally good across the range of patch sizes. Tree growth had been somewhat slower in the smallest patches than in the largest ones in the range. Natural regeneration was capable of yielding good regeneration results in most patches, especially when site preparation was applied. Stocking levels and height development were higher yet in the planted patches. 相似文献
18.
19.
Keisuke Kojiro Yuzo Furuta Makoto Ohkoshi Yutaka Ishimaru Misao Yokoyama Junji Sugiyama Shuichi Kawai Takumi Mitsutani Hiromasa Ozaki Minoru Sakamoto Mineo Imamura 《Journal of Wood Science》2008,54(6):515-519
To investigate the changes in microstructures of wood with elapsed time in the environment, CO2 adsorption onto dry wood was measured at ice-water temperature (273 K) for samples aged from 0.1 years to over 1000 years.
The micropore size distribution was obtained using the Horvath-Kawazoe method. Micropores smaller than 0.6 nm in wood decreased
in number with elapsed time in the environment, and a negative correlation was found between cumulative pore volume for pores
smaller than 0.6 nm and elapsed time in the environment. Cumulative pore volume in the 1000-year sample was almost half of
that in the 0.1- year sample. Micropores smaller than 0.6 nm in wood with a few decades or more of elapsed time increased
in number after rewetting and drying. Consequently, microstructures of wood with longer time elapsed in the environment were
considered to be more stable, because of longer-term thermal motion and possibly more repeated moisture adsorption and desorption
and/or temperature variation in the environment. 相似文献
20.
《Scandinavian Journal of Forest Research》2012,27(6):530-542
Abstract The success of natural regeneration on patch clear-cuts in Norway spruce stands in Southern Finland was examined in terms of stocking and tree height. The experiment was established in mature spruce stands in the submesic Myrtillus (MT) site type. In each of the eight study sites, three plots were treated with clear-cutting and planting, clear-cutting with partial tree retention and planting, and patch clear-cutting without site preparation, respectively. In three of the study sites, one plot with patch clear-cutting and site preparation was established. Each plot was 1 ha, out of which three patches of 40×40 m were clear-cut in the patch treatments. 10–11 years after cutting, the patches had on average 1316 crop trees ha–1, of which 91% were spruces. Some 27% of the stands were up to the target stocking level (≥1600 ha?1), and 36% were at least satisfactory (≥1300 ha?1). Site preparation did not yield greater stocking levels on patches, but that result is ambiguous due to a difference in initial stocking. The average spruce tree height in the patches (0.76 m) was much smaller than in the case of clear-cutting and planting (2.42 m). In conclusion, the patches had been restocked tolerably well with spruce and birch for practical purposes during the 10- to 11-year period, but the regeneration process had been very slow compared to clear-cutting and planting. 相似文献