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1.
选取帽儿山地区阔叶红松林、红松人工林和水曲柳天然次生林3种典型群落,基于方差均值比、L函数和角尺度方法比较研究各群落乔灌层优势种的空间分布格局与空间关系。结果表明,帽儿山典型森林群落优势种的空间分布格局主要呈聚集分布或随机分布。阔叶红松林乔木优势种呈随机分布或不显著聚集分布;红松人工林中红松呈随机分布;水曲柳次生林乔木优势种主要呈随机分布。各群落灌木优势种均呈聚集分布。帽儿山典型森林群落中各乔木优势种间主要呈空间正关联或无空间关联,红松与阔叶树小尺度无关联,大尺度正关联,阔叶树种间主要呈正关联。红松人工林与水曲柳天然次生林乔木优势种间均呈正关联。帽儿山典型森林群落优势种空间关系良好,空间结构稳定。  相似文献   

2.
为了解南岭保护区主要树种的群落空间格局特征。本研究基于固定样地,通过对样地中植物的调查分析,进而对群落主要树种空间分布格局进行研究。结果表明:样地中共有39科58属104种木本植物,根据重要值排序,华润楠、马尾松、甜槠、广西紫荆、虎皮楠、密花山矾、尖叶杨桐等7种为优势种。华润楠在0~2.5 m尺度上表现为聚集分布,2.5~4.0 m为随机分布,4.0~6.0 m为均匀分布。马尾松0~25.0 m表现为随机分布。其余物种呈现为小尺度聚集分布,大尺度随机分布。群落内部种间竞争不明显,仍有较大生存空间。  相似文献   

3.
突脉青冈的空间分布格局   总被引:5,自引:0,他引:5  
应用多种方法检验突脉青冈空间分布,结果表明突脉青冈呈聚集分布,符合负二项分布和会曼分布。  相似文献   

4.
甘肃小陇山锐齿栎林空间分布格局分析   总被引:5,自引:0,他引:5  
锐齿栎是小陇山国家级自然保护区主要植被类型,其分布格局是判断林型恢复与否的指标之一。本文通过方差/均值、负二项参数、丛生指数、Cassie指数、聚块性指数等指标对小陇山锐齿栎种群的分布格局进行了分析。结果表明:锐齿栎现阶段年龄结构不合理,属稳定型种群;其分布格局总体属聚集分布,且聚集强度较高,随林分成熟度的升高,聚集强度逐渐下降。  相似文献   

5.
为深入研究广东始兴南山保护区的地带性植被亚热带常绿阔叶林的物种格局特征,在保护区设置了1 hm2的固定监测样地,对样地主要物种的空间分布格局及其关联性进行了研究.结果表明:面积为1 hm2样地中共有94个乔木树种,3359个植物个体,在群落占优势的这4个物种为罗浮栲Castanopsis fabri、栲Castanop...  相似文献   

6.
为深入研究广东始兴南山保护区的地带性植被亚热带常绿阔叶林的物种格局特征,在保护区设置了1 hm~2的固定监测样地,对样地主要物种的空间分布格局及其关联性进行了研究。结果表明:面积为1 hm~2样地中共有94个乔木树种,3 359个植物个体,在群落占优势的这4个物种为罗浮栲Castanopsis fabri、栲Castanopsis fargesii、华南木姜子Litsea greenmaniana和罗浮柿Diospyros morrisiana。华南木姜子和罗浮柿的分布格局主要呈现聚集分布,但罗浮栲和栲的聚集程度较低,物种的分布格局受物种特性和生境异质性的影响。群落主要物种的关联性不明显,整体竞争不明显,群落会继续演替。  相似文献   

7.
以吉林蛟河2块1 hm2阔叶红松林样地全林每木定位数据为基础,运用基于RipleyK (d)函数和Mark相关函数的O-ring统计分析方法,分析了2块样地中红松种群与主要优势种群林分中层与林分上层空间分布格局及树种的空间关联性,结果表明:水曲柳红松林中的红松种群和水曲柳种群在小尺度上为聚集分布的趋势,林分中层的红松种...  相似文献   

8.
采用百度试验法对云南青冈栋(Quercus spp.)板材的干燥特性进行了研究,提出了青冈栎板材的干燥基准并进行了工艺试验。结果表明,制定的干燥基准合适,厚25mm的青冈栎板材从初含水率50%干燥到终含水率7.8%,干燥周期为18d,板材可达一等材国家质量要求。  相似文献   

9.
探索林分形高模型的构建与评价方法,可为湖南省青冈栎林分蓄积量的精准测定提供理论依据。以芦头林场和青羊湖林场的青冈栎次生林为研究对象,基于35个样地的1 055株单木实测数据,建立青冈栎次生林一元、二元林分形高模型。由孔兹干曲线推导出青冈栎树高曲线以计算林分条件平均高,基于林分形高与林分平均胸径、林分条件平均高的一元、二元相关关系,选取6个一元模型和8个二元模型,以决定系数(R2)、均方根误差(RMSE)、解释方差(EA)、平均绝对误差(MAE)和模型预估精度(P1)作为评价指标。经过评估和比较,选定一元林分形高模型为f(D)=2.870 7×D0.261 8、f(H)=2.022 4+0.339 5×H和二元林分形高模型为f(D,H)=0.590 6×exp(-0.008 3×D)×H、f(D,H)=(0.710 2-0.070 1×logD)H和f(D,H)=2.479 9×(D2×H)0.109 2。通过留一交叉验证和配对T检验对模型进行检验,结果显示一元、二元林分形高模型...  相似文献   

10.
【目的】以云冷杉红松林(Spruce-fir-Korean pine forest)为研究对象,探究林隙干扰后优势种群之间的关系。【方法】基于凉水国家级自然保护区外业调查的基本数据,利用点格局分析方法对优势种群的空间格局进行分析,利用χ2检验和联结系数AC两种方法对优势种群的种间关联性进行分析。【结果】1)红松Pinus koraiensis在空间尺度为0~1.9 m时呈现随机分布,在≥1.9 m时为聚集分布。臭冷杉Abies nephrolepis、白桦Betula platyphylla和红皮云杉Picea koraiensis在所有尺度上均表现为聚集分布,紫椴Tilia amurensis在尺度为0~35 m时呈现聚集分布,在>35 m时为随机分布。2)红松与臭冷杉在所有尺度上均为聚集分布,红松与其他优势种群多为离散分布,红松与其他优势种群的种间关联性表现为无关。臭冷杉与白桦、紫椴在空间格局上主要为聚集分布,种间关联性为极显著负相关,表现为强烈的竞争关系。臭冷杉与红皮云杉在小尺度表现为离散分布,大尺度上为随机分布,种间关联性为不显著的正相关,说明其间的依赖性不强。白桦、红皮云杉和紫椴3种优势种群之间的空间格局主要为聚集分布,红皮云杉与白桦、紫椴与红皮云杉之间的种间关联性为显著负相关,白桦与紫椴之间为显著正相关。【结论】2个树种中优势度较高的树种的胸径决定了其空间格局的聚集程度以及种间关联性的显著程度,即平均胸径大的树种与其他树种表现为空间上离散,平均胸径小的树种之间表现为空间上聚集。  相似文献   

11.
ABSTRACT

The management of non-native tree species in European forests has a long history, but the information on the current number and geographic distribution of these species in European forests is incomplete and scattered across various datasets. This study aims to perform an inventory of the most frequent non-native tree species growing in European forests and analyse their current extent, geographic distribution and geographic origin. Our results show that at least 150 non-native tree species are currently growing in European forests and provenance trials. The genera represented by largest number of species are Eucalyptus, Pinus, Acacia and Abies. Species growing at the largest areas are Robinia pseudoacacia (2.44 million ha), Eucalyptus globulus (1.46 million ha), Picea sitchensis (1.16 million ha) and Pseudotsuga menziesii (0.83 million ha). In total, non-native tree species in Europe are found in an area of approximately 8.54 million ha, or 4.0% of the European forest area, and the five most abundant species account for up to 77% of this area. The largest number of these 150 species were introduced from North America (71), followed by Asia (45) and Australia (20). North American species occupy by far the largest area.  相似文献   

12.
Analyzing spatial patterns in plant communities may provide insights in the importance of different processes for community assembly and dynamics. We applied techniques of spatial point pattern analysis to data from a fully mapped plot of a temperate forest community (Corylus avellana, Crataegus monogyna, Fagus sylvatica, Ilex aquifolium and Taxus baccata) in North-western Spain to conduct a community wide assessment of the type and frequency of intra and interspecific spatial association patterns. We first explored the overall intra and interspecific patterning, and then classified the types of association patterns at various neighbourhoods. By conditioning on the larger scale pattern we then explored small-scale (0–15 m) intraspecific and interspecific patterns. Association patterns varied from strong positive association at small scales to, as a by-product, repulsion at intermediate scales. Surprisingly, there were no negative associations at small scales, but trees were arranged in multi-species clumps, up to 2.5 m in diameter and comprising a few individuals. Ilex and Corylus, the understorey species, were frequently involved in the clumps, showing positive small-scale association with the other tree species. Our analyses highlighted that animal mediated seed dispersal, interspecific facilitation and perturbation processes may operate successively to shape tree distributional patterns, although their relative importance vary among species. Given the complexity of the patterns described and the current threats to some of the species studied, directed experiments in the field are needed to further elucidate some of the hypotheses derived.  相似文献   

13.
光照强度对青冈栎容器苗生长和生理特征的影响   总被引:4,自引:0,他引:4  
研究不同光照强度(100%,60%,40%,20%,5%透光率)青冈栎容器苗形态和生理特征.结果表明:不同光照强度下,青冈栎容器苗地径、生物量、质量指数等参数差异达显著水平,其值由高到低分别为100%,60%,40%,20%,5%处理.随着透光率的增加,Chla/Chlb,Car/Chl、根质量比、比叶质量呈现上升趋势,色素(Chla,Chlb,Car)含量、比叶面积、叶质量比呈现下降趋势.遮荫明显增加青冈栎叶片电子传递的量子效率(ΦPSⅡ)和光化学猝灭系数(qP),全光照处理青冈栎叶片ΦPSⅡ只有0.131,而5%光强的处理中叶片ΦPSⅡ达到0.701,5%光强的处理中叶片qP为0.925,全光照下的处理中叶片qP为0.32.遮荫降低非光化学猝灭系数(NPQ),全光照处理青冈栎叶片非光化学猝灭系数NPQ为2.54,而5%透光率处理非光化学猝灭系数为0.16.随着透光率的提高,青冈栎叶片丙二醛( MDA)含量呈现下降趋势,游离脯氨酸含量(Pro)呈上升趋势.青冈栎为喜阳性树种,但也具有耐荫性.  相似文献   

14.
白石砬子自然保护区森林植被和主要树种分布的环境解释   总被引:1,自引:0,他引:1  
应用典范对应分析(CCA)对辽宁东部白石砬子国家级自然保护区56个样地中的森林植被和44种主要树种与8个环境因子间的关系进行了研究。结果表明,海拔高度、样地坡度、土壤有机质、林冠都闭度和土壤酸度是影响白石砬子森林树种和植被分布的主要因素。结合双向指示种分析(TWINSPAN),在CC样地一环境因子双序图上区分出8个样地组,分析了8个样地组的植被成员组成及其分布与环境因子间的关系。  相似文献   

15.
光皮桦与青冈栎苗期生理生化特性研究   总被引:2,自引:0,他引:2  
对光皮桦和青冈栎幼苗进行硝酸还原酶活力、氨基态氮含量及全氮含量测定,结果显示光皮桦的三项生理生化指标均明显高于青冈栎。硝酸还原酶活力在光皮桦各营养器官中的分布大小是叶>根>茎;在青冈栎各器官的分布是叶最高,茎其次,根最低。氨基态氮含量在两树种的分布情况与硝酸还原酶活力类似。生长盛期的硝酸还原酶活力及氨基态氮含量达到高峰。研究表明光皮桦的氮素同化能力和贮藏能力高于青冈栎,因此营养生长旺盛。  相似文献   

16.
为比较秃瓣杜英Elaeocarpus glabripetalus和青冈Cyclobalanopsis glauca对酸雨胁迫的抗性强弱及差异,通过盆栽法,以蒸馏水(pH值7.0)处理作为对照组,研究在轻度酸雨(pH值5.6)、重度酸雨(pH值2.5)胁迫下,秃瓣杜英和青冈的光合指标、叶绿素和生物量差异。结果表明:1)在无酸雨胁迫下,秃瓣杜英和青冈的最大净光合速率(Pnmax)、暗呼吸速率(Rd)、光饱和点(LSP)、光补偿点(LCP)无显著差异。2)在轻度酸雨胁迫下,秃瓣杜英的Pnmax和LSP显著升高(P <0.05),叶绿素a、叶绿素b、叶绿素a+b的含量以及茎干质量、根干质量、总干质量指标都显著下降(P <0.05),其他参数无显著变化;青冈的Pnmax、Rd、LSP、叶绿素a、叶绿素b和叶绿素a+b的含量以及叶干质量、根干质量、总干质量都显著下降(P <0.05),其他参数无显著变化。3)在重度酸雨胁迫下,秃瓣杜英的Pnmax和LSP进一步升高(P <0.05),叶绿素a、叶绿素b和叶绿素a+b的含量以及生物量指标都进一步显著下降(P <0.05),Rd和LCP出现显著下降(P <0.05),其他参数无显著变化;青冈幼苗的Pnmax、Rd、LSP以及叶干质量、根干质量、总干质量指标都显著低于对照组(P <0.05),但叶绿素a含量显著增加(P <0.05),其余参数无显著变化。综上可得,秃瓣杜英与青冈相比更能适应在酸雨环境下生存,具有更为成熟的酸雨防御机制,而青冈对酸雨表现更为敏感。  相似文献   

17.
The nitrogen (N) cycling was elucidated in a 40-year-old subtropical evergreen broad-leaved forest dominated by Cyclobalanopsis glauca growing on red soil in Zhejiang Province, East China. The concentrations of N in the representative species ranged from 0.49% to 1.64%, the order of which in various layers was liana and herb layers > understory layer > tree and subtree layers; in various organs was leaf > branch > root > trunk; and aboveground parts > underground parts. The sequence of the concentrations of N in C. glauca was understory > tree > subtree layer; young and high-growing > old organs; reproductive > vegetative organs. Seasonal dynamics of the concentrations of N in C. glauca in the tree and subtree layers was comparatively stable. It was lower in autumn (October) in root, branch, and leaf in the tree layer, and low in January in the understory. There was no evident change in regularity of the concentrations of N in varying diameter classes. The concentrations of N in the litterfall, precipitation, throughfall, litter layer, and soil were 0.74%–2.30%, 0.000,038%, 0.000,09%, 1.94%, and 0.59%, respectively. The standing crop of N in the plant community was 1,025.28 kg/hm2, accumulation in the litter layer was 224.88 kg/hm2, and reserve in the soil was 55,151 kg/hm2. Annual retention of N was 119.47 kg/hm2, return was about 84.13 kg/hm2, among which litterfall was 78.49 kg/hm2 and throughfall, 5.64 kg/hm2. Annual absorption of N was 203.60 kg/hm2. Annual input of N through incident precipitation was 4.88 kg/hm2. Compared with other forest types, cycling rate of N in the community was lower than in deciduous broad-leaved forests, rain forests, and mangroves, and was moderate in evergreen broad-leaved forests. N use efficiency of this forest was moderate among the forest types cited. According to the characteristics of the biocycle of phosphorous, it was concluded that N availability in the soil of this forest was not lower, and phosphorous not N was the limiting factor in the growth of plants in this community. __________ Translated from Acta Ecologica Sinica, 2005, 25(4): 740–748 [译自: 生态学报, 2005, 25(4): 740–748]  相似文献   

18.
根据所调查样方的树种综合优势比值,对广东西部(粤西)廉江谢鞋山次生季雨林最重要的三个建群树种,进行了空间格局分析。分析方法采用了Poisson分布、负两项分布、Neyman分布的频次比较模型和聚合度指数测定以及Taylor指数和 Iwao's 方程模拟。结果表明这三个建群种均符合聚集分布。荔枝(Litchi chinensis )和山杜英(Elaeocarpus sylvestris)两种群有基本型聚集分布的特点并表现出个体间的聚集现象。橄榄(Canarium album)有可能随着密度的增大而趋于均匀分布。树种的空间分布格局依赖于其繁殖特性之外,还受该次生季雨林保护的影响。这些主要建群种的空间格局表明进行该林区保护的迫切性。  相似文献   

19.
Water is the key factor in vegetation growth in a loess area. Researchers have been keen on the study of tree transpiration for a long time. To provide a scientific basis and practical instruction for vegetation reconstruction and recovery in a loess area, the paper measured and calculated the water consumption of potted Platycladus orientalis, Robinia pseudoacacia, Armeniaca vulgaris and Pyrus hopeiensis separately during the growing season (from Apr. to Nov.). The four were the main afforestation species in a loess area of western Shanxi based on the principle of water balance. Using data on soil water dynamics and the range of available moisture on potted mature trees, the relationship between water supply and consumption and soil moisture availability and deficit state were analyzed. Several conclusions are listed as follows: 1) In the dry year (2002), during the growing season the precipitation was 430.7 mm and the water consumption of potted trees was from 430 to 490 mm. More water consumption and less available water supply occurred, showing a serious water deficiency. In the rainfall-rich year (2003), during the growing season the precipitation was 870.2 mm and the water consumption of potted trees was from 480 to 515 mm. Due to the uneven distribution of rainfall, the water budget balance was slightly affected in May and November. 2) The curves of soil water content of different species had similar annual changes, although the trends were different in the same month, and those of the same tree species in different test plots also had different trends in the same month. 3) Non-available soil water content of Platycladus orientalis, Robinia pseudoacacia, Armeniaca vulgaris and Pyrus hopeiensis was less than 8.0%, 8.4%, 9.2% and 9.7% respectively, which indicated that Pyrus orentalis used water more efficiently than the others. In the dry year (2002), for several months, soil water content of potted trees was lower than its threshold value for non-available soil water content, which could influence the healthy growth of trees. After supplements of precipitation of winter in the year and spring in the next year, soil water content was higher than the lower limit of soil readily available moisture content, which implied that a balance between inter-annual water supply and consumption could be maintained. __________ Translated from Scientia Silvae Sinicae, 2006, 42(9): 18–23 [译自: 林业科学]  相似文献   

20.
IntroductionUnderstanding the distribution patterns of biomassalong environmental gradients change from swampsthrough ecotones to forests is vital not only for revealing the law of ecotoneal community structure,function and succession, but also for conserving andmanaging ecotoneal communities. Research resultsshowed that conditions stressful in other environments might increase primary production in plantsadapted to wetland ecotones. For example, Sharmaand Gopal (1977) studied biomass structu…  相似文献   

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