辽宁省东北红豆杉天然种群特征研究

东北红豆杉是国家Ⅰ级重点保护野生濒危物种。通过对辽宁省现存东北红豆杉的地理分布特征、种群数量以及种群结构进行调查分析,结果表明:辽宁省天然东北红豆杉仅存60株;在5个区域呈相对集中分布;个体林木胸径分布在6cm以下;种群结构不均衡,通过自然繁育困难。亟待加强保护和人工促进种群恢复。     

天然东北红豆杉种群生殖力与开花结实特性

在黑龙江省穆棱东北红豆杉自然保护区,路线踏查到271株天然东北红豆杉,选择其中具有生殖活力(开花)的29雄株和30雌株作为样株,采用标准枝法对孢子叶球和结实状况及其与生态因子关系进行研究.结果表明:现实东北红豆杉天然种群中,♀♂性比为1:2;天然东北红豆杉有性生殖持续时间长,雄株胸径在1.5～92cm,雌株胸径在9.5～68.1 cm保持生殖状态,雄株较雌株早约20年进入花期;天然东北红豆杉小孢子叶球数量平均为大孢子叶球数量的3倍,大孢子叶球转化为果实的数量不足1/10,孢子叶球数量、结实数量与样株的胸径、冠幅、树高显著相关,与其他立地因子相关不显著;孢子叶球数量在冠层间的分布呈现由上至下的递减规律,而结实数量在冠层间沿中、上、下递减,结实率沿冠层自上而下递增;孢子叶球与结实数量在树冠不同朝向上也呈现出一定的特点,但总体上差异不显著.天然东北红豆杉的上述生殖特征的形成,既是物种本身与环境相适应的结果,也有动物和人类活动的影响.     

海南霸王岭坡垒分布格局初步研究

通过实地调查,对坡垒随地形因子(海拔、坡向、坡度)的分布规律进行了分析。结果表明,坡垒分布主要集中在中低海拔600~900 m,先随海拔增高而增加,海拔700~800m时候达到最高值,随后随海拔升高而减少;不同坡向对坡垒数量分布影响为:北坡西南坡东北坡南坡西北坡西坡东南坡东坡,阴坡上分布的坡垒数显著高于阳坡上的分布数量;坡垒集中分布在坡度20~25°范围内。可见坡垒的分布格局与海拔、坡向及坡度密切相关。     

天山南坡红果小檗种群特性及其与地理变量关联性分析

以焉耆县霍拉山临时样地数据为基础,研究了红果小檗种群特性,通过不同生境类型分析红果小檗与地理变量的关联性。结果表明:红果小檗种群平均密度为75.6株/hm2;海拔750~920 m的阳坡带为其分布主生境;其空间格局介于随机到成群分布之间;长势有明显的生境差异,山谷带为最佳;红果小檗喜坡度较小的生境类型,群落多度受海拔、坡度影响明显;冠幅大小随坡位变化具有一定的梯度变化趋势。     

东北红豆杉不同性别基因组的RAPD标记

东北红豆杉(Taxus cuspidata)具有很高的观赏价值、药用价值及保健价值(杨波等,2007).红豆杉属植物种群竞争力弱,天然更新缓慢和地理分布局限等客观因素,导致其处于濒危状态,1999年被列为国家一级保护植物(叶水英,2006).红豆杉属为雌雄异株,据周志强等(2009)对天然东北红豆杉种群生殖力进行调查研究结果,东北红豆杉天然种群中,雌雄性比为1:2,雌株和雄株的生殖生存特点不同;张春雨等(2009)通过树木年轮学方法,发现雄株生长速率显著大于雌株,这可能是种群维持自身长期发展的一种适应.这说明东北红豆杉的性别分化及其机制有深入研究的价值.目前对于东北红豆杉性别的鉴定还停留在东北红豆杉雌株结实的阶段,还没有对东北红豆杉早期性别鉴定的有效方法.21世纪以来分子标记技术的应用为很多植物的遗传多样性以及性别相关基因的研究提供了可靠的技术支撑.     

石门国家级森林公园植被垂直分布规律研究

对石门国家级森林公园植被垂直分布按100 m垂直海拔高度分段进行调查和分析,并对植被垂直分布规律进行研究。结果表明,植物群落指数在总体上是随着海拔上升呈下降趋势;在海拔、坡度、坡向3个因子中,海拔因子是对群落分布影响最大的生态因子。     

黑龙江省穆棱东北红豆杉种群结构与分布格局

2005年4月对黑龙江省穆棱东北红豆杉(Taxus cuspidata Sieb.etZucc.)天然林分的组成结构、立地条件、及种群年龄结构。进行了调查研究。结果表明,该地区东北红豆杉种群生存的林分结构以天然针阔混交林为主,土壤含水量较高(40%-60%),pH值偏酸(4.7~5.5);野生东北红豆杉的种群结构不合理,属于衰退种群,这也是导致野生东北红豆杉种群下降的原因之一。虽然穆棱地区的立地条件适合东北红豆杉野生种群的生长,但目前成年东北红豆杉树干中空、腐烂,中等胸径的健壮成年树被盗伐,而且幼树经常被野生动物啃食,该地区东北红豆杉的种群仍然是下降趋势,处于濒危状态。     

陕西周至国家级自然保护区红豆杉资源调查

红豆杉在周至保护区有一定数量的野生资源分布,采取现地核实法对其分布数量,种群结构、更新状况和生境因子进行调查研究,掌握保护区红豆杉的珍稀濒危状况,使其得到更好的保护和利用。     

巴山北坡不同干扰条件下栓皮栎种群结构与动态

对巴山北坡2个干扰环境下的栓皮栎种群结构、数量动态和空间分布格局进行对比研究.种群A分布于较低海拔地区,距离居民点近,持续受到砍柴、放牧等强烈干扰,群落发育较差;种群B分布于较高海拔,远离居民点,受人为干扰少,群落发育较好.结果表明:A种群的更新能力较弱,幼龄个体数量少,并以萌生起源幼龄个体占优势,呈现衰退势态,种群B更新能力较强,幼龄个体数量丰富,以实生起源个体占优势,呈现持续发展势态;2个种群存活曲线均属于Deevey Ⅲ,在Ⅰ-Ⅲ龄期,幼苗死亡率最高;萌生苗在资源利用方面占有明显优势,在幼苗到幼树的生长转化过程中,比例逐渐增大;不同生境栓皮栎种群幼苗、小幼树、大幼树和大树均呈聚集分布,但种群聚集强度均随着年龄的增加而逐渐减小;对影响栓皮栎种群生长和发育的环境因素主成分分析表明,人为干扰是最主要的影响因子.在未来的经营和管理中,低海拔地区应尽量减少人为干扰和间伐频次,保留足够数量的结实母树,促进种群结实及种子成苗;应适时对高海拔地区种群进行抚育,间伐非目的树种,调整环境因素和种间关系.促进天然条件下种群结实和种子成苗.     

浅析本溪县东北红豆杉的现状及保护措施

红豆杉是我国一级保护树种,也是具有极大药用价值的濒危保护树种,特别是近年来通过开发利用,使其在市场上的价格不断飙升。在经济利益推动下,人为破坏情况日益突出,使其数量减少,步入了濒危状态。通过调查基本查清了本溪县境内野生东北红豆杉的种群数量、分布、生境状况等,分析了东北红豆杉保护现状,存在的主要问题,提出了加强对野生东北红豆杉资源的保护、管理和利用措施。     

Population structure and distribution pattern of Taxus cuspidata in Muling region of Heilongjiang Province, China

An investigation was conducted on distribution pattern, site condition and population structure of yew Taxus cuspidata Sieb. et Zucc. in Muling Forest Bureau of Heilongjiang Province, China in April, 2005. Results showed that yew is mainly distributed under the main storey of natural mixed forest of conifer and broadleaf, the soil moisture content of the yew site is high （40%-60%）, the pH value of soil is relatively lower （4.7-5.5）, and that the population structure of wild yew is not rational, belonging to the degeneration population, which is one of the reasons leading to the population decline. Although the site conditions of Muling area are suitable for the growth of wild yew, the population of wild yew shows a decline tendency, due to the fact that the middle-sized adult yew trees have been cut, young yews are often grazed by wildlife, and that the trunks of adult yew tend to be hollow.     

封山育林对小兴安岭东部地区蒙古栎林主要乔木种群径级结构的影响

在黑龙江省小兴安岭东部地区(东经444-4726 N?北纬2633-13141? 海拔400-1000 m), 对不同封育时间、不同坡向的蒙古栎林中的主要乔木树种径级结构进行分析。在阳坡,针对封育5年 16年和24年蒙古栎种群, 分别选择6个重复样地。在阴坡,也同样分别选择6块样地。每块样地的面积为20 m×20 m。在每块样地中, 测量各树的胸高直径,树高和冠幅直径。结果表明:在封育5年样地内,蒙古栎、糠椴和黄榆种群的数量均随着径级的增加而单调下降,表明均为增长型种群;在封育16年以后,由于林内乔木层的盖度较大,糠椴和黄榆种群均呈不同程度的衰退,已经成为蒙古栎种群的伴生种群;封育24年样地中,蒙古栎种群明显成为优势树种。在阳坡随封育时间延长乔木层盖度增长较快,而阴坡乔木层盖度增长较慢;糠椴和黄榆种群随封育时间延长逐步衰退的现象在阳坡比阴坡表现明显。图2表1参8。     

Spatial distribution of soil carbon and nitrogen storage and forest productivity in a watershed planted to Japanese cedar (Cryptomeria japonica D. Don)

Digital terrain modeling was used to evaluate landscape-level spatial variation of soil C and N storage and site productivity in Japanese cedar (Cryptomeria japonica D. Don) stands. Soil C and N storage were measured in samples from surface soils (0–25 cm depth) of 29 Japanese cedar stands in the 205-ha Myougodani watershed, Toyama Prefecture. The site index (C. japonica tree height at age 40 years) was used as a measure of forest productivity. Seven terrain attributes (elevation, slope gradient, aspect, profile curvature, plan curvature, openness, and wetness index) were calculated from a digital elevation model. Soil C and N storage were negatively correlated with slope gradient and positively correlated with openness. Variation in the site index was closely related to the wetness index. The prediction models using terrain attributes as explanatory variables explained 50% of the variability in soil C storage, 53% of the variability in soil N storage, and 75% of the variability in site index. This result demonstrated that this technique is useful for estimating the spatial distribution of soil properties and productivity in forest landscapes. On the other hand, there was no correlation between site index and soil C and N storage. Use of the prediction models in a geographic information system revealed that the spatial distribution of forest productivity differed considerably from those of soil C and N storage.     

老挝北部5省橡胶林提取及时空扩张研究

[目的]分析老挝北部"金三角"地区橡胶林提取方法及橡胶林时空扩张特征,为合理规划橡胶种植、区域生态环境保护等提供方法和依据。[方法]基于MODIS影像和橡胶林物候特征,选取不同地类特征参数,实现橡胶林空间分布快速可重复的决策树提取新方法,并基于单一土地利用率模型研究橡胶林扩张机制。[结果](1)橡胶林提取时间窗口为1月至3月,基于不同地类特征参数生成的橡胶成林、幼林决策树提取方法总精度为80.67%,高分一号影像通过面向对象方法验证MODIS影像提取结果精度可靠。(2)2010—2015年,老挝北部5省橡胶林由12.6万hm~2扩张到16.96万hm~2,面积变化率最大的是乌多姆赛省,丰沙里省扩张速度最慢。[结论]MODIS影像提取橡胶林方法和结果简单有效。橡胶林分布在海拔和坡度上呈现不断上升的趋势,海拔1 500 m以上零星分布,坡度上分布上限为35°,而坡向扩张无明显规律。从LUCC视角分析得到橡胶林时空扩张的主要影响因素是社会政策和经济因素。     

Comparison of ecological condition and conservation status of English yew population in two Austrian gene conservation forests

English yew Taxus baccata L. has been catalogued as endangered tree species and prone to extinction in Austria as well as many other parts of Europe. The present work is based on the comparison of the natural population of two gene conservation forests from different geographic locations in Austria where the spatial structure, regeneration status and possible conservation measures are examined. The pole stand distribution varied distinctly in each sites. The total no of individuals per ha （DBH ≥5 cm）, average DBH and average height were 492 n.hm^-2, 8.8 cm and 6.3 m in Stiwollgraben whereas in Leininger Riese 45 n.hm^-2, 16.3 cm and 7.6 m respectively. Over 79% of the Stiwollgraben population were represented the good health condition, while in Leininger Riese it was less then 49 % which means population of Stiwollgraben is in better condition compared to Leininger Riese. The sites differed considerably in the pattern of regeneration but pattern were consistent with the dynamics depicted by the age distribution. Considering the one-year-old seedlings Stiwollgraben contains 13 019 individuals.hm^-2 whereas Leininger Riese only 1 368. Surprisingly there were no any saplings in respect of 51 to 150 cm height classes in both sites and 30 to 50 cm in Stiwollgraben. In that context the conservation of English yew on the forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species.     

Altitudinal variability of stand structure and regeneration in the subalpine spruce forests of the Pol’ana biosphere reserve,Central Slovakia

The structure of natural subalpine spruce forest in the Zadná Pol’ana massif of the Western Carpathians was analysed. We focused on the variability of different aspects of stand structure, tree decay and regeneration processes in altitudinal gradient. We used systematic sampling, covering an area of 2 km², to detect even subtle changes in stand structure within one forest type over a range of less than 200 m in elevation. Mean stand density was 290 trees (>7 cm DBH) per hectare, average basal area was 41 m² ha⁻¹, and the volume accumulation in living trees amounted to 500 m³/ha⁻¹. Stand volume decreased by more than 50% between 1,260 and 1,434 m a.s.l. This means for an increase of altitude of 100 m that stand volume decreased by nearly 200 m³. Neither stand density nor basal area was related to elevation. Maximum tree height was strongly correlated to elevation, and it decreased on average by 6 m for each 100 m increment of altitude. No significant changes in the maximum spruce diameter were recorded in relation to the elevation gradient. Spatial distribution of trees was biased toward regularity at lower altitudes. Tree clustering increased with increasing altitude. The stock of coarse woody debris (CWD) decreased slightly along the altitudinal gradient, but changes were not significant. Density of spruce saplings and their number growing on CWD significantly increased across the elevation gradient. Despite the fact that the analysed forest tract was relatively large, highly variable in respect to environmental factors, and that stand volume, spatial structure, and tree height displayed strong variability along the elevation gradient, the diameter structure of stands and regeneration measures were uniform. Our results suggest that the recruitment of new trees in the Zadná Pol’ana subalpine spruce forest is not temporally continuous even at a scale of several square kilometres.     

Structural diversity of English yew (<Emphasis Type="Italic">Taxus baccata</Emphasis> L.) populations

In Europe, the English yew species (Taxus baccata L.) is endangered. Intensive human land-use, including forest management, has caused a decrease of the yew populations all over Europe. In Austria, gene conservation forests are used for the in situ conservation of populations of this rare tree species by silvicultural treatments. In order to improve the conservation management in these gene conservation forests, this study addresses the relation between competition and viability of yew populations through the use of structural diversity indices. The structural indices, which include mingling, tree–tree distance, diameter, and tree height differentiation, were determined for a structural group of four trees as well as the neighbouring trees of the male and female yews at the monitoring plots on a regular grid in three gene conservation forests. Although the three study sites provided quite different environmental conditions for English yew, the vitality of each individual yew was influenced by the inter-specific competition of the neighbouring tree species at all sites. Low vitality was associated with a small mean distance to neighbours and large tree height differentiation. In conclusion, we suggest that a combination of different structural indicators is needed for an integrative assessment of conservation status in the gene conservation forests. This would help improve the evaluation of the impact management has on yew population viability.     

Extractable sulfate content in Japanese forest soils

The amounts of extractable sulfate in 12 forest soils were measured as a preliminary work to study sulfur dynamics in forest ecosystems. The sulfate content determined by the distillation method varied widely (10–880 × 10⁻⁶ gSg⁻¹) depending on the soil type and the depth. Japanese forest soils were broadly divided into two groups in sulfate level: one retains a large amount of sulfate and the other does not. In general, the surface soils to the depth of 10 cm contained small amounts of sulfate (< 100 × 10⁻⁶ gSg⁻¹), while subsoils contained more. The soil samples with low (< 4.6) or high (6 <) pH (H₂O) retained small amounts of sulfate. Black soils derived from volcanic ash retained great quantities of sulfate. The two levels of sulfate contents in Japanese forest soils suggests that the sulfur dynamics are different in these soils.     

Blackening of Diospyros genus xylem in connection with boron content

The amount of boron contained in the xylem of Japanese persimmon (Diospyros kaki Thunb.) and ebony (Diospyros ebenum Koen) was determined by inductively coupled plasma (ICP) emission spectrometry and a modified curcumin–acetic acid method. The boron content was compared between the heartwood and sapwood of ebony as well as between a blackened portion (“kurogaki”) and normal portion of Japanese persimmon. The kurogaki contained a higher level of boron than the normal portion of the same individual, although the boron content varied among individuals. Moreover, the boron content of the heartwood of ebony was much higher than that of the sapwood. These results suggest the participation of boron in the blackening of Japanese persimmon. Because both kurogaki and heartwood of ebony are durable to fungal attack, the blackening of Diospyros genus appears to be related to the formation of defensive substances in which boron seems to take part. The convenient curcumin–acetic acid method is an alternative to the ICP method with comparable accuracy.     

Simulation of soil water dynamics in a Caragana intermedia woodland in Huangfuchuan watershed

As vegetation coverage increases, soil water content can decrease due to water uptake and evapotranspiration. At a very high level of plant density, poor growth and even mortality can occur due to the decrease of soil water content. Hence, a better understanding of the relationship between soil water content and the density of plants is important to design effective restoration projects. To study these relationships, we developed a soil water dynamic simulation model of a Caragana intermedia woodland under different slope gradient and slope aspect conditions in the Huangfuchuan watershed on the basis of the previous studies and field experiments. The model took into account the major processes that address the relationships of plants and the environment, including soil characteristics, precipitation, infiltration, vegetation transpiration, and soil evaporation. Daily changes in soil water content, transpiration, and evaporation of the Caragana intermedia woodland with different vegetation coverage, slope gradient, and slope aspect were simulated from 1971 to 2000. Based on the model simulations, we determined the functional relationships among soil water content, plant coverage and slope as well as the optimal plant density on flat slopes. We also determined the effects of slope gradient and slope aspect on soil water content. When slope gradient was less than 10°, the optimal plant density was sensitive to slope gradient. In the slope range from 10° to 30°, plant density was not sensitive to slope gradient. Therefore, it is important to consider planting densities on the hillsides with slope gradients less than 10° for reconstructing vegetation. __________ Translated from Acta Phytoecologica Sinica, 2005, 29(6): 910–917 [译自: 植物生态学报]