Point pattern analysis of different age-classes of Larix principis-rupprechtii in Luya Mountain Reserve, Shanxi Province, China

Larix principis-rupprechtii forest is an important vegetation formation and has a large distribution area in Luya Mountain Reserve, China. Spatial pattern analysis on individual trees in different age-classes of Larix principis-rupprechtii was made in this paper. Here, we employed the technique of point pattern analysis, which could analyze patterns under all scales along a gradient. It was based on spatial mapped points of individual distribution. The results of this study showed that the densities of the five age-classes varied in the order: age-class 3 > age-class 4 > age-class 5 > age-class 2 > age-class 1. Although age-classes 1 and 2 have much fewer individuals than other three age-classes do, the population was stable at present. However, it would be necessary to take some measures for improving population regeneration for a long-time view. The individuals of all age-classes focused on clumping distribution in space; however, their distribution pattern varied with the change of scale. This mainly depended on biological features of Larix principis-rupprechtii and forest environments, but it also meant that the scale was an important factor in controlling spatial distribution pattern of tree individuals. The feature of clumping distribution became more significant with the increase of age. The relationships between individuals in different age-classes were almost all significantly correlated with each other. These associations became more significant within the older age-classes. This suggested that the individuals of different age-classes were interdistributed, by which the population could get benefits in resource utilization. The technique of point pattern analysis is effective and easy to be used in species pattern study. Its results are more closer to the reality, especially for community structure. Translated from Acta Ecologica Sinica, 2004, 24(1): 35–40 [译自: 生态学报]     

Point pattern analysis of different age-classes of Larix principis-rupprechtii in Luya Mountain Reserve, Shanxi Province, China

Larix principis-rupprechtii forest is an important vegetation formation and has a large distribution area in Luya Mountain Reserve,China.Spatial pattern analysis on individual trees in different age-classes of Larix principisrupprechtii was made in this paper.Here,we employed the technique of point pattern analysis,which could analyze patterns under all scales along a gradient.It was based on spatial mapped points of individual distribution.The results of this study showed that the densities of the five age-classes varied in the order:age-class 3＞age-class 4＞age-class 5＞age-class 2＞age-class 1.Although age-classes 1 and 2 have much fewer individuals than other three age-classes do,the population was stable at present.However,it would be necessary to take some measures for improving population regeneration for a long-time view.The individuals of all age-classes focused on clumping distribution in space;however,their distribution pattern varied with the change of scale.This mainly depended on biological features of Larix principis-rupprechtii and forest environments,but it also meant that the scale was an important factor in controlling spatial distribution pattern of tree individuals.The feature of clumping distribution became more significant with the increase of age.The relationships between individuals in different age-classes were almost all significantly correlated with each other.These associations became more significant within the older age-classes.This suggested that the individuals of different age-classes were interdistributed,by which the population could get benefits in resource utilization.The technique of point pattern analysis is effective and easy to be used in species pattern study.Its results are more closer to the reality,especially for community structure.     

长白落叶松半同胞家系生长和木材性状遗传变异与联合选择

长白落叶松（Larix olgensis）是我国东北重要的用材树种,根据生长和木材性状对其进行综合选择至关重要。本研究以吉林省延边自治区汪清林业局32年生的49个长白落叶松半同胞家系为材料,对其9个生长性状（树高、地径、胸径、3 m径、材积、尖削度、冠幅、分枝角和通直度）和4个木材性状（木材基本密度、管胞长度、管胞宽度和管胞长宽比）进行测定与分析。结果表明：不同变异来源间所有性状差异均达极显著水平（P<0.01）;各性状家系遗传力均较高（0.51~0.96）;表型变异系数为3.04%（分枝角）~23.15%（冠幅）;各性状相关系数为-0.367（管胞宽度与管胞长宽比）~0.994（胸径与材积）;主成分分析结果表明,4个主成分的累计贡献率达到78.46%,包含了家系生长性状和木材性状的大部分信息;分别以生长和木材性状对家系进行综合评价,初步筛选出5个生长性状优良家系（S78、S81、S80、S84和S83）和5个木材性状优良家系（S37、S51、S6、S30和S19）,结合生长和木材性状初步筛选出5个优良家系（S89、S74、S76、S82和S83）。本研究初选的材料可以为良种选育提供基础,亲本可以为改良种子园营建提供材料。     

First record of the invasive woodwasp,Urocerus albicornis (Hymenoptera: Siricidae), from a local forest in Japan

The woodwasp Urocerus albicornis (Fabricius, 1781) (Hymenoptera: Siricidae) is a forest pest native to North America and occasionally introduced into European countries. One of these invasive woodwasps was collected in a local forest in Nagano Prefecture, Central Japan. The collected individual was an adult female ovipositing on a log from a Japanese larch (Larix kaempferi (Lamb.) Carrière). Although several of these woodwasps have been found on imported logs in Japan, this is the first record of the alien woodwasp in a local forest within Japan and Asia. This finding indicates that a population of this invasive woodwasp may be established in Japanese forests.     

太白红杉群落物种多样性与环境因子的关系

定量研究了太白红杉群落物种多样性与环境因子的关系,结果表明:(1)海拔与物种丰富度和种间相遇机率呈极显著的负相关;与Shannon指数、Simpson指数和Pielou指数表现为"中间高度膨胀"的规律,即中等海拔高度上多样性高而低海拔和高海拔多样性较低。(2)岩石裸露度与物种丰富度呈显著的负相关。(3)土壤含水量与物种丰富度呈极显著的正相关;与种间相遇机率呈先降后升的趋势。(4)环境因子与物种多样性逐步回归结果是:海拔和岩石裸露度与物种丰富度关系密切,其回归方程为:S=90.62-0.02E-14.14B(r=0.769,P<0.05)。     

Importance of permafrost as a source of water for plants in east Siberian taiga

Stable oxygen isotope ratios of plant water (sap water) were observed at Spasskaya Pad experimental forest near Yakutsk, Russia in 1997–1999. The ¹⁸O of sap water in larch trees (Larix gmelinii) decreased soon after leaf unfolding every year, indicating that snowmelt water was used in the beginning of summer. During mid to late summer, a clear difference in the water source used by plants was observed between wet summers and severe drought summers. The ¹⁸O values of water in larch trees were high (–17.8 to –16.1) in August 1999 (wet summer), but low (–20.4 to –19.7) in August 1998 (drought summer). These results indicated that plants used rainwater during a wet summer, but meltwater from permafrost was used by plants during a drought summer. One important role of permafrost is to provide a direct source of water for plants in a severe drought summer; another role is to keep surplus water in the soil until the next summer. If this permafrost system is disturbed by future global warming, unique monotypic stands of deciduous larch trees in east Siberia might be seriously damaged in a severe drought summer.     

长白落叶松激素含量与生长的关系及在早期选择中的应用

用间接酶联免疫吸附法测定了不同季节不同种源长白落叶松激素含量。结果表明：不同季节长白落叶松的激素含量不同,速生期长白落叶松赤霉素、生长素和细胞分裂素含量高,脱落酸含量低,赤霉素／脱落酸比值大,生长缓慢期测定结果恰好相反。各类激素含量在不同种源长白落叶松间的变异显著,且与生长性状的差异密切相关。生长快的种源赤霉素,细胞分裂素含量高,脱落酸含量低,赤霉素／脱落酸之比大。生长慢的种源则相反。回归分析表明     

Somatic embryogenesis and plant regeneration from immature zygotic embryos of Japanese larch (Larix leptolepis)

Embryogenic tissue was initiated using LM, LP and MS media from open-pollinated immature embryos of Larix leptolepis. The initiation frequency varied with collection dates. The highest frequencies of embryogenic tissue initiation (60, 67 and 59% on LM, LP and MS media, respectively) were observed from cones collected on July 30. At this time, all the excised embryos were at the cotyledonary stage. ABA over a wide concentration and length of exposure range did not promote maturation, but was beneficial in reducing precocious germination. Of over 400 plants regenerated, 72 were transplanted into soil mixtures and to date, 69 of these (95%) have survived. This revised version was published online in June 2006 with corrections to the Cover Date.     

地统计学方法在长白落叶松人工林凋落物现存量估测中的应用

采用地统计学的变异函数分析方法定量研究了15年生落叶松(Larix olgensis)人工纯林凋落物层重量的空间异质性特征,利用地统计学的克里格内插法结合定积分,对凋落物层的重量进行了估测.结果表明1)不同分解层次的凋落物重量的变异函数曲线理论模型均为球状模型,空间变异主要是由结构性因素引起,且空间自相关程度均属中等以上(空间结构比＞25%).2)非参数统计的成对样本符号检验结果表明,变异函数分析结果基础上的克里格内插法适用于凋落物重量的估计.利用此估计值,拟合其与位置坐标值之间的多元回归关系均为二元十次余弦级数多项式.利用此多项式,通过定积分的方法(积分区间为整块样地的大小),估计出15年生落叶松人工纯林中凋落物层的未分解、半分解、完全分解和腐殖质层的重量分别为4.7753、5.4129、8.0742、10.9269t hm-2.3)采用地统计学的克里格空间插值,结合多元回归和定积分的方法,可以实现落叶松人工林凋落物层重量的准确估计.     

帽儿山地区落叶松人工林CO2通量特征及对林分碳收支的影响

2008年,采用涡度协方差法测定了黑龙江省尚志市帽儿山地区落叶松人工林的CO₂通量,并于生长季(5—10月)不同月份测定了落叶松叶片光合日变化.结果表明: 不同时间段环境因子变化对落叶松人工林净生态系统交换量的影响存在差异,下午(12:00—24:00) 的净生态系统交换量对其饱和蒸汽压亏缺的变化反应较上午(0:00—12:00)迟钝;上午光能利用效率为0.6284 mol·mol^-1,是下午的1.14倍;随温度上升,上午净生态系统交换量的增幅是下午的1.5倍(气温>15 ℃).这种差异使落叶松林净碳交换量的88%在上午完成,而下午仅完成净碳交换量的12％;上、下午生态系统生产力分别占全天的60%和40%,上午叶片的光合能力为下午的3倍.落叶松人工林全年净生态系统交换量在263～264 g C·m^-2,生态系统呼吸在718～725 g C·m^-2,总初级生产力在981～989 g C·m^-2.