柳杉毛虫卵空间分布型及抽样技术研究

对衢州市柯城区柳杉毛虫卵进行了调查分析,结果表明：该虫卵个体间相互吸引,种群空间分布格局为聚集型,基本成份为个体群,具有一个公共Kc=1．4173的负二项分布。聚集原因是由于昆虫本身的聚集行为所致,或是由于环境异质性和昆虫本身的聚集行为两因素作用结果。有卵枝率（Z）与平均虫口密度（X）关系为：X=0．001 698Z^2.020298,卵集中分布在树冠的下部,其次为中部、上部;理论抽样数为：N=1／D^2（5．12610／X＋0．38137）。     

孪斑唇瓢虫卵块空间分布型和抽样技术研究

用5种聚集度指标对南疆林果有害生物主要天敌孪斑唇瓢虫(Chilocorus geminus Zaslavskij)卵块的空间分布状况进行调查与分析。结果表明:该虫卵块的空间分布符合负二项分布,其空间图式是聚集的,卵块之间相互排斥;最适抽样数N与平均卵密度m及允许误差D的关系为N=(1/D)2[(-0.208/m)+1.704]。     

绿竹林碳,氮动态研究

主要讨论了闽南绿竹（Dendrocalamopsisoldhami）林C、N元素的含量、库存量、年动态及C／N。结果表明：（1）绿竹林各组分C、N元素含量有一定差异,含量范围分别为：C38．74％～44．77％、No．557％～1．012％;C／N在38．281～77．792之间。（2）绿竹林C、N元素的现存库存量分别为6760．0369／m2和112．3979／m2,其中地上部分别为5891．5739／m2和94．101g／m2;地下部分别为868．463g／m2和18．296g／m2。（3）1996年7月至1997年6月一年中绿竹叶的C、N元素含量基本上是在生长期的春末夏初含量高,在冬季含量低：C／N在24．707～38．281之间,在生长期的春季比例低,在冬季比例高。（4）绿竹细根的分解过程中C、N元素含量处于释放或累积的相间波动之中,而C／N在细根分解的前几个月下降,而后处于上升和下降的波动之中。     

祁连山北坡苔藓-青海云杉林优势种空间分布格局研究

用负二项参数（k）、扩散系数（C）、丛生指数（I）、CA值、平均拥挤度（m^＊）、聚块性指标（m^＊／m）等5种聚集度指标判定出祁连山北坡苔藓青海云杉种群的空间分布型趋向于随机分布，再应用Taylor幂法则、Iwao回归方程进行数学拟合，进一步证明祁连山北坡苔藓类青海云杉种群的空间分布型为随机分布。     

大青叶蝉卵痕在果树上的空间分布及其应用

本文采用扩散系数C、负二项分布K值、CA指数等6种聚集度指标测定大青叶蝉卵痕在沙果树上的空间分布，其结果为聚集分布。并用聚集均数λ说明聚集是由种群的生物学特性引起的，同时探讨了空间分布型在序贯抽样中的应用。     

杉木中龄林施肥效应与效益研究

对中亚热带黄红壤上中等立地条件下杉木中龄林的需肥规律、不同施肥配比对杉木径级分布的影响进行了研究，并比较了不同施肥配比的经济效益．结果表明：氮肥肥效最显著，单施N200kg／hm2，可增加蓄积量40．9m3／hm2；磷肥肥效较明显．单施P2O5400kg／hm2，可增加蓄积量31．0m3／hm2；而单施钾肥肥效不明显．P，K肥单施效应明显低于N，NP，PK和NPK肥，尤以处理N2P2K，即每hm2施200kgN，200kgP2O5，200kgK2O为最优，可增加蓄积49．1m3／hm2．以经济效益而论，较好施肥方案为N1（即施肥量为100kgN／hm2），N2（200kgN／hm2），N1p1（100kgN／hm2．100kgP2O5／hm2），N1K（100kgN／hm2，200kgK2O／hm2）和P1K（100kgP2O5／hm2，200kgK2O／hm2），其内部收益率达15％以上．沟施与撤施肥效差异不大．合理的施肥方案可提高杉木大、中径材比例．     

榕片圆蚧雌成虫空间分布型研究

榕片圆蚧雌成虫空间分布型研究曹葵光，潘涌智，吴加林（西南林学院）苏志远，赵谦，苏继祥（凉山州林业局）赵应全（四川省宁南县林业局）本文采用聚集度指标法，包括聚集度指标（Ｉ）、扩散系数（Ｃ）、Ｃ。指数、。１１．”／ｉ指数、扩散型指数（Ｉ。）和Ｉｗａｏ法，...     

山楂叶螨卯在桃树上的空间分布型研究

运用8种聚集度指标对山楂叶螨卵在桃树上的空间分布型进行了研究,所有的指标都表明,山楂叶螨卵的空间分布型呈聚集分布,分布的基本成份是个体群,通过方差分析,山楂叶螨卵在桃树树冠的上、中、下3个层的分布数量差异都不显著。     

山楂叶螨卵在桃树上的空间分布型研究

运用8种聚集度指标对山楂叶螨卵在桃树上的空间分布型进行了研究,所有的指标都表明,山楂叶螨卵的空间分布型呈聚集分布,分布的基本成份是个体群,通过方差分析,山楂叶螨卵在桃树树冠的上、中、下3个层的分布数量差异都不显著.     

黑蚱蝉成虫与卵在柚园的分布规律及抽样技术

研究表明：黑蚱蝉出土若虫蜕壳多在叶背；卵粒聚集基本在1个产卵段，香柚产卵枝长度变异大而直径变异小；丘岗腰部柚园，产卵枝密度大、变异系数大。黑蚱蝉成虫和产卵枝在柚园的分布型为核心分布，是由于种群聚集性或与环境异质性共同作用引起的；分布基本成分均是个体群，个体群聚集分布随着种群密度提高呈线性增加，并渐趋向于随机分布。大田调查，当平均密度〈5只（枝）／株时，取样10～30株，当平均密度〉5只（枝）／株时，取样5～10株。     

弧目大蚕蛾幼虫取食量研究

弧目大蚕蛾Neoris haraldi Schawerda幼虫5龄,平均龄期29.67 d。1龄幼虫取食量较少,平均日取食叶面积为4.25 mm2,2龄幼虫平均日取食叶面积为7.00 mm2,3龄幼虫取食量猛增,平均日取食叶面积为83.06 mm2,4龄幼虫平均日取食叶面积为231.90 mm2,5龄幼虫平均日取食叶面积为278.86 mm2。2龄以前幼虫食量较小,仅占全部食量的1.19%;3龄后幼虫食量占全部食量的98.81%。5龄幼虫日均食量较多,取食天数也达到8 d,占总取食量的52.35%,危害也较2龄以前的幼虫严重。弧目大蚕蛾幼虫头宽、体长、体重、取食量与龄期相关极显著。     

Spatial distribution of leaf dry weight per area and leaf nitrogen concentration in relation to local radiation regime within an isolated tree crown

To assess the spatial distribution of photosynthetic capacity within an isolated 20-year-old walnut tree (Juglans regia L.) crown, the distribution of relevant leaf characteristics was measured. Variations in leaf dry weight per area (W(a)), and nitrogen content on a weight (N(w)) and area basis (N(a)) were studied along two horizontal and one vertical gradients of leaf irradiance, at two dates (July 30 and September 3). In addition, the content of total nonstructural carbon on a weight (TNC(w)) and area basis (TNC(a)) was measured on July 30. Concurrently, the spatial distribution of daily integrated leaf irradiance within the crown was simulated by a three-dimensional radiation transfer model over a one week period before sampling at each date. High spatial heterogeneity was observed for W(a) (from 50 to 140 g m(-2)), TNC(a) (from 4 to 17 g m(-2)) and N(a) (from 1.2 to 3.6 g m(-2)) among the foliage. Although TNC(w) and N(w) were not correlated and only weakly correlated to daily leaf irradiance, respectively, W(a), TNC(a) and N(a) were strongly correlated to daily leaf irradiance. The relationship between observed N(a) and simulated daily leaf irradiance was used to assess the spatial distribution of N(a) within the crown at each date. Total leaf nitrogen in the foliage was estimated to be 339 g in late July and 317g in early September. For the whole crown (i.e., 1729 current-year shoots), N(a) increased strongly with basal shoot diameter (an index of "shoot vigor"), highlighting the fact that large shoots were mainly located in sunlit locations and exhibited high photosynthetic capacity.     

Effects of clump spacing on nutrient distribution and root activity of <Emphasis Type="Italic">Dendrocalamus strictus</Emphasis> in the humid region of Kerala,peninsular India

The humid agroclimatic conditions of Kerala, India permit the cultivation of an array of bamboo species of which Dendrocalamus strictus Roxb. (Nees.) is an important one on account of its high growth rate and multiple uses. Stand density, a potential tool in controlling the productivity of woody ecosystems, its effect on growth and root distribution patterns may provide a better understanding of productivity optimization especially when bamboo-based intercropping options are considered. Growth attributes of 7-year-old bamboo (D. strictus) stands managed at variable spacing (4 × 4 m, 6 × 6 m, 8 × 8 m, 10 × 10 m, 12 × 12 m) were studied. Functional root activity among bamboo clumps were also studied using a radio tracer soil injection method in which the radio isotope ³²P was applied to soil at varying depths and lateral distances from the clump. Results indicate that spacing exerts a profound influence on growth of bamboo. Widely spaced bamboo exhibited higher clump diameters and crown widths while clump heights were better under closer spacing. Clump height was 30% lower and DBH 52% higher at the widest spacing (12 × 12 m) compared to the closest spacing (4 × 4 m). With increasing soil depth and lateral distance, root activity decreased significantly. Root activity near the clump base was highest (809 counts per minute, cpm; 50 cm depth and 50 cm lateral distance) at 4 × 4 m. Tracer study further showed wider distribution of root activity with increase in clump spacing. It may be concluded that the intensive foraging zone of bamboo is within a 50-cm radius around the clump irrespective of spacing. N, P and K content in the upper 20 cm was 2197, 21, and 203 kg/ha respectively for the closely spaced bamboo (4 × 4 m) which were significantly higher than corresponding nutrient content at wider spacings. About 50% of N, P and K were present within the 0–20 cm soil layer, which decreased drastically beyond the 20 cm depth. The results suggest that stand management practices through planting density regulation can modify the resource acquisition patterns of D. strictus which in turn can change growth and productivity considerably. Such information on root activities, spatial and temporal strategies of resource sharing will be helpful in deciding the effective nutrition zone for D. strictus. Further, the study throws light on the spatial distribution of non-competitive zones for productivity optimization yields, especially when intercropping practices are considered.     

秦岭天然华山松林碳素空间分布规律及其动态变化

基于野外调查和实验室仪器分析数据,研究了秦岭天然华山松林生物量、碳密度、碳储量的空间分布及其随龄级、海拔变化的规律。结果表明:碳在华山松各器官中的分配以树干所占比例最大,其次为树枝,树皮最小;不同器官含碳率波动在0.488 6～0.519 8之间,顺序为叶>根>干>枝>皮;华山松林生态系统的生物量碳密度为133.59t/hm~2,其中地下部分(0～80cm)约占2/3,地上部分约占1/3;华山松林生态系统的生物量碳密度在海拔1 800～1 900m最大,达142.73t/hm~2,海拔低于1 700m和超过2 300m,都较小,分别为120.81t/hm~2和107.21t/hm~2;6个龄级的天然华山松林的生物量碳密度以平均树龄20a为最小,60a为最大;通过两期清查数据对比可知,其生物量增加了2.17t/hm~2,生物量碳密度增加了0.64t/hm~2。     

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.     

自然生草桃园表层土壤水分和草地地上生物量的空间分布及其关系

【目的】阐明桃树果园短期自然生草条件下土壤水分空间分布特征及其与草地地上生物量的关系。【方法】以信阳沙壤土五月鲜桃园为研究对象,在冬春季短期自然生草条件下,采用1 m×1 m网格采样法,以经典统计学和地统计学半方差函数为工具,研究表层(0~5 cm)土壤水分和草地地上生物量空间分布特征。【结果】表层(0~5 cm)土壤含水量和地上草地生物量符合正态分布,平均体积含水量为10.08%,95%置信区间为9.84%~10.32%,变异系数为16.36%,0.2 m×0.2 m草地地上生物量均值为9.17 g,变异系数为56.71%。区域田块尺度上,自然生草桃园草地地上生物量和表层(0~5 cm)土壤水分空间分布均符合指数函数模型,模型块金值/基台值分别为0.477 3和0.499 8,变程分别为7.20和2.51。即二者均具有中等程度的空间依赖性,草地地上生物量较表层(0~5 cm)土壤含水量具有更强的空间依赖性。克里格插值结果表明,表层(0~5 cm)土壤含水量和草地地上生物量空间上呈斑块状分布,且表现为距离树体越远值越大的分布特征。相关分析结果表明,地上生物量与表层(0~5 cm)土壤含水量之间极显著正相关(P<0.001)。【结论】果园短期自然生草有利于保蓄表层土壤水分,改善土壤水分条件,草地地上生物量是影响果园表层土壤水分空间分布的重要因素。     

Spatial distributions of tropical tree species in northern Vietnam under environmentally variable site conditions

Ecological interactions of species and thus their spatial pat- terns may differ between homogeneous and heterogeneous forests. To account for this, techniques of point pattern analysis were implemented on mapped locations of tree individuals from two 1-ha tropicalforest plots in Vietnam. We analyzed the effect of environmental heterogeneity on tree distributions; spatial distribution patterns of dominant species; inter-specific associations; and conspecific associations between life stages. Our analyses showed that： environmental conditions were homo- geneous at plot 1 but heterogeneous at plot 2; in both plots, all six domi- nant species were aggregated at various scales up to 30 m, and tree spe- cies were aggregated at larger scales in the homogeneous site than in the heterogeneous site; attraction between pairs of species was remarkably higher at the homogeneous site while negative associations were more frequent in the heterogeneous site; some species, H. kurzii, T. ilicifolia （homogeneous plot） and D. sylvatica, S. wightianum （heterogeneous plot） showed a lack of early life-stage individuals near conspecific adults. Moreover, additional clustering of young individuals was independent from conspecific adults, except D. sylvatica in both sites. These findings are consistent with the Janzen-ConneU hypothesis. Overall, habitat het- erogeneity influences spatial patterns and inter-specific associations of the tree species and evidences of self-thinning are shown in most species.     

Occurrence of Neodolichodorus persiangulfus n. sp. (Nematoda: Dolichodoridae) in mangrove forests of southern Iran

An infestation of mangrove forests with Neodolichodorus persiangulfus n. sp. in southern Iran is reported. This paper is the first to report a representative species of the genus in the country. The new species was characterized by 2,120 (1795–2400) µm long females, and 1755 (1533–2019) µm long males, a continuous to slightly offset cephalic region separated from the rest of the body by a shallow depression, having 5–7 annuli and a distinct labial plate, a lateral field with four lines, the outer ones crenate, irregularly areolated in anterior and posterior body region, 79 (66–85) μm long female stylet, a didelphic‐amphidelphic female reproductive system with asymmetric sclerotized vaginae, phasmids 5–10 annuli behind the anus, female tail elongate conoid, suddenly narrowing at 5–12 annuli posterior to anus and males with trilobed bursa, 52.5 (47–58) μm long spicules and 21.5 (18–27) μm gubernaculum. With the elongate‐conoid female tail and c? >1.2, the new species is close to five known species of the genus: N. brevistylus, N. leiocephalus, N. paralongicaudatus, N. rageshi and N. sinensis, but is distinguished from them by the morphology of the female tail, areolation type of the lateral field, position of hemizonid and phasmid and morphometric data. Molecular phylogenetic analyses using sequences of the near full‐length fragment of the small and the D2‐D3 expansion segments of the large subunit ribosomal DNA (SSU and LSU rDNA D2‐D3) revealed the new species placed in a clade including one isolate of Neodolichodorus sp. and some species of Globodera, Heterodera and Rotylenchulus with 0.89 Bayesian posterior probability (BPP) in SSU phylogeny. The only available SSU sequence of the genus was the tentative closest relative to the new species in the inferred SSU tree. In the reconstructed LSU phylogenetic tree, N. persiangulfus n. sp. formed a poorly supported clade with Rotylenchulus spp. in Bayesian inference (BI), and the only other available D2‐D3 sequence of the genus occupied a distant placement to the new species.