The use of principal component analysis in studying physical, chemical and biological soil properties in southern caspian forests (North of Iran)

This research was conducted in Khanikan forests located in lowland of Mazandaran province (North of Iran). Eighteen profiles were dug and several chemical, physical and biological soil properties were investigated. The soil properties evaluated were soil pH, bulk density, saturation moisture content, electrical conductivity, organic carbon, total nitrogen, cation exchangeable capacity, available phosphorous, soil texture, calcium carbonate content, number and biomass of earthworms, litter carbon and litter nitrogen. Principal Component Analysis (PCA) was used to identify the variation of soil properties. PCA, a technique which reduces the dimensionality of multivariate data by removing Interco relations among variables, has a number of useful applications in forest researches. The results showed significant relationships between some soil factors with PC1 and PC2 axes, also, among different soil factors, the distribution of forest types was most strongly controlled with some soil characteristics such as acidity, bulk density, texture, phosphorous, organic carbon, total nitrogen and cation exchangeable capacity.     

Application of natural forest structures to riparian greenways

This study analyzed structures of natural riparian forests and explored planning models applicable to establishing riparian greenways. Twenty-one streams or valleys were selected considering watersheds and climate regions of four major rivers in South Korea. The study surveyed mature structures and growth environments of the forests typical of the study streams in 122 sample plots. Forest communities associated with environmental gradients from floodplains to uplands were typified based on importance values of woody plant species and classification criteria of forest types in the country. The riparian forests were classified into 6–12 community types for each river watershed. The majority of dominant community tree species were distributed widely over the study streams, but some tree species were dominant in community types found in warmer regions only. This study presented planning models for restoring riparian greenways that reflect the distinct structural characteristics of the native community types. The planning models included species selection and composition, density and distance, and soil properties for tree plantings by community type, as well as a minimum width for riparian greenways. The models emphasized highly diverse ecological planting to enhance the multiple functions of riparian greenways, and establish native landscapes earlier through direct tree plantings rather than natural succession. A case study greenway was designed and planted to illustrate application of the planning model.     

文昌8个森林群落结构与物种多样性研究

以文昌航天发射缓冲区不同森林群落为研究对象,选择8个不同植被类型,分别设置1 hm2固定大样地,对森林植物群落的多样性、森林植物群落的物种均匀度、森林植物群落的物种优势度进行观测。结果表明：不同森林群落乔木层物种多样性差异显著,半红树林群落树种种类最高,物种多样性最高达到2.38,其次分别是天然次生林和人工混交林;不同森林群落中不同层次植物均匀度总体表现出草本层＞灌木层＞乔木层的规律,但天然次生林由于郁闭度较高,林下草本较灌木少,多样性和均匀度均小于灌木层;红树林物种优势度最小,各物种优势差异不显著。     

海南文昌滨海台地不同森林林下灌草多样性及其与土壤因子关联分析

采用典型抽样法,选取海南岛滨海台地3种典型热带森林类型（椰子林、人促更新次生林、次生林）,对林下物种多样性及其土壤理化性质进行调查研究,并探讨物种多样性与土壤因子的相关性。 结果表明：灌木层中东风桔(Atalantia buxifolia)、 琼崖海棠(Calophyllum inophyllum)是3种森林类型的共有物种,其中在椰子林和人促更新次生林林型下占有较大优势;草本层中牛膝(Achyranthes bidentata)和地桃花(Urena lobata)是3种森林类型共有草本植物,但并非是优势种。次生林和人促更新次生林林下灌木层的多样性指数与均匀度指数都较高,林下物种组成相对复杂,共有树种有11种,相似系数高达45％。次生林林下植物多样性与土壤全氮、全磷、有效磷、速效钾及铵态氮之间达极显著正相关关系;人促更新次生林植物多样性与土壤全钾、全氮、速效钾、无机氮及铵态氮之间达极显著正相关;椰子林林下植物多样性与土壤各养分含量之间的相关性不明显。经多元逐步回归分析证实：滨海台地热带林土壤pH、全磷、全钾、速效钾、有效磷、铵态氮及无机氮共7个土壤因子对林下植物多样性具有显著影响。     

Flora, life forms and chorotypes of plants of Salok protected area (North Khorassan Province Iran)

Salok protected Area is located in the 37 degrees 15' to 37 degrees 08' of the North latitude and 57 degrees 16' to 57 degrees 06' of East longitude, in West North Esfarayen in North khorassan province. In this research 52 families, 174 genera and 213 species were identified. The largest plant family is Asteraceae (34 species), Poaceae (18 species), Brassicaceae (17 species) and Fabaceae (17 species), respectively. Chief life forms are Hemicryptopytes (49.29%), Therophytes 23.47% and cryptophytes (12.67%). The most of plants chorotype with 62.91% is influenced by Irano-Touranina elements. Among 213 identified species of this region and 15 species endemic of Iran contain 0.87% of total endemic species of Iran's flora.     

东北地区栽培大豆品种资源分类探讨

资源研究的目的是利用，资源分类也应围绕这一中心。据此，本研究栽培大豆品种资源的栽培区，栽培型，单株粒重，百粒重，生育期，抗病性（花叶病毒，霜霉病，灰斑病，孢囊线虫１号，３号），抗虫性（食心虫），株高，油分，蛋白质，叶形，花以及茸毛色，把东北三省（黑龙江，吉林，辽宁）１７７８份栽培大豆品种资源划分为１个区，１个型，５类，２５群，９９亚群，１６６３个类型。提出了栽培大豆品种资源分类的基本模式及今后的发     

海南岛甘什岭热带低地雨林植物组成与地理成分

为揭示海南岛甘什岭热带低地雨林区域植物群落特征、性质和规律,以期为进一步分析生物多样性保育与恢复策略及生态服务功能评估等提供科学依据,在海南岛南部甘什岭自然保护区选择典型低地雨林建立1 hm~2固定样地,进行立地因子和植被调查,并研究其物种组成与地理成分。结果表明:维管植物隶属于65科150属213种,种子植物63科148属211种,分别占海南岛和全国种子植物总科、属、种的32.66%、19.29%,13.56%、4.69%和7.65%、0.78%~0.81%;优势科明显,单种科36个,寡种科24个,共占总科数的92.31%;属内种的变化范围为1~6,单种属最多,占总数的76.00%;科和属的分布区类型均以泛热带分布为主,热带性质占绝对优势,这不同于尖峰岭山地雨林热带-亚热带过度性明显的特点;根据种-面积曲线研究表明,甘什岭热带低地雨林最小取样面积为范围在3 600~6 400 m~2之间,其上限高于海南岛霸王岭热带山地雨林的4 000 m~2最小面积;相较于山地雨林,其植物种类较丰富,地理成分更复杂。     

Scale-dependent effects of habitat area on species interaction networks: invasive species alter relationships

ABSTRACT: BACKGROUND: The positive relationship between habitat area and species number is considered a fundamental rule in ecology. This relationship predicts that the link number of species interactions increases with habitat area, and structure is related to habitat area. Biological invasions can affect species interactions and area relationships. However, how these relationships change at different spatial scales has remained unexplored. We analysed understory plant-pollinator networks in seven temperate forest sites at 20 spatial scales (radius 120-2020 m) to clarify scale-associated relationships between forest area and plant-pollinator networks. RESULTS: The pooled data described interactions between 18 plant (including an exotic) and 89 pollinator (including an exotic) species. The total number of species and the number of interaction links between plant and pollinator species were negatively correlated with forest area, with the highest correlation coefficient at radii of 1520 and 1620 m, respectively. These results are not concordant with the pattern predicted by species-area relationships. However, when associations with exotic species were excluded, the total number of species and the number of interaction links were positively correlated with forest area (the highest correlation coefficient at a radius of 820 m). The network structure, i.e., connectance and nestedness, was also related to forest area (the highest correlation coefficients at radii of 720-820 m), when associations with exotics were excluded. In the study area, the exotic plant species Alliaria petiolata, which has invaded relatively small forest patches surrounded by agricultural fields, may have supported more native pollinator species than initially expected. Therefore, this invasive plant may have altered the original relationships between forest area and plant-pollinator networks. CONCLUSIONS: Our results demonstrate scale-dependent effects of forest area on the size and structure of plant-pollinator networks. We also suggest that a single exotic plant species can impact plant-pollinator networks, even in temperate continental habitats.     

海南东寨港国家级自然保护区及其周边陆域植物资源与植被调查研究

东寨港国家级自然保护区及其周边陆域植被类型复杂多样,除在保护区内分布有中国典型的红树林群落外,在保护区外分布有种类多样、结构复杂的农村周边自然、半自然森林植被及多样化的人工植被。该区域现有植物种类940种,其中红树林植物28种;在非红树林植物中,有国家I级保护植物1种,国家II级保护植物3种,省级保护植物7种,其中3个省级保护植物为野生分布。该地区的植被类型和植物种类资源具有极高的观赏价值和植物生态多样性保护价值,从更大的尺度上开展东寨港国家级自然保护区及其周边区域陆域植物生态调查研究,更全面地展示该地区的植物资源,对加强东寨港国家级自然保护区与过渡地带陆域植物生态的协同保护,从而更好地保护红树林生态系统的安全具有重要意义。      

The correlation of genetic diversity and geographic distribution of Fusarium graminearum in North part of Iran

Fusarium Head Blight (FHB), caused mainly by Fusarium graminearum, is one of the most notorious diseases in North part of Iran. Due to lack of sufficient information regarding genetic diversity of FHB, the correlation between genetic diversity and geographic distribution of 52 isolates that collected from infected wheat kernels from four main grown region of North part of Iran were analyzed with 10 simple Sequence Repeat (SSR) primers and 15 Random Amplified Polymorphic DNA (RAPD) primers. The un-weighed pair group method using arithmetic means (UPGMA) was used and a dendrogram was constructed based on Jaccard's similarity coefficient. Principal Component Analysis (PCA) of SSR and RAPD markers revealed that the first two factors accounted for 51 and 41% of the total variance, respectively. SSR and RAPD data classified isolates into four and seven groups, respectively. SSR analysis showed that there was a correlation between genetic clusters of isolates and geographical origin in F. graminearum. However, results of cluster analysis using RAPD data didn't show any relation with geographical distribution but the results of this analysis confirmed a genetic variation among all isolates.     

Integrating models of relative abundance of species with the dry-weight-rank method for the botanical analysis of forest understorey vegetation

The objective of this work was to determine the applicability of the dry‐weight‐rank (DWR) method for evaluating the botanical composition of forest understorey vegetation. An analysis of plant species abundance was carried out, and instead of ranking the three most abundant species, as is commonly used, up to twelve ranks were scored. Concurrently, four models of relative abundance distribution (RAD) of species were compared for their ability to explain the abundance of species in the study area. The Power‐fraction model resulted in the best goodness‐of‐fit and it was subsequently used to produce the coefficients for the DWR method. Lin's concordance correlation coefficient, the adjusted coefficient of determination, the residual standard deviation and Spearman's rank‐order correlation coefficient indicated a good performance of the DWR method. Biomass data and the Shannon index for diversity were also considered. Further analyses showed that there was a trade‐off between the number of ranks scored and the accuracy of the botanical composition produced by the DWR method. It is concluded that, so long as the RAD model that explains the distribution of plant species is known, the DWR method can be applied to forest understorey vegetation.     

Application of IRS-1D data in water erosion features detection (case study: Nour roud catchment, Iran)

The aim of this study was capability of Indian Remote Sensing (IRS) data of 1D to detecting erosion features which were created from run-off. In this study, ability of PAN digital data of IRS-1D satellite was evaluated for extraction of erosion features in Nour-roud catchment located in Mazandaran province, Iran, using GIS techniques. Research method has based on supervised digital classification, using MLC algorithm and also visual interpretation, using PMU analysis and then these were evaluated and compared. Results indicated that opposite of digital classification, with overall accuracy 40.02% and kappa coefficient 31.35%, due to low spectral resolution; visual interpretation and classification, due to high spatial resolution (5.8 m), prepared classifying erosion features from this data, so that these features corresponded with the lithology, slope and hydrograph lines using GIS, so closely that one can consider their boundaries overlapped. Also field control showed that this data is relatively fit for using this method in investigation of erosion features and specially, can be applied to identify large erosion features.     

The effect of type of marginal land use on the plant diversity

The objective of this study closely focuses on the settlement of the effect of marginal land use on plant diversity. The location of this study was Sar Firouze Abad region with rainfall of over 350 mm and slope of over 12%. Five treatments in terms of land use (exclusion area, grazed range, fallow, annual medic cultivation, wheat cultivation) done with the repetition of five times. The factors, such as the number of species and the number of plant bases in each species in each sampling were measured. The method used here is based upon complete randomized design applying Duncan test and Raunchier method for classification of plant species and also Shannon-Wiener index of diversity and homogeny utilized. The results show that there are 76 species belonging to 60 genus and 19 families spreading in the region under study. The most dominant families are Fabaceae with 15 species covering 20% and Poaceae with 13 species covering 17%, respectively. According to Raunchier method the life form of the region species can be classified as Therophytes 66%, Geophytes 3%, Hemicryptophytes 26% and Chamaephytes 5%. The results also illustrate that the treatment of exclusion area has the most plant diversity in comparison with treatments of fallow, annual medic cultivation, wheat cultivation and range grazed.     

The effect of type of marginal land use on the production of biomass and plant diversity

The objective of this study closely focuses on the settlement of the effect of marginal land use on plant diversity. The location of this study was Sar Firouze Abad region with rainfall of over 350 mm and slope of over 12%. Five treatments in terms of land use (exclusion area, grazed range, fallow, annual medic cultivation, wheat cultivation) done with the repetition of five times. The factors, such as the number of species, the number of plant bases in each species, the percentage of plant cover and biomass in each sampling were measured. The method used here is based upon complete randomized design applying Duncan test and Raunkiaer method for classification of plant species and also Shannon's diversity index of diversity and homogeny utilized. The results show that there are 76 species belonging to 60 genus and 19 families spreading in the region under study. The most dominant families are Fabaceae with 15 species covering 20% and Poaceae with 13 species covering 17%, respectively. According to Raunkiaer method the life form of the region species can be classified as Therophytes 66%, Geophytes 3%, Hemicryptophytes 26% and Chamaephytes 5%. The results also illustrate that the treatment of exclusion area has the most plant diversity, the percentage of plant cover and biomass in comparison with the rest of treatment cultivation and range grazed.     

Classifying plant species indicators of eutrophication in Korean lakes

The objectives of this study were to establish a method of classifying plants as indicator species of eutrophication, as a key metric for assessing lake ecosystem health, and to select sensitive and tolerant plant species among aquatic macrophytes and hygrophytes. Thus, 38 natural and artificial lakes throughout Korea were investigated. The distribution and abundance of plant species were investigated. As a measure of eutrophication, the modified trophic state index (TSI_KO), derived from total phosphorus and chlorophyll a, was used. Using TSI_KO criteria and the response curves of plants to TSI_KO, a selection method of classifying sensitive and tolerant species was developed. Overall, 15 sensitive and 11 tolerant species among 117 macrophytes and hygrophytes were classified. The applicability of the selected indicator species was verified by a comparison with the results of a multimetric analysis using eight variables. The results suggest that the selected indicator species is expected to be useful as a metric for assessing lake ecosystem health.     

Leaf litter decomposition and diversity of arthropod decomposers in tropical <Emphasis Type="Italic">Muyong</Emphasis> forest in Banaue,Philippines

The Muyong forest, an indigenous secondary forest in Banaue, Ifugao, Philippines, plays a crucial role in the Muyong–Payoh system, a continuum of secondary forest and rice terrace, of the Banaue rice terraces by providing water and nutrients to the rice plants in the Payoh terraces. In recent decades, the planting of introduced tree species in the Muyong forest has threatened the sustainable provision of ecosystem services such as water balance and nutrient cycling. To further understand nutrient cycling in the Muyong–Payoh systems, this study was conducted in Poitan, Banaue, Ifugao to gather preliminary baseline data on floral diversity, leaf litterfall rate, leaf litter decomposition rate, and diversity and succession of arthropods in decomposing leaf litter in a Muyong forest. Vegetation analysis was done by identifying and describing the trees growing inside the five 10 m × 10 m quadrat sampling plots. Monthly leaf litter fall was collected in 1 m × 1 m litter traps, and the dry weight was determined after oven-drying at 65 °C for 48 h. Leaf litter decomposition experiment was established by laying out 12 nylon mesh bags containing fresh leaf litter in each of the four sites on the forest floor and one bag was retrieved every month to determine the change in dry weight of the leaf litter. Six bulk soil samples were collected from the Muyong forest floor and analyzed for organic matter, pH, available P and exchangeable K. Fresh leaf litter samples were analyzed for total N, P and K contents. Arthropods in the collected decomposing leaf litter were extracted using Berlese funnel and later identified up to families level using arthropod taxonomic key. The diversity of plants in the Muyong forest includes thirty-eight tree species belonging to 19 families dominated by indigenous tree species. Results showed that the monthly leaf litter fall was higher during the dry months of March to May and lower during the wet months. The estimated total leaf litter fall in Muyong forest was comparable to published litter fall from tropical secondary forests. The N, P and K contents of fresh leaf litter range from 1.0 to 1.2, 0.11 and 0.40%, respectively. The first month of decomposition has the fastest rate while the decomposition rate during the next 4 months ranged from 0.125 to 0.251. Complete decomposition or mass lost in the leaf litter in the Muyong forest took place within 5 months. The soil arthropods identified in the decomposing leaf litter were composed of 13 orders and 28 families. Majority of the collected arthropods were insects while other species including mites, spiders, millipedes and sowbugs were also present. Detrivore and fungivore Families were found to be dominant in the decomposing leaf litter. Moreover, the composition and succession of arthropod decomposer community varied in the three sampling methods and with the changing quality of the litter material as decomposition progressed. The wide diversity and succession of leaf litter decomposers consisting of detritivores, predators, fungivore and herbivore coupled with abundant rainfall and warm temperature are the two main factors that contribute to the fast rate of leaf litter decomposition and nutrient turn over in the Muyong forest. Thus, the Muyong forest can sustain the productivity of rice planted in the adjoining downstream Payoh terraces. Hence, the conservation and management of the Muyong forest is critical in maintaining the ecological functions of the Muyong–Payoh continuum.     

The children reference range of thyroid hormones in Northern Iran

Hypothyroidism is associated with mental and growth abnormality in children. The aim of this study was to determine the reference range of thyroid stimulating hormone (TSH). Thyroxin (T4) and triodothyronine (T3) of children in Northern Iran. The sample population for this study consists of subjects of 4 age groups up to 21 years. The subjects were selected randomly from people referred to Danesh Medical Diagnostic Laboratory in Gorgan Northern Iran. Thyroid hormone level were investigated with Radio immunoassay. The mean concentration for T4, T3, TSH for the sample population of 4 groups were as follow (113.5, 107.4, 102.9, 99.2 nmol L(-1)), (1.9, 1.7, 1.9, 1.6 nmol L(-1)) and (2.1,3.5, 2.9, 2.7 mIu L(-1)). The mean value of T3, TSH were higher for females but the mean value of T4 was slightly higher in males. The findings of this investigation indicated that there is an inverse age correlation in particular for T4 in all age groups. On the bases of the results from this study, we conclude that reference range, in all age groups and lower, upper limits of our reference range are not universally similar; therefore determination of reference range in each region is a critical need for clinical practice.     

不同林龄木麻黄沿海防护林林下植被多样性研究

为了揭示木麻黄防护林群落不同演替阶段的物种多样性的变化规律,为中国沿海木麻黄防护林的恢复和重建提供理论依据,采用典型抽样法,选取了海南文昌滨海台地不同林龄的木麻黄(Casuarina equisetifolia)防护林,对林下植物物种组成和植物多样性进行调查研究。结果表明,木麻黄防护林下出现的植物种类为19科31属32种,其中木本植物6科6属8种;草本植物14科24属24种。黑面神(Breynia fruticosa)、马樱丹(Lantana camara)、银合欢(Leucaena leucocephala)、丰花草(Borreria stricta)、白花草(Habenaria dentata)等物种几乎在木麻黄林的各个年龄阶段出现。随着林龄的增加,林下物种总丰富度指数明显在增长。Simpson指数和Shannon-Wiener指数表现为前期物种多样性随林龄的增加而增高,后期稳定不变。说明滨海台地的木麻黄沿海防护林随着林龄的增长,植被群落的生境趋于稳定。     

稻属叶绿体DNA限制性片段长度多态性

 对稻属（Oryza）的14个种和李氏禾属（Leersia）的 2个种共 138份材料进行了叶绿体 DNA限制性片段长度多态性的分析。用内切酶EcoRⅠ酶切、4 个叶绿体 DNA探针杂交,共发现10种叶绿体 DNA变异类型。在稻属各个种内没有观察到叶绿体 DNA的变异,叶绿体 DNA变异类型基本上以稻属的染色体组型水平划分,因此认为稻属的叶绿体 DNA在进化过程中变异程度很低。推测 CCDD组的O. alta、O. grandiglumis和O. latifolia 及 CC组的 O.officinalis 和 O. eichingeri各有共同的原始祖先。遗传距离分析显示 CC、CCDD、BBCC组之间亲缘关系很近,这3个组与 EE组亲缘关系也较近。李氏禾属的 2个种 L. perrieri 和 L. tisseranti 与稻属的遗传距离很远。