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研究表明,四川林木病害可分为针叶林、阔叶林和经济林三个垂直分布带.在各带内的低山、中山和亚高山分布带具有林木病害的种类差异性、地带集中性和发生阶性的特点,可以认为是综合治理的森林地理学、森林生态学和森林经营学的基础. 相似文献
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系统调查了祁连山自然保护区森林病害种类，采到罹病林木11科22种（属），鉴定出林木病原107种，引起病害134种。病原分类分别为真菌83种、螨类6种、寄生植物3种、细菌1种，生理性病原14类。病害种类按寄生部位分，叶部病害74种，干部病害38种，枝梢病害17种，种实、根部病害较少。按树种分，青海云杉病害23种，青杄病害13种，人工栽培杨树病害18种，山杨病害18种，桦树病害10种，山柳病害8种，华北落叶松病害6种，祁连圆柏病害5种，油松病害5种，梅属植物病害5种，苹果属植物病害3种，小檗属植物病害4种，杜鹃类病害3种，忍冬病害2种，其他林木病害8种。 相似文献
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林木根部病害种类不多，但往往对林木造成毁灭性危害。林木根病主要是由真菌、细菌和线虫引起的。根病的传播速度较慢，但由于病害在地下发展，初期不易发现，往往失去了早期防治的机会。 相似文献
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林木根部病害种类不多，但往往对林木造成毁灭性危害。林木根病主要是由真菌、细菌和线虫引起的。根病的传播速度较慢，但由于病害在地下发展，初期不易发现，往往失去了早期防治的机会。 相似文献
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真菌病害是林木的主要生物胁迫之一，严重影响林业生态安全和经济效益。近年来随着组学技术的突破，转录组技术和代谢组技术已成功应用于林木真菌病害研究，主要包括致病和抗病关键基因的挖掘、林木防御物质的动态合成、抗病分子育种等方面，但林木如何抵御真菌病害及其两者间的互作机制仍是今后研究的热点与难点。文中通过对林木遭受真菌侵染后的转录组信息和代谢组信息进行探讨，包括类黄酮物质合成途径、植物激素信号转导、林木防御关键基因和关键代谢物、关键防御机制及功能网络等，将在理论上丰富林木响应真菌病害侵染的过程，为林木和真菌病害的互作研究奠定基础，并为林木抗性育种和化学防治提供参考；此外，基于目前转录组和代谢组在林木真菌病害防御反应方面的研究，对林木基因组研究、多组学联合研究以及病原菌组学研究等进行展望，以期为林木真菌病害研究提供新思路。 相似文献
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大青山林场位于东经110°46′到111°32′,北纬40°38′到40°56′,在呼和浩特郊区西北面,总面积136万亩,分高山带、中山带和低山带。高山和中山为太古代片麻岩、石英岩组成的较硬岩层,低山为中生代砂岩、页岩、砾岩组成较软岩层,由新生代产生了喜马拉雅造山运动形成了横断山脉,构成了石质山区,山势险峻,坡度较大。由于人为长期活动的结果,失去了原始森林环境,水土流失严重,森林覆被率仅为31％,有林地面积为42.2万亩,其中白桦用材林12万亩,有经营前途的5万亩,需要按照规程进行抚育间伐,其余多数都是改造对象。 相似文献
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Martín Juan A. Sobrino-Plata Juan Rodríguez-Calcerrada Jesús Collada Carmen Gil Luis 《New Forests》2019,50(2):183-215
New Forests - Elms (Ulmus spp.) were once dominant trees in mixed broadleaf forests of many European territories, mainly distributed near rivers and streams or on floodplains. Since ancient times... 相似文献
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E. Ring O. Widenfalk G. Jansson H. Holmström L. Högbom J. Sonesson 《Scandinavian Journal of Forest Research》2018,33(2):133-146
This study investigated characteristics of riparian forests on managed forest land in Sweden. Forest and site characteristics were inventoried at three sites, located along a south to north gradient, in 139 transects placed perpendicular to 38 stream reaches (<10?m wide), in forests representing the age classes 0–25, 26–75 and >75 years. Starting from the stream edge, the 30?m long transects were divided into three zones: 0–5, 5–15 and 15–30?m. The stem volumes of Pinus sylvestris L., Picea abies (L.) H. Karst, Betula spp. and broadleaved trees, the basal area share of Alnus spp., the stem density, and Sphagnum spp. coverage all showed an effect of zone (p?P. sylvestris and the highest volumes of P. abies, Betula spp. and broadleaved trees as well as the highest total stem density and basal area share of Alnus spp. Some characteristics of the northernmost site tended to differ from the two sites located in south-central Sweden. Knowledge of the characteristics of riparian forests as found in this study could aid long-term forestry planning and improve precision in the preservation and development of riparian forests with certain qualities. 相似文献
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我国主要森林生态系统类型降水截留规律的数量分析 总被引：92，自引：0，他引：92
通过对大量林林生态系统水文生态功能研究资料的分析，从林冠层、枯枝落叶层和土壤三个森林水文生态功能的发挥最主要的层次出发，比较分析了我国主要森林生态系统类型的降水截留规律。 相似文献
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燕山东段森林群落枯落物现存量平均为４．３５－２８．６７ｔ／ｈｍ＾２，以山杨混交林、松栎混交林、椴树混交林最高，栎林和油松林次之，侧柏林最低。灌木群落枯落物现存量平均为４．１５－１８．９４ｔ／ｈｍ＾２，低于森林群落。森林枯落物现存量受树种组成、年龄、立地条件及人为干扰的影响。其中，人为干扰影响最大，几乎使枯落物损失殆尽。森林枯落物营养元素总贮量０．１７６－１．５３４ｔ／ｈｍ＾２，最大贮水量３．９－５ 相似文献
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Variation in litter decomposition-temperature relationships between coniferous and broadleaf forests in Huangshan Mountain, China 总被引：3，自引：0，他引：3
HE Xing-bing SONG Fu-qiang ZHANG Peng LIN Yong-hui TIAN Xing-jun REN Li-li CHEN Cheng LI Xiao-na Tan Hai-xia 《林业研究》2007,18(4):291-297
A study was conducted to identify the differences in the decompositions of leaf litter, lignin and carbohydrate between coniferous forest and broadleaf forest at 20℃ and 30℃ in Huangshan Mountain, Anhui Province, China. Results showed that at 20℃ mass loss of leaf litter driven by microbial decomposers was higher in broadleaf forest than that in coniferous forest, whereas the difference in mass loss of leaf litter was not significant at 30℃. The temperature increase did not affect the mass loss of leaf litter for coniferous forest treatment, but significantly reduced the decomposition rate for broadleaf forest treatment. The functional decomposers of microorganism in broadleaf forest produced a higher lignin decomposition rate at 20℃, compared to that in coniferous forest, but the difference in lignin decomposition was not found between two forest types at 30℃. Improved temperature increased the lignin decomposition for both broadleaf and coniferous forest. Additionally, the functional group of microorganism from broadleaf forest showed marginally higher carbohydrate loss than that from coniferous forest at both temperatures. Temperature increase reduced the carbohydrate decomposition for broadleaf forest, while only a little reduce was found for coniferous forest. Remarkable differences occurred in responses between most enzymes （Phenoloxidase, peroxidase, !5-glucosidase and endocellulase） and decomposition rate of leaf litter to forest type and temperature, although there exist strong relationships between measured enzyme activities and decomposition rate in most cases. The reason is that more than one enzyme contribute to the mass loss of leaf litter and organic chemical components. In conclusion, at a community scale the coniferous and broadleaf forests differed in their temperature-decomposition relationships. 相似文献
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The appropriate management of streamside forests and use of riparian strips is poorly resolved for many systems because of a lack of understanding of the extent to which riparian forests function as environmental buffers for aquatic species versus core (essential) habitat for semi-aquatic and terrestrial species. We studied streamside forests in western North Carolina and eastern Tennessee, USA, to help delineate their functional value for plethodontid salamanders. We established 30 m × 40 m plots at 17 sites (823–1716 m in elevation) in unmanaged forests with closed canopies. Plots contained a portion of a seep or first-order stream along one edge and typically extended 36–38 m into the adjoining forest. We examined use of stream and streamside habitats based on captures during area-constrained searches of cover objects. We observed 6423 plethodontid salamanders belonging to 7 terrestrial-breeding and 12 aquatic-breeding species. Terrestrial-breeders (primarily Plethodon spp.) comprised 37% of terrestrial specimens and were more abundant at higher elevations. Aquatic-breeders (primarily Desmognathus spp.) increased their proportionate use of terrestrial habitat, but declined in overall abundance with elevation. Catches of aquatic-breeders were greatest within 8 m of aquatic habitats (49% of total terrestrial catch of aquatic-breeders), particularly at low elevation sites. The terrestrial zone provided core habitat for one terrestrial-breeder (D. wrighti) and six semi-aquatic species (Desmognathus spp., Gyrinophilus porphyriticus and Eurycea wilderae) that were broadly distributed throughout plots, and acted as an aquatic buffer for four highly aquatic species (Desmognathus spp.). The remaining species were terrestrial-breeders (Plethodon spp.) that were evenly distributed across plots, suggesting that riparian strips would function as important source populations for recolonization following timbering on adjoining land. Because of the vulnerability of plethodontid salamanders to edge effects, effective management of southern Appalachian streamside habitats may require the addition of a terrestrial buffer to protect terrestrial core habitat that immediately adjoins streams and seeps. 相似文献
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Vanessa L. Fox Charlotte P. BuehlerChad M. Byers Summer E. Drake 《Forest Ecology and Management》2010
Within the eastern deciduous forest region, forest composition varies, with some areas dominated by a mix of oaks (Quercus spp.) and other areas dominated by a mix of sugar maple (Acer saccharum) and other tree species. Prescribed fire is being used on an experimental basis to assess its effectiveness in restoring and maintaining oak-dominated forests. Maple-dominated forests are susceptible to invasion by non-native earthworms, such as Lumbricus terrestris, given the palatability of leaf litter and suitable soil conditions, especially in northern parts of the region. What are the implications of this variation on leaf litter availability and habitat for ground-nesting songbirds? We investigated this question by comparing forest composition, leaf litter, and songbird communities in maple-dominated forests in west-central Indiana and oak-dominated forests, recently burned and unburned, in southeastern Ohio. We also assessed abundance of earthworms and decomposition rates of different types of leaves in the maple-dominated forests in Indiana. Leaf litter and ground-nesting bird species were abundant in unburned oak-dominated forests, but were absent or nearly absent in recently burned oak-dominated forests and in maple-dominated forests. The lack of leaf litter and absence of ground-nesting bird species in maple-dominated forests may be due to the combination of abundant non-native earthworms, alkaline and calcium-rich soils, palatable leaves, and rapid leaf litter decomposition rates. Effects of burning on leaf litter and ground-nesting bird species in oak-dominated forests are probably temporary, as long as prescribed fires are not applied on a frequent or widespread basis. Our study is the first one to show a correlation between forest composition, leaf litter availability, earthworm abundance, and songbird populations. Many researchers are investigating effects of non-native earthworm invasions on ecosystem properties in eastern deciduous forests. We recommend that researchers should also monitor songbird populations to assess whether declines in ground-nesting bird populations are occurring in response to these changes. 相似文献
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Seyed Armin Hashemi Sasan Babaei Kafaki Asadollah Mataji 《Journal of Sustainable Forestry》2013,32(7):697-712
We selected 15 beech trees (Fagus orientalis) from the study area in a mountainous region from 520 to 1310 m above sea level. Ground observations of the beech tree growth process from January to December 2004 in 7- to 15-day intervals were performed both visually and by measuring leaf chlorophyll concentration (chlorophyll meter SPAD-502). Results for the regression analysis showed that the leaved period positively correlated with the air temperature (r?=?.894). Anthesis and SPAD measurements have a negative relationship with air temperature and as temperature increases they appear earlier in the year. Anthesis and SPAD measurements had correlation coefficients of r?=??.883 and r?=??.855, respectively. The anthesis and bud bursting and leaf tip appearance have a negative relationship with increasing altitude from sea level and as altitude increases they appear later in the year. To make phenological events in deciduous broadleaf forests recognizable, we used a seasonal 8-day composite Moderate Resolution Imaging Spectroradiometer/Normalized Difference Vegetation Index (MODIS/NDVI). Prior to leaf expansion, NDVI increased from the 109th day of the year or earlier. Existence of the evergreen plants (Ruscus hyrcanus) on the ground and snow-melting exert an influence on inconsistency of phenology monitoring of MODIS/NDVI images. Regression analysis showed that there is a positive relationship between NDVI and SPAD measurements (chlorophyll content) in beech trees. 相似文献
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Recently, it is documented that bamboo (Mousouchiku:Phyllostachys pubescens Mazel) invasion deteriorates ecological and/or landscape diversity. In order to investigate the ecological effects on forest-floor
arthropods caused by bamboo invasion, we compared the myrmecofauna among broadleaf forests, bamboo-broadleaf mixed forests,
and bamboo forests in Hiroshima City and its vicinity. Myrmecofauna in bamboo forests were more impoverished than in broadleaf
forests. Myrmecofauna in the mixed forests, however, were similar to that in broadleaf forests in both species diversity and
species composition. The change in myrmecofauna may occur relatively late after the initial bamboo invasion. 相似文献
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We estimated the potential of plantation forests for the restoration of the original plant community. We compared the understory vegetation in hinoki (Chamaecyparis obtusa [Sieb. et Zucc.] Endlicher) plantations at the understory re-initiation stage and in adjacent natural forests. To estimate the effect of the original natural forests on the understory species composition of plantation forests, we established study sites in five types of natural forests (mature evergreen broadleaf, mature deciduous broadleaf, mature evergreen coniferous, immature deciduous broadleaf warm-temperate, and immature deciduous broadleaf cool-temperate) and nearby plantation forests. The understory vegetation of the plantation forests had a higher species richness, a higher proportion of early-seral species, and a higher proportion of herb or fern species than the natural forests. The differences between natural and plantation forests varied according to the species composition of the natural forests. The composition of the understory vegetation of the plantations at the understory re-initiation stage was similar to that of the immature deciduous forests. The characteristics of immature, disturbed forests remained in the understory vegetation of the hinoki forests. No great loss of species was observed. Our findings suggest that most of the original forest species still survive in the understory of the plantation forests. These forests have the potential to follow the successional pathway to broadleaf or mixed forests via thinning or clear-cutting without planting. 相似文献