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Plant life form determines spatiotemporal variability and climate response of plant seed rain in subtropical forests
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作者 Yuyang Xie Zehao Shen +2 位作者 Xuejing Wang Liu Yang Jie Zhang 《Forest Ecosystems》 SCIE CSCD 2024年第2期193-201,共9页
Spatiotemporal variation of seed rain reflects the response of plants in terms of their reproductive strategy to environmental gradients.In this study,we collected seeds from four sites in the Dalaoling Nature Reserve... Spatiotemporal variation of seed rain reflects the response of plants in terms of their reproductive strategy to environmental gradients.In this study,we collected seeds from four sites in the Dalaoling Nature Reserve,Hubei Province,China,between 2011 and 2014,measured seed output and seed mass as seed rain traits,and compared their interannual and elevational variation.Then,we ran phylogenetic generalized mixed linear models(PGLMMs) to explore the effects of temperature and precipitation as well as interspecific differences on seed rain,and fitted the best regression models for seed rain vs.weather of canopy and understory species.The results showed no correlation between values of seed output and seed mass.However,the variation of the two traits showed significantly positive correlation.Seed output of canopy species generally decreased with increasing elevation,and showed significant interannual difference;however,seed output of understory species and seed mass for both canopy and understory species did not show consistency tends along elevational or in interannual variation.Seed output was significantly affected by temperature and precipitation,while seed mass mainly varied due to interspecific differences.Weather explained more the variation of the seed output of canopy species than that of understory species,with R^(2) values of 43.0%and 29.9%,respectively.These results suggested that canopy plants contributed more to the reproductive dynamics of the whole communities,and the canopy's buffer effect on the underground weakened the response of understory plants to weather variation in terms of their reproductive strategy. 展开更多
关键词 seed rain seed output seed mass ELEVATION Interannual variation Lifeform
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Spatiotemporal characteristics of seed rain and soil seed bank of artificial Caragana korshinskii Kom. forest in the Tengger Desert, China
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作者 SHEN Jianxiang WANG Xin +9 位作者 WANG Lei WANG Jiahui QU Wenjie ZHANG Xue CHANG Xuanxuan YANG Xinguo CHEN Lin QIN Weichun ZHANG Bo NIU Jinshuai 《Journal of Arid Land》 SCIE CSCD 2024年第4期550-566,共17页
Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants durin... Vegetation restoration and reconstruction are effective approaches to desertification control and achieving social and economic sustainability in desert areas.However,the self-succession ability of native plants during the later periods of vegetation restoration remains unclear.Therefore,this study was conducted to bridge the knowledge gap by investigating the regeneration dynamics of artificial forest under natural conditions.The information of seed rain and soil seed bank was collected and quantified from an artificial Caragana korshinskii Kom.forest in the Tengger Desert,China.The germination tests were conducted in a laboratory setting.The analysis of species quantity and diversity in seed rain and soil seed bank was conducted to assess the impact of different durations of sand fixation(60,40,and 20 a)on the progress of vegetation restoration and ecological conditions in artificial C.korshinskii forest.The results showed that the top three dominant plant species in seed rain were Echinops gmelinii Turcz.,Eragrostis minor Host.,and Agropyron mongolicum Keng.,and the top three dominant plant species in soil seed bank were E.minor,Chloris virgata Sw.,and E.gmelinii.As restoration period increased,the density of seed rain and soil seed bank increased first and then decreased.While for species richness,as restoration period increased,it gradually increased in seed rain but decreased in soil seed bank.There was a positive correlation between seed rain density and soil seed bank density among all the three restoration periods.The species similarity between seed rain or soil seed bank and aboveground vegetation decreased with the extension of restoration period.The shape of the seeds,specifically those with external appendages such as spines and crown hair,clearly had an effect on their dispersal,then resulting in lower seed density in soil seed bank.In addition,precipitation was a crucial factor in promoting rapid germination,also resulting in lower seed density in soil seed bank.Our findings provide valuable insights for guiding future interventions during the later periods of artificial C.korshinskii forest,such as sowing and restoration efforts using unmanned aerial vehicles. 展开更多
关键词 ecological restoration soil seed bank seed rain artificial forest vegetation desertification Caragana korshinskii Tengger Desert
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Similarity between seed rain and neighbouring mature tree communities in an old-growth temperate forest 被引量:2
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作者 Yunyun Wang Jalene M.La.Montagne +4 位作者 Fei Lin Zuoqiang Yuan Ji Ye Xugao Wang Zhanqing Hao 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第6期2435-2444,共10页
Seed distribution and deposition patterns around parent trees are strongly aff ected by functional traits and therefore infl uence the development of plant communities.To assess the limitations of seed dispersal and t... Seed distribution and deposition patterns around parent trees are strongly aff ected by functional traits and therefore infl uence the development of plant communities.To assess the limitations of seed dispersal and the extent to which diaspore and neighbouring parental traits explain seed rain,we used a 9-year seed data set based on 150 seed traps in a 25-ha area of a temperate forest in the Changbai Mountain.Among 480,598 seeds belonging to 12 families,17 genera,and 26 species were identifi ed,only 54%of the species with mature trees in the community were represented in seeds collected over the 9 years,indicating a limitation in seed dispersal.Understory species were most limited;overstory species were least limited.Species with wind-dispersed seed had the least limitation,while the lowest similarity in species richness was for animal-dispersed species followed by gravity-dispersed species;fl eshy-fruited species had stronger dispersal limitations than dry-fruited species.Generalized linear mixed models showed that relative basal area had a signifi cant positive eff ect on seed abundance in traps,while the contribution of diaspore traits was low for nearly all groups.These results suggest that tree traits had the strongest contribution to seed dispersal and deposition for all functional groups examined here.These fi ndings strengthen the knowledge that tree traits are key in explaining seed deposition patterns,at least at the primary dispersal stage.This improved knowledge of sources of seeds that are dispersed could facilitate greater understanding of seedling and community dynamics in temperate forests. 展开更多
关键词 seed rain Dispersal mechanisms Tree traits Basal area Changbai mountain Temperate forest
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Spatial pattern and utility of Populus euphratica seed rain:a simulation study combined with field investigations 被引量:1
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作者 HAO Peng LI Jing-wen +2 位作者 ZHOU Wei-lei LIU Qian-wen ZHANG Yu-bo 《Forestry Studies in China》 CAS 2012年第3期169-179,共11页
Seed dispersal is a fundamental process affecting destinies of seeds and seedlings, as well as regeneration dynamics and distribution patterns of communities. Recently however, declining Populus euphratica forests hav... Seed dispersal is a fundamental process affecting destinies of seeds and seedlings, as well as regeneration dynamics and distribution patterns of communities. Recently however, declining Populus euphratica forests have failed to regenerate by seeding, while the spatial pattern and utility of their seed rains are unclear. In this study, we designed a model to simulate seed rains based on field investigations by fitting our observations to a normal distribution and testing the model with data from three years, with ac- ceptable results. We examined the simulated results of dispersed seeds patterns on the classification of three factors, i.e., density of Sophora alopecuroides, surface soil moisture and surface soil salinity. The results of seed rain simulation show that over 70% of seeds were dispersed and confined to each of the three plots where their mother trees located. The proportion of 3:7 seeds dispersed inside and outside each plots remained largely unaltered. The differences in the amounts of dispersed seed among the different levels of each of the factors were not significant, although the distributing pattern of P. euphratica in each plot varied. Therefore, in P. eu- phratica communities, the amount of seed does not become a constraint in subsequent germination, although the surface environment does. We conclude that successful P. euphratica seed regeneration relies on less than 30% of seeds dispersed over longer distance to colonize favorable growth habitats. 展开更多
关键词 Populus euphratica forest seed rain spatial pattern UTILITY wind direction
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Long-lasting effects of unplanned logging on the seed rain of mixed conifer-hardwood forests in southern South America
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作者 Alexandre F.Souza Angela Luciana deÁvila +1 位作者 Maristela M.Araújo Solon Jonas Longhi 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第4期1409-1418,共10页
Understanding the effects of disturbance on seed rain is critical to predict changes in forest species composition and diversity.Logging effects on seed rain in a mixed conifer-hardwood forest complex in southern Braz... Understanding the effects of disturbance on seed rain is critical to predict changes in forest species composition and diversity.Logging effects on seed rain in a mixed conifer-hardwood forest complex in southern Brazil were evaluated.One year of seed rain data were collected from a large-scale observational experiment in logged and protected forests and quantity and average seed size weighted by species abundance(CWM)were compared between old-growth and logged stands 55 years after logging activities.Using these data,variations in frequency of functional groups of species in the seed rain were examined to see if they could be attributed to logging.Results show that the number of seeds per trap was highly right-skewed,ranging from 13 to 12,788 seeds per trap in one year.Seed rain was affected by logging history,with seed traps in old-growth plots receiving significantly less seeds than traps in logged plots.All species included mean seed size weighted by species abundance were significantly smaller in logged than in old-growth forests.This difference persisted after the exclusion of Arawcaria a large-seeded pioneer which was intensively logged,although the difference of seed size between the two forest classes was greatly reduced.Species abundance in the seed rain differed significantly from the established tree community,between logged and oldgrowth stands.The composition of the seed rain was much more variable than the composition of the established tree community and its points more scattered over the ordination space than the points corresponding to the protected forests.The number of collected seeds across different functional groups of species significantly differed between logged and old-growth plots.The seed rain of logged forests reflects their arrested succes sion as indicated by reduced abundance of functional groups such as pioneers,large seeded pioneers and A raucaria,as well as reduced functional diversity.S eed rain differences between logged and old-growth stands reflect the intensive logging of A.angustifolia. 展开更多
关键词 Arrested succession Brazil LOGGING Long-lived pioneers seed rain
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Seed rain and soil seed bank compensatory roles on Nassella tenuis(Phil.)Barkworth seedling recruitment in ungrazed and grazed sites
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作者 Cintia Vanesa LEDER Dianela Alejandra CALVO Guadalupe PETER 《Journal of Arid Land》 SCIE CSCD 2022年第5期550-560,共11页
In semi-arid lands,vegetation is distributed in shrub patches immersed in a less vegetated interpatch matrix.Grazing affects perennial grass seed bank through a decrease in seed rain and an increase in seed predation ... In semi-arid lands,vegetation is distributed in shrub patches immersed in a less vegetated interpatch matrix.Grazing affects perennial grass seed bank through a decrease in seed rain and an increase in seed predation and soil compaction.Nevertheless,some species with anchorage mechanisms in their seeds might overcome this,such as Nassella tenuis(Phil.)Barkworth.This is an important species in grazing paddocks because it has an intermediate palatability and its relatively tolerant to grazing.These characteristics allow N.tenuis to increase its abundance in grazed sites.Our objective was to assess how grazing affects the key palatable species from seeds to seedlings:i.e.,seed rain,soil seed bank,and seedling recruitment in different microsites along a windward-leeward transect across shrub canopy.We hypothesized that:(1)the negative effects of grazing on N.tenuis fructification are reflected in its seed rain,soil seed bank,and seedling recruitment,especially in interpatches;(2)Nassella tenuis seed rain reduction,soil compaction by cattle in grazed sites,and removal of seeds by wind decrease its soil seed bank,especially in microsites exposed to the predominant wind;and(3)the decrease in N.tenuis soil seed bank and cover increase in annual species in grazed sites have negative effects on its seedling recruitment,especially in microsites exposed to predominant wind.We placed seed traps,collected soil samples,and monitored seedling recruitment in different locations around shrub canopy to address our hypotheses.Also,we established a manipulative experiment in which we sow N.tenuis seeds and followed its recruitment in different microsites.We compared the seed rain,soil seed bank,natural seedling recruitment,and sown seeds recruitment of N.tenuis between grazed and ungrazed sites.We analyzed differences between microsites along a windward-leeward transect across shrubs patches.Seed rain and soil seed bank had the same density in patches and interpatches both in ungrazed and grazed sites.But seed rain was higher,and soil seed bank was lower in ungrazed sites than in grazed sites.Almost all under-canopy microsites showed greater soil seed bank abundance and natural seedling recruitment in ungrazed sites.Sown seeds recruitment was the same between grazed and ungrazed sites,but it showed protective effects of shrubs in leeward microsites under grazed sites.As a conclusion,seed rain and soil seed bank are complementary under grazed sites. 展开更多
关键词 seed rain soil seed bank seedling recruitment MICROSITES GRAZING
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A seed rain community in a reforested post-agricultural field and adjacent secondary forest of Mount Papandayan Nature Reserve,West Java,Indonesia
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作者 Nuri Nurlaila Setiawan Endah Sulistyawati 《Journal of Forestry Research》 SCIE CAS CSCD 2021年第3期1013-1023,共11页
Understanding the mechanisms and barriers to the restoration of degraded land,especially post agriculture,will help provide protocols on effective ways of restoration into functional ecosystems.One of the barriers in ... Understanding the mechanisms and barriers to the restoration of degraded land,especially post agriculture,will help provide protocols on effective ways of restoration into functional ecosystems.One of the barriers in early stages of forest restoration is the arrival and availability of propagules.Seed rain and factors affecting it(i.e.,distance to the forest edge,species diversity and surrounding vegetation)were measured in a reforested post-agricultural field and in an adjacent secondary forest.Multivariate g lm analysis was used on the seed rain community data and univariate lm analysis on the most abundant seed captured(i.e.,Schima wallichii(DC.)Korth.).After 8 months of seed rain collection,there was a total of 3596 seeds from eight tree species.Seeds were more abundant and more diverse in the secondary forest(74.9%,8 species)compared to the reforested field(24.1%,2 species).There was a limitation on seed dispersal in reforested field from the adjacent forest.The abundance of S.wallichii seeds determined by the dominance of adult trees(136 trees/ha in the forest and 115 trees/ha in the reforested field).Our study suggests,that after 7 years of planting,the reforested field has received limited seed rain and has not yet recovered. 展开更多
关键词 seed rain Montane tropical forest Post-agriculture succession Forest edge Multivariate analysis
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Community Dynamics of Seed Rain in Mixed Evergreen Broad-leaved and Deciduous Forests in a Subtropical Mountain of Central China 被引量:9
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作者 Ze-Hao Shen Yuan-Yuan Tang +3 位作者 Nan Lü Jun Zhao Dao-Xing Li Gong-Fang Wang 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2007年第9期1294-1303,共10页
Seed dispersal is a key process within community dynamics. The spatial and temporal variations of seed dispersal and the interspecific differences are crucial for understanding species coexistence and community dynami... Seed dispersal is a key process within community dynamics. The spatial and temporal variations of seed dispersal and the interspecific differences are crucial for understanding species coexistence and community dynamics. This might also hold for the mixed evergreen broadleaved and deciduous forests in the mountains of subtropical China, but until now little existing knowledge is available for this question. In 2001, we chose to monitor the seed rain process of our mixed evergreen broad-leaved and deciduous forest communities in Mount Dalaoling National Forest Park, Yichang, Hubei Province, China. The preliminary analyses show obvious variations in seed rain density, species compositions and timing of seed rain among four communities. The average seed rain densities of the four communities are 2.43 ± 5.15, 54.13 ±182.75, 10.05 ±19.30 and 24.91 ± 58.86 inds/m^2, respectively; about one tenth the values in other studies in subtropical forests of China. in each community, the seed production is dominated by a limited number of species, and the contributions from the others are generally minor. Fecundity of evergreen broadleaved tree species is weaker than deciduous species. The seed rain of four communities begins earlier than September, and stops before December, peaking from early September to late October. The beginning date, ending date and peak times of seed rain are extensively varied among the species, indicating different types of dispersal strategies. According to the existing data, the timing of seed rain is not determined by the climate conditions in the same period, while the density of seed rain may be affected by the disturbances of weather variations at a finer temporal resolution. 展开更多
关键词 interspecific difference Mount Dalaoling mountain mixed evergreen broad-leaved and deciduous forests seed rain species composition weather effect.
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Seed Dynamics in Relation to Gaps in a Tropical Montane Rainforest of Hainan Island,South China:(Ⅰ)Seed Rain 被引量:1
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作者 Run-Guo Zang Wei-Yin Zhang Yi Ding 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2007年第11期1565-1572,共8页
Seed dynamics is an important part of stand dynamics in forest ecosystems. In this paper, 26 gaps were randomly selected to study the influence of gaps on the spatial and temporal patterns of seed rains in a tropical ... Seed dynamics is an important part of stand dynamics in forest ecosystems. In this paper, 26 gaps were randomly selected to study the influence of gaps on the spatial and temporal patterns of seed rains in a tropical montane rainforest of Hainan Island, South China. Three zones for each gap, including outside gap zone (Non-gap), transitional gap zone (EG-CG), and central gap zone (CG), were designed, and fourseed traps (each lm x lm in size) were placed in each zone. Seed rains were collected by these traps every 10 days from June 2001 to May 2002. Seed rain varied greatly with season and generally exhibited a pattern of unimodal change during the study period: seed abundance and species richness were both greater in the wet season than in the dry season. Gaps significantly influenced the temporal patterns of both species richness and density of seed rains. Gaps had no significant influences on the spatial distribution patterns of seed rain species richness, but significantly affected the spatial distribution pattern of seed rain densities. Among the three different zones of gaps, the outside gap zone generally received more seeds inputs than the two other gap zones. 展开更多
关键词 forest regeneration gap dynamics Hainan Island seed dispersal seed rain supply-side process tropical montane rain forest.
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Effects of simulated acid rain on seedling emergence and growth of five broad-leaved species 被引量:1
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作者 樊后保 李传荣 《Journal of Forestry Research》 SCIE CAS CSCD 1999年第2期83-86,共4页
Seeds and seedlings of five broad-leaved species were separately exposed to simulated acid rain at pH values of 2.0, 3.5, 5.0, and 6.0, or to distilled water (the control). The results showed that seed germination was... Seeds and seedlings of five broad-leaved species were separately exposed to simulated acid rain at pH values of 2.0, 3.5, 5.0, and 6.0, or to distilled water (the control). The results showed that seed germination was remarkably inhibited by pH 2.0 treatment for three species. Significant foliar damage, decline in chlorophyll contents, and retardation of the seedlings growth of all the species, were observed at pH 2.0 treatment. The pH 2.0 treatment seemed to be a threshold level for inhibition of seed germination and seedling growth for all the treated species, while seedling was stimulated at pH value between 3.5 and 5.0. 展开更多
关键词 Simulated acid rain Broad-leaved species seed germination seedling growth
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Characteristics of Soil Seed Bank and Natural Regenerations in Pinus densata Natural Forest of Southeast Tibet 被引量:6
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作者 卢杰 李照青 +1 位作者 唐晓琴 薛敬丽 《Agricultural Science & Technology》 CAS 2017年第7期1248-1254,共7页
Pinusdensata is one of the main constructive species for coniferous forests in southeast Tibet. P. densata forests are important water conservation forests in the drainage basins of the middle and lower reaches of Yal... Pinusdensata is one of the main constructive species for coniferous forests in southeast Tibet. P. densata forests are important water conservation forests in the drainage basins of the middle and lower reaches of Yalu Tsangpo River, Nyang River and Parlung Zangbo River. In this study, with P. densata forest distributed in southeast Tibet as research object, the seed rain, soil seed bank, seed germination and natural regeneration of P. densata were monitored and ana- lyzed by field investigation, located monitoring and indoor experimental analysis. The results showed that the average intensity of the seed rain of P. densata was 249.30±78.42 seeds/m2, in which the intensity of full seeds was 168.09±56.36 seeds/m2, the intensity of seeds damaged by worms was 41.11±20.25 seeds/m2, and the intensity of empty seeds was 40.10±21.04 seeds/m2. The intensity of the seed rain exhibited a single-peak trend of increasing at first and decreasing then over time. The spatial distribution patterns in the whole seed falling process and at different seed falling time all exhibited clumping distribution, and within in certain range, with the distance from the seed tree increasing, the diffusion intensity of the seed rain was weakened, exhibiting approximately normal distribution. In average density of P. densata seeds in the soil seed bank of P. densata was 231 seeds/m2, in which 62.77% of seeds were distributed in the litter layer, and 37.23% of seeds were distributed in the soil layer, and about 8% of seeds were lost during the pro- cess from seed rain to soil seed bank. Field sowing observation showed that the accumulated germination rate curve of P. densata fitted with Logistics equation y= 91.404/(1+e66194.449). The height structure, basal diameter structure and age structure of seedlings and young trees of P. densata were all of reverse "J" type, indicating good natural regeneration of P. densata. This study would provide a science basis for protection and resource management of P. densata, and further enrich the eval- uation content of national ecological safety curtain of the Tibet plateau. 展开更多
关键词 Pinus densata natural foresti seed rain Soil seed bank seed germi-nation Natural regeneration Southeast Tibet
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天目山常绿落叶阔叶混交林种子雨特征及其与群落组成的关系 被引量:2
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作者 王通 郑枭 +4 位作者 庞春梅 丁山 宋思婧 余树全 《生态学报》 CAS CSCD 北大核心 2024年第2期780-792,共13页
林木种子是森林更新的重要物质基础,其数量多少与组成会对群落动态和生态系统的结构与功能产生深刻影响。为了更好的了解天目山常绿落叶阔叶混交林动态变化,利用种子收集器对天目山常绿落叶阔叶混交林种子雨进行了一年定位监测,分析了... 林木种子是森林更新的重要物质基础,其数量多少与组成会对群落动态和生态系统的结构与功能产生深刻影响。为了更好的了解天目山常绿落叶阔叶混交林动态变化,利用种子收集器对天目山常绿落叶阔叶混交林种子雨进行了一年定位监测,分析了种子雨物种组成、季节动态、空间动态、种子性状以及种子雨与群落树种空间关系。结果表明:(1)天目山常绿落叶阔叶混交林种子雨密度为921.33粒m^(-2) a^(-1),一年中每月都能收集到一定数量种子,月平均种子雨密度为76.78粒/m^(2),种子雨密度最大高峰是在10月份,达到263.78粒/m^(2),种子雨散布具有很大的空间变异,群落种子雨空间分布格局呈聚集分布。(2)一年中共收集到30个物种的种子,单粒种子平均重量为0.065 g,其中小叶青冈重量最大为0.405 g,最小的为柳杉重量为0.003 g,不同散布方式和不同果实类型的物种种子重量差异显著,在散布方式中重力散布的种子重量最大,在果实类型中坚果的种子重量最大。(3)植物群落物种对种子雨组成,特别是优势种的物种丰富度有很大贡献,种子不同的散布方式会影响种子雨与母树组成的相似性,风力散布的相似系数的最高值(R_(max))和距种子雨收集器的距离(d)均最大(风力散布:R_(max)=0.212,d=8 m;动物散布:R_(max)=0.143,d=6 m;重力散布:R_(max)=0.100,d=7 m),种子雨密度与周围母树数量在一定范围内呈显著正相关。综上,天目山常绿落叶阔叶混交林种子物种种类丰富,种子雨具有明显的季节动态和空间变异,符合亚热带常绿落叶阔叶混交林种子雨时空动态的典型特征,通过风力散布的种子在远距离传播上有更大的优势。 展开更多
关键词 天目山 常绿落叶阔叶混交林 种子雨 密度 季节动态 空间分布
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新疆天山云杉种子雨时空动态分布及种子萌发特性
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作者 赵鑫 陈虹 +3 位作者 赵善超 陈兵权 郭来珍 周昊亮 《浙江农林大学学报》 CAS CSCD 北大核心 2024年第3期542-548,共7页
【目的】研究新疆天山云杉Picea schrenkiana var.tianschanica种子雨时空动态分布规律和种子萌发状况,为预测森林群落的演替趋势,并为保护天山森林生态系统的物种多样性提供科学依据。【方法】在林场设置3块面积为1 hm^(2)天然林永久... 【目的】研究新疆天山云杉Picea schrenkiana var.tianschanica种子雨时空动态分布规律和种子萌发状况,为预测森林群落的演替趋势,并为保护天山森林生态系统的物种多样性提供科学依据。【方法】在林场设置3块面积为1 hm^(2)天然林永久固定监测样地,采用机械布局的方法以10 m×10 m的样方为单位,在样方中心设置1个种子雨收集器,每个样地共100个收集器。采用方差/均值(C_(x))、负二项指数(K)、聚集度指标(I)、Cassie R M指标(CA)等4种空间分布类型评价方法判别种子雨空间分布状态。此外,进行种子萌发试验,分别测定种子千粒重、发芽势和发芽率。【结果】9月下旬至10月中旬散种量较高;2022年的种子雨总量极显著高于2021年的种子雨总量;C_(x)为2047.01、K为1.02、I为2046.01、CA为0.99,4个指标均显示种子空间分布呈聚集分布;各样地高峰期的天山云杉种子千粒重显著高于初始期和末尾期的天山云杉种子千粒重;而种子雨初始期和高峰期的种子平均发芽势与平均发芽率差异不显著,但都显著高于末尾期的种子的平均发芽势和平均发芽率。【结论】天山云杉种子的散种量存在较大的年际变化,且种子空间分布呈聚集分布,落种高峰期为9月下旬至10月中旬,此时种子质量最大,平均发芽率和发芽势最高。 展开更多
关键词 天山云杉林 种子雨 空间分布 种子萌发
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Regenerative Role of Soil Seed Banks of Different Successional Stages in A Saline-alkaline Grassland in Northeast China 被引量:5
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作者 MA Hongyuan LI Jingpeng +3 位作者 YANG Fan Lü Xiaotao PAN Yuepeng LIANG Zhengwei 《Chinese Geographical Science》 SCIE CSCD 2018年第4期694-706,共13页
Soil seed banks can act as a potential seed source for natural revegetation and restoration. However, in a saline-alkaline grassland, it remains unclear how the stages of vegetation succession affect the characteristi... Soil seed banks can act as a potential seed source for natural revegetation and restoration. However, in a saline-alkaline grassland, it remains unclear how the stages of vegetation succession affect the characteristics of soil seed banks and the potential of soil seed banks of different successional stages for vegetation restoration. In this study, seasonal changes of the soil seed bank, and seed production and dispersal dynamics along degradation successional gradients were investigated in a saline-alkaline grassland in Northeast China, where the dominant grass during the 1960 s, Leymus chinensis was replaced with the secondary successional order of Puccinellia chinampoensis, Chloris virgata, and Suaeda salsa, together with bare patches. It was found that the soil seed bank composition varied according to the changing vegetation and had the highest species richness(7–16) in the climax successional stage, but had a low S?rensen similarity(0.22–0.37) with the aboveground vegetation. There was a high seed density of the soil seed bank(21 062–62 166/m2 in August and December) and also high S?rensen similarity index values(0.47–0.60) in the secondary successional stages of P. chinampoensis, C. virgata, and S. salsa. In bare patches, there were many seeds in the soil seed bank and some seedlings also appeared in the aboveground vegetation, indicating the existence of a persistent soil seed bank. Seed density and species richness differed substantially among the different successional stages, which was related to the reproductive characteristics of the standing plants in vegetation communities. Due to the lack of propagules of perennial species, especially the climax species of L. chinensis, in the soil, the successful restoration of the degraded saline-alkaline grassland was not possible. The study proved that in a degraded saline-alkaline grassland dominated by biennial or annual species, the soil seed bank was important for the revegetation of the current dominant plants, but not for the restoration of the original target species. Therefore, it is necessary to induce seeds or other propagules of the target perennial species. 展开更多
关键词 soil seed bank seed dispersal ecological restoration PHENOLOGY SUCCESSION seed rain
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Controls of seed quantity and quality on seedling recruitment of smith fir along altitudinal gradient in southeastern Tibetan Plateau 被引量:2
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作者 WANG Jing-sheng FENG Ji-guang +6 位作者 CHEN Bao-xiong SHI Pei-li ZHANG Jun-long FANG Jiang-ping WANG Zhi-kai YAO Shuai-chen DING Lu-bin 《Journal of Mountain Science》 SCIE CSCD 2016年第5期811-821,共11页
Alpine treeline ecotones are harsh environment for tree establishment due to low temperature. Tree establishment at treelines requires favorable climate, suitable microsites, and viable seeds. But most researches have... Alpine treeline ecotones are harsh environment for tree establishment due to low temperature. Tree establishment at treelines requires favorable climate, suitable microsites, and viable seeds. But most researches have been addressed treeline microclimate and its effects on tree regeneration, the knowledge of seed quantity and quality and its controls on seedling recruitment were limited. We measured seed rain, soil seed bank, seed germination rate and seedling recruitment in natural forests in combination with seed transplanting manipulation to evaluate the controls of seed quantity and quality on seedling recruitment of Abies georgei var. smithii (smith fir) along altitudinal gradient, with focus on treeline ecotone in the Sygera Mountains, southeastern Tibetan Plateau. Both seed quantity and seed quality of smith fir decreased with increasing altitude and was thereby associated with decline in seed germination rate. Seed quantity and seedling recruitment were better in north-facing slope than in south slope. The treeline ecotone above 42oo m appeared as the threshold altitude to sharply decrease seed quality and seedling recruitment. The emergence and overwintering rates of transplanting seeds from 3600-38oo m also went down remarkably above 4200 m at north-facing slope. It also underpins the fact that treeline ecotone is the bottleneck of seedling recruitment. Our results suggest that seed quantity and quality are the principal limitation of treeline upward advance. This study also provides evidence to support stable treeline position in southeastern Tibetan Plateau. 展开更多
关键词 Abies georgei var. smithii TREELINE seed rain Soil seed bank seed quality seedling recruitment
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黑龙江中央站保护区种子雨和凋落物特征
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作者 岳阳 王洪峰 +2 位作者 郑兰涛 代铁柱 李显达 《高师理科学刊》 2024年第5期76-81,共6页
在中央站保护区,采用机械布点法设置收集器对种子雨和凋落物进行动态监测,并对主要树种的种子雨的组成、各月份之间的动态差异、时间动态、空间分布格局、凋落物的组成和时间动态进行分析.结果表明,种子雨主要由白桦、黑桦伴随少量兴安... 在中央站保护区,采用机械布点法设置收集器对种子雨和凋落物进行动态监测,并对主要树种的种子雨的组成、各月份之间的动态差异、时间动态、空间分布格局、凋落物的组成和时间动态进行分析.结果表明,种子雨主要由白桦、黑桦伴随少量兴安落叶松和蒙古栎种子组成;6月收集到的种子雨总量最多,其中种子雨量最多的树种是白桦;4个树种的种子雨的空间分布格局都呈现聚集分布;总凋落量和主要成分的凋落量呈明显的单峰型,其中凋落量以树叶为主,不同类别的凋落量都呈明显的单峰值. 展开更多
关键词 黑龙江中央站保护区 种子雨 凋落物 物种组成
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环境湿度影响人工催化消减雨效果的数值模拟研究
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作者 花少烽 查思佳 陈宝君 《大气科学》 CSCD 北大核心 2024年第2期572-584,共13页
利用耦合了碘化银催化过程的WRF(Weather Research and Forecast)模式,对2014年8月16日南京青奥会开幕式当天实施的人工催化作业开展数值模拟,评估催化效果并通过敏感性数值试验调查低空环境干层对催化效果的影响。结果表明,催化作业产... 利用耦合了碘化银催化过程的WRF(Weather Research and Forecast)模式,对2014年8月16日南京青奥会开幕式当天实施的人工催化作业开展数值模拟,评估催化效果并通过敏感性数值试验调查低空环境干层对催化效果的影响。结果表明,催化作业产生了减雨效果,低空干区的存在是影响催化效果的关键。当低空存在深厚的相对湿度很小的干层时,催化导致减雨效果;当增加低层的相对湿度即弱化低空干层,催化减雨效果减弱甚至出现增雨效果。催化增强了雪的形成过程但减弱了雪的增长过程尤其是凝华增长,导致雪粒子浓度增加但粒径减小,融化产生更多的小雨滴增强了蒸发过程,最终导致地面降水减少。 展开更多
关键词 人工消减雨 碘化银催化 环境干层 雪融化 雨蒸发
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Embryo Rescue via Artificial Seed Technique and Long-Term Preservation of Zephyranthes
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作者 Amir Ali Khoddamzadeh Bruce L. Dunn 《American Journal of Plant Sciences》 CAS 2022年第11期1347-1359,共13页
Zephyranthes is valued as a native ornamental landscaping plant and a traditional medicinal herb. Due to the low seed viability, this study was carried out to evaluate the potential of seed embryo rescue using the art... Zephyranthes is valued as a native ornamental landscaping plant and a traditional medicinal herb. Due to the low seed viability, this study was carried out to evaluate the potential of seed embryo rescue using the artificial seed technique and long-preservation in Z. atamasca and Z. grandiflora. Seed embryos were selected for encapsulation with different concentration of sodium alginate (3%, 4%, and 5%) and calcium chloride (either 25, 50, 75, and 100 mM) followed by no encapsulated embryos as a control. The greatest viability of encapsulated embryos was 95% in Z. grandiflora and 85% in Z. atamasca with the combination of 4% sodium alginate and 100 mM calcium chloride after two weeks at 5°C. The highest viability with A<sub>490nm</sub>0.12 and A<sub>490nm</sub>0.16 were achieved when embryos were cultured in pretreatment medium with 30 g/L sucrose in Z. grandiflora and Z. atamasca, respectively. The highest viability by TTC assay after cryopreservation was observed with 54% viability for Z. grandiflora and 48% viability with Z. atamasca, after 2 h of dehydration. Rain lilies embryos were successfully preserved functioned as artificial seed and cryopreservation using encapsulation-dehydration method has been established for both species that can be used for other flower species with some modifications. 展开更多
关键词 rain Lily Synthetic seed CRYOPRESERVATION ENCAPSULATION Ornamental Landscape Zephyranthes atamasc Zephyranthes grandiflora
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酸雨胁迫对玉米种子萌发及其生理机制的影响
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作者 王爱斌 《上饶师范学院学报》 2023年第6期51-56,共6页
采用人工配制pH=2.0、3.0、4.0、5.0、6.0和7.0(对照组,CK)的人工模拟酸雨培养玉米种子,通过对种子发芽率、发芽势、发芽指数以及种子萌发后贮藏物质消耗率、运转效率等数据的分析,探明酸雨胁迫对玉米种子萌发及其生理机制的影响。结果... 采用人工配制pH=2.0、3.0、4.0、5.0、6.0和7.0(对照组,CK)的人工模拟酸雨培养玉米种子,通过对种子发芽率、发芽势、发芽指数以及种子萌发后贮藏物质消耗率、运转效率等数据的分析,探明酸雨胁迫对玉米种子萌发及其生理机制的影响。结果表明:pH=5.0人工模拟酸雨胁迫处理组玉米种子的发芽指标、贮藏物质消耗率和运转效率均较对照组显著提高,而其他pH值人工模拟酸雨胁迫处理组玉米种子的发芽率、发芽势和发芽指数均显著下降;在萌发过程1-7 d内,所有人工模拟酸雨胁迫处理组玉米种子的呼吸强度均呈“先增后降”的趋势,而细胞质膜透性均呈“持续增加”的趋势;酸雨胁迫显著抑制玉米种子发芽率的pH阈值为3.0,显著抑制玉米种子发芽势、发芽指数、贮藏物质消耗率、贮藏物质运转效率和呼吸强度的pH阈值均为4.0,显著提高玉米种子细胞质膜透性的pH阈值为4.0。 展开更多
关键词 玉米(Zea mays L.) 酸雨胁迫 种子萌发 生理机制
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千岛湖片段化生境中木本植物种子雨基本特征及其影响因子 被引量:2
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作者 包明慧 方中平 +3 位作者 胡来庭 南歌 徐高福 于明坚 《广西植物》 CAS CSCD 北大核心 2023年第9期1600-1610,共11页
为探究片段化生境中木本植物种子雨的基本特征,该研究根据2015—2020年(研究期间)在千岛湖样岛上的植物群落长期监测样地内每月收集的种子雨数据,采用Kruskal-Wallis检验对木本植物的种子雨密度进行年际差异分析,对不同传播方式物种的... 为探究片段化生境中木本植物种子雨的基本特征,该研究根据2015—2020年(研究期间)在千岛湖样岛上的植物群落长期监测样地内每月收集的种子雨数据,采用Kruskal-Wallis检验对木本植物的种子雨密度进行年际差异分析,对不同传播方式物种的种子雨密度进行月份间差异性分析,并利用线性混合效应模型,探究岛屿空间特征(岛屿面积、距最近岛屿的距离、距大陆的距离)以及气候因子(0℃以上积温、降水量)对木本植物以及不同传播方式物种的种子雨密度的影响。结果表明:(1)2015—2020年6年间,在29个样岛用240个收集器共收集到877 178粒木本植物的成熟种子,属于26科40属52种。(2)动物传播是木本植物主要的种子传播方式,不同传播方式物种的种子雨时间动态存在较大差异。(3)木本植物的种子雨年密度与岛屿面积和年积温呈显著正相关,与年降水量呈显著负相关。(4)自主传播物种的种子雨月密度与距最近岛屿的距离呈显著正相关,而动物传播物种的种子雨月密度则与距大陆的距离呈显著正相关,风力传播物种的种子雨月密度与月积温呈极显著正相关。综上表明,生境片段化通过岛屿空间特征影响了木本植物种子雨的时间动态。 展开更多
关键词 种子雨 传播方式 生境片段化 时间动态 木本植物
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