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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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Differential seed removal,germination and seedling growth as determinants of species suitability for forest restoration by direct seeding–A case study from northern Thailand
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作者 Khuanphirom Naruangsri Pimonrat Tiansawat Stephen Elliott 《Forest Ecosystems》 SCIE CSCD 2023年第4期526-534,共9页
Background Direct seeding is potentially a more cost-effective alternative to conventional tree planting for restoring tropical forest ecosystems.However,seed loss,due to removal and damage by animals,can substantiall... Background Direct seeding is potentially a more cost-effective alternative to conventional tree planting for restoring tropical forest ecosystems.However,seed loss,due to removal and damage by animals,can substantially reduce seedling establishment.Therefore,this study examined the impact of seed predation on seedling establishment of five tree species,native to upland evergreen forests of northern Thailand:Hovenia dulcis,Alangium kurzii,Prunus cerasoides,Choerospondias axillaris and Horsfieldia amygdalina.We tested the hypothesis that excluding animals would significantly reduce seed removal,and increase both germination and seedling survival.The objective was to calculate a composite index of the relative suitability of the species studied for direct seeding.Methods Seeds were placed on the ground in a deforested site and subjected to five predator-exclusion treatments:wire cage,insecticide,cage+insecticide,open cage and no exclusion(control).Results Seed loss was highest for H.amygdalina(the largest seed tested).Across species,wire cages significantly reduced seed loss by 12.4%compared with controls(P<0.001)suggesting that vertebrates were the major seed predators.Seed germination ranged from 0 to 77%among the species tested.Based on relative species-performance scores(combining measures of survival and seedling growth),P.cerasoides was the most suitable species for direct seeding,followed by A.kurzii and C.axillaris,whilst H.dulcis and H.amygdalina were unsuitable.H.dulcis had small seeds with low seed germination,whereas H.amygdalina was subjected to high seed removal.Conclusion Exclusion of seed predators and the selection of suitable species may substantially increase the success of direct seeding,as a technique for restoring upland evergreen forest ecosystems.Testing more species for their suitability is needed,to provide more diverse options for forest restoration. 展开更多
关键词 Direct seeding Seed predation seedling survival species performance Northern Thailand
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Comparing the Seedling Growth of Six Precious Species in Southern China
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作者 Shijun Wu Jinyun Zhang +4 位作者 Guang Yang Jie Song Guifang Yang Yingping Chen Yao Liu 《生物工程前沿(中英文版)》 2023年第2期10-14,共5页
Seedling stage is an important period for forestry.The aim of this study was to estimate the growth trend of six local precious species and consider their implications for silviculture on forestry.We assessed height,d... Seedling stage is an important period for forestry.The aim of this study was to estimate the growth trend of six local precious species and consider their implications for silviculture on forestry.We assessed height,diameter near ground and crown width at 1,4,6 and 8-month.The variance analysis indicated that there were significant differences between species on all traits except diameter near ground and crown width at 8-month.There were no significant differences on height and crown width at all ages among replicates whereas there were significant differences on diameter near ground at 1 and 4 months,differences on diameter near ground at 6 months and no difference on diameter near ground at 8-month.The significant differences among interaction of species and replicates on diameter near ground at 1-months,4-month,6-month and crown width at 8-month were also found.Dalbergia odorifera had a higher growth period after 6-month.Aquilaria sinensis(Lour.)Spreng,Swietenia mahagoni(L.)Jacq.,Hopea hainanensis Merr.et Chun,Homalium hainanense Gagnep.and Cassia siamea Lam.had the same growth trend on all traits at the whole time. 展开更多
关键词 Local species Precious species Growth Traits seedlING
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Species spatial distributions in a warm-temperate deciduous broad-leaved forest in China 被引量:3
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作者 Huiyan Gu Jiaxin Li +1 位作者 Guang Qi Shunzhong Wang 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第4期1187-1194,共8页
Spatial distribution is fundamental for understanding species coexistence mechanisms in forest communities.Here we comprehensively explored fine-scale spatial patterns of tree species in a secondary warm-temperate dec... Spatial distribution is fundamental for understanding species coexistence mechanisms in forest communities.Here we comprehensively explored fine-scale spatial patterns of tree species in a secondary warm-temperate deciduous broad-leaved forest community in north China.Aggregated distribution patterns were predominant.Species functional traits had no significant effects on their spatial patterns.The aggregation intensity decreased with increasing DBH and abundance.The multivariate linear stepwise regression showed that abundance and maximum DBH were correlated with the aggregation intensity.Our results partially confirm that species attributes(abundance,DBH)and habitat heterogeneity may primarily contribute to spatial patterns and species coexistence in this secondary forest. 展开更多
关键词 Spatial distributions Aggregation intensity species functional trait Secondary warm-temperate deciduous broad-leaved forest
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Recovery of species diversity after disturbance of broad-leaved Korean pine mixed forest in Changbai Mountain
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作者 郝占庆 王庆礼 +1 位作者 邹春静 布仁仓 《Journal of Forestry Research》 SCIE CAS CSCD 1998年第3期147-151,共5页
Recovery of species diversity after catastrophic disturbance was influenced by a few factors, such as intensity of disturbance, availability of propagules, and the environmental conditions, In this paper, we examined ... Recovery of species diversity after catastrophic disturbance was influenced by a few factors, such as intensity of disturbance, availability of propagules, and the environmental conditions, In this paper, we examined pattems of species development after nearly 60a succession in bumed broad-leaved Korean pine mixed forest on northem slope of ChangbaiMountain. We aasessed the recovery of plant species diversity in 3 types of forests under the contition with gradient of soil moisture. Results revealed that recovery of plant species (liversity varied greatly under different environmental conditions.Species richness of secondary forests greatly related to the site condition. Secondary birch forest on mesic site had the greatest number of plant species and the following was poplar-birch forest and larch-birch forest.Most of characteristic taxa couldbe found in birch forest after 60a succession. For larch-birch forest on hydra site, most of climax species were still not able to invade, so it had the lowest species diversity. 展开更多
关键词 RECOVERY broad-leaved KOREAN PINE mixed FOREST Environmental conditions species DIVERSITY
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Effect of Lanthanum (Ⅲ) on Reactive Oxygen Metabolism of Soybean Seedlings under Supplemental UV-B Irradiation 被引量:7
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作者 闫生荣 黄晓华 周青 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第3期352-358,共7页
The effect of lanthanum (Ⅲ) on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation(UV-B:280~320 nm)at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydropon... The effect of lanthanum (Ⅲ) on reactive oxygen metabolism of soybean seedlings under elevated ultraviolet-B radiation(UV-B:280~320 nm)at 0.15 and 0.45 W·cm-2 levels respectively was studied through hydroponics in the laboratory.Plasmolemma permeability and contents of malonadialdehyde(MDA),hydrogen peroxide(H2O2),and proline gradually increased during the imposition of UV-B radiation and subsequently decreased during recovery from UV-B stress.The dynamic tendency of catalase(CAT)activity was similar to that of the above four indices.The activity of peroxidase(POD)initially increased,then remained at a high level,and finally dropped steeply when soybean seedlings were exposed to a low dosage of UV-B radiation.However,POD activity rose throughout and declined slightly on the eleventh day when soybean seedlings were stressed by a high dosage.With the addition of La (Ⅲ) of 20 mg·L-1,the rising tendency of plasmolemma permeability and contents of MDA,H2O2,and proline were slowed down during the stress period,whereas the declining speed was accelerated during the recovery period.The activities of CAT and POD were higher than those without La (Ⅲ) in all experiments.It suggested that the regulative effect of La (Ⅲ) on antioxidant enzymes such as CAT and POD could strengthen their capacities to scavenge reactive oxygen species(ROS),decrease contents of MDA and proline,and maintain normal plasmolemma permeability.Further more,the protective potential of La (Ⅲ) was better under low UV-B radiation than under a high one. 展开更多
关键词 lanthanum (Ⅲ) ultraviolet-B radiation soybean seedlings metabolism of reactive oxygen species CATactivity POD activity
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Combined community ecology and floristics,a synthetic study on the upper montane evergreen broad-leaved forests in Yunnan,southwestern China 被引量:6
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作者 Hua Zhu Yong Chai +3 位作者 Shisun Zhou Lichun Yan Jipu Shi Guoping Yang 《Plant Diversity》 SCIE CAS CSCD 北大核心 2016年第6期295-302,共8页
The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive... The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous,island-like,distribution.It is diverse,rich in endemic species,and likely to be sensitive to climate change.Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan.All trees with d.b.h.>1 cm in each plot were identified.Patterns of seed plant distributions were quantified at the specific,generic and family levels.The forests are dominated by the families Fagaceae,Lauraceae,Theaceae and Magnoliaceae,but are very diverse with only a few species shared between sites.Floristic similarities at the family and generic level were high,but they were low at the specific level,with species complementarity between plots.Diversity varied greatly among sites,with greater species richness and more rare species in western Yunnan than central Yunnan.The flora is dominated by tropical biogeographical elements,mainly the pantropic and the tropical Asian distributions at the family and genus levels.In contrast,at the species level,the flora is dominated by the southwest or the southeast China distributions,including Yunnan endemics.This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin,and has adapted to cooler temperatures with the uplift of the Himalayas.Due to great sensitivity to climate,high endemism and species complementarity,as well as the discontinuous,island-like,distribution patterns of the upper montane forest in Yunnan,the regional conservation of the forest is especially needed. 展开更多
关键词 BIOGEOGRAPHY Floristic composition Montane evergreen broad-leaved forest PHYSIOGNOMY species diversity YUNNAN
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Spatial structure and species composition of soil seed banks in moving sand dune systems of northeast China 被引量:2
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作者 Chunping Miao Xuehua Li +2 位作者 Meiyu Jia Xu Han Deming Jiang 《Journal of Forestry Research》 SCIE CAS CSCD 2016年第1期75-80,共6页
Soil seed banks can provide a mechanistic for understanding the recruitment dynamics and can inform conservation management of ecosystems. To investigate the contribution of soil seed banks to vegetation restoration i... Soil seed banks can provide a mechanistic for understanding the recruitment dynamics and can inform conservation management of ecosystems. To investigate the contribution of soil seed banks to vegetation restoration in moving sand dune systems, we compared seed structure and species similarity between soil seed banks and standing vegetation among moving sand dunes, ecotones and dune slacks in northeast China. Average seed density in dune slacks was greater than in ecotones or moving sand dunes. Seed density in the soil layer of 0-10 cm was greater than at 10-20 cm both in the moving sand dunes and the eco- tones, but seed densities were similar at depths of 10-20 and 20-30 cm in moving sand dunes. Moreover, the spatial autocorrelation of seed density on moving sand dunes was weak but was strong on the ecotones and dune slacks. The species in the soil seed bank of moving sand dune systems were nearly all annuals, and the low similarity was mainly due to the lack of perennial species that were common in standing vegetation. Consequently, vegetation restoration cannot mainly rely on the soil seed banks in the movingsand dunes and more attention should be paid to protection of the dune slacks because they are the main source of seed disperse and seedling recruitment in moving sand dune systems. 展开更多
关键词 Compositional similarity Seed density seedling recruitment species composition Horqin sandyland
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Different environmental factors drive tree species diversity along elevation gradients in three climatic zones in Yunnan,southern China 被引量:1
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作者 Xiaoyang Song Min Cao +7 位作者 Jieqiong Li Roger L.Kitching Akihiro Nakamura Melinda J.Laidlaw Yong Tang Zhenhua Sun Wenfu Zhang Jie Yang 《Plant Diversity》 SCIE CAS CSCD 2021年第6期433-443,共11页
Elevational patterns of tree diversity are well studied worldwide.However,few studies have examined how seedlings respond to elevational gradients and whether their responses vary across climatic zones.In this study,w... Elevational patterns of tree diversity are well studied worldwide.However,few studies have examined how seedlings respond to elevational gradients and whether their responses vary across climatic zones.In this study,we established three elevational transects in tropical,subtropical and subalpine mountain forests in Yunnan Province,southern China,to examine the responses of tree species and their seedlings to elevational gradients.Within each transect,we calculated species diversity indices and composition of both adult trees and seedlings at different elevations.For both adult trees and seedlings,we found that species diversity decreased with increasing elevation in both tropical and subalpine transects.Species composition showed significant elevational separation within all three transects.Many species had specific elevational preferences,but abundant tree species that occurred at specific elevations tended to have very limited recruitment in the understory.Our results highlight that the major factors that determine elevational distributions of tree species vary across climatic zones.Specifically,we found that the contribution of air temperature to tree species composition increased from tropical to subalpine transects,whereas the contribution of soil moisture decreased across these transects. 展开更多
关键词 Air temperature Climate zones Montane forest Soil moisture seedlING Tree species distribution
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Pre-sowing treatments for improved germination and growth of two rare native species of Bangladesh
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作者 M.A.Hossain K.S.Islam +2 位作者 N.Rajasree M.K.Hossain M.S.Alam 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第5期1277-1282,共6页
Pre-sowing treatments are expected to increase seed germination.This evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata Roxb.and Vitex glabrata R.... Pre-sowing treatments are expected to increase seed germination.This evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata Roxb.and Vitex glabrata R.Br.The hard seed coats were treated by rubbing with sand paper,nail clipping,and immersion in water and acid(H_2SO_4).Results indicate that G.pinnata showed a 90% germination rate and 30% germination energy when seed coats were nicked with a nail clipper.Rubbing with sand paper was the best pre-sowing treatment for V.glabrata,resulting a 80% germination rate and 30% germination energy.G.pinnata and V.glabrata seedlings from seeds soaked 24h in water resulted in maximum heights and collar diameters.These were significantly higher(at p〈0.05) than those of other treatments.The results indicate that scarification or nicking of seeds may have some negative impacts on seedling growth.Therefore,it is difficult to recommend a pre-sowing treatment of seeds for achieving both maximum germination and good early seedling growth. 展开更多
关键词 GERMINATION Early seedling growth HEIGHT Native species Garuga pinnata Vitex glabrata
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Functional relationships of nodulation response and biomass production at nursery stages of two fast-growing, leguminous-multipurpose tree species in Bangladesh: Albizia saman and Leucaena leucocephala
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作者 Md.Salim AZAD Samir MONDOL Md.Abdul MATIN 《Forestry Studies in China》 CAS 2013年第4期274-285,共12页
This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, ro... This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, root and shoot lengths, root biomass and shoot biomass) in Albizia saman and Leucaena leucocephala. The assessment started 60 days after seeding. The study revealed that nodulation response and biomass production in both species showed significant differences over time(p < 0.05) in all variables except in the root-shoot ratio(oven-dry) of L. leucocephala. The study also showed significant differences(p < 0.05) in nodule formation and biomass production at the end of the study period between the two species except in the number of nodules and leaves and the green root-shoot ratio. There were strong positive correlations between nodule formation and biomass production, i.e., the number of nodules and the age of plants, the number of nodules and leaves, as well as the number of nodules and biomass(root biomass and shoot biomass) in both species. The results obtained using principal component analysis(PCA) and correlation coefficients of the different characteristics of nodulation and biomass production were similar in both species. The PCA showed that shoot biomass(shoot green weight and shoot oven-dry weight) is positively correlated with PC1(with an eigenvalue of 7.50) and root length is positively correlated with PC2(with an eigenvalue of 0.19) in the case of A. saman. In the case of L. leucocephala, the PCA revealed that root biomass(root green weight and root oven-dry weight), shoot biomass and shoot length are also positively correlated with PC1, while nodule formation and the number of leaves are positively correlated with PC2(with an eigenvalue PC1 of 6.92 and PC2 of 0.49). 展开更多
关键词 leguminous tree species nitrogen fixation nodule formation nursery practice seedling growth
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Phenotype,Physiology,and Gene Expression of Barley Seedlings in Response to Nano Zinc Oxide Stress
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作者 Mengyuan Dong Rong Sun +6 位作者 Qianhui Yang Lantian Zhang Yangying Yong Yunxia Fang Xian Zhang Xiaoqin Zhang Dawei Xue 《Phyton-International Journal of Experimental Botany》 SCIE 2021年第6期1589-1598,共10页
In recent years,zinc oxide nanoparticles(ZnO NPs)have been widely used as zinc fertilizers and pesticides.The use of ZnO NPs in this way can provide benefits to humans,but also has potential risks.ZnO NPs inevitably e... In recent years,zinc oxide nanoparticles(ZnO NPs)have been widely used as zinc fertilizers and pesticides.The use of ZnO NPs in this way can provide benefits to humans,but also has potential risks.ZnO NPs inevitably enter the environment during their production and use,which affects the ecological environment and crop growth.In order to investigate the phenotype,physiology,and gene expression of barley(Hordeum vulgare L.)seedlings under ZnO NPs stress,the barely cultivars ZJU3(P21),Golden Promise(GP)and L23 were chosen for study.Different ZnO NPs concentrations were applied to compare the physiological and biochemical indexes of the barley seedlings and the responses of six stress-related genes,when seedlings were cultured to the two-leaf stage through hydroponics.The results showed that the density of brown spots on the leaf surface increased with increasing ZnO NPs concentration.ZnO NPs stress inhibited the root growth of barley seedlings,and P21 was the most sensitive.Furthermore,ZnO NPs stress could stimulate plants to produce a large number of reactive oxygen species(ROS),resulting in an imbalance between the production and removal of ROS and membrane lipid peroxidation in plants.This imbalance inhibited the growth and development of the barley seedlings.With increasing ZnO NPs concentration,the activity of superoxide dismutase was gradually increased,the activity of catalase was progressively decreased,and the contents of malondialdehyde and proline were increased.Compared with the control,among six stress-related genes,the expression levels of five genes were downregulated and one gene was upregulated in the experimental group.This study preliminarily revealed the toxic effect of ZnO NPs on seedlings and the effect on the expression of stress-related resistance genes in different barley varieties. 展开更多
关键词 Antioxidant enzymes barley seedlings reactive oxygen species gene expression zinc oxide nanoparticles
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Habitat heterogeneity and biotic interactions mediate climate influences on seedling survival in a temperate forest
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作者 Haikun Liu Hang Shi +5 位作者 Quan Zhou Man Hu Xiao Shu Kerong Zhang Quanfa Zhang Haishan Dang 《Forest Ecosystems》 SCIE CSCD 2023年第5期579-588,共10页
Seedling stage has long been recognized as the bottleneck of forest regeneration,and the biotic and abiotic processes that dominate at seedling stage largely affect the dynamics of forest.Seedlings might be particular... Seedling stage has long been recognized as the bottleneck of forest regeneration,and the biotic and abiotic processes that dominate at seedling stage largely affect the dynamics of forest.Seedlings might be particularly vulnerable to climate stress,so elucidating the role of interannual climate variation in fostering community dynamics is crucial to understanding the response of forest to climate change.Using seedling survival data of 69 woody species collected for five consecutive years from a 25-ha permanent plot in a temperate deciduous forest,we identified the effects of biotic interactions and habitat factors on seedling survival,and examined how those effects changed over time.We found that interannual climate variations,followed by biotic interactions and habitat conditions,were the most significant predictors of seedling survival.Understory light showed a positive impact on seedling mortality,and seedling survival responded differently to soil and air temperature.Effects of conspecific neighbor density were significantly strengthened with the increase of maximum air temperature and vapor pressure deficits in the growing season,but were weakened by increased maximum soil temperature and precipitation in the non-growing season.Surprisingly,seedling survival was strongly correlated with interannual climate variability at all life stages,and the strength of the correlation increased with seedling age.In addition,the importance of biotic and abiotic factors on seedling survival differed significantly among species-trait groups.Thus,the neighborhood-mediated effects on mortality might be significantly contributing or even inverting the direct effects of varying abiotic conditions on seedling survival,and density-dependent effects could not be the only important factor influencing seedling survival at an early stage. 展开更多
关键词 seedling survival Extreme interannual climate Negative density-dependence species coexistence
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富硅或富磷育秧降低水稻砷含量的效果及其分子机制
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作者 贾梦凡 李燕丽 +2 位作者 王兴祥 周志高 丁昌峰 《生态与农村环境学报》 CAS CSCD 北大核心 2024年第4期581-588,共8页
砷(As)主要通过硅和磷通道进入水稻根系,合理的硅和磷施用方式可有效调控水稻对As的吸收转运。研究通过在水稻育秧阶段进行硅或磷富集,探讨富硅或富磷秧苗移栽至As污染土壤后对糙米As含量的影响及分子机制。试验结果表明,富硅或富磷育... 砷(As)主要通过硅和磷通道进入水稻根系,合理的硅和磷施用方式可有效调控水稻对As的吸收转运。研究通过在水稻育秧阶段进行硅或磷富集,探讨富硅或富磷秧苗移栽至As污染土壤后对糙米As含量的影响及分子机制。试验结果表明,富硅或富磷育秧在不影响生长的前提下,可使秧苗的硅或磷整株吸收量分别增至对照的19.6和2.3倍。与常规育秧相比,富硅育秧处理糙米中总砷、三价砷、五价砷以及二甲基砷含量分别降低31.1%、32.1%、58.3%、33.5%。富磷育秧对糙米总砷含量没有显著影响,但使糙米五价砷含量降低59.2%。富硅或富磷育秧可显著增加As在水稻根系中的滞留且不同程度影响As在水稻各部位之间的转移系数。根系As转运基因相对表达量的分析结果表明,与对照相比,富硅育秧对OsLsi1的相对表达量没有显著影响,使OsLsi2的相对表达量下调26%,OsABCC1的相对表达量上调203%;富磷育秧对OsPT1的相对表达量没有显著影响,使OsPT4以及OsPT8的相对表达量分别下降51%和71%,OsABCC1的相对表达量上调22%。综上,富硅或富磷育秧可通过调控水稻根系As相关转运基因的表达来影响水稻对As的吸收及转运,从而降低糙米As含量。研究结果可为稻田As污染风险管控提供重要参考。 展开更多
关键词 育秧 转运基因 砷形态
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PAW及其与LTP的联合作用对小麦种子萌发及幼苗生长的影响
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作者 齐先科 李淼 +1 位作者 李彩虹 渠琛玲 《河南农业科学》 北大核心 2024年第4期20-29,共10页
以济麦22、百农307为材料,研究等离子体活化水(PAW,制备时间分别为5.0、7.5、10.0 min,分别命名为PAW-5、PAW-7.5、PAW-10)及其与低温等离子体(LTP)联合处理(LTP+W-5、LTP+W-7.5、LTP+W-10)对小麦种子萌发及幼苗生长的影响,以期为PAW、... 以济麦22、百农307为材料,研究等离子体活化水(PAW,制备时间分别为5.0、7.5、10.0 min,分别命名为PAW-5、PAW-7.5、PAW-10)及其与低温等离子体(LTP)联合处理(LTP+W-5、LTP+W-7.5、LTP+W-10)对小麦种子萌发及幼苗生长的影响,以期为PAW、LTP在小麦种子活力提高方面的应用提供理论依据。结果表明,2个小麦品种种子均于LTP处理9 s时的发芽率及发芽指数达到最佳,因此选用LTP处理时间9 s进行PAW与LTP联合作用效果研究。PAW、PAW与LTP联合处理均能提高小麦种子的发芽率、株高、幼苗鲜质量和干质量,并显著提高种子的活力指数,总体以LTP+W-7.5处理效果最好;未经LTP处理的种子与蒸馏水之间的接触角最大,表明其润湿性能最弱,相较之下,未经LTP处理的种子与PAW之间的接触角有所下降,而经LTP处理后的种子与蒸馏水或PAW之间的接触角极显著下降;与蒸馏水处理相比,PAW及其与LTP联合处理的小麦幼苗中的活性氧氮(RONS)含量总体上显著增加,而仅LTP处理的小麦幼苗中RONS含量无显著变化。综上,PAW及其与LTP联合处理均有效地促进了小麦种子萌发及幼苗生长,其中LTP+W-7.5处理的促进效果最佳。 展开更多
关键词 小麦 种子萌发 幼苗生长 低温等离子体 等离子体活化水 活力指数 润湿性能 活性氧氮
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五常市村庄绿化美化建设模式分析研究
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作者 王钦昊 《林业勘查设计》 2024年第1期22-26,共5页
村庄绿化美化建设包括现状调研、建设模式选择、树种与苗木选择,以及密度与配置等多个关键要素。通过对五常市村庄绿化美化现状和管理机制的调查,了解村庄绿化美化建设面临的问题,分析研究五常市村庄绿化美化的多种建设模式,提出乔灌草... 村庄绿化美化建设包括现状调研、建设模式选择、树种与苗木选择,以及密度与配置等多个关键要素。通过对五常市村庄绿化美化现状和管理机制的调查,了解村庄绿化美化建设面临的问题,分析研究五常市村庄绿化美化的多种建设模式,提出乔灌草花相结合的多种园林景观式建设模式,以期对村庄绿化建设提供全面的指导和建议。 展开更多
关键词 村庄绿化 建设模式 树种选择 苗木 五常市
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Does a shift in shade tolerance as suggested by seedling morphology explain differences in regeneration success of northern red oak in native and introduced ranges?
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作者 Peter Nosko Kerri Moreau +2 位作者 Christian Kuehne Kelly C.Major Jürgen Bauhus 《Journal of Forestry Research》 SCIE CAS CSCD 2022年第3期949-962,共14页
Across North America, forests dominated by Quercus rubra L. (northern red oak), a moderately shade-tolerant tree species, are undergoing successional replacement by shade-tolerant competitors. Under closed canopies, Q... Across North America, forests dominated by Quercus rubra L. (northern red oak), a moderately shade-tolerant tree species, are undergoing successional replacement by shade-tolerant competitors. Under closed canopies, Q. rubra seedlings are unable to compete with these shade-tolerant species and do not recruit to upper forest strata. In Europe, natural regeneration of introduced Q. rubra is often successful despite the absence of fire, which promotes regeneration in the native range. Considering that understorey light availability is a major factor affecting recruitment of seedlings, we hypothesized that Q. rubra seedlings are more shade tolerant in the introduced range than in the native range. Morphological traits and biomass allocation patterns of seedlings indicative of shade tolerance were compared for Q. rubra and three co-occurring native species in two closed-canopy forests in the native range (Ontario, Canada) and introduced range (Baden-Württemburg, Germany). In the native range, Q. rubra allocated a greater proportion of biomass to roots, while in the introduced range, growth and allocation patterns favored the development of leaves. Q. rubra seedlings had greater annual increases in height, diameter and biomass in the introduced range. Q. rubra seedlings in the introduced range were also younger;however, they had a mean area per leaf and a total leaf area per seedling that were five times greater than seedlings in the native range. Such differences in morphological traits and allocation patterns support the hypothesis that Q. rubra expresses greater shade tolerance in the introduced range, and that natural regeneration of Q. rubra is not as limited by shade as in the native range. The ability of Q. rubra seedlings to grow faster under closed canopies in Europe may explain the discrepancy in regeneration success of this species in native and introduced ranges. Future research should confirm findings of this study over a greater geographical range in native and introduced ecosystems, and examine the genetic and environmental bases of observed differences in plant traits. 展开更多
关键词 Alien species Cross-continental study Forest regeneration Introduced species seedling morphology Plant functional traits Quercus rubra
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Study on successions sequence of evergreen broad-leaved forest in Gutian Mountain of Zhejiang,Eastern China:species diversity
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作者 Zhenghua HU Mingjian YU 《Frontiers in Biology》 CSCD 2008年第1期45-49,共5页
Using the widely adopted scheme of space-for-time substitution for investigating 16 typical plots distri-buted as a pattern of contiguous grid quadrates within a sampling plot,the expressions of Shannon-Wiener index(H... Using the widely adopted scheme of space-for-time substitution for investigating 16 typical plots distri-buted as a pattern of contiguous grid quadrates within a sampling plot,the expressions of Shannon-Wiener index(H)for species diversity,Pielou index(J_(sw),J_(SI))for evenness and Simpson index(D)for ecological dominance are employed to investigate the species diversity(SD)of four evergreen broadleaved communities in the successions sequence within the Nature Reserve of the Gutian Mountains.Results showed that in the successions process from the coniferous to the mixed coniferous-broadleaved,then to Schima superba and finally to Castanopsis eyrei forest,the arbor layer SD showed the Shannon-Wiener index(H)as 1.9670,2.4975,2.6140 and 2.4356,respectively,characterized by their rise before drop and the shrub(herb)layer SD shows the maximum to be in the mixed coniferous-broadleaved(coniferous)forest(H arriving at 2.8625(1.5334)).In the vertical structure,on the other hand,for the sequenced coniferous forest,coniferous-broad mixed forest and Castnaopsis eyrei forest,the number of SD ranges in a decreasing order from the shrub,arbor to herb layer in contrast to the SD in a decreasing order of Schima superba forest ranging from the arbor to shrub and then to herb layer,and during the succession,the herb layer exhibits the maximum range of SD change among these layers,with its variation coefficients of 0.1572,0.0806,0.0899 and 0.1884 for H,J_(SW),J_(SI) and D,in order,in sharp contrast to the minimal SD range in the shrub layer,with the corresponding figures of 0.0482,0.0385,0.0142,and 0.1553. 展开更多
关键词 evergreen broad-leaved forest successions species diversity COMMUNITY Gutian Mountain
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不同强度光强胁迫对海带(Saccharina japonica)幼苗光合生理的影响
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作者 牛建峰 冯泽中 +6 位作者 孙振杰 王伟伟 张晓雯 梁广津 王立军 李晓捷 王广策 《海洋与湖沼》 CAS CSCD 北大核心 2023年第1期160-172,共13页
海带(Saccharinajaponica)是我国藻类生产的主要品种之一,其栽培面积和产量均居世界首位。2021~2022年产季,山东荣成海带主产区先后暴发了大规模病烂灾害,给当地水产经济造成了巨大损失。引起病烂的原因可能来自多方面,其中藻体所受光... 海带(Saccharinajaponica)是我国藻类生产的主要品种之一,其栽培面积和产量均居世界首位。2021~2022年产季,山东荣成海带主产区先后暴发了大规模病烂灾害,给当地水产经济造成了巨大损失。引起病烂的原因可能来自多方面,其中藻体所受光照过强及水体营养盐水平较低可能起到了一定作用,为此,基于海带幼苗的最小饱和光强、烟台高新区牟平自然海区海水氮磷浓度及不同海水深度下的光照强度测定结果,研究了梯度强光在不同海水营养盐水平下对海带生理的影响,以期为“烂菜”现象的病因分析提供一定的线索。结果显示,海带幼苗在700~900μE/(m^(2) s)强光胁迫3 d后, Fv/Fm可恢复至对照水平,光合色素合成活跃,营养盐含量较高的海水更有助于PSII的修复,但1 300~1 500μE/(m^(2) s)的强光辐射导致PSII不能恢复,岩藻黄素、叶绿素a及β-胡萝卜素含量显著降低。整个胁迫实验中,藻体总抗氧化能力(T-AOC)及其他抗氧化酶比活力大体上在强光胁迫的起始至第3天上调,而在胁迫第5天时又出现下降趋势,且在营养盐含量较高的处理组中,各样本活性均高于天然海水处理组样本。抗氧化酶基因的表达也呈现类似的变化趋势。在低于900μE/(m^(2) s)的光照条件下,抗氧化酶活性可以得到较好的维持,而海水中相对较为丰富的营养盐则有利于藻体抗氧化能力的维持。研究结果为荣成海带病烂暴发的原因分析提供了一定的借鉴。 展开更多
关键词 强光胁迫 活性氧清除 光系统修复 海带幼苗 抗氧化酶 岩藻黄素 β-胡萝卜素
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长江中下游地区28个常见乡土树种幼苗光合固碳能力比较
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作者 王晓荣 胡兴宜 +3 位作者 龚苗 付甜 庞宏东 杨佳伟 《湖北农业科学》 2023年第1期112-117,共6页
为筛选出固碳能力强和适应性好的树种,采用文献检索的方式,设置了生长条件相似、苗龄相近、试验方法相同,且为湖北省常见乡土树种等条件,筛选出符合条件的树种28个。对各树种的日净同化量、单位叶面积日净固碳量以及光响应参数等进行比... 为筛选出固碳能力强和适应性好的树种,采用文献检索的方式,设置了生长条件相似、苗龄相近、试验方法相同,且为湖北省常见乡土树种等条件,筛选出符合条件的树种28个。对各树种的日净同化量、单位叶面积日净固碳量以及光响应参数等进行比较分析,利用聚类分析法对28个树种按固碳能力和光合效率等级划分并归类。结果表明,28个树种的单位叶面积日净固碳量为4.00~16.49 g/(m^(2)·d),以榉树(Zelkova serrata)、夹竹桃(Nerium oleander)、黄栌(Cotinus coggygria var.cinerea)的日净固碳量较高。夹竹桃、栓皮栎(Quercus variabilis)、枫杨(Pterocarya stenoptera)为强阳性树种,香樟(Cinnamomum camphora)、乌桕(Triadica sebifera)、榉树(Zelkova serrata)等9个树种属阳性树种,楸树(Catalpa bungei)、喜树(Camptotheca acuminata)、无患子(Sapindus saponaria)等12个树种属中性树种,油茶(Camellia oleifera)、杜英(Elaeocarpus decipiens)、钩栗(Castanopsis tibetana)、香果树(Emmenopterys henryi)属耐阴树种。固碳能力强和适应性强的枫杨、乌桕、榉树、红椿(Toona ciliata)、楸树、喜树、栓皮栎可优先用于湖北省乃至长江中下游地区碳汇造林。在构建固碳高效的碳汇林时,应考虑将强阳性乔木和耐阴性灌木合理搭配。 展开更多
关键词 乡土树种 幼苗 光合固碳 长江中下游
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