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Inter- and intraspecific variability of plant individual growth and its role on species ranking in grasslands

Journal of Plant Ecology 2020年第3期13卷 378-386页

作者： Rémi Perronne Franck Jabot Julien Pottier UCA INRAEVetAgro SupUMR Ecosystème Prairialsite de Crouel5 chemin de BeaulieuF-63000 Clermont-FerrandFrance UCA INRAEUR LISCCentre de Clermont-Ferrand9 avenue Blaise PascalF-63178 AubièreFrance

Aims Individual growth constitutes a major component of individual ***,measuring growth rates of herbaceous plants non-destructively at the individual level is notoriously *** study,based on an accurate non-destructive method of aboveground biomass estimation,aims to assess individual relative growth rates(RGRs)of some species,identify its environmental drivers and test its consequences on community *** specifically address three questions:(i)to what extent environmental conditions explain differences in individual plant growth between sites,(ii)what is the magnitude of intraspecific variability of plant individual growth within and between sites and(iii)do species-averaged(dis-)advantage of individual growth compared with the whole vegetation within a site correlate with species ranking at the community level?Methods We monitored the growth of individuals of four common perennial species in 18 permanent grasslands chosen along a large pedoclimatic gradient located in the Massif Central,*** measured soil properties,levels of resources and meteorological parameters to characterize environmental conditions at the site *** design enables us to assess the influence of environmental conditions on individual growth and the relative extent of inter-individual variability of growth explained within and between *** determined the ranking of each of the four species in each site with botanical surveys to assess the relationship between species-averaged growth(dis-)advantage relative to the whole community and species rank in the *** Findings We found that environmental conditions explain a significant proportion of individual growth variability,and that this proportion is strongly variable between *** availability was the main driver of plant growth,followed by rainfall amount and potential evapotranspiration,while soil properties had only a slight *** further highlighted a moderate to high wit

关键词： relative growth rate species ranking non-destructive biomass estimation temperate permanent grasslands inter-individual variability

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relative effects of different leaf attributes on sapling growth in tropical dry forest

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Journal of Plant Ecology 2014年第6期7卷 544-558页

作者： Ravi K.Chaturvedi A.S.Raghubanshi J.S.Singh Institute of Environment and Sustainable Development Banaras Hindu UniversityVaranasi 221005India Ecosystems Analysis laboratory Department of BotanyBanaras Hindu UniversityVaranasi 221005India

Aims Soil moisture content(SMC)influences establishment,survival and development of plant species and is considered as the most important limiting factor in tropical dry forest(TDF).In this study we attempt to establish the relationship between leaf attributes and of tree saplings in TDF and address the following questions:(i)how are the functional attributes of dominant tree saplings of TDF affected by seasonal changes in SMC at different habitats?,(ii)what is the relationship of functional attributes with each other?,(iii)how are the functional attributes and their plasticity affected by habitat con-ditions?and(iv)can the functional attributes in single or in com-bination predict the growth rate of tree saplings of TDF?The study was conducted on four sites(Hathinala,Gaighat,Harnakachar and Ranitali,listed in order of decreasing SMC)within the tropical dry deciduous forest in northern *** We analysed eight leaf attributes,specific leaf area(SLA);leaf dry matter content(LDMC);leaf nitrogen concentration(leaf N);leaf phosphorus concentration(leaf P);chlorophyll concentration(Chl);mass-based photosynthetic rate(Amass);mass-based stomatal con-ductance(Gsmass);intrinsic water use efficiency(WUEi)and three growth attributes,relative diameter increment(RDI);relative height increment(RHI);relative growth rate(RGR)of the 10 dominant tree saplings(viz.,Acacia catechu,Anogeissus latifolia,Boswellia serrata,Buchanania lanzan,Diospyros melanoxylon,Hardwickia binata,Lagerstroemia parviflora,Lannea coromandelica,Shorea robusta and Terminalia tomentosa)of a TDF and observed the effects of site,season and species for a period of 2 *** were selected in gradients of ***-wise multiple regression was performed to predict RDI,RHI and RGR from mean values of SMC and leaf *** Findings All the 11 attributes were interrelated and differed significantly among the 10 *** response varied across sites and *** the SMC g

关键词： tropical dry forest soil moisture content deciduousness tree saplings leaf attributes relative growth rate

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Effect of NaNO_3 Concentrations on the growth and Fatty Acid Compositions of Nitzschia closterium and Chaetoceros gracilis*

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Marine Science Bulletin 2003年第1期5卷 69-74页

作者：梁英麦康森孙世春 Key Laboratory of Mariculture Ministry of Education Ocean University of Qingdao Qingdao 266003

Fatty acid compositions of two strains of marine diatoms Nitzschia closterium ( MACC B222 ) and Chaetoceros gracilis ( MACC B13 ) have been examined. The microalgae have been grown at different initial NaNO3 concentrations ( 75, 375, 750, 1 125, 1 500, 1 875 mg/L ) and harvested at the late exponential phase. The results by one factor analysis of variance show that the NaNO3 concentrations have no significant influence on the relative growth rate of two strains of marine diatoms; the influence of NaNO3 concentrations on the fatty acids differs from species to species. The major fatty acids of two --diatom strains are 14:0, 16:0, 16:1n7 and 20:5n3 ( EPA ) , B13 also has high percentage -of 20:4n6 ( 6.0 ~ 9.1% ).

关键词： Nitzschia closterium Chaetoceros gracilis NaNO3 relative growth rate fatty acid

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Regeneration characteristics of gaps and their effect on Abies fargesii forests in the Shennongjia National Nature Reserve,China

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Forestry Studies in China 2010年第4期12卷 206-212页

作者： FU Chan-juan LIU Yan-hong XIONG Wen-juan Key Laboratory for Silviculture and Conservation of the Ministry of Education Beijing Forestry University Beijing 100083 P. R.China

Abiesfargesii is an evergreen tree species of the Pinaceae family, one of the most important cultivated timber species, endemic to China. It is of great importance for the maintenance of vegetation landscape and the preservation of endangered animal species. Community regeneration of forest gaps and their effect on A. fargesii forests in the Shennongjia National Nature Reserve were studied based on two-year field survey data. The results show that 1） forest gap regeneration is an important approach for the regeneration of A. fargesii communities; regeneration characteristics in the gaps of the broad-leaved species Betula albo-sinensis Burk. and the shade-tolerant species A. fargesii differed from those of understory species. 2） A. fargesii is most predominant in early gap regeneration but, over time, is gradually replaced by other species. Seedlings less than three years old accounted for 45.7% of all seedlings and only 6.3% of saplings older than seven years. 3） In terms of height and basal diameter in different sized gaps, size of seedlings showed the following trend： medium 〉 small 〉 large 〉 understory; the relative growth rate appeared in the same order. 4） The size of seedlings did not appear different between within-gap positions in medium and small gaps, but the tallest seedlings grew in the south of the large gaps and declined towards the center and north edges. 5） Principal component analysis suggests that the most important factors for the growth and distribution ofA. fargesii seedlings decreased in order of gap size, slope direction, gap microenvironment and tree-shrub-grass cover.

关键词： Abiesfargesii regeneration gap relative growth rate

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Predicting Compensatory growth and Reproduction in Agricultural Weeds Using a Plant＇s growth rate Trajectory： A Test with Defoliation of Abutilon theophrasti

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Journal of Agricultural Science and Technology(A) 2016年第4期6卷 255-260页

作者： David Alexander Wait Department of Biology Missouri State University Springfield MO 65897 USA

A plant＇s capacity to compensate for pest damage as a function of resource availability needs to be predictable in order to apply biocontrol agents effectively. In this research, it was hypothesized that a weedy plant species＇ capacity to compensate for defoliation is related to how resource availability affects a plant＇s growth trajectory. growth rate trajectory is defined as the percent change in relative growth rate or the slope of a plant＇s relative growth rate. 90 Abutilon theophrasti, a common weed species, in cultivated fields of corn and soybean, grew in a greenhouse for 70 d under three nitrogen （N） fertilization treatments. ＂Unfertilized＂ plants were not fertilized, ＂bulk＂ fertilized plants received 0.6 g N on day 15 and ＂exponential＂ fertilized plants received a total of 0.6 g N supplied at an exponential rate of 10% per day with a starting concentration of 0.02 g N on day 15. On day 25, 15 plants in each N treatment had 75% of total leaf area removed. Biomass and reproductive compensation were determined after 50 d and 70 d of growth. Results showed that bulk plants had the greatest absolute growth, but also the greatest decline in growth rates and the least capacity for compensation. Unfertilized plants had the lowest absolute growth, but declines in growth rates were similar to bulk plants with only a slightly greater compensatory capacity. Exponential plants had intermediate absolute growth, but the least decline in growth rates and the greatest capacity for compensation. This experiment indicates that a plant＇s growth rate trajectory, and not high or low relative growth rates or N availability per se, can be used to predict a weedy plant＇s capacity to compensate for herbivory, and has implications for biocontrol of weedy species.

关键词： Biocontrol compensatory growth herbivory nitrogen fertilization relative growth rate reproductive allocation.

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Carbon Dioxide Concentrations and Light Levels on growth and Mineral Nutrition of Juvenile Cacao Genotypes

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American Journal of Plant Sciences 2021年第5期12卷 818-839页

作者： Virupax C. Baligar Marshall K. Elson Alex-Alan F. Almeida Quintino R. de Araujo Dario Ahnert Zhenli He USDA-ARS-Beltsville Agricultural Research Center Beltsville USA Department of Biological Science State University of Santa Cruz Ilhéus Brazil Indian River Research and Education Center IFAS University of Florida Fort Pierce USA

In many countries cacao (Theobroma cacao L.) is invariably grown as an understory crop in agroforestry types of cropping systems and subjected to low levels photosynthetic photon flux density (PPFD) due to presence of large number of upper story shade trees with poorly managed canopy structure. In recent years carbon dioxide concentration in the atmosphere is steadily increasing and it is unclear what impact this will have on performance of cacao grown under shade of upper story shade trees. A climatically controlled greenhouse experiment was undertaken to evaluate the effects of ambient and elevated carbon dioxide (400 and 700 μmol·mol-1) and three levels of PPFD (100, 200, and 400 μmol·m-2·s-1) on growth, and macro- and micronutrient use efficiency of three genetically contrasting cacao genotypes (CCN 51, VB 1117 and NO 81). Intraspecific variations were observed in cacao genotypes for growth parameters at ambient to elevated carbon dioxide and low to adequate levels of PPFD. With the exceptions of total root length and leaf area, irrespective of carbon dioxide and PPFD levels, all three genotypes showed significant differences in all the growth parameters. For all the cacao genotypes, increasing PPFD from 100 to 400 μmol·m-2·s-1 and carbon dioxide from 400 to 700 μmol·mol-1

关键词： relative growth rate Net Assimilation rate Mineral Nutrient Influx and Transport Mineral Nutrient Uptake Efficiency

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Impacts of Date Palm Seeds （Phoenix dactyliferous L.） on growth Indices and Nutrient Utilization of Common Carp Cyprinus carpio L,

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Journal of Agricultural Science and Technology(B) 2017年第4期7卷 280-284页

作者： Vian Mohammed Ahmed Nasreen Mohialddin Abdulrahman Sarwar Abubaker HamaAmeen Bakhan Rafiq Hassan Abu Baker Kamil Abbas Baxan Akram Hussen Idres Shexa Hamad Sana Abdulla Karem Kale Mamand Aziz Department of Animal Sciences College of Agricultural Sciences University of Sulaimani Sulaimaniya lraq

This study was carried out to study the effect of adding different levels of date palm seed （Phoentix dactyliJProus） powder in the diet of common carp （Cyprinus carpio） at fish laboratory of Animal Production Department, College of Agricultural Sciences, Sulaimani University, Sulaimani, Iraq. The actual experimental feeding trials were conducted for 70 d and the adaptation period for 21 d. A total of 81 common carp fingerlings weighted 62 ± 2 g were divided into three experimental groups. The control treatment T1 was with 0 g date palm seed, T2 with 2.5 g date palm seed per kg diet and T3 with 5 g date palm seed per kg diet. Each treatment was in three replicates in which three common carp fingerlings were stocked in each aquarium which fed the experimental diets twice daily. The results indicated that weight gain （WG） and specific growth rate （SGR） in the third treatment （T3） group were significantly higher than those of fish fed control diets. T2 consumed more diet than other treatments with 306.940 g with higher feed conversion ratio （FCR）; T3 was higher significantly in food efficiency. No significant （P 〈 0.05） differences obtained from consumed protein while the protein efficiency ratio was significantly higher in T3 with 319.323. Control was higher significantly in flesh weight without viscera with the third treatment; in flesh weight without head and viscera each the control and the second treatment was significantly higher than the third treatment. As a conclusion, the date palm seeds powder have a positive effect on growth performance of common carp.

关键词： Weight gain specific growth rate relative growth rate feed conversion ratio food efficiency protein efficiency ratio date palm seeds common carp.

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