检索结果-南通市图书馆

Alpine grassland degradation intensifies the burrowing behavior of small mammals:evidence for a negative feedback loop

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第2期19卷 240-252页

作者： Zaiwei WANG Jiawen YAN Amy MARTIN Dianne HBRUNTON Jiapeng QU Jin-Sheng HE Weihong JI Zhibiao NAN State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhouChina Manaaki Whenua-landcare research LincolnNew Zealand School of Natural Sciences Massey University(Albany Campus)AucklandNew Zealand Key Laboratory of Adaptation and Evolution of Plateau Biota Northwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina Qinghai Haibei National Field research Station of Alpine Grassland Ecosystem Northwest Institute of Plateau BiologyChinese Academy of SciencesXiningChina Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking UniversityBeijingChina

Globally,grassland degradation is an acute ecological problem.In alpine grassland on the Tibetan Plateau,increased densities of various small mammals in degraded grassland are assumed to intensify the degradation process and these mammals are subject to lethal control.However,whether the negative impact of small mammals is solely a result of population size or also a result of activity and behavior has not been tested.In this study,we use plateau pika as a model to compare population size,core area of colony,and the number of burrow entrances and latrines between lightly and severely degraded grassland.We test whether the alleged contribution of pika to grassland degradation is a result of increased population size or increased burrowing activities of individuals in response to lower food abundance.We found that grassland degradation resulted in lower plant species richness,plant height,and biomass.Furthermore,the overall population size of pika was not significantly affected by location in lightly and severely degraded grassland.However,pika core areas in severely grassland degradation were significantly larger and had significantly higher densities of burrows and latrines.Our study provides convincing evidence that habitat-induced changes in the behavior of small,burrowing mammals,such as pika,can exacerbate grassland degradation.This finding has significant implications for managing small mammals and restoring degraded grassland ecosystems.

关键词： burrowing behavior grassland degradation plateau pika population size small mammals

A thelytokous predatory mite is more cannibalistic towards distant kin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2023年第5期69卷 578-584页

作者： Keshi Zhang Zhi-Qiang Zhang School of Biological Sciences University of Auckland3A Symonds StreetAuckland1072New Zealand and Manaaki Whenua-landcare research 231 Morrin RoadAuckland1072New Zealand

Kin recognition has been widely observed in various taxa.Cannibalism avoidance may be a strong driver for the evolution of kin recognition,as it may avoid a reduction in inclusive fitness.Kin recognition has recently been observed in a generalist phytoseiid,Amblyseius herbicolus(Acari:Phytoseiidae).This study experimentally examined the degree of relatedness needed between prey larvae and cannibal adults of A.herbicolus for the occurrence of kin discrimination.The adults were individually placed in enclosed arenas with two prey,a daughter and a more distant related larva,to observe their cannibalizing choice.The adults of A.herbicolus did not discriminate between close relatives(daughter versus niece)but preferably cannibalized more distant kin(i.e.,first and second cousins once removed).Phenotype matching and familiarization seem prominent as recognition mechanisms used by A.herbicolus adults.The effect of learning on kin recognition through prior contact in A.herbicolus requires further investigation.Studies on other adaptive functions of kin recognition of A.herbicolus,such as cooperation and parental care,may provide meaningful insights.

关键词： Acari cannibalism choice test close kin discrimination kin recognition

Prey life stages modulate effects of predation stress on prey lifespan,development,and reproduction in mites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2023年第3期30卷 844-856页

作者： Xiaoying Weil Guangyun Li Zhi-Qiang Zhang School of Biological Sciences The University of AucklandAucklandNew Zealand Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionSouthwest UniversityChongqingChina Manaaki Whenua-landcare research AucklandNewZealand

The non-consumptive effects of predator-induced stress can influence a variety of life-history traits.Many previous studies focused only on short-term effects such as development and reproductive rates.Recent studies have showed that long-term predation stress(given during the whole life of the prey)and short-term predation stress(provided during the immature stage of the prey)could generate completely opposite results:the former could decrease lifespan,whereas the later could increase lifespan.However,it is still unclear whether the advantage is because of the short duration of exposure or the early stage of life during which exposure was exerted.Thus,in this study,the prey(Tyrophagus putrescentiae)was exposed to predation stress from the predator(Neoseiulus cucumeris)during different life stages(larva,protonymph,tritonymph,first 5 d of oviposition,the full lifespan or none of the above).The results showed that the predation stress supplied during larval and protonymphal stage delayed development,reduced fecundity and prolonged lifespan of the prey,while the stress given during tritonymphal stage only reduced lifespan slightly and the stress given during the first 5 d of oviposition did not change lifespan but reduced fecundity.This study indicated that the effects of predation stress are dependent on prey life stage and the predation stress experienced in the early life stages is important to lifespan modulation.

关键词： early life experience lifespan non-consumptive effects predation stress tyrophagus

Age-specific mortality and fecundity of a spider mite under diet restriction and delayed mating

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2022年第3期29卷 889-899页

作者： Guang-Yun Li Zhi-Qiang Zhang Centre for Biodiversity and Biosecurity School of Biological SciencesUniversity of AucklandAucklandNew Zealand Manaaki Whenua-landcare research AucklandNew Zealand Key Laboratory of Entomology and Pest Control Engineering College of Plant ProtectionSouthwest UniversityChongqingChina

Numerous experimental life-history studies on aging are mainly baised on two classical models—fruit fly Drosophila melanogaster(Meigen)and nematode Caenorhab-ditis elegans(Maupas)—with relatively little attention given to other organisms with different life-history characters.Two-spotted spider mite Tetranychus urticae Koch(Acari:Tetranychidae)differs from many other arthropods in that the females continue their growth in the early adult stage and can reproduce sexually and asexually.In this study,the influences of dietary restriction and delayed mating on the aging patterns of the spider mite were examined with the prevailing survival and reproduction trade-off hypothesis of aging being tested.Significant sex-specific responses of the spider mites were found.The females showed longevity extension on diet restriction(fasting for 2 days in every 4 days)compared with their counterparts being fed ad libitum,and after delayed mating for 9 days,while the males displayed a decrease in lifespan when experiencing diet restriction but were not significantly influenced by delayed mating.Path analysis was used to investigate the relationship between mite survival and reproduction traits,including longevity,female lifetime reproduction,age at first reproduction,early reproductive efforts and late reproductive efforts,yielding no evidence for trade-offs between these life-history traits.The additive effects of dietary restriction and delayed mating in lifespan extension of female spider mites were confirmed,proving that diet restriction is a robust anti-aging intervention,and that later onset of reproduction can prolong adult lifespan in females.

关键词： age-specific mortality delayed mating diet restriction reproduction sex difference trade-off

Enough dogma： Seeking the middle ground on the role of dingoes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2012年第6期58卷 856-858页

作者： A. S. Glen landcare research PO Box 40 Lincoln 7640 New Zealand

Numerous recent studies present evidence that Australian dingoesCanis lupus dingocan benefit native biodiversity by suppressing mesopredators and large herbivores. Allen and colleagues have challenged the reliability of this evidence. Although they make some valid criticisms, I question some of their assertions. While the existing evidence is inconclusive, I argue that to dismiss it completely would be just as dangerous as to embrace it uncritically. I aim to establish a middle ground.

关键词：地带毛绒找中生物多样性证据可靠性危险

Diurnal and spatial variations of soil NO_x fluxes in the northern steppe of China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2015年第6期27卷 54-61页

作者： Bing Wang Xinqing Lee Benny K.G. Theng Jianzhong Cheng Fang Yang State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences landcare research Private Bag 11052 Graduate University of the Chinese Academy of Sciences

NOx emissions from biogenic sources in soils play a significant role in the gaseous loss of soil nitrogen and consequent changes in tropospheric chemistry. In order to investigate the characteristics of NOx fluxes and factors influencing these fluxes in degraded sandy grasslands in northern China, diurnal and spatial variations of NOx fluxes were measured in situ. A dynamic flux chamber method was used at eight sites with various vegetation coverages and soil types in the northern steppe of China in the summer season of 2010.Fluxes of NOx from soils with plant covers were generally higher than those in the corresponding bare vegetation-free soils, indicating that the canopy plays an important role in the exchange of NOx between soil and air. The fluxes of NOx increased in the daytime,and decreased during the nighttime, with peak emissions occurring between 12：00 and14：00. The results of multiple linear regression analysis indicated that the diurnal variation of NOx fluxes was positively correlated with soil temperature（P 〈 0.05） and negatively with soil moisture content（P 〈 0.05）. Based on measurement over a season, the overall variation in NOx flux was lower than that of soil nitrogen contents, suggesting that the gaseous loss of N from the grasslands of northern China was not a significant contributor to the high C/N in the northern steppe of China. The concentration of NOx emitted from soils in the region did not exceed the 1-hr National Ambient Air Quality Standard（0.25 mg/m^3）.

关键词： Desertification N cycle Land-use change Nitrogen oxides

Global Reference Grids for Big Earth Data

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Big Earth Data 2022年第3期6卷 251-255页

作者： Robert G.Gibb Matthew B.J.Purss Zoheir Sabeur Peter Strobl Tengteng Qu Manaaki Whenua–landcare research Palmerston NorthNew Zealand Pangaea Innovations Pty.Ltd CanberraAustralia Department of Computing and Informatics Talbot CampusUniversity of BournemouthBournemouthUK European Commission Joint Research Centre(JRC)IspraItaly College of Engineering Peking UniversityBeijingChina

The emerging field of Discrete Global Grid Systems(DGGS)provides a way to organise,store and analyse spatio-temporal data at multiple resolutions and scales(from near global scales down to microns).DGGS partition the entire planet into a discrete hierarchy of global tessellations of progressively finer resolution zones(or cells).Data integration,decomposition and aggregation are optimised by assigning a unique spatio-temporal identifier to each zone.These identifiers are encodings of both the zone’s location and its resolution.As a result,complex multi-dimensional,multi-resolution spatio-temporal operations are simplified into sets of 1D array and filter operations.

关键词： operations simplified partition

Net ecosystem carbon exchange for Bermuda grass growing in mesocosms as affected by irrigation frequency

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2022年第3期32卷 393-401页

作者： Yuan LI Gabriel *** Timothy J.CLOUGH John E.HUNT David WHITEHEAD Department of Soil and Physical Sciences Lincoln UniversityLincoln 7647(New Zealand) Manaaki Whenua-landcare research P.O.Box 69040Lincoln 7640(New Zealand) State Key Laboratory of Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730020(China) Soil Biology Group Wageningen University and ResearchP.O.Box 47Wageningen 6700 AA(The Netherlands)

Intensification of grazed grasslands following conversion from dryland to irrigated farming has the potential to alter ecosystem carbon(C)cycling and affect components of carbon dioxide(CO_(2))exchange that could lead to either net accumulation or loss of soil C.While there are many studies on the effect of water availability on biomass production and soil C stocks,much less is known about the effect of the frequency of water inputs on the components of CO_(2)exchange.We grew Bermuda grass(Cynodon dactylon L.)in mesocosms under irrigation frequencies of every day(I_(1) treatment,30 d),every two days(I_(2) treatment,12 d),every three days(I_(3) treatment,30 d),and every six days(I_(6) treatment,18 d,after I_(2) treatment).Rates of CO_(2)exchange for estimating net ecosystem CO_(2)exchange(F_(N)),ecosystem respiration(R_(E)),and soil respiration(R_(S))were measured,and gross C uptake by plants(F_(G))and respiration from leaves(R_(L))were calculated during two periods,1–12 and 13–30 d,of the 30-d experiment.During the first 12 d,there were no significant differences in cumulative F_(N)(mean±standard deviation,61±30 g C m^(-2),n=4).During the subsequent 18 d,cumulative F_(N) decreased with decreasing irrigation frequency and increasing cumulative soil water deficit(W),with values of 70±22,60±16,and 18±12 g C m^(-2) for the I_(1),I_(3),and I_(6) treatments,respectively.There were similar decreases in F_(G),R_(E),and R_(L) with increasing W,but differences in R_(S) were not significant.Use of the C_(4) grass growing in a C_(3)-derived soil enabled partitioning of R_(S) into its autotrophic(R_(A))and heterotrophic(R_(H))components using a^(13)C natural abundance isotopic technique at the end of the experiment when differences in cumulative W between the treatments were the greatest.The values of R_(H) and its percentage contributions to R_(S)(43%±8%,42%±8%,and 8%±5%for the I_(1),I_(3),and I_(6) treatments,respectively)suggested that R_(H) remained unaffected across a wide range of W and then decreased under extreme W.Th

关键词： ^(13)C natural abundance CO_(2)exchange N_(2)O emission soil heterotrophic respiration water deficit

POLYMER CHARGE AND MOLECULAR WEIGHT EFFECTS ON TREATED IRRIGATION FURROW PROCESSES

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment research 2000年第1期15卷 17-30页

作者： R. D. Lentz(USDA-ARS, Northwest Irrigation and Soils research Laboratory, Kimberly, ID)R. E. Sojka (landcare research, New Zealand, Ltd, Palmerston North, New ZealandNote: The manucript of this paper was received in March 1999, Discussion open until March USDA-ARS Northwest Irrigation and Soils Research Laboratory Kimberly ID United States landcare research New Zealand Ltd Palmerston North New Zealand

Application of 5-10 mg L-1 water soluble anionic polyacrylamide (PAM) to furrow irrigation water during flow advance substantially reduces sediment loss and increases net infiltration. We hypothesized that PAM_s solvated molecular conformation influences its irrigation-management efficacy. The study was conducted in Kimberly, Idaho, on Portneuf silt loam (Durinodic Xeric Haplocalcids), under furrowirrigated beans (Phaseolus vulgaris ) at a 1.5% slope. Polyacrylamides with contrasting molecular weight (anionic; 4-7, 12- 15 and 14-17 MDa, i.e. Mg mol-1 ), charge type (neutral, anionic, cationic), and charge density (8, 19, 35 mol %) were tested in two studies. Inflow rate was 23 L min-1 during furrow advance, and 15 L min-1 for the remaining set. Anionic and neutral PAMs were twice as effective as cationic PAMs for controlling sediment loss in new furrows. The order of effectiveness for overall soilloss control was : anionic ＞neutral ＞cationic PAM, and efficacy increased with increasing charge density and/or molecular weight. Net furrow infiltration increased by 14 to 19% when PAM treatment molecular weight was reduced from 17 to 4 MDa. General trends suggested that medium and high charge density anionic and neutral PAM produced the greatest increase in infiltration compared with controls.Compared with untreated furrows, neutral PAM gave the greatest season-long net infiltration gains (5%),while charged PAMs tended to increase net infiltration early in the season on new furrows but decreased infiltration on repeat-irrigated furrows later in the season.

关键词： Polymer charge Molecular weight effect Soil loss control Charge Density Infiltration capacity