Abstract:
:Alpine grasslands play important functions in mitigating climate change and regulating water resources. However, the spatiotemporal variability of their carbon and water budgets remains unquantified. Here, 47 site-year observations of CO2 and water vapor fluxes (ET) are analyzed at sites situated along a hydrothermal gradient across the Qinghai-Tibetan Plateau, including an alpine wetland (wettest), an alpine shrub (coldest), an alpine meadow, an alpine meadow-steppe, and an alpine steppe (driest and warmest). The results show that the benchmarks for annual net ecosystem exchange (NEE) are -79.3, -77.8, -66.7, 20.2, and 100.9 g C m-2 year-1 at the meadow, shrub, meadow-steppe, steppe, and wetland, respectively. The peak daily NEE normalized by peak leaf area index converges to 0.93 g C m-2 d-1 at the 5 sites. Except in the wetland (722.8 mm), the benchmarks of annual ET fluctuate from 511.0 mm in the steppe to 589.2 mm in the meadow. Boosted regression trees-based analysis suggests that the enhanced vegetation index (EVI) and net radiation (Rn) determine the variations of growing season monthly CO2 fluxes and ET, respectively, although the effect is to some extent site-specific. Inter-annual variability in NEE, ecosystem respiration (RES), and ET are tightly (R2 > 0.60) related to the inter-growing season NEE, RES, and ET, respectively. Both annual RES and annual NEE are significantly constrained by annual gross primary productivity (GPP), with 85% of the per-unit GPP contributing to RES (R2 = 0.84) and 15% to NEE (R2 = 0.12). Annual GPP significantly correlates with annual ET alone at the drier sites of the meadow-steppe and the steppe, suggesting the coupling of carbon and water is moisture-dependent in alpine grasslands. Over half of the inter-annual spatial variability in GPP, RES, NEE, and ET is explained by EVI, atmospheric water vapor, topsoil water content, and bulk surface resistance (rs), respectively. Because the spatial variations of EVI and rs are strongly regulated by atmospheric water vapor (R2 = 0.48) and topsoil water content (R2 = 0.54), respectively, we conclude that atmospheric water vapor and topsoil water content, rather than the expected air/soil temperatures, drive the spatiotemporal variations in CO2 fluxes and ET across temperature-limited grasslands. These findings are critical for improving predictions of the carbon sequestration and water holding capacity of alpine grasslands.
journal_name
Sci Total Environjournal_title
The Science of the total environmentauthors
Li H,Wang C,Zhang F,He Y,Shi P,Guo X,Wang J,Zhang L,Li Y,Cao G,Zhou Hdoi
10.1016/j.scitotenv.2021.148379keywords:
["Alpine grasslands","Boosted regression trees","Bulk surface resistance","CO(2) and water vapor exchanges","Enhanced vegetation index","Net radiation"]subject
Has Abstractpub_date
2021-10-15 00:00:00pages
148379eissn
0048-9697issn
1879-1026pii
S0048-9697(21)03450-1journal_volume
791pub_type
杂志文章相关文献
文献大全abstract::The developed method enables the quantification of estrogens in sewage samples down to 1 ng/l and in river water down to 0.5 ng/l. Mean recoveries of the analytes in ground water after SPE extraction, clean-up and derivatization generally exceeded 75%. The determined R.S.D. varied from 0 to 14% at a spiking level of 0...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(98)00334-9
更新日期:1999-01-12 00:00:00
abstract::This survey was conducted to examine the extent of the exposure of Bangkok citizens to lead (Pb) and cadmium (Cd), and to evaluate the role of rice as the source of these heavy metals. In practice, 52 non-smoking adult women in an institution in the vicinity of Bangkok, volunteered to offer blood, spot urine, boiled r...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(98)00370-2
更新日期:1999-02-02 00:00:00
abstract::The aim of this study was to determine the temporal variation in the concentrations of arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), manganese (Mn), mercury (Hg), nickel (Ni), lead (Pb), tin (Sn), thallium (Tl), vanadium (V) and zinc (Zn) in soil and vegetation near an old municipal solid waste incinerato...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(98)00386-6
更新日期:1999-02-09 00:00:00
abstract::Concentrations of the essential elements Zn and Cu and potentially toxic elements Pb and Cd in different milk samples and baby food materials were measured, primarily to assess whether the intakes comply with recommended desired levels for essential and permissible levels for toxic elements. The geometric mean concent...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00018-2
更新日期:1999-03-09 00:00:00
abstract::Serum and urine selenium levels were determined in patients with diabetes by hydride generation atomic absorption spectrometry. Mean serum selenium concentrations measured in patients with diabetes mellitus (64.9 +/- 22.8 micrograms/l) were significantly lower than those determined in the control group (74.9 +/- 27.3 ...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00034-0
更新日期:1999-03-22 00:00:00
abstract::Automobile exhaust catalytic converters emit fine dispersed elemental platinum, Pt (0), in the nanometer range coated on larger aluminium oxide carrier particles. A pre-requisite for a potential systemic toxic effect of the emitted platinum is its bioavailability which was investigated using laboratory animals. To thi...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00049-2
更新日期:1999-04-05 00:00:00
abstract::Polycyclic aromatic hydrocarbons (PAHs) are a group of compounds that have attracted much attention over the past several years. The United States Environmental Protection Agency (USEPA) has identified numerous PAHs as known or probable human carcinogens. The quantity of PAHs in the environment has dramatically increa...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00065-0
更新日期:1999-05-07 00:00:00
abstract::Residue levels of organochlorine pesticides have been determined in raw fruits, vegetables and tubers from markets in Nigeria. In the fruits, total HCH, aldrin and total DDT were detected in 77, 38 and 30% of all samples, respectively. In the vegetables, total HCH, HCB, total DDT and aldrin were detected from 95, 53, ...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00067-4
更新日期:1999-07-01 00:00:00
abstract::This study discusses the potential exposure of occupational workers and general consumers in the European Union (EU) to polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) caused by exposure to pentachlorophenol (PCP) and its derivatives. A synthesis of reported exposure data relating e...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00089-3
更新日期:1999-08-01 00:00:00
abstract::In 1996, The Centre for Environment, Fisheries and Aquaculture Science (CEFAS) initiated a project to establish whether oestrogenic materials are present in UK estuarine and marine waters at biologically significant concentrations, and to investigate some of the possible effects which these may have in flounder (Plati...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00175-8
更新日期:1999-08-15 00:00:00
abstract::Nonylphenol is present in surface water and aquatic sediments and because of its lipophilic characteristics shows a considerable potential to bioaccumulate in aquatic organisms. Nonylphenol inhibits testicular growth and induces vitellogenin synthesis in male rainbow trout. In order to better understand the effects of...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00225-9
更新日期:1999-08-15 00:00:00
abstract::The indoor exposure of 381 women (52-59 years old) to lead and cadmium was assessed by measuring the levels of the contaminants in sedimented house dust. The study was conducted in the areas surrounding the towns of Hettstedt, a region of mining and smelting of non-ferrous ores, of Bitterfeld, a centre of chemical pro...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00164-3
更新日期:1999-08-30 00:00:00
abstract::Analyses of unfiltered and filtered (< 0.45 micron and < 0.10 micron) groundwater samples from 15 selected wells in crystalline bedrock aquifers of the Oslo area, Norway, have been studied for 62 chemical elements. While concentrations of almost all elements vary over several orders of magnitude between the individual...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00165-5
更新日期:1999-08-30 00:00:00
abstract::The quality of pavement runoff water from a 275-m motorway section has been studied for 1 year, during which approximately 50 rain events have been sampled. Two different types of pollution have been revealed. One type can be defined as chronic and includes suspended solids, chemical oxygen demand, total hydrocarbons,...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00207-7
更新日期:1999-09-01 00:00:00
abstract::Platinum has been increasing in the environment as a result of emissions from catalytic converters. The platinum emitted is principally located in the vicinity of roads but might be transported to urban rivers through highway and urban run-off water. Platinum concentrations in the freshwater isopod Asellus aquaticus w...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00203-x
更新日期:1999-09-01 00:00:00
abstract::The purpose of this study was to determine the relationship between the pollution levels recorded in Madrid and the number of hospital admissions made on the grounds of respiratory disorders. ...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00244-2
更新日期:1999-09-01 00:00:00
abstract::Dispersal patterns for fluoride and damage to vegetation was studied near three aluminium smelters in Norway. Leaf samples from three broad-leaved species (Betula pubescens Ehrh., Salix caprea L. and Sorbus aucuparia L.) were collected and leaf injury and the plants overall vitality were evaluated systematically in ar...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00268-5
更新日期:1999-09-15 00:00:00
abstract::A mussel watch survey was conducted in 1988-1989 along the Mediterranean coast of France and Italy, between Sete and Genoa, in order to assess contamination by organochlorine pesticides, PCBs and petroleum hydrocarbons. Results show concentrations of DDTs (average 130 ng g-1 dry wt.) and PCBs (average 527 ng g-1 dry w...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00124-2
更新日期:1999-09-30 00:00:00
abstract::The paper presents the results of the joint project carried out in Germany in order to assess the consequences in the marine environment from the dumping of nuclear wastes in the Kara and Barents Seas. The project consisted of experimental work on measurements of radionuclides in samples from the Arctic marine environ...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00134-5
更新日期:1999-09-30 00:00:00
abstract::Between June 1946 and October 1958, Enewetak and Bikini Atolls were used by the US as testing grounds for 66 nuclear devices. The combined explosive yield from these tests was 107 million t (million t TNT equivalents). This testing produced close-in fallout debris that was contaminated with quantities of radioactive f...
journal_title:The Science of the total environment
pub_type: 杂志文章,评审
doi:10.1016/s0048-9697(99)00145-x
更新日期:1999-09-30 00:00:00
abstract::A towed survey system, the GIMS/CS3, has been developed to enable the rapid measurement and mapping of a variety of physical and geochemical parameters in the surficial sediments of aquatic environments while the survey vessel is underway. With its capability for measuring radiometric, elemental and organic compound c...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00157-6
更新日期:1999-09-30 00:00:00
abstract::Sodium chloride was added to aquaculture pond sediment to determine effects of different salinities on degradation of chloramphenicol (CM). In this experiment, freshwater (0 ppt salinity) eel pond sediment slurries (10% w/v) were amended with sodium chloride to obtain salinities of 12, 24 and 36 ppt. There were no sig...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00330-7
更新日期:1999-10-01 00:00:00
abstract::Massive amounts of acidic waters and mud (pH approximately 3) containing toxic metals such as zinc, lead, arsenic, copper, antimony, cobalt, thallium, bismuth, cadmium, silver, mercury and selenium were released in the surroundings of Doñana Park as a consequence of the mine tailings spill accident in Aznalcollar (SW ...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00372-1
更新日期:1999-12-06 00:00:00
abstract::The initial effects of the toxic waste spill in April 1998 at the Aznalcóllar mine (SW Spain) on the nektonic community of the Guadalquivir Estuary were examined at three sampling sites using univariate and multivariate techniques. Since studied communities showed a considerable seasonal trend, only seasonally homogen...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00395-2
更新日期:1999-12-06 00:00:00
abstract::The use of Hydra attenuata in acute toxicity assessment is a potentially useful tool in (waste) water biomonitoring. The purpose of this study was to compare the sensitivity of H. attenuata with the extensively used Microtox test on 14 (waste) water samples from the Kraków region (South Poland). To this end, specific ...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00369-1
更新日期:1999-12-15 00:00:00
abstract::Data for cadmium and mercury in Greenland marine biota (blue mussels, polar cod, shorthorn sculpin, glaucous gull and ringed seals) over a period of 20 years has been analysed in order to assess temporal changes. Most of the comparisons were conducted between tissue samples collected in the mid-1980s and mid-1990s. Ca...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00432-5
更新日期:2000-01-17 00:00:00
abstract::Lake sediments and landlocked Arctic char (Salvelinus alpinus) were sampled in 1994 and 1995 at four different locations in Greenland, three at the west coast and one at the east coast. Sediments, char muscle and char liver were analysed for PCBs (10 congeners), DDTs (pp'), HCHs (alpha, beta, gamma), dieldrin, HCB and...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00442-8
更新日期:2000-01-17 00:00:00
abstract::Trihalomethanes (THMs) are important disinfection byproducts (DBPs) in drinking water. To understand the magnitude of exposure to THMs for the people in southern Taiwan, models are used to estimate the inhalation exposure associated with drinking water based on raw water quality. Two parts of models are used in this s...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00420-9
更新日期:2000-01-31 00:00:00
abstract::Knowledge of trace and toxic metal concentrations in livestock is important for assessing the effects of pollutants on domestic animals and contaminant intakes by humans. Metal levels in cattle have been measured in various countries but not in Spain. In this study, the (wet wt.) concentrations of three toxic elements...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00461-1
更新日期:2000-02-10 00:00:00
abstract::Smoking is thought to be one of the most important anthropogenic risk factors involved in the development of urinary bladder cancer in humans. Tobacco smoke contains a complex mixture of chemicals including potent carcinogens such as aromatic amines. In the present study the amounts of several freebase aromatic amines...
journal_title:The Science of the total environment
pub_type: 杂志文章
doi:10.1016/s0048-9697(99)00471-4
更新日期:2000-02-28 00:00:00