| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Wingate, L., et al.
(författare)
-
Interpreting canopy development and physiology using a European phenology camera network at flux sites
- 2015
-
Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4189. ; 12:20, s. 5995-6015
-
Tidskriftsartikel (refereegranskat)abstract
- Plant phenological development is orchestrated through subtle changes in photoperiod, temperature, soil moisture and nutrient availability. Presently, the exact timing of plant development stages and their response to climate and management practices are crudely represented in land surface models. As visual observations of phenology are laborious, there is a need to supplement long-term observations with automated techniques such as those provided by digital repeat photography at high temporal and spatial resolution. We present the first synthesis from a growing observational network of digital cameras installed on towers across Europe above deciduous and evergreen forests, grasslands and croplands, where vegetation and atmosphere CO2 fluxes are measured continuously. Using colour indices from digital images and using piecewise regression analysis of time series, we explored whether key changes in canopy phenology could be detected automatically across different land use types in the network. The piecewise regression approach could capture the start and end of the growing season, in addition to identifying striking changes in colour signals caused by flowering and management practices such as mowing. Exploring the dates of green-up and senescence of deciduous forests extracted by the piecewise regression approach against dates estimated from visual observations, we found that these phenological events could be detected adequately (RMSE < 8 and 11 days for leaf out and leaf fall, respectively). We also investigated whether the seasonal patterns of red, green and blue colour fractions derived from digital images could be modelled mechanistically using the PROSAIL model parameterised with information of seasonal changes in canopy leaf area and leaf chlorophyll and carotenoid concentrations. From a model sensitivity analysis we found that variations in colour fractions, and in particular the late spring 'green hump' observed repeatedly in deciduous broadleaf canopies across the network, are essentially dominated by changes in the respective pigment concentrations. Using the model we were able to explain why this spring maximum in green signal is often observed out of phase with the maximum period of canopy photosynthesis in ecosystems across Europe. Coupling such quasi-continuous digital records of canopy colours with co-located CO2 flux measurements will improve our understanding of how changes in growing season length are likely to shape the capacity of European ecosystems to sequester CO2 in the future.
|
|
| 12. |
- Franz, D, et al.
(författare)
-
Towards long-term standardised carbon and greenhouse gas observations for monitoring Europe´s terrestrial ecosystems: a review
- 2018
-
Ingår i: International Agrophysics. - : Walter de Gruyter GmbH. - 0236-8722 .- 2300-8725. ; 32, s. 439-455
-
Tidskriftsartikel (refereegranskat)abstract
- Research infrastructures play a key role in launching a new generation of integrated long-term, geographically distributed observation programmes designed to monitor climate change, better understand its impacts on global ecosystems, and evaluate possible mitigation and adaptation strategies. The pan-European Integrated Carbon Observation System combines carbon and greenhouse gas (GHG; CO2, CH4, N2O, H2O) observations within the atmosphere, terrestrial ecosystems and oceans. High-precision measurements are obtained using standardised methodologies, are centrally processed and openly available in a traceable and verifiable fashion in combination with detailed metadata. The Integrated Carbon Observation System ecosystem station network aims to sample climate and land-cover variability across Europe. In addition to GHG flux measurements, a large set of complementary data (including management practices, vegetation and soil characteristics) is collected to support the interpretation, spatial upscaling and modelling of observed ecosystem carbon and GHG dynamics. The applied sampling design was developed and formulated in protocols by the scientific community, representing a trade-off between an ideal dataset and practical feasibility. The use of open-access, high-quality and multi-level data products by different user communities is crucial for the Integrated Carbon Observation System in order to achieve its scientific potential and societal value.
|
|
| 13. |
- Luyssaert, S., et al.
(författare)
-
CO2 balance of boreal, temperate, and tropical forests derived from a global database
- 2007
-
Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 13:12, s. 2509-2537
-
Forskningsöversikt (refereegranskat)abstract
- Terrestrial ecosystems sequester 2.1 Pg of atmospheric carbon annually. A large amount of the terrestrial sink is realized by forests. However, considerable uncertainties remain regarding the fate of this carbon over both short and long timescales. Relevant data to address these uncertainties are being collected at many sites around the world, but syntheses of these data are still sparse. To facilitate future synthesis activities, we have assembled a comprehensive global database for forest ecosystems, which includes carbon budget variables (fluxes and stocks), ecosystem traits (e.g. leaf area index, age), as well as ancillary site information such as management regime, climate, and soil characteristics. This publicly available database can be used to quantify global, regional or biome-specific carbon budgets; to re-examine established relationships; to test emerging hypotheses about ecosystem functioning [e.g. a constant net ecosystem production (NEP) to gross primary production (GPP) ratio]; and as benchmarks for model evaluations. In this paper, we present the first analysis of this database. We discuss the climatic influences on GPP, net primary production (NPP) and NEP and present the CO2 balances for boreal, temperate, and tropical forest biomes based on micrometeorological, ecophysiological, and biometric flux and inventory estimates. Globally, GPP of forests benefited from higher temperatures and precipitation whereas NPP saturated above either a threshold of 1500 mm precipitation or a mean annual temperature of 10 degrees C. The global pattern in NEP was insensitive to climate and is hypothesized to be mainly determined by nonclimatic conditions such as successional stage, management, site history, and site disturbance. In all biomes, closing the CO2 balance required the introduction of substantial biome-specific closure terms. Nonclosure was taken as an indication that respiratory processes, advection, and non-CO2 carbon fluxes are not presently being adequately accounted for.
|
|
| 14. |
|
|
| 15. |
|
|
| 16. |
- Yuan, W., et al.
(författare)
-
Thermal adaptation of net ecosystem exchange
- 2011
-
Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4189. ; 8:6, s. 1453-1463
-
Tidskriftsartikel (refereegranskat)abstract
- Thermal adaptation of gross primary production and ecosystem respiration has been well documented over broad thermal gradients. However, no study has examined their interaction as a function of temperature, i.e. the thermal responses of net ecosystem exchange of carbon (NEE). In this study, we constructed temperature response curves of NEE against temperature using 380 site-years of eddy covariance data at 72 forest, grassland and shrubland ecosystems located at latitudes ranging from similar to 29 degrees N to 64 degrees N. The response curves were used to define two critical temperatures: transition temperature (T-b) at which ecosystem transfer from carbon source to sink and optimal temperature (T-o) at which carbon uptake is maximized. T-b was strongly correlated with annual mean air temperature. T-o was strongly correlated with mean temperature during the net carbon uptake period across the study ecosystems. Our results imply that the net ecosystem exchange of carbon adapts to the temperature across the geographical range due to intrinsic connections between vegetation primary production and ecosystem respiration.
|
|
| 17. |
- Menchon, JM, et al.
(författare)
-
A prospective international multi-center study on safety and efficacy of deep brain stimulation for resistant obsessive-compulsive disorder
- 2021
-
Ingår i: Molecular psychiatry. - : Springer Science and Business Media LLC. - 1476-5578 .- 1359-4184. ; 26:4, s. 1234-1247
-
Tidskriftsartikel (refereegranskat)abstract
- Deep brain stimulation (DBS) has been proposed for severe, chronic, treatment-refractory obsessive-compulsive disorder (OCD) patients. Although serious adverse events can occur, only a few studies report on the safety profile of DBS for psychiatric disorders. In a prospective, open-label, interventional multi-center study, we examined the safety and efficacy of electrical stimulation in 30 patients with DBS electrodes bilaterally implanted in the anterior limb of the internal capsule. Safety, efficacy, and functionality assessments were performed at 3, 6, and 12 months post implant. An independent Clinical Events Committee classified and coded all adverse events (AEs) according to EN ISO14155:2011. All patients experienced AEs (195 in total), with the majority of these being mild (52% of all AEs) or moderate (37%). Median time to resolution was 22 days for all AEs and the etiology with the highest AE incidence was ‘programming/stimulation’ (in 26 patients), followed by ‘New illness, injury, condition’ (13 patients) and ‘pre-existing condition, worsening or exacerbation’ (11 patients). Sixteen patients reported a total of 36 serious AEs (eight of them in one single patient), mainly transient anxiety and affective symptoms worsening (20 SAEs). Regarding efficacy measures, Y-BOCS reduction was 42% at 12 months and the responder rate was 60%. Improvements in GAF, CGI, and EuroQol-5D index scores were also observed. In sum, although some severe AEs occurred, most AEs were mild or moderate, transient and related to programming/stimulation and tended to resolve by adjustment of stimulation. In a severely treatment-resistant population, this open-label study supports that the potential benefits outweigh the potential risks of DBS.
|
|
| 18. |
- Nemitz, E, et al.
(författare)
-
Standardisation of eddy-covariance flux measurements of methane and nitrous oxide
- 2018
-
Ingår i: International Agrophysics. - : Walter de Gruyter GmbH. - 0236-8722 .- 2300-8725. ; 32, s. 517-549
-
Tidskriftsartikel (refereegranskat)abstract
- Commercially available fast-response analysers for methane (CH4) and nitrous oxide (N2O) have recently become more sensitive, more robust and easier to operate. This has made their application for long-term flux measurements with the eddycovariance method more feasible. Unlike for carbon dioxide (CO2) and water vapour (H2O), there have so far been no guidelines on how to optimise and standardise the measurements. This paper reviews the state-of-the-art of the various steps of the measurements and discusses aspects such as instrument selection, setup and maintenance, data processing as well as the additional measurements needed to aid interpretation and gap-filling. It presents the methodological protocol for eddy covariance measurements of CH4 and N2O fluxes as agreed for the ecosystem station network of the pan-European Research Infrastructure Integrated Carbon Observation System and provides a first international standard that is suggested to be adopted more widely. Fluxes can be episodic and the processes controlling the fluxes are complex, preventing simple mechanistic gap-filling strategies. Fluxes are often near or below the detection limit, requiring additional care during data processing. The protocol sets out the best practice for these conditions to avoid biasing the results and long-term budgets. It summarises the current approach to gap-filling.
|
|
| 19. |
- Pavelka, M., et al.
(författare)
-
Standardisation of chamber technique for CO2, N2O and CH4 fluxes measurements from terrestrial ecosystems
- 2018
-
Ingår i: International Agrophysics. - : Walter de Gruyter GmbH. - 0236-8722 .- 2300-8725. ; 32:4, s. 569-587
-
Tidskriftsartikel (refereegranskat)abstract
- Chamber measurements of trace gas fluxes between the land surface and the atmosphere have been conducted for almost a century. Different chamber techniques, including static and dynamic, have been used with varying degrees of success in estimating greenhouse gases (CO2, CH4, N2O) fluxes. However, all of these have certain disadvantages which have either prevented them from providing an adequate estimate of greenhouse gas exchange or restricted them to be used under limited conditions. Generally, chamber methods are relatively low in cost and simple to operate. In combination with the appropriate sample allocations, chamber methods are adaptable for a wide variety of studies from local to global spatial scales, and they are particularly well suited for in situ and laboratory-based studies. Consequently, chamber measurements will play an important role in the portfolio of the Pan-European long-term research infrastructure Integrated Carbon Observation System. The respective working group of the Integrated Carbon Observation System Ecosystem Monitoring Station Assembly has decided to ascertain standards and quality checks for automated and manual chamber systems instead of defining one or several standard systems provided by commercial manufacturers in order to define minimum requirements for chamber measurements. The defined requirements and recommendations related to chamber measurements are described here.
|
|
| 20. |
- Polme, S., et al.
(författare)
-
FungalTraits: a user-friendly traits database of fungi and fungus-like stramenopiles
- 2020
-
Ingår i: Fungal Diversity. - : Springer Science and Business Media LLC. - 1560-2745 .- 1878-9129. ; 105:1, s. 1-16
-
Tidskriftsartikel (refereegranskat)abstract
- The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies. Over the past decades, rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats. Yet, in spite of the progress of molecular methods, knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging. In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels. Combining the information from previous efforts such as FUNGuild and Fun(Fun) together with involvement of expert knowledge, we reannotated 10,210 and 151 fungal and Stramenopila genera, respectively. This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera, designed for rapid functional assignments of environmental studies. In order to assign the trait states to fungal species hypotheses, the scientific community of experts manually categorised and assigned available trait information to 697,413 fungal ITS sequences. On the basis of those sequences we were able to summarise trait and host information into 92,623 fungal species hypotheses at 1% dissimilarity threshold.
|
|
| 21. |
- Vanhees, L, et al.
(författare)
-
Importance of characteristics and modalities of physical activity and exercise in the management of cardiovascular health in individuals with cardiovascular risk factors : recommendations from the EACPR. Part II.
- 2012
-
Ingår i: European journal of preventive cardiology. - : Oxford University Press (OUP). - 2047-4881 .- 2047-4873. ; 19:5, s. 1005-33
-
Tidskriftsartikel (refereegranskat)abstract
- In a previous paper, as the first of a series of three on the importance of characteristics and modalities of physical activity (PA) and exercise in the management of cardiovascular health within the general population, we concluded that, in the population at large, PA and aerobic exercise capacity clearly are inversely associated with increased cardiovascular disease risk and all-cause and cardiovascular mortality and that a dose–response curve on cardiovascular outcome has been demonstrated in most studies. More and more evidence is accumulated that engaging in regular PA and exercise interventions are essential components for reducing the severity of cardiovascular risk factors, such as obesity and abdominal fat, high BP, metabolic risk factors, and systemic inflammation. However, it is less clear whether and which type of PA and exercise intervention (aerobic exercise, dynamic resistive exercise, or both) or characteristic of exercise (frequency, intensity, time or duration, and volume) would yield more benefit for each separate risk factor. The present paper, therefore, will review and make recommendations for PA and exercise training in the management of cardiovascular health in individuals with cardiovascular risk factors. The guidance offered in this series of papers is aimed at medical doctors, health practitioners, kinesiologists, physiotherapists and exercise physiologists, politicians, public health policy makers, and individual members of the public. Based on previous and the current literature overviews, recommendations from the European Association on Cardiovascular Prevention and Rehabilitation are formulated regarding type, volume, and intensity of PA and regarding appropriate risk evaluation during exercise in individuals with cardiovascular risk factors.
|
|
| 22. |
- de Beeck, M. O., et al.
(författare)
-
Soil-meteorological measurements at ICOS monitoring stations in terrestrial ecosystems
- 2018
-
Ingår i: International Agrophysics. - : Walter de Gruyter GmbH. - 0236-8722 .- 2300-8725. ; 32:4, s. 619-631
-
Tidskriftsartikel (refereegranskat)abstract
- The Integrated Carbon Observation System is a pan-European research infrastructure providing standardized, long-term observations of greenhouse gas concentrations and earth-atmosphere greenhouse gas interactions. The terrestrial component of Integrated Carbon Observation System comprises a network of monitoring stations in terrestrial ecosystems where the principal activity is the measurement of ecosystem-atmosphere fluxes of greenhouse gases and energy by means of the eddy covariance technique. At each station a large set of ancillary variables needed for the interpretation of observed fluxes and for process studies is additionally monitored. This set includes a subset of variables that describe the thermal and moisture conditions of the soil and which are here conveniently referred to as soil-meteorological variables: soil temperature, volumetric soil water content, water table depth, and soil heat flux density. This paper describes the standard methodology that has been developped for the monitoring of these variables at the ecosystem stations.
|
|
| 23. |
- Gielen, Marij, et al.
(författare)
-
Body mass index is negatively associated with telomere length : A collaborative cross-sectional meta-analysis of 87 observational studies
- 2018
-
Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165. ; 108:3, s. 453-475
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Even before the onset of age-related diseases, obesity might be a contributing factor to the cumulative burden of oxidative stress and chronic inflammation throughout the life course. Obesity may therefore contribute to accelerated shortening of telomeres. Consequently, obese persons are more likely to have shorter telomeres, but the association between body mass index (BMI) and leukocyte telomere length (TL) might differ across the life span and between ethnicities and sexes. Objective: A collaborative cross-sectionalmeta-analysis of observational studies was conducted to investigate the associations between BMI and TL across the life span. Design: Eighty-seven distinct study samples were included in the meta-analysis capturing data from 146,114 individuals. Studyspecific age- and sex-adjusted regression coefficients were combined by using a random-effects model in which absolute [base pairs (bp)] and relative telomere to single-copy gene ratio (T/S ratio) TLs were regressed against BMI. Stratified analysis was performed by 3 age categories ("young": 18-60 y; "middle": 61-75 y; and "old": >75 y), sex, and ethnicity. Results: Each unit increase in BMI corresponded to a-3.99 bp (95% CI: -5.17, -2.81 bp) difference in TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -7.67 bp (95% CI:-10.03,-5.31 bp) difference. Each unit increase in BMI corresponded to a -1.58 × 10-3 unit T/S ratio (0.16% decrease; 95% CI: -2.14 × 10-3, -1.01 × 10-3) difference in ageand sex-adjusted relative TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -2.58 × 10-3 unit T/S ratio (0.26% decrease; 95% CI: -3.92 × 10-3, -1.25 × 10-3). The associations were predominantly for the white pooled population. No sex differences were observed. Conclusions: A higher BMI is associated with shorter telomeres, especially in younger individuals. The presently observed difference is not negligible. Meta-analyses of longitudinal studies evaluating change in body weight alongside change in TL arewarranted.
|
|
| 24. |
|
|
| 25. |
- Laurent, M. R., et al.
(författare)
-
Lower bone turnover and relative bone deficits in men with metabolic syndrome : a matter of insulin sensitivity? The European Male Ageing Study
- 2016
-
Ingår i: Osteoporosis International. - : Springer Science and Business Media LLC. - 0937-941X .- 1433-2965. ; 27:11, s. 3227-3237
-
Tidskriftsartikel (refereegranskat)abstract
- Summary: We examined cross-sectional associations of metabolic syndrome and its components with male bone turnover, density and structure. Greater bone mass in men with metabolic syndrome was related to their greater body mass, whereas hyperglycaemia, hypertriglyceridaemia or impaired insulin sensitivity were associated with lower bone turnover and relative bone mass deficits. Introduction: Metabolic syndrome (MetS) has been associated with lower bone turnover and relative bone mass or strength deficits (i.e. not proportionate to body mass index, BMI), but the relative contributions of MetS components related to insulin sensitivity or obesity to male bone health remain unclear. Methods: We determined cross-sectional associations of MetS, its components and insulin sensitivity (by homeostatic model assessment-insulin sensitivity (HOMA-S)) using linear regression models adjusted for age, centre, smoking, alcohol, and BMI. Bone turnover markers and heel broadband ultrasound attenuation (BUA) were measured in 3129 men aged 40–79. Two centres measured total hip, femoral neck, and lumbar spine areal bone mineral density (aBMD, n = 527) and performed radius peripheral quantitative computed tomography (pQCT, n = 595). Results: MetS was present in 975 men (31.2 %). Men with MetS had lower β C-terminal cross-linked telopeptide (β-CTX), N-terminal propeptide of type I procollagen (PINP) and osteocalcin (P <0.0001) and higher total hip, femoral neck, and lumbar spine aBMD (P ≤ 0.03). Among MetS components, only hypertriglyceridaemia and hyperglycaemia were independently associated with PINP and β-CTX. Hyperglycaemia was negatively associated with BUA, hypertriglyceridaemia with hip aBMD and radius cross-sectional area (CSA) and stress–strain index. HOMA-S was similarly associated with PINP and β-CTX, BUA, and radius CSA in BMI-adjusted models. Conclusions: Men with MetS have higher aBMD in association with their greater body mass, while their lower bone turnover and relative deficits in heel BUA and radius CSA are mainly related to correlates of insulin sensitivity. Our findings support the hypothesis that underlying metabolic complications may be involved in the bone’s failure to adapt to increasing bodily loads in men with MetS.
|
|
| 26. |
- Lee, David M., et al.
(författare)
-
Frailty and Sexual Health in Older European Men
- 2013
-
Ingår i: Journals of Gerontology - Series B Psychological Sciences and Social Sciences. - : Oxford University Press (OUP). - 1079-5014. ; 68:7, s. 837-844
-
Tidskriftsartikel (refereegranskat)abstract
- Background. There has been little research on how late-life frailty interrelates with sexual health. Our objective was to examine the association of frailty with sexual functioning and satisfaction among older men. Methods. The study population consisted of 1,504 men aged 60 to 79 years, participating in the European Male Aging Study. Self-report questionnaires measured overall sexual functioning, sexual function related distress, and erectile dysfunction. Frailty status was defined using a phenotype (FP) or index (FI). Associations between frailty and sexual function were explored using regression models. Results. Based on the frailty phenotype, 5% of men were classified as frail, and the mean frailty index was 0.18 (SD = 0.12). Frailty was associated with decreasing overall sexual functioning and increasing sexual function related distress in multiple linear regressions adjusted for age, smoking, alcohol consumption, living arrangements, comorbidities, and depression. Frailty was also associated with an increased odds of erectile dysfunction after adjustment for the same confounders: odds ratio = 1.99 (95% confidence interval = 1.14, 3.48) and 4.08 (95% confidence interval = 2.63, 6.36) for frailty phenotype and frailty index, respectively. Conclusions. Frailty was associated with impaired overall sexual functioning, sexual function related distress, and erectile dysfunction. Individuals assessed for frailty-related deficits may also benefit from an appraisal of sexual health as an important aspect of well-being and quality of life.
|
|
| 27. |
- Linde, C, et al.
(författare)
-
The Membership Committee of the ESC
- 2019
-
Ingår i: Cardiovascular research. - : Oxford University Press (OUP). - 1755-3245 .- 0008-6363. ; 115:12, s. E130-E132
-
Tidskriftsartikel (refereegranskat)
|
|
| 28. |
|
|
| 29. |
- McKibben, Jodi B. A., et al.
(författare)
-
Epidemiology of burn injuries II : Psychiatric and behavioral perspectives
- 2009
-
Ingår i: International Review of Psychiatry. - : Informa UK Limited. - 0954-0261 .- 1369-1627. ; 21:6, s. 512-521
-
Tidskriftsartikel (refereegranskat)abstract
- Modern technological advances have decreased the incidence and severity of burn injuries, and medical care improvements of burn injuries have significantly increased survival rates, particularly in developed countries. Still, fire-related burn injuries are responsible for 300,000 deaths and 10 million disability-adjusted life years lost annually worldwide. The extent to which psychiatric and behavioural factors contribute to the incidence and outcomes of these tragedies has not been systematically documented, and the available data is often insufficient to reach definitive conclusions. Accordingly, this article reviews the evidence of psychiatric and behavioural risk factors and prevention opportunities for burn injuries worldwide. Psychiatric prevalence rates and risk factors for burn injuries, prevalence and risks associated with 'intentional' burn injuries (self-immolation, assault, and child maltreatment), and prevention activities targeting the general population and those with known psychiatric and behavioural risk factors are discussed. These issues are substantially interwoven with many co-occurring risk factors. While success in teasing apart the roles and contributions of these factors rests upon improving the methodology employed in future research, the nature of this entanglement increases the likelihood that successful interventions in one problem area will reap benefits in others.
|
|
| 30. |
- Niu, Shuli, et al.
(författare)
-
Thermal optimality of net ecosystem exchange of carbon dioxide and underlying mechanisms.
- 2012
-
Ingår i: New Phytologist. - : Wiley. - 1469-8137 .- 0028-646X. ; 194:3, s. 775-783
-
Tidskriftsartikel (refereegranskat)abstract
- • It is well established that individual organisms can acclimate and adapt to temperature to optimize their functioning. However, thermal optimization of ecosystems, as an assemblage of organisms, has not been examined at broad spatial and temporal scales. • Here, we compiled data from 169 globally distributed sites of eddy covariance and quantified the temperature response functions of net ecosystem exchange (NEE), an ecosystem-level property, to determine whether NEE shows thermal optimality and to explore the underlying mechanisms. • We found that the temperature response of NEE followed a peak curve, with the optimum temperature (corresponding to the maximum magnitude of NEE) being positively correlated with annual mean temperature over years and across sites. Shifts of the optimum temperature of NEE were mostly a result of temperature acclimation of gross primary productivity (upward shift of optimum temperature) rather than changes in the temperature sensitivity of ecosystem respiration. • Ecosystem-level thermal optimality is a newly revealed ecosystem property, presumably reflecting associated evolutionary adaptation of organisms within ecosystems, and has the potential to significantly regulate ecosystem-climate change feedbacks. The thermal optimality of NEE has implications for understanding fundamental properties of ecosystems in changing environments and benchmarking global models.
|
|
| 31. |
- Yao, Yunjun, et al.
(författare)
-
Estimation of high-resolution terrestrial evapotranspiration from Landsat data using a simple Taylor skill fusion method
- 2017
-
Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 553, s. 508-526
-
Tidskriftsartikel (refereegranskat)abstract
- Estimation of high-resolution terrestrial evapotranspiration (ET) from Landsat data is important in many climatic, hydrologic, and agricultural applications, as it can help bridging the gap between existing coarse-resolution ET products and point-based field measurements. However, there is large uncertainty among existing ET products from Landsat that limit their application. This study presents a simple Taylor skill fusion (STS) method that merges five Landsat-based ET products and directly measured ET from eddy covariance (EC) to improve the global estimation of terrestrial ET. The STS method uses a weighted average of the individual ET products and weights are determined by their Taylor skill scores (S). The validation with site-scale measurements at 206 EC flux towers showed large differences and uncertainties among the five ET products. The merged ET product exhibited the best performance with a decrease in the averaged root-mean-square error (RMSE) by 2–5 W/m2 when compared to the individual products. To evaluate the reliability of the STS method at the regional scale, the weights of the STS method for these five ET products were determined using EC ground-measurements. An example of regional ET mapping demonstrates that the STS-merged ET can effectively integrate the individual Landsat ET products. Our proposed method provides an improved high-resolution ET product for identifying agricultural crop water consumption and providing a diagnostic assessment for global land surface models.
|
|
