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  • Wiley  (104)
  • 1
    In: Land Degradation & Development, Wiley, Vol. 33, No. 8 ( 2022-05-15), p. 1219-1234
    Kurzfassung: The Hola basin in the northern Da Xing'anling Mountains in Northeast China has been extensively developed for coal mining since the 1980s, resulting in a significantly degrading permafrost environment. However, the changing thermal state of permafrost under the boreal forest remains unclear. Based on ground temperature records from nine monitoring boreholes at three areas (disturbed, backfilled, and undisturbed areas) from 2015 to 2020, the thermal state of permafrost under the dual influences of climate change and human activities were evaluated. It is found that the temperatures at the depth of zero annual amplitude (T ZAA ) in the disturbed area increased by 0.2–0.5°C during the past 6 years, turning the cold permafrost (T ZAA  ≤ −1.0°C) into a warm one (−1 ≤ T ZAA  ≤ 0°C). Additionally, the permafrost table was lowered by 0.8–7.0 m. As a result, subaerial supra‐permafrost talik occurred. However, T ZAA in the undisturbed areas lowered by 0.03–0.11°C, possibly due to the lagged response of the local climate cooling during 2001–2010. In the meantime, T ZAA rose sharply in the disturbed areas, indicating more significant influences of intense human activities on permafrost in comparison with that of climate change. As the permafrost degrades, the boreal permafrost eco‐environment has changed dramatically, as revealed by the draining and drying up of the Yueya'hu Lake in the southern Hola basin. These results help reveal the physical mechanisms, evaluate the rates and amplitudes of environmental changes, and manage the boreal forest environment and resources in a sustainable manner.
    Materialart: Online-Ressource
    ISSN: 1085-3278 , 1099-145X
    URL: Issue
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2022
    ZDB Id: 2021787-0
    ZDB Id: 1319202-4
    SSG: 14
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    In: Land Degradation & Development, Wiley, Vol. 33, No. 16 ( 2022-10), p. 3133-3149
    Kurzfassung: Boreal forest and wetland have important influences on the development and protection of the ecosystem‐dominated Xing'an permafrost. However, the responses of different ecosystems to climate change and the impacts on the underlying permafrost are still unclear. Here, based on the multi‐period land use/land cover (LULC) data and long‐time series of air temperature, combined with the ordinary least squares (OLS) and ordinary kriging (OK) methods, the effects of land use and cover change (LUCC) on the distribution of mean annual air temperature (MAAT) and permafrost in Northeast China were analyzed. From 1980s to 2010s, MAAT showed an upward trend (0.025°C per yr) and extents of permafrost showed a decreasing trend (−3668 km 2 yr −1 ) in Northeast China. Permafrost degradation mainly occurred in forested land and grassland, with areal reductions of 4.0106 × 10 4 and 3.8754 × 10 4  km 2 , respectively. The transformation of LULC aggravates the degradation of permafrost. The conversions of forested land and grassland to cultivated land and forested land to grassland resulted in the shrinkage of permafrost extent by 6233 km 2 from 1980s to 2010s . Our results confirm the significant impacts of LUCC on the Xing'an permafrost resulting in its degradation. Additionally, they can provide a scientific basis for ecological environment protection and restoration and sustainable development of boreal forest and wetland ecosystems in permafrost regions of Northeast China.
    Materialart: Online-Ressource
    ISSN: 1085-3278 , 1099-145X
    URL: Issue
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2022
    ZDB Id: 2021787-0
    ZDB Id: 1319202-4
    SSG: 14
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 3
    In: Permafrost and Periglacial Processes, Wiley, Vol. 29, No. 4 ( 2018-10), p. 257-270
    Kurzfassung: To investigate and monitor permafrost in the Bayan Har Mountains (BHM), north‐eastern Qinghai–Tibet Plateau, southwest China, 19 boreholes ranging from 20 to 100 m in depth were drilled along an elevational transect (4,221–4,833 m a.s.l.) from July to September 2010. Measurements from these boreholes demonstrate that ground temperatures at the depth of zero annual amplitude ( T ZAA ) are generally higher than −2.0°C. The lapse rates of T ZAA are 4 and 6 °C km −1 , and the lower limits of permafrost with T ZAA   〈  −1°C are approximately 4,650 and 4,750 m a.s.l. on the northern (near Yeniugou) and southern (near Qingshui'he) slopes, respectively. T ZAA changes abruptly within short distances from −0.2 to +1.2°C near the northern lower limits of permafrost and from about +0.5 to +1.5°C near the southern lower limits of permafrost. Thawing and freezing on the ground surface at Qingshui'he (4,413 m a. s. l.) are 13.3 d earlier and 26 d later than that at Chalaping (4,724 m a. s. l.), respectively. The temperature gradient at Qingshui'he is clearly larger than that at Chalaping. The changes of permafrost T ZAA ranged from 0.03°C to 0.2°C from 2010 to 2017. A 3.5‐m‐thick permafrost near Qingshui'he was observed to disappear in summer 2013. There is no significant correlation between elevation and permafrost temperature changes in the study area, whereas the changes of very warm (close to 0°C) permafrost seem to be slow in the intermontane basins.
    Materialart: Online-Ressource
    ISSN: 1045-6740 , 1099-1530
    URL: Issue
    RVK:
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2018
    ZDB Id: 1479993-5
    SSG: 14
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 4
    In: Land Degradation & Development, Wiley, Vol. 34, No. 9 ( 2023-05-30), p. 2652-2667
    Kurzfassung: As an active ecological agent in the boreal forest, wildfires have many important impacts on the underlying permafrost. However, investigations of post‐fire changes in the features of ecosystem‐protected permafrost are extremely limited in the patchy permafrost regions, Northeast China. Additionally, the impacts of wildfires on patchy permafrost are complicated in this region. In this paper, based on field surveys and observations, permafrost features and their influencing factors were analyzed in the area burned in 2006. The results showed notably lower soil temperatures in shrub‐wetland (NWH1, unburned and NWH2, light burn) in comparison with those in the birch‐larch forest (NWH3, light burn and NWH4, moderate burn). Changes in shallow ground temperatures (0–4 m in depth) were significant. Mean annual soil temperatures (MAST) and annual maximum soil temperature at the light‐burn NWH2 site were 0.3–5.2°C higher than those of unburned NWH1, but annual minimum soil temperatures, 0.3–2.1°C lower. MASTs at the moderately burned NWH4 were 0.6–1.6°C higher than those at the light‐burn NWH3. The active layer thickness (ALT) was greater at burned sites, and; at the moderately burned site, only seasonal frost was found when 13 years after the burn. The contents of soil organic carbon and total nitrogen were the highest at the unburned NWH1 from 0.0 to 0.4 m in depth, followed by those at the lightly‐burned NWH2 and NWH3, and the lowest at the moderately‐burned NWH4. Climate warming, forest fires, and changing local factors (e.g., soil moisture contents, snow cover, soil texture and drainage conditions) worked together to increase ground temperature and ALT. These research results could provide important scientific basis for the protection of boreal forest and wetlands and the ecosystem‐protected permafrost under a warming climate.
    Materialart: Online-Ressource
    ISSN: 1085-3278 , 1099-145X
    URL: Issue
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2023
    ZDB Id: 2021787-0
    ZDB Id: 1319202-4
    SSG: 14
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 5
    In: Permafrost and Periglacial Processes, Wiley, Vol. 30, No. 3 ( 2019-07), p. 163-177
    Kurzfassung: Forest fires have significantly impacted the permafrost environment, and many research programs looking at this have been undertaken at higher latitudes. However, their impacts have not yet been systematically studied and evaluated in the northern part of northeast China at mid‐latitudes. This study simultaneously measured ecological and geocryological changes at various sites in the boreal forest at different stages after forest fires (chronosequence approach) in the northern Da Xing'anling (Hinggan) Mountains, Northeast China. We obtained results through field investigations, monitoring and observations, remote sensing interpretations, and laboratory tests. The results show that forest fires have resulted in a decreased Normalized Difference Vegetation Index (NDVI) and soil moisture contents in the active layer, increased active layer thickness (ALT) and ground temperatures, and the release of a large amount of C and N from the soils in the active layer and at shallow depths of permafrost. NDVI and species biodiversity have gradually increased in the years since forest fires. However, the vegetation has not fully recovered to the climax community structures and functions of the boreal forest ecosystems. For example, ground temperatures, ALT, and soil C and N contents have been slowly recovering in the 30 years after the forest fires, but they have not yet been restored to pre‐fire levels. This study provides important scientific bases for assessment of the impacts of forest fires on the boreal forest ecosystems in permafrost regions, environmental restoration and management, and changes in the carbon stock of soils at shallow ( 〈 3 m) depths in the Da Xingan'ling Mountains in northeast China.
    Materialart: Online-Ressource
    ISSN: 1045-6740 , 1099-1530
    URL: Issue
    RVK:
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2019
    ZDB Id: 1479993-5
    SSG: 14
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 6
    In: Permafrost and Periglacial Processes, Wiley
    Kurzfassung: Global climate warming is accelerating permafrost degradation. The large amounts of soil organic matter in permafrost‐affected soils are prone to increased microbial decomposition in a warming climate. Along with permafrost degradation, changes to the soil microbiome play a crucial role in enhancing our understanding and in predicting the feedback of permafrost carbon. In this article, we review the current state of knowledge of carbon‐cycling microbial ecology in permafrost regions. Microbiomes in degrading permafrost exhibit variations across spatial and temporal scales. Among the short‐term, rapid degradation scenarios, thermokarst lakes have distinct biogeochemical conditions promoting emission of greenhouse gases. Additionally, extreme climatic events can trigger drastic changes in microbial consortia and activity. Notably, environmental conditions appear to exert a dominant influence on microbial assembly in permafrost ecosystems. Furthermore, as the global climate is closely connected to various permafrost regions, it will be crucial to extend our understanding beyond local scales, for example by conducting comparative and integrative studies between Arctic permafrost and alpine permafrost on the Qinghai–Tibet Plateau at global and continental scales. These comparative studies will enhance our understanding of microbial functioning in degrading permafrost ecosystems and help inform effective strategies for managing and mitigating the impacts of climate change on permafrost regions.
    Materialart: Online-Ressource
    ISSN: 1045-6740 , 1099-1530
    RVK:
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2023
    ZDB Id: 1479993-5
    SSG: 14
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 7
    In: Annals of Neurology, Wiley, Vol. 78, No. 4 ( 2015-10), p. 594-605
    Kurzfassung: We aimed to investigate the roles of different resting‐state networks in predicting both the actual level of consciousness and its recovery in brain injury patients. Methods We investigated resting‐state functional connectivity within different networks in patients with varying levels of consciousness: unresponsive wakefulness syndrome (UWS; n = 56), minimally conscious state (MCS; n = 29), and patients with brain lesions but full consciousness (BL; n = 48). Considering the actual level of consciousness, we compared the strength of network connectivity among the patient groups. We then checked the presence of connections between specific regions in individual patients and calculated the frequency of this in the different patient groups. Considering the recovery of consciousness, we split the UWS group into 2 subgroups according to recovery: those who emerged from UWS (UWS‐E) and those who remained in UWS (UWS‐R). The above analyses were repeated on these 2 subgroups. Results Functional connectivity strength in salience network (SN), especially connectivity between the supragenual anterior cingulate cortex (SACC) and left anterior insula (LAI), was reduced in the unconscious state (UWS) compared to the conscious state (MCS and BL). Moreover, at the individual level, SACC‐LAI connectivity was more present in MCS than in UWS. Default‐mode network (DMN) connectivity strength, especially between the posterior cingulate cortex (PCC) and left lateral parietal cortex (LLPC), was reduced in UWS‐R compared with UWS‐E. Furthermore, PCC‐LLPC connectivity was more present in UWS‐E than in UWS‐R. Interpretation Our findings show that SN (SACC‐LAI) connectivity correlates with behavioral signs of consciousness, whereas DMN (PCC‐LLPC) connectivity instead predicts recovery of consciousness. Ann Neurol 2015;78:594–605
    Materialart: Online-Ressource
    ISSN: 0364-5134 , 1531-8249
    URL: Issue
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2015
    ZDB Id: 2037912-2
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 8
    In: Journal of Animal Ecology, Wiley, Vol. 92, No. 7 ( 2023-07), p. 1345-1356
    Kurzfassung: Over the last 40 years, a burrowing mammal eradication policy has been prevalent on the Qinghai–Tibetan Plateau (QTP). This policy is based on similar burrowing mammal eradication programs in other areas and is justified on the assumptions that burrowing mammals compete with livestock for forage and contribute to grassland degradation. However, there is no clear theoretical or experimental evidence supporting these assumptions. This paper synthesizes the ecological functioning of small burrowing mammals in natural grasslands and discusses the irrationality and consequences of burrowing mammal eradication for sustainable livestock grazing and grassland degradation. Past burrowing mammal eradication efforts have failed because increased food availability for the remaining rodents and reduced predator populations led to rapid population rebounds. Herbivores differ in diet, and there is clear evidence that burrowing mammals, especially plateau zokors Myospalax baileyi , have a different diet than livestock. In QTP meadows, burrowing mammal eradication induces a shift towards plant communities with fewer species preferred by livestock and more species preferred by burrowing mammals. Thus, eradicating burrowing mammals has the opposite effect, a reduction in livestock preferred vegetation. We suggest that the policy of poisoning burrowing mammals needs to be reconsidered and revoked as soon as possible. We argue that incorporating density‐dependent factors such as predation and food availability are essential for maintaining a low burrowing mammal density. For degraded grasslands, we suggest that the optimal sustainable approach is to decrease the intensity of livestock grazing. Lower grazing induces changes in vegetation structure and plant species composition that increases predation on burrowing mammals and decreases the abundance of plants preferred by burrowing mammals. Such a nature‐based grassland management system maintains the density of burrowing mammals at a low stable density while minimizing human management and interventions.
    Materialart: Online-Ressource
    ISSN: 0021-8790 , 1365-2656
    URL: Issue
    RVK:
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2023
    ZDB Id: 2006616-8
    SSG: 12
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 9
    In: Chemistry – An Asian Journal, Wiley, Vol. 15, No. 9 ( 2020-05-04), p. 1478-1483
    Kurzfassung: Natural UV photoprotection plays a vital role in physiological protection. It has been reported that UVC radiation can make resveratrol (RSV) and piceatannol (PIC) accumulate in grape skin. In this work, we demonstrated that RSV and PIC could significantly absorb UVA and UVB, and confirmed their satisfactory photostability. Furthermore, we clarified the UV photoprotection mechanism of typical stilbenoids of RSV and PIC for the first time by using combined femtosecond transient absorption (FTA) spectroscopy and time‐dependent density functional theory (TD‐DFT) calculations. RSV and PIC can be photoexcited to the excited state after UVA and UVB absorption. Subsequently, the photoisomerized RSV and PIC quickly relax to the ground state via nonadiabatic transition from the S 1 state at a conical intersection (CI) position between potential energy surfaces (PESs) of S 1 and S 0 states. This ultrafast trans ‐ cis photoisomerization will take place within a few tens of picoseconds. As a result, the UV energy absorbed by RSV and PIC could be dissipated by an ultrafast nonadiabatic photoisomerization process.
    Materialart: Online-Ressource
    ISSN: 1861-4728 , 1861-471X
    URL: Issue
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2020
    ZDB Id: 2233006-9
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 10
    In: Molecular Microbiology, Wiley, Vol. 72, No. 2 ( 2009-04), p. 354-367
    Kurzfassung: Trichothecenes are isoprenoid mycotoxins produced in wheat infected with the filamentous fungus Fusarium graminearum . Some fungal genes for trichothecene biosynthesis ( Tri genes) are known to be under control of transcription factors encoded by Tri6 and Tri10 . Tri6 and Tri10 deletion mutants were constructed in order to discover additional genes regulated by these factors in planta . Both mutants were greatly reduced in pathogenicity and toxin production and these phenotypes were largely restored by genetic complementation with the wild‐type gene. Transcript levels for over 200 genes were altered ≥ twofold for Δtri6 or Δtri10 mutants including nearly all known Tri genes. Also reduced were transcript levels for enzymes in the isoprenoid biosynthetic pathway leading to farnesyl pyrophosphate, the immediate molecular precursor of trichothecenes. DNA sequences 5′ to isoprenoid biosynthetic genes were enriched for the Tri6p DNA binding motif, YNAGGCC, in F. graminearum but not in related species that do not produce trichothecenes. To determine the effect of trichothecene metabolites on gene expression, cultures were treated with trichodiene, the first metabolic intermediate specific to the trichothecene biosynthetic pathway. A total of 153 genes were upregulated by added trichodiene and were significantly enriched for genes likely involved in cellular transport. Differentially regulated genes will be targeted for functional analysis to discover additional factors involved in toxin biosynthesis, toxin resistance and pathogenesis.
    Materialart: Online-Ressource
    ISSN: 0950-382X , 1365-2958
    URL: Issue
    Sprache: Englisch
    Verlag: Wiley
    Publikationsdatum: 2009
    ZDB Id: 1501537-3
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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