Influence Of Climate Warming Research Articles

Influence of climate warming and resin collection on the growth of Masson pine (Pinus massoniana) in a subtropical forest, southern China

Influence of climate warming and resin collection on the growth of Masson pine (Pinus massoniana) in a subtropical forest, southern China

Comparison of permafrost degradation under natural ground surfaces and embankments of the Qinghai–Tibet Highway

Permafrost under road embankments often degrades more seriously than that under natural ground surfaces due to the influences of both climate warming and road embankment. In a companion paper, we analyzed the states of permafrost degradation under road embankments in the five typical regions along the Qinghai–Tibet Highway (Yu et al., 2013a). In this paper, the states of permafrost degradation under natural ground surfaces, near the road embankments, are analyzed based on up to 15years of in-situ geothermal data, while that under road embankments are also further analyzed. On this basis, the states of permafrost degradation and related processes are compared between the natural ground surfaces and road embankments. Possible influences of climate warming and road embankment on permafrost degradation are discussed. The results show different characteristics of permafrost degradation under natural ground surfaces and road embankments. The contributions of climate warming and road embankment on the thermal regime of permafrost may vary during the process of permafrost degradation.

Complex response of runoff–precipitation ratio to the rising air temperature: the source area of the Yellow River, China

The impact of climate warming on the water cycle and water resources is an important issue in science and for sustainable socioeconomic development. The drainage area above Tangnaihai station is the source area of the Yellow River, which is located in the Qinghai–Tibet Plateau and yields 41.3 % of the river’s total natural runoff. Thus, it is known as the “water tower of the Yellow River.” Based on climate and hydrometric data from 1956 to 2008, the purpose of this study is to deal with the influence of climate warming on the water cycle in this region and thereby to provide some knowledge for sustainable water resources management of the Yellow River. The statistical analysis shows basically no trend in annual precipitation, but a significant rising trend in air temperature. Hence, this area is ideal to study the response of the water cycle system to climate warming. We found nonlinear variations in annual runoff (Qw) and the runoff–precipitation ratio (Rrp): they increased to a peak and then decreased. According to the response of Rrp to rising temperature, we established a three-stage descriptive model for the complex response of runoff generation to the rising air temperature. The mechanism of the complex response is explained based on the evidence of environmental changes previously reported in the study area, driven by rising temperatures.

A re-evaluation of the Pleistocene behavior of the Scoresby Sund sector of the Greenland Ice Sheet

Limited data on the past dynamics of the Greenland Ice Sheet, exceeding the ice-core records, have led to partly contradictory reconstructions. Whereas the Scoresby Sund sector of the Greenland Ice Sheet has been suggested to be stable and not much larger than at present during the peak Pleistocene glaciations, the southeastern sector of the ice sheet has been inferred to be much more dynamic. Here we present seismic data showing that glacigenic debris-flow deposits dominate the younger than ca. 2.58 Ma succession of the Scoresby Sund trough mouth fan on the East Greenland continental margin, suggesting much more frequent expansions of the Greenland Ice Sheet to the shelf break than found previously. From our new observations of the Pleistocene stratigraphy, we revise previous findings and conclude that the Scoresby Sund sector of the Greenland Ice Sheet during the Pleistocene (1) developed in line with other parts of the East Greenland Ice Sheet, and (2) was more dynamic and sensitive to past climatic changes than hitherto realized. This rapid response of the glacier to climate forcing indicates how dynamic is the glacier ice front and what one might expect of the glacier as the influences of climate warming become more pronounced.

Influence of climate warming and nitrogen deposition on soil phosphorus composition and phosphorus availability in a temperate grassland, China

Climate warming and nitrogen (N) deposition change ecosystem processes, structure, and functioning whereas the phosphorus (P) composition and availability directly influence the ecosystem structure under conditions of N deposition. In our study, four treatments were designed, including a control, diurnal warming (DW), N deposition (ND), and combined warming and N deposition (WN). The effects of DW, ND, and WN on P composition were studied by 31P nuclear magnetic resonance (31P NMR) spectroscopy in a temperate grassland region of China. The results showed that the N deposition decreased the soil pH and total N (TN) concentration but increased the soil Olsen-P concentration. The solution-state 31P NMR analysis showed that the DW, ND and WN treatments slightly decreased the proportion of orthophosphate and increased that of the monoesters. An absence of myo-inositol phosphate in the DW, ND and WN treatments was observed compared with the control. Furthermore, the DW, ND and WN treatments significantly decreased the recovery of soil P in the NaOH-EDTA solution by 17%–20%. The principal component analysis found that the soil pH was positively correlated with the P recovery in the NaOH-EDTA solution. Therefore, the decreased soil P recovery in the DW and ND treatments might be caused by an indirect influence on the soil pH. Additionally, the soil moisture content was the key factor limiting the available P. The positive correlation of total carbon (TC) and TN with the soil P composition indicated the influence of climate warming and N deposition on the biological processes in the soil P cycling.

Common beech Fagus sylvatica L; survival and longevity in changing times

Veteran trees not only have an intrinsic interest in themselves; they also provide information about climatic conditions and masting over periods equal to many human generations. This paper endeavours to highlight existing records of veteran populations of Fagus sylvatica L. in Europe, especially in Sweden, and also provides fresh information regarding trees in Germany and the Carpathian Mountains of the Ukraine.For reasons of space it is not possible to list all the very many papers dealing with the influence of climatic warming on forest trees, but it is clear from those quoted here that common beech is particularly influenced by it. In general the effect has been to move the areas favourable to the species northwards in the lowlands and upwards in mountainous regions. This is very much the case in Britain where the Forest Authority no longer approves of beech planting in southern and eastern England. The use of sweet chestnut Castanea sativa as its replacement in broad-leaved forests is likely to result in ecosystems markedly different from those which evolved under beech. Sweet chestnut is predicted to increase in growth and productivity in the east of England as beech retreats north and west.The English Beech Mast Survey was initiated in 1980; its recorders have in consequence observed the storm damage to beech stands, particularly in the south, during that time. The remarkable response by beech to lava flows on the presently dormant volcano of Etna, Sicily, is both described and illustrated. In many cases lava that engulfed the trees had destroyed the main trunks, but left scorched bases from which the trees had coppiced successfully.

Degradation process of permafrost underneath embankments along Qinghai-Tibet Highway: An engineering view

Abstract Embankment settlement is closely related to the process of degrading of underling permafrost. Previous studies have focused on the process of permafrost degradation under natural ground surfaces, and the degradation process under roadway embankments has yet to be investigated. With the influence of climate warming, this study becomes more and more important in the analysis of embankment settlement. In this paper, based on the in-situ geothermal data of up to 15 years of 5 typical sections along the Qinghai-Tibet Highway (QTH), the characteristics of permafrost degradation are extensively investigated. According to the characteristics, the trends of thawing and temperature rise in the process of permafrost degradation are analyzed. Corresponding to the tendencies, four stages are defined according to the mean annual ground temperature (MAGT). Combining the features of permafrost degradation in each stage with the in-situ data of embankment settlements along QTH, the sources of the embankment settlement are identified. The main results are as follows. The permafrost degrades extensively in the five typical sections with different characteristics. With the increase in MAGT, the thawing rate firstly increases and then fluctuates as temperature rise rate increases and then decreases at MAGT of about − 0.5 °C. The four stages are divided: initial degradation stage, for MAGT ≤ − 2.5 °C; the intensive degradation stage, for − 2.5 °C 0 °C. When MAGT is less than about − 1.2 °C, the main contribution of total settlement is probably thawing settlement, with the negligible creep of permafrost; when MAGT higher than − 1.2 °C, creep of permafrost starts to have an increasing share in the total settlement.

Light and Heavy Fractions of Soil Organic Matter in Response to Climate Warming and Increased Precipitation in a Temperate Steppe

Soil is one of the most important carbon (C) and nitrogen (N) pools and plays a crucial role in ecosystem C and N cycling. Climate change profoundly affects soil C and N storage via changing C and N inputs and outputs. However, the influences of climate warming and changing precipitation regime on labile and recalcitrant fractions of soil organic C and N remain unclear. Here, we investigated soil labile and recalcitrant C and N under 6 years' treatments of experimental warming and increased precipitation in a temperate steppe in Northern China. We measured soil light fraction C (LFC) and N (LFN), microbial biomass C (MBC) and N (MBN), dissolved organic C (DOC) and heavy fraction C (HFC) and N (HFN). The results showed that increased precipitation significantly stimulated soil LFC and LFN by 16.1% and 18.5%, respectively, and increased LFC∶HFC ratio and LFN∶HFN ratio, suggesting that increased precipitation transferred more soil organic carbon into the quick-decayed carbon pool. Experimental warming reduced soil labile C (LFC, MBC, and DOC). In contrast, soil heavy fraction C and N, and total C and N were not significantly impacted by increased precipitation or warming. Soil labile C significantly correlated with gross ecosystem productivity, ecosystem respiration and soil respiration, but not with soil moisture and temperature, suggesting that biotic processes rather than abiotic factors determine variations in soil labile C. Our results indicate that certain soil carbon fraction is sensitive to climate change in the temperate steppe, which may in turn impact ecosystem carbon fluxes in response and feedback to climate change.

Influence of Climatic Warming on Distributional Changes in Tropical and Subtropical Insect Pests

Influence of Climatic Warming on Distributional Changes in Tropical and Subtropical Insect Pests

Topographically controlled thermal-habitat differentiation buffers alpine plant diversity against climate warming

Aim We aim to: (1) explore thermal habitat preferences in alpine plant species across mosaics of topographically controlled micro-habitats; (2) test the predictive value of so-called 'indicator values'; and (3) quantify the shift in micro-habitat conditions under the influence of climate warming. Location Alpine vegetation 2200-2800 m a.s.l., Swiss central Alps. Methods High-resolution infra-red thermometry and large numbers of small data loggers were used to assess the spatial and temporal variation of plant-surface and ground temperatures as well as snow-melt patterns for 889 plots distributed across three alpine slopes of contrasting exposure. These environmental data were then correlated with Landolt indicator values for temperature preferences of different plant species and vegetation units. By simulating a uniform 2 K warming we estimated the changes in abundance of micro-habitat temperatures within the study area. Results Within the study area we observed a substantial variation between micro-habitats in seasonal mean soil temperature (Delta T = 7.2 K), surface temperature (Delta T = 10.5 K) and season length (< 32 days). Plant species with low indicator values for temperature (plants commonly found in cool habitats) grew in significantly colder micro-habitats than plants with higher indicator values found on the same slope. A 2 K warming will lead to the loss of the coldest habitats (3% of current area), 75% of the current thermal micro-habitats will be reduced in abundance (crowding effect) and 22% will become more abundant. Main conclusions Our results demonstrate that the topographically induced mosaics of micro-climatic conditions in an alpine landscape are associated with local plant species distribution. Semi-quantitative plant species indicator values based on expert knowledge and aggregated to community means match measured thermal habitat conditions. Metre-scale thermal contrasts significantly exceed IPCC warming projections for the next 1 years. The data presented here thus indicate a great risk of overestimating alpine habitat losses in isotherm-based model scenarios. While all but the species depending on the very coldest micro-habitats will find thermally suitable 'escape' habitats within short distances, there will be enhanced competition for those cooler places on a given slope in an alpine climate that is 2 K warmer. Yet, due to their topographic variability, alpine landscapes are likely to be safer places for most species than lowland terrain in a warming world.

Influence of Climate Change, Fire, Insect and Harvest on Carbon Dynamics for Jack Pine in Central Canada: Simulation Approach with the EFIMOD Model

Changes in disturbance regimes, both natural and anthropogenic, will be an important mechanism by which northern ecosystems respond to climate change, and are an important feedback mechanism in changing ecosystem processes. A forest ecosystem model, EFIMOD, was applied to the jack pine (Pinus banksiana Lamb.) stands in Central Canada to simulate the influence of climate warming, fire, insects and harvesting on jack pine productivity and pools of soil carbon (C). For the climate change simulations, temperature and precipitation prediction data from three General Circu- lationModels(GCMs)wereused:theCanadianClimateCentreforModellingandAnalysis,CGCM2; the UK Hadley Centre, HadCM3; and the Australian CSIRO Mark 2 GCM. In all three of these scen- arios, whole trees biomass increased, whereas the soil organic C pool consistently decreased. The CSIRO and CGCM scenarios had the strongest affect on biomass, soil, and ecosystem processes (net primary productivity, soil respiration, and net ecosystem productivity). Assessing the net ecosystem productivity over 150 years for jack pine stands shows a C sink under different disturbance regimes: 'nodisturbances>harvest-fire>twofires>insectattack>harvesting>fire-harvest';andnetcarbon source under a four fires scenario. The disturbance frequency was found to have a strong and lasting influence onthedynamicsoftheCstocks,andadirecteffectonCsource/sinkrelationship.Soilnitrogen content, which reflect the productivity potential, modify the effect of climate change and disturbances.

Permafrost Characteristics of the Qinghai‐Tibet Plateau and Methods of Roadbed Construction of Railway

AbstractPermafrost along the Qinghai‐Tibet railway is featured by abundant ground ice and high ground temperature. Under the influence of climate warming and engineering activities, the permafrost is under degradation process. The main difficulty in railway roadbed construction is how to prevent thawing settlement caused by degradation of permafrost Therefore the proactively cooling methods based on controlling solar radiation, heat conductivity and heat convection were adopted instead of the traditional passive methods, which is simply increasing thermal resistance. The cooling methods used in the Qinghai‐Tibet railway construction include sunshine‐shielding roadbeds, crushed rock based roadbeds, roadbeds with rock revetments, duct‐ventilated roadbeds, thermosyphon installed roadbeds and land bridges. The field monitored data show that the cooling methods are effective in protecting the underlying permafrost, the permafrost table was uplifted under the embankments and therefore the roadbed stability was guaranteed.

Long term trend of chemical oxygen demand in Saroma-ko Lagoon, Japan; possible effects of climatic warming

A trend of shortening duration of ice coverage has been reported in many rivers, ponds and lakes around the world due to climatic warming. The shortening will have much influence on organic production due to the greater supply of light intensity and hence on water quality. Chemical Oxygen Demand (COD), a useful measure of water quality, has been monitored over the past thirty years in Saroma-ko Lagoon, a boreal lake in Japan characterized by wintertime ice coverage. Here the data set of water quality in the lagoon is analyzed to reveal long-term trends in COD and the influence of climatic warming on such trends. There has been a significant increasing trend, caused primarily by an abrupt increase in the early 1990s. However, the increase could not be explained by the increased load of organic matter on the lagoon from the river basin and organic production in the lagoon. On the other hand, periods of freezing of the entire surface have tended to be shorter with inevitable thinning of ice over the past forty years, probably due to climatic warming. Ice and planktonic algae are exposed to the low light intensity in situ, which is not optimum for the algal production of organic matter. The shortening and thinning should thus bring an improvement in ambient light conditions for algae, resulting in an increase of organic matter in winter. Most of the organic matter possibly remains even after spring because of the low water temperature. It is highly possible that climatic warming promotes deterioration in water quality in ice-covered lakes.

Long term trend of chemical oxygen demand in Saroma-ko Lagoon, Japan; possible effects of climatic warming

AbstractA trend of shortening duration of ice coverage has been reported in many rivers, ponds and lakes around the world due to climatic warming. The shortening will have much influence on organic production due to the greater supply of light intensity and hence on water quality. Chemical Oxygen Demand (COD), a useful measure of water quality, has been monitored over the past thirty years in Saroma-ko Lagoon, a boreal lake in Japan characterized by wintertime ice coverage. Here the data set of water quality in the lagoon is analyzed to reveal long-term trends in COD and the influence of climatic warming on such trends. There has been a significant increasing trend, caused primarily by an abrupt increase in the early 1990s. However, the increase could not be explained by the increased load of organic matter on the lagoon from the river basin and organic production in the lagoon. On the other hand, periods of freezing of the entire surface have tended to be shorter with inevitable thinning of ice over the past forty years, probably due to climatic warming. Ice and planktonic algae are exposed to the low light intensity in situ, which is not optimum for the algal production of organic matter. The shortening and thinning should thus bring an improvement in ambient light conditions for algae, resulting in an increase of organic matter in winter. Most of the organic matter possibly remains even after spring because of the low water temperature. It is highly possible that climatic warming promotes deterioration in water quality in ice-covered lakes.

Influence of Climate Warming on Tick-borne Encephalitis Expansion to Higher Altitudes during the Last Decade (1997-2006) in the Highland Region (Czech Republic)

The steep rise in the incidence of tick-borne encephalitis (TBE) in the 1990s and its subsequent high level in the Czech Republic are not even over the whole territory. It is manifested markedly in the Czech-Moravian Highland region. In the decades of 1971 through 1992, TBE incidence in the Highland Region did not reach the countrywide average. The rise has been noted only since 1997; in the year 2006 TBE incidence in that administrative region was more than double the countrywide average. Analysis of the situation have not found any socio-economic shifts or land-use changes, or in the numbers of game animals, that could have had an effect on TBE incidence. The rise of infections in localities 500 m above sea level (a.s.l.) and more was markedly steeper than that below that altitudinal limit. At those altitudes there has been found an increase in average monthly temperatures exceeding countrywide averages namely in the period of maximum Ixodes ricinus activity (May-August). Detailed analysis of meteorological conditions and comparison with a long-term study of the influence of modifications of the mountain climate in the Krkonose Mts. on I. ricinus tick distribution and the pathogens transmitted by them, have led to the conclusion that likewise in the Czech-Moravian Highland a marked warming had influenced the local population of the vector I. ricinus, caused an activation of foci of TBE, increased contacts of humans with the vector, consequently giving rise to an apparent increase in the incidence of human cases of TBE.

An assessment of potential change in wildfire activity in the Russian boreal forest zone induced by climate warming during the twenty-first century

The problem of forest fires is very important for Russia. In this paper we consider this problem in the connection with the projection of significant climate change. An approach to determine the magnitude of change in wildfire risk in Russia under the influence of climate warming is discussed. Observations for the European part of Russia and for Siberia have been used in this analysis. A statistical correlation between drought indices calculated by use of monthly sums of temperature and precipitation and the frequency of fire danger was obtained for the forest zone of Russia. The change in fire danger potential was evaluated using temperature and precipitation monthly means at the nodes of a regular spatial grid. Climate change scenarios were obtained from Global Climate Models (GCM) ensemble projections. The maximum increases (about 12–30%) of the number of days with fire danger conditions during the twenty-first century fire season were obtained for the southern forest zone boundary in both the European region of Russia and in Siberia. In the Baikal and Primoriye Regions, fire danger distributions in the twenty-first century are not projected to change significantly.

Permafrost monitoring in the Hovsgol mountain region, Mongolia

The Hovsgol mountain region (49°–52°N, 98°–102°E) of northern Mongolia contains widespread mountain permafrost and comprises the southern fringe of the Siberian continuous permafrost zone. In this paper, we report our initial monitoring of permafrost by means of measuring ground temperatures and active layer thickness in boreholes and some cryogenic processes under the influence of climate warming and human activities in the region. The average rate of increase in mean annual permafrost temperatures is from 0.2°C to 0.4°C per decade. Permafrost has been degrading more intensively during the last 15 years (since 1990s) than during the previous 15–20 years (1970s and 1980s). Recent degradation of permafrost under climate warming in the Hovsgol mountain region is generally more intensive than in the Hentei and Hangai Mountain regions. Moreover, livestock grazing in some local areas accelerates degradation of permafrost due to loss of vegetation cover. Year‐round temperature recordings by data loggers placed beneath different vegetation covers showed marked differences in active layer thickness and ground temperature.

Phänologie – ein Biomonitoring und seine Anwendungen | Phenology – a bio-monitoring and its applications

Phenology studies the seasonally recurring growth and development of living creatures and abiotic phenomenon. It deals with observing the dates of plant developmental phases (from leafing to leaf fall), of bird migrations(arrival and takeoff of migratory birds), or frost occurrence and freezing of water courses and other phenomenon. Plant phenology is well suited as an indicator for bio-monitoring of environmental changes, such as actual climate warming, as organisms reflect the integrated reaction to the environment. In Switzerland Meteo-Swiss has run a national phenological observation network since 1951 that includes all regions and altitudinal belts, while a whole range of special networks operate for specific objectives: for example work in schools. The international and global cooperation in phenology starts gradually. In Europe, actively working groups prepare a standardization of observations and a central pool base for the observation data. At the moment, phenology serves above all as an indicator for the influence of climate warming on vegetation, but is also applied to frost warnings, pollen forecasts or for the optimization of plant protection in agriculture.

Influence of climatic warming in the Southern and Northern Hemisphere on the tropical cyclone over the western North Pacific Ocean

Based on analyzing the surface air temperature series in the Southern and Northern Hemisphere and the tropical cyclone (TC) over the western North Pacific Ocean, the relationships between climatic warming and the frequency and intensity of tropical cyclone are investigated. The results showed that with the climatic warming in both hemispheres, the frequency of the tropical cyclone over the western North Pacific Ocean reduces and its intensity weakens simultaneously. A possible explanation might be that the cold air invasion from the Southern Hemisphere weakens due to global warming.

The effects of ultraviolet-B radiation on freshwater ecosystems of the Arctic: Influence from stratospheric ozone depletion and climate change

Depletion of stratospheric ozone, the principal atmospheric attenuator of ultraviolet-B (UVB) radiation, by man-made chemicals has raised scientific and public concern regarding the biological effects of increased UVB radiation on Earth. There is an increased awareness that existing levels of solar UV radiation have an important influence on biological and chemical processes in aquatic ecosystems. For aquatic organisms, numerous studies have shown direct detrimental effects of UVB radiation at each trophic level. Fortunately, many aquatic organisms also possess a range of photoprotective mechanisms against UV radiation toxicity. In addition to its direct impact, harmful effects of UVB radiation at a single-trophic level can cascade through the food web and indirectly affect organisms from other trophic levels. Because UV radiation photochemically reacts with humic substances and other photosensitive agents in the water, increases in solar UVB can also indirectly affect aquatic organisms through the production and (or) release of different photoproducts like biologically available nutrients and harmful reactive oxygen species. Polar aquatic ecosystems have been of particular concern, since stratospheric ozone-related UVB increases have been the greatest in these regions. With the influences of climate warming and the possibility of future volcanic eruptions, ozone losses are expected to get worse in the Arctic stratosphere, and the ozone layer recovery may not follow the slow decline of industrial ozone-depleting compounds in the atmosphere. Climate warming is also expected to bring important changes in underwater ultraviolet radiation (UVR) penetration in Arctic freshwaters that would be more significant to the aquatic biota than stratospheric ozone depletion.Key words: Arctic, UV radiation, UVB, ozone depletion, climate change, aquatic ecosystems.