scholarly journals Contrasting Temperature and Precipitation Patterns of Trees in Different Seasons and Responses of Infrared Canopy Temperature in Two Asian Subtropical Forests

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 902
Author(s):  
Zhi Chen ◽  
Guirui Yu ◽  
Junhua Yan ◽  
Huimin Wang
Keyword(s):  
Air Temperature ◽  
Seasonal Variations ◽  
Canopy Temperature ◽  
Ambient Air ◽  
Future Climate Change ◽  
Precipitation Pattern ◽  
Canopy Conductance ◽  
Subtropical Forests ◽  
Precipitation Patterns ◽  
Temperature And Precipitation

Canopy temperature (Tc), one of the most important plant ecophysiological parameters, has been known to respond rapidly to environmental change. However, how environmental factors—especially the temperature and precipitation pattern—impact Tc has been less discussed for forest stands. In this study, we investigated seasonal variations and responses of the Tc and canopy-to-air temperature difference (ΔT) associated with environmental conditions in two subtropical forests with contrasting temperature and precipitation patterns—Dinghushan (DHS) (temperature and precipitation synchronous site: hot and wet in the summer) and Qianyanzhou (QYZ) (temperature and precipitation asynchronous site: hot and arid in the summer). The results showed that Tc exhibits clear diurnal and seasonal variations above air temperature throughout the day and year, suggesting that the canopy of both DHS and QYZ is typically warmer than ambient air. However, the canopy-warming effect was substantially intensified in QYZ, and the difference of ΔT between dry and wet seasons was small (−0.07 °C) in DHS, while it was up to 0.9 °C in QYZ. Regression analysis revealed that this resulted from the combined effects of the increased solar radiation and vapor pressure deficit (VPD), but reduced canopy conductance (gc) caused by drought in the summer in QYZ. Sensitivity analysis further indicated that the responses of ΔT to VPD and gc changes were quite divergent, presenting negative responses to the enhanced VPD and gc in QYZ, while there were positive responses in DHS. The high productivity coupled with low transpiration cooling that occurs in a temperature and precipitation synchronous condition mainly contributes to the positive responses of ΔT in DHS. This study reveals the seasonal variations, environmental responses, and underlying causes of Tc under different temperature and precipitation patterns, providing useful information for the regional assessment of plant responses to future climate change.

The impact of increased temperatures on germination patterns of semi-aquatic plants

2019 ◽  
Vol 29 (3) ◽  
pp. 204-209
Author(s):  
Jade Dessent ◽  
Susan Lawler ◽  
Daryl Nielsen
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Soil Seed Bank ◽  
Ambient Air ◽  
Future Climate Change ◽  
Ambient Air Temperature ◽  
Threshold Temperatures ◽  
Soil Temperatures ◽  
The Impact ◽  
Number Of Seeds

AbstractFuture climate change predictions indicate that there will be an increase in ambient air temperature. Increases in ambient air temperature will result in a corresponding increase in soil temperature. The consequences of further increases in soil temperature will potentially be detrimental for the soil seed bank of plants in terms of length of dormancy and viability of seeds. This experiment investigated the effect of different exposure temperatures and duration of exposure on the germination of semi-aquatic plant species. Seeds of four species (Alternanthera denticulata, Juncus usitatus, Persicaria lapathifolia and Persicaria prostrata) were exposed to temperatures ranging from 25 to 100°C for durations between 1 and 14 days, before being germinated in an incubator for 6 weeks. Germination occurred in all four species after exposure to temperatures ranging from 25 to 60°C. These temperatures appeared to promote germination as the temperature and duration of exposure increased. However, in P. lapathifolia and P. prostrata, the number of seeds germinating declined when exposed to 70°C and there was no germination for temperatures exceeding this. In contrast, A. denticulata and J. usitatus only began to decline when exposed to 80°C, with no germination at higher temperatures. These results suggest that soil temperatures exceeding potential threshold temperatures of 70 and 80°C will result in a decline in the number of seeds germinating and may potentially see a change in species distributions. As such soil temperatures are already being experienced throughout Australia, some species may already be close to their thermal threshold.

The effect of ambient air temperature and precipitation on monthly counts of salmonellosis in four regions of Kazakhstan, Central Asia, in 2000–2010

2013 ◽  
Vol 142 (3) ◽  
pp. 608-615 ◽  
Author(s):  
A. M. GRJIBOVSKI ◽  
A. KOSBAYEVA ◽  
B. MENNE
Keyword(s):  
Climate Change ◽  
Confidence Interval ◽  
Central Asia ◽  
Air Temperature ◽  
Positive Association ◽  
Ambient Air ◽  
Ambient Air Temperature ◽  
Temperature And Precipitation ◽  
Similar Association ◽  
Level Of Significance

SUMMARYWe studied associations between monthly counts of laboratory-confirmed cases of salmonellosis, ambient air temperature and precipitation in four settings in Kazakhstan. We observed a linear association between the number of cases of salmonellosis and mean monthly temperature during the same months only in Astana: an increase of 1°C was associated with a 5·5% [95% confidence interval (CI) 2·2–8·8] increase in the number of cases. A similar association, although not reaching the level of significance was observed in the Southern Kazakhstan region (3·5%, 95% CI −2·1 to 9·1). Positive association with precipitation with lag 2 was found in Astana: an increase of 1 mm was associated with a 0·5% (95% CI 0·1–1·0) increase in the number of cases. A similar association, but with lag 0 was observed in Southern Kazakhstan region (0·6%, 95% CI 0·1–1·1). The results may have implications for the future patterns of salmonellosis in Kazakhstan with regard to climate change.

scholarly journals Biophysical Effects of Temperate Forests in Regulating Regional Temperature and Precipitation Pattern across Northeast China

2021 ◽  
Vol 13 (23) ◽  
pp. 4767
Author(s):  
Yue Jiao ◽  
Kun Bu ◽  
Jiuchun Yang ◽  
Guangshuai Li ◽  
Lidu Shen ◽  
...  
Keyword(s):  
Air Temperature ◽  
Forest Ecosystem ◽  
Northeast China ◽  
Climate Model ◽  
Temperate Forests ◽  
Regional Climate ◽  
Precipitation Pattern ◽  
Temperature And Precipitation ◽  
Water Cycling ◽  
Regional Temperature

The temperate forests in Northeast China are an important ecological barrier. However, the way in which temperate forests regulate the regional temperature and water cycling remains unclear. In this study, we quantitatively evaluated the role that temperate forests play in the regulation of the regional temperature and precipitation by combining remote sensing observations with a state-of-the-art regional climate model. Our results indicated that the forest ecosystem could slightly warm the annual air temperature by 0.04 ± 0.02 °C and bring more rainfall (17.49 ± 3.88 mm) over Northeast China. The temperature and precipitation modification function of forests varies across the seasons. If the trees were not there, our model suggests that the temperature across Northeast China would become much colder in the winter and spring, and much hotter in the summer than the observed climate. Interestingly, the temperature regulation from the forest ecosystem was detected in both forested regions and the adjacent agricultural areas, suggesting that the temperate forests in Northeast China cushion the air temperature by increasing the temperature in the winter and spring, and decreasing the temperature in the summer over the whole region. Our study also highlights the capacity of temperate forests to regulate regional water cycling in Northeast China. With high evapotranspiration, the forests could transfer sufficient moisture to the atmosphere. Combined with the associated moisture convergence, the temperate forests in Northeast China brought more rainfall in both forest and agricultural ecosystems. The increased rainfall was mainly concentrated in the spring and summer; these seasons accounted for 93.82% of the total increase in rainfall. These results imply that temperate forests make outstanding contributions to the maintainance of the sustainable development of agriculture in Northeast China.

scholarly journals Hydrologic State Influence on Riverine Flood Discharge for a Small Temperate Watershed (Fall Creek, United States): Negative Feedbacks on the Effects of Climate Change

2017 ◽  
Vol 18 (2) ◽  
pp. 431-449 ◽  
Author(s):  
James O. Knighton ◽  
Arthur DeGaetano ◽  
M. Todd Walter
Keyword(s):  
Climate Change ◽  
United States ◽  
New York ◽  
Air Temperature ◽  
Climate Change Impacts ◽  
Future Climate Change ◽  
State Variables ◽  
Temperature And Precipitation ◽  
Flood Discharge ◽  
Flood Hydrology

Abstract Watershed flooding is a function of meteorological and hydrologic catchment conditions. Climate change is anticipated to affect air temperature and precipitation patterns such as altered total precipitation, increased intensity, and shorter event durations in the northeastern United States. While significant work has been done to estimate future meteorological conditions, much is currently unknown about future changes to distributions of hydrologic state variables. High-resolution hydrologic simulations of Fall Creek (Tompkins County, New York), a small temperate watershed (324 km2) with seasonal snowmelt, are performed to evaluate future climate change impacts on flood hydrology. The effects of hydrologic state and environmental variables on river flood stage are isolated and the importance of groundwater elevation, unsaturated soil moisture, snowpack, and air temperature is demonstrated. It is shown that the temporal persistence of these hydrologic state variables allows for an influence on watershed flood hydrology for up to 20 days. Finally, six hypothetical climate change forcing scenarios are simulated to estimate the influence of catchment conditions on the watershed runoff response. The possibility of drier summers and wetter springs with a reduced winter snowpack in the Northeast is also simulated. These hydrologic changes influence flood discharge in the opposite direction as climate effects because of a reduced snowpack accumulation and melt time. Strong hydrologic state influence on flood discharge may be most attributable to increased air temperature and decreased precipitation. Hydrologic state variables may change both the location and shape of seasonal flood discharge distributions despite expected consistency in the shape of precipitation statistic distributions.

scholarly journals On the USCRN Temperature System

2005 ◽  
Vol 22 (7) ◽  
pp. 1095-1100 ◽  
Author(s):  
K. G. Hubbard ◽  
X. Lin ◽  
C. B. Baker
Keyword(s):  
Air Temperature ◽  
Temperature Sensor ◽  
Measurement Errors ◽  
Surface Air Temperature ◽  
Future Climate Change ◽  
Reference Network ◽  
Current Configuration ◽  
Detection And Attribution ◽  
Temperature And Precipitation

Abstract In 2004 a new aspirated surface air temperature system was officially deployed nationally in the U.S. Climate Reference Network (USCRN) commissioned by the National Oceanic and Atmospheric Administration. The primary goal of the USCRN is to provide future long-term and high-quality homogeneous observations of surface air temperature and precipitation that can be coupled to past long-term observations for the detection and attribution of present and future climate change. In this paper two precision air temperature systems are included for evaluating the new USCRN air temperature system based on a 1-yr side-by-side field comparison. The measurement errors of the USCRN temperature sensor are systematically analyzed, and the components of error attributable to the datalogger, lead wires, fixed resistors, and the temperature coefficient of the resistors are presented. Although the current configuration is adequate, a more desirable configuration of USCRN temperature sensor coupled with the datalogger is proposed as a means of further reducing the uncertainty for the USCRN temperature measurement.

scholarly journals Future climate change and it`s impact on precipitation and temperature in Ukraine

2017 ◽  
pp. 76-82
Author(s):  
V. Khokhlov ◽  
N. Yermolenko
Keyword(s):  
Climate Change ◽  
Climatic Change ◽  
Air Temperature ◽  
Climate Model ◽  
Global Climate ◽  
Regional Climate ◽  
Annual Precipitation ◽  
Future Climate Change ◽  
Temperature And Precipitation ◽  
Southern Ukraine

Global climate change has provoked an active development in modern methods relating to the prediction of spatiotemporal hydrometeorological fields. Numerical modeling of nearest-future climatic changes allows to generate strategies of development for different areas of economic activity. The paper aims to assess the expected air temperature and precipitation features in Ukraine considering different scenarios of climatic change. The modeling future changes of air temperature and precipitation were carried out using the A1B and A2 scenarios of climatic change. The outcomes of regional climate model ECHAM5 from ENSEMBLES Project were used as initial data. It was revealed that the air temperature will gradually increase in most of Ukrainian regions. Moreover highest air temperature will be recorded in Southern Ukraine during 2031-2050. The analysis of linear trends for 2031-2050 showed that the air temperature for the scenario A1B will exhibit a tendency to the decrease of temperature. However, the annually mean temperature in 2031-2050 for the ‘moderate’ scenario A1B will be higher than for the ‘hard’, in terms of greenhouse gases concentrations, scenario A2. The annual precipitation in Ukraine, both for the A1B and A2 scenario, will slightly increase toward the 2050 with the exception of Southern Ukraine. Also, the highest annual precipitation will be registered in the western part of Ukraine, and lowest – in the southern one. The paper can be expanded to the analysis of future dangerous weather phenomena depending on the changes of air temperature and precipitation.

scholarly journals Impact of annual and seasonal precipitation and air temperature on gross primary production in Mediterranean ecosystems in Europe

2016 ◽  
Author(s):  
Svenja Bartsch ◽  
Bertrand Guenet ◽  
Christophe Boissard ◽  
Juliette Lathière ◽  
Jean-Yves Peterschmitt ◽  
...  
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
Air Temperature ◽  
Seasonal Variations ◽  
Carbon Fixation ◽  
Gross Primary Production ◽  
Mediterranean Ecosystems ◽  
Early Spring ◽  
Annual Variations ◽  
Temperature And Precipitation

Abstract. Mediterranean ecosystems are significant carbon sinks but are also particularly sensitive to climate change but the carbon dynamic in such ecosystem is still not fully understood. An improved understanding of the drivers of the carbon fixation by plants is needed to better predict how such ecosystems will respond to climate change. Here, for the first time, a large dataset collected through the FLUXNET network is used to estimate how the gross primary production (GPP) of different Mediterranean ecosystems was affected by air temperature and precipitation between the years 1996 and 2013. We showed that annual precipitation was not a significant driver of annual GPP. Our results also indicated that seasonal variations of air temperature significantly affected seasonal variations of GPP but without major impact on inter annual variations. Inter-annual variations of GPP seemed largely controlled by the precipitation during early spring (March–April), making this period crucial for the future of Mediterranean ecosystems. Finally, we also observed that the sensitivity of GPP in Mediterranean ecosystems to climate drivers is not ecosystem type dependent.

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