Factors Controlling Litterfall Production of Forest in China

2013 ◽  
Vol 726-731 ◽  
pp. 4248-4251 ◽  
Author(s):  
Guo Hong Lv ◽  
Guang Shen Zhou ◽  
Xiao Ying Wang
Keyword(s):  
Relative Humidity ◽  
Minimum Temperature ◽  
Climatic Factors ◽  
Natural Forest ◽  
Maximum Temperature ◽  
Planted Forest ◽  
Planted Forests ◽  
Litterfall Production ◽  
Path Analyses ◽  
Extreme Minimum Temperature

Litterfall production was shown to have a significant linear relationship with NPP in both natural and planted forests (R2= 0.67, 0.30,P<0.001). Correlation of litterfall production and climatic factors was higher in natural forest than in planted forest. Through correlative and path analyses, it was found that the climatic factors that most affect litterfall production in natural forest are annual mean maximum temperature, annual mean minimum temperature, annual extreme minimum temperature, and relative humidity, but in planted forest, they are annual extreme minimum temperature and annual mean minimum temperature. In both natural and planted forests, climatic factors could not account for the error in litterfall production predicted using the NPP.

scholarly journals Climatic Factors Affecting The Population Dynamics Of Lentil Aphid In Inner Terai Region Of Nepal

2020 ◽  
Vol 17 (2) ◽  
pp. 155-164
Author(s):  
S Neupane ◽  
S Subedi
Keyword(s):  
Population Dynamics ◽  
Relative Humidity ◽  
Minimum Temperature ◽  
Negative Impact ◽  
Climatic Factors ◽  
Block Design ◽  
Winter Season ◽  
Research Field ◽  
Aphid Population ◽  
Maximum Temperature

Population dynamics of lentil aphid Aphis craccivora (Hemiptera: Aphididae) was assessed in relation with climatic parameters at the research field of National Maize Research Program (NMRP), Rampur, Chitwan during winter season of two consecutive years 2016 to 2018. The experiment was organized in randomized complete block design consisting 20 lentil varieties with three replications. The crop was sown during last week of November in both the years. The daily meteorological parameters like maximum temperature (Tmax), minimum temperature (Tmin), relative humidity (RH) and rainfall (Rf) were recorded at the meteorological station located in NMRP, Rampur, Chitwan and then converted into weekly basis as the standard meteorological week (SMW) with correspondence to weekly population of aphid. The incidence of aphid was started from 2nd SMW of January (2 aphid/plant/10 cm apical twigs) during both experimentation years. Initially the population was low and gradually increased and reached to its peak (49 aphid/plant/10cm apical twigs) on 9th SMW i.e. first week of March with correspondence to weather parameters viz. maximum and minimum temperature (°C), relative humidity (%) and rainfall (mm) were 30.80, 15.34, 67.72 and 0, respectively over the years. The aphid population had significant positive correlation with Tmax (r= 0.94) while the Tmin showed highly significant correlation (r=0.99). The relative humidity (RH) had non significant negative correlation (r= -0.90) and rainfall (Rf) showed non significant negative impact (r= - 0.15) with aphid population. The regression model developed could explain 99% variation in aphid population in different cultivars of lentil. SAARC J. Agri., 17(2): 155-164 (2019)

scholarly journals Strong controls of daily minimum temperature on the autumn photosynthetic phenology of subtropical vegetation in China

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Peixin Ren ◽  
Zelin Liu ◽  
Xiaolu Zhou ◽  
Changhui Peng ◽  
Jingfeng Xiao ◽  
...  
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Vegetation Index ◽  
Climatic Factors ◽  
Time Lag ◽  
Evergreen Forest ◽  
Maximum Temperature ◽  
Daily Minimum Temperature ◽  
Study Region ◽  
Cumulative Precipitation

Abstract Background Vegetation phenology research has largely focused on temperate deciduous forests, thus limiting our understanding of the response of evergreen vegetation to climate change in tropical and subtropical regions. Results Using satellite solar-induced chlorophyll fluorescence (SIF) and MODIS enhanced vegetation index (EVI) data, we applied two methods to evaluate temporal and spatial patterns of the end of the growing season (EGS) in subtropical vegetation in China, and analyze the dependence of EGS on preseason maximum and minimum temperatures as well as cumulative precipitation. Our results indicated that the averaged EGS derived from the SIF and EVI based on the two methods (dynamic threshold method and derivative method) was later than that derived from gross primary productivity (GPP) based on the eddy covariance technique, and the time-lag for EGSsif and EGSevi was approximately 2 weeks and 4 weeks, respectively. We found that EGS was positively correlated with preseason minimum temperature and cumulative precipitation (accounting for more than 73% and 62% of the study areas, respectively), but negatively correlated with preseason maximum temperature (accounting for more than 59% of the study areas). In addition, EGS was more sensitive to the changes in the preseason minimum temperature than to other climatic factors, and an increase in the preseason minimum temperature significantly delayed the EGS in evergreen forests, shrub and grassland. Conclusions Our results indicated that the SIF outperformed traditional vegetation indices in capturing the autumn photosynthetic phenology of evergreen forest in the subtropical region of China. We found that minimum temperature plays a significant role in determining autumn photosynthetic phenology in the study region. These findings contribute to improving our understanding of the response of the EGS to climate change in subtropical vegetation of China, and provide a new perspective for accurately evaluating the role played by evergreen vegetation in the regional carbon budget.

scholarly journals Temperature Change and Its Elevation Dependency in the Source Region of the Yangtze River and Yellow River

2014 ◽  
Vol 6 (2) ◽  
pp. 124 ◽  
Author(s):  
Chongyi E ◽  
Hongchang Hu ◽  
Hong Xie ◽  
Yongjuan Sun
Keyword(s):  
Temperature Change ◽  
Minimum Temperature ◽  
Yangtze River ◽  
Yellow River ◽  
Source Region ◽  
Maximum Temperature ◽  
Climatic Data ◽  
The Yangtze River ◽  
Extreme Minimum Temperature ◽  
The Mean

The study of temperature change and its elevation dependency in the source region of the Yangtze River and Yellow River have been insufficient owing to the lack of adequate observation stations and long-term climatic data. In this study five temperature indices of 32 stations from 1961 to 2007 in and near the source region are used. The 32 stations all have experienced significant warming; the warming amplitudes are higher than the mean warming amplitude of the Qinghai-Tibetan plateau. The warming amplitudes and the numbers of stations showing significant warming trends in mean minimum temperature and extreme minimum temperature are higher than that of the mean maximum temperature and extreme maximum temperature. The elevation dependency of climatic warming and the amount of significant warming stations are not obvious; the influence of human activity and urbanization may be higher. The warming amplitudes of 26 stations above 3000 m tend to be uniform, and there is no significant law at 6 stations below 3000 m. On the contrary, the ratio of stations showing significant warming in minimum temperature above 4000 m is far less than that of the stations below 4000 m.

scholarly journals Weather parameters vulnerability on tea production in north western Himalaya, India

2016 ◽  
Vol 8 (4) ◽  
pp. 2262-2267
Author(s):  
Parmod Verma ◽  
Ranbir Singh Rana ◽  
Ramesh Ramesh ◽  
Ranu Pathania
Keyword(s):  
Relative Humidity ◽  
Minimum Temperature ◽  
Positive Relationship ◽  
Western Himalaya ◽  
Green Leaf ◽  
Maximum Temperature ◽  
Leaf Yield ◽  
Tea Production ◽  
Weather Parameters ◽  
June July

The study assessed the sensitivity of weather parameters with respect to total green leaf and two leaves and bud (T & B) productivity of tea crop {Camellia sinensis (L.) Kuntze}. The maximum temperature ranging from 20.0 to 29.0 oC during March, May, August and September showed positive relationship with values ranging from 0.26 to 3.38 and 0.22 to 3.22 for green leaf and T & B yield, respectively. Similarly, minimum temperature ranging from 9.1 to 20.0 oC during March and July to October found positive 0.001 to 2.93 and 0.28 to 2.91 for green leaf and T & B productivity, respectively. The mean monthly rainfall amounting 52.7 to 664.7 mm during March, May, July to October and 52.7 to 488.4 mm during June, July, September and October also showed positive sensitivity with values ranging from 0.03 to 0.33 and 0.007 to 0.35 for green leaf and T & B yield, respectively. The relative humidity ranging between 41.2 to 77.3% during April to May for green leaf yield (0.32 to 1.71) and during April to May and October for two leaf and bud yield (0.00 to 1.70) showed positive relationship. So, maximum and minimum temperature between 20.0 to 29.0 oC and 9.1 to 20.0 oC, respectively with rainfall of 52.7 to 488.4 mm and relative humidity 41.2 to 77.3% are the most beneficial weather parameters for tea cultivation at Palampur conditions.

scholarly journals Impact of abiotic factors on build-up of citrus psylla, Diaphorina citri Kuwayama population in Punjab, India

2014 ◽  
Vol 6 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Hijam S. Devi ◽  
D. R. Sharma
Keyword(s):  
Relative Humidity ◽  
Disease Transmission ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Winter Season ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Weak Links ◽  
Diaphorina Citri ◽  
Citrus Psylla

Seasonal abundance of citrus psylla (Diaphorina citri) Kuwayama was studied on Kinnow mandarin under Punjab conditions during 2012 and 2013. Population of D. citri was present throughout the year but only adults found surviving during December and February. There was no nymphal population when maximum temperature was > 39°C or < 7°C. Two population peaks of nymphs wer e observed, first in April-May and second in August- September. Thereafter, there was abrupt decline in nymphal population during June and July during both the years when the weather conditions i.e. maximum, minimum temperature (°C), relative humidity (%), rainfall (m m) and sunshine (hrs) ranged from 24.4-44, 22.4-31.8, 25.5-100, 0-108.0 and 0-13.5, respectively. Highest peaks of adult were found during May followed by June. With the decrease in temperature from the end of September, the population of D. citri started to decrease and reached its lowest during winter season. Correlation analysis for both the years indicated that maximum and minimum temperature, sunshine and rainfall were positively correlated with nymphal, adult and mixed population but the effect of rainfall on adult population was non-significant, while relative humidity was negatively correlated. The study is useful to find out the weak links of psyllid populations in relation to abiotic factors and that could be exploited to curb its infestation and disease transmission.

scholarly journals Influence of Climatic Factors on Malaria Epidemic in Gulu District, Northern Uganda: A 10-Year Retrospective Study

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ouma Simple ◽  
Arnold Mindra ◽  
Gerald Obai ◽  
Emilio Ovuga ◽  
Emmanuel Igwaro Odongo-Aginya
Keyword(s):  
Retrospective Study ◽  
Relative Humidity ◽  
Malaria Control ◽  
Malaria Infection ◽  
Climatic Factors ◽  
Indoor Residual Spraying ◽  
Sub Saharan Africa ◽  
Maximum Temperature ◽  
Northern Uganda ◽  
Gulu District

Background. Globally, 15 countries, mainly in Sub-Saharan Africa, account for 80% of malaria cases and 78% of malaria related deaths. In Uganda, malaria is endemic and the mortality and morbidity due to malaria cause significant negative impact on the economy. In Gulu district, malaria is the leading killer disease among children <5 years. In 2015, the high intensity of malaria infection in Northern Uganda revealed a possible link between malaria and rainfall. However, available information on the influence of climatic factors on malaria are scarce, conflicting, and highly contextualized and therefore one cannot reference such information to malaria control policy in Northern Uganda, thus the need for this study. Methods and Results. During the 10 year’s retrospective study period a total of 2,304,537 people suffered from malaria in Gulu district. Malaria infection was generally stable with biannual peaks during the months of June-July and September-October but showed a declining trend after introduction of indoor residual spraying. Analysis of the departure of mean monthly malaria cases from the long-term mean monthly malaria cases revealed biannual seasonal outbreaks before and during the first year of introduction of indoor residual spraying. However, there were two major malaria epidemics in 2015 following discontinuation of indoor residual spraying in the late 2014. Children <5 years of age were disproportionally affected by malaria and accounted for 47.6% of the total malaria cases. Both rainfall (P=0.04) and relative humidity (P=0.003) had significant positive correlations with malaria. Meanwhile, maximum temperature had significant negative correlation with malaria (P=0.02) but minimum temperature had no correlation with malaria (P=0.29). Conclusion. Malaria in Gulu disproportionately affects children under 5 years and shows seasonality with a generally stable trend influenced by rainfall and relative humidity. However, indoor residual spraying is a very promising method to achieve a sustained malaria control in this population.

scholarly journals Responses to climatic factors by foragers of Plebeia pugnax Moure (in litt.) (Apidae, Meliponinae)

2001 ◽  
Vol 61 (2) ◽  
pp. 191-196 ◽  
Author(s):  
S. D. HILÁRIO ◽  
V. L. IMPERATRIZ-FONSECA ◽  
A. de M. P. KLEINERT
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Minimum Temperature ◽  
Climatic Factors ◽  
Flight Activity ◽  
Wide Range ◽  
The Hours ◽  
Recorded Data

Flight activity of Plebeia pugnax Moure (in litt.) was studied in six colonies coming from Cunha, SP, from July to October 1994. Twice a week, from 8:00 a.m. to 6:00 p.m., for 5 minutes every half-hour, all the bees entering and leaving the hives were counted. Six hundred counts were made and the materials that foragers carried were recorded. Data were analysed in relation to temperature, relative humidity, light intensity and day time. Foragers' flight activity was relatively constant in a wide range of temperature, from 22°C to 34°C. The minimum temperature for the beginning of flight activity was 14°C. Effective flight activity (when foragers of all colonies were leaving the hives) occurred at 15°C. These bees also flew within a wide range of relative humidity, from 30% to 100%, decreasing slowly after 50%. Flight activity increased as light intensity rose and it has also increased as the hours passed by, reaching a peak around midday and decreasing gradually afterwards. Pollen was collected all day long, while resin collection was relatively constant and debris transportation was slightly higher after 10:00 h. From all known Plebeia species, this one flew on the lowest temperature ever registered for this genus.

scholarly journals Climate Change Effects on the Crop Yield and Its Variability in Telangana, India

2020 ◽  
Vol 8 (1) ◽  
pp. 119-148
Author(s):  
Raju Guntukula ◽  
Phanindra Goyari
Keyword(s):  
Production Function ◽  
Minimum Temperature ◽  
Agricultural Development ◽  
Climatic Factors ◽  
Estimation Procedure ◽  
Maximum Temperature ◽  
Climate Change Effects ◽  
Enhancing Factor ◽  
Risk Reducing ◽  
Positive Effect

This study has examined the effects of climatic factors on mean yields and yield variability of four primary crops (rice, cotton, jowar and groundnut) in Telangana state by applying the Just and Pope production function over a period of 1956–2015. Using the three-stage feasible generalised least squares estimation procedure, we have estimated the production function of four crops. The empirical results have revealed that the effects of changes in climatic factors vary among crops under study. Maximum temperature has a significant adverse effect on rice, cotton and groundnut yields. Minimum temperature has a substantial positive effect on rice, cotton and groundnut. Further, rainfall is adversely related to cotton and groundnut yields. Maximum temperature has appeared as a risk-reducing factor for all study crops while minimum temperature as a risk-enhancing factor for rice, cotton and jowar. Lastly, rainfall has been found as a risk-enhancing factor for rice and groundnut whereas it is a risk-reducing factor for jowar and cotton. Results from the study have important implications on how Telangana’s farming sector will adapt to climate variability and change for sustainable agricultural development. JEL Codes: C23, Q18, Q51, Q54

scholarly journals Studies on some diseases of fruits and vegetable crops in relation to meteorological parameters

MAUSAM ◽  
2021 ◽  
Vol 51 (3) ◽  
pp. 269-274
Author(s):  
S. V. DATAR ◽  
R. C. DUBEY ◽  
N. CHATTOPADHYAY
Keyword(s):  
Relative Humidity ◽  
Minimum Temperature ◽  
Early Blight ◽  
Meteorological Parameters ◽  
Maximum Temperature ◽  
Vegetable Crops ◽  
Correlation Techniques

The role of different meteorological parameters controlling the incidences of some diseases on tomato, guava and fig grown at Pune and Padegaon in Maharashtra state were studied by graphical superimposition and correlation techniques. Peak infestation of rust on fig was observed in January at Padegaon whereas maximum infestation of fruit canker on guava and early blight on tomato were reported respectively from September to first week of October and September to November at Pune. Increase in maximum temperature was found to increase the infestation of both fruit canker and early blight. Decrease in afternoon relative humidity favoured the infestation of fruit canker and rust. Fall of minimum temperature and rise in bright hours of sunshine also aggravated the incidences of fruit canker and rust respectively.

scholarly journals Future climate uncertainty and spatial variability over Tamilnadu State, India

2015 ◽  
Vol 17 (1) ◽  
pp. 175-185
Keyword(s):  
Wind Speed ◽  
Relative Humidity ◽  
Solar Radiation ◽  
Minimum Temperature ◽  
Climate Models ◽  
Regional Climate ◽  
Future Climate ◽  
Maximum Temperature ◽  
Projection Data ◽  
Climate Uncertainty

<div> <p>The present study analyses future climate uncertainty for the 21st century over Tamilnadu state for six weather parameters: solar radiation, maximum temperature, minimum temperature, relative humidity, wind speed and rainfall. The climate projection data was dynamically downscaled using high resolution regional climate models, PRECIS and RegCM4 at 0.22&deg;x0.22&deg; resolution. PRECIS RCM was driven by HadCM3Q ensembles (HQ0, HQ1, HQ3, HQ16) lateral boundary conditions (LBCs) and RegCM4 driven by ECHAM5 LBCs for 130 years (1971-2100). The deviations in weather variables between 2091-2100 decade and the base years (1971-2000) were calculated for all grids of Tamilnadu for ascertaining the uncertainty. These deviations indicated that all model members projected no appreciable difference in relative humidity, wind speed and solar radiation. The temperature (maximum and minimum) however showed a definite increasing trend with 1.8 to 4.0&deg;C and 2.0 to 4.8&deg;C, respectively. The model members for rainfall exhibited a high uncertainty as they projected high negative and positive deviations (-379 to 854 mm). The spatial representation of maximum and minimum temperature indicated a definite rhythm of increment from coastal area to inland. However, variability in projected rainfall was noticed.</p> </div> <p>&nbsp;</p>

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