scholarly journals Winter Tick Burdens for Moose Are Positively Associated With Warmer Summers and Higher Predation Rates

2021 ◽  
Vol 9 ◽  
Author(s):  
Sarah R. Hoy ◽  
Leah M. Vucetich ◽  
Rolf O. Peterson ◽  
John A. Vucetich

Climate change is expected to modify host-parasite interactions which is concerning because parasites are involved in most food-web links, and parasites have important influences on the structure, productivity and stability of communities and ecosystems. However, the impact of climate change on host–parasite interactions and any cascading effects on other ecosystem processes has received relatively little empirical attention. We assessed host-parasite dynamics for moose (Alces alces) and winter ticks (Dermacentor albipictus) in Isle Royale National Park over a 19-year period. Specifically, we monitored annual tick burdens for moose (estimated from hair loss) and assessed how it covaried with several aspects of seasonal climate, and non-climatic factors, such as moose density, predation on hosts by wolves (Canis lupus) and wolf abundance. Summer temperatures explained half the interannual variance in tick burden with tick burden being greater following hotter summers, presumably because warmer temperatures accelerate the development of tick eggs and increase egg survival. That finding is consistent with the general expectation that warmer temperatures may promote higher parasite burdens. However, summer temperatures are warming less rapidly than other seasons across most regions of North America. Therefore, tick burdens seem to be primarily associated with an aspect of climate that is currently exhibiting a lower rate of change. Tick burdens were also positively correlated with predation rate, which could be due to moose exhibiting risk-sensitive habitat selection (in years when predation risk is high) in such a manner as to increases the encounter rate with questing tick larvae in autumn. However, that positive correlation could also arise if high parasite burdens make moose more vulnerable to predators or because of some other density-dependent process (given that predation rate and moose density are highly correlated). Overall, these results provide valuable insights about interrelationships among climate, parasites, host/prey, and predators.

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 172
Author(s):  
Yuan Xu ◽  
Jieming Chou ◽  
Fan Yang ◽  
Mingyang Sun ◽  
Weixing Zhao ◽  
...  

Quantitatively assessing the spatial divergence of the sensitivity of crop yield to climate change is of great significance for reducing the climate change risk to food production. We use socio-economic and climatic data from 1981 to 2015 to examine how climate variability led to variation in yield, as simulated by an economy–climate model (C-D-C). The sensitivity of crop yield to the impact of climate change refers to the change in yield caused by changing climatic factors under the condition of constant non-climatic factors. An ‘output elasticity of comprehensive climate factor (CCF)’ approach determines the sensitivity, using the yields per hectare for grain, rice, wheat and maize in China’s main grain-producing areas as a case study. The results show that the CCF has a negative trend at a rate of −0.84/(10a) in the North region, while a positive trend of 0.79/(10a) is observed for the South region. Climate change promotes the ensemble increase in yields, and the contribution of agricultural labor force and total mechanical power to yields are greater, indicating that the yield in major grain-producing areas mainly depends on labor resources and the level of mechanization. However, the sensitivities to climate change of different crop yields to climate change present obvious regional differences: the sensitivity to climate change of the yield per hectare for maize in the North region was stronger than that in the South region. Therefore, the increase in the yield per hectare for maize in the North region due to the positive impacts of climate change was greater than that in the South region. In contrast, the sensitivity to climate change of the yield per hectare for rice in the South region was stronger than that in the North region. Furthermore, the sensitivity to climate change of maize per hectare yield was stronger than that of rice and wheat in the North region, and that of rice was the highest of the three crop yields in the South region. Finally, the economy–climate sensitivity zones of different crops were determined by the output elasticity of the CCF to help adapt to climate change and prevent food production risks.


Parasitology ◽  
1989 ◽  
Vol 99 (S1) ◽  
pp. S59-S79 ◽  
Author(s):  
R. M. Anderson ◽  
R. M. May ◽  
S. Gupta

SUMMARYThe paper examines non-linear dynamical phenomena in host—parasite interactions by reference to a series of different problems ranging from the impact on transmission of control measures based on vaccination and chemotherapy, to the effects of immunological responses targeted at different stages in a parasite's life-cycle. Throughout, simple mathematical models are employed to aid in interpretation. Analyses reveal that the influence of a defined control measure on the prevalence or intensity of infection, whether vaccination or drug treatment, is non-linearly related to the magnitude of control effort (as defined by the proportion of individuals vaccinated or treated with a drug). Consideration of the relative merits of gametocyte and sporozoite vaccines against malarial parasites suggests that very high levels of cohort immunization will be required to block transmission in endemic areas, with the former type of vaccine being more effective in reducing transmission for a defined level of coverage and the latter being better with respect to a reduction in morbidity. The inclusion of genetic elements in analyses of the transmission of helminth parasites reveals complex non-linear patterns of change in the abundance of different parasite genotypes under selection pressures imposed by either the host immunological defences or the application of chemotherapeutic agents. When resistance genes are present in parasite populations, the degree to which abundance can be suppressed by chemotherapy depends critically on the frequency and intensity of application, with intermediate values of the former being optimal. A more detailed consideration of the impact of immunological defences on parasite population growth within an individual host, by reference to the erythrocytic cycle of malaria, suggests that the effectiveness of a given immunological response is inversely related to the life-expectancy of the target stage in the parasite's developmental cycle.


2021 ◽  
Author(s):  
Giovanna Battipaglia ◽  
Francesco Niccoli ◽  
Arturo Pacheco-Solana

<p>Climate-induced forest mortality is a critical issue in the Mediterranean basin, with major consequences for the functioning of these key ecosystems. Indeed, in Mediterranean ecosystems, where water stress is already the most limiting factor for tree performance, climatic changes are expected to entail an increase in water deficit. In this context, annual growth rings can provide short- (e.g., years) and long-term (e.g., decades) information on how trees respond to drought events. With climate change, <em>Pinus pinaster</em> and <em>Pinus pinea</em> L. are expected to reduce their distribution range in the region, being displaced at low altitudes by more drought tolerant taxa such as sub Mediterranean <em>Quercus</em> spp.</p><p>This study aims was to assess the physiological response of <em>Pinus</em> and <em>Quercus</em> species growing in the Vesuvio National park, located in Southern Italy and where an increase of temperature and drought events has been recorded in the recent years. Our preliminary results underlined the importance of temperature on the tree ring width of all the analyses species. The high temperatures can cause a change in the constant kinetics of the RuBisCo, leading to a consequent decrease in carboxylation rate and thus to a reduction in tree growth. On the other hand, also precipitation seemed to affect the growth of the sampled trees: indeed, in all the chronologies a reduction in growth was found after particular dry years: for example, the low rainfall in 1999 (455 mm/year) determined a drastic decline in growth in 2000 in all the species. In addition to the climatic factors, competition can also play an important role in the growth rate: dendrochronological analyzes have highlighted how stand specific properties (i.e. density, structure and composition) can influence individual tree responses to drought events. The knowledge of those researches should be integrated into sustainable forest management strategies to minimize the potential impacts of climate change on forest ecosystems.</p>


2005 ◽  
Vol 272 (1581) ◽  
pp. 2571-2576 ◽  
Author(s):  
S.J Kutz ◽  
E.P Hoberg ◽  
L Polley ◽  
E.J Jenkins

Global climate change is altering the ecology of infectious agents and driving the emergence of disease in people, domestic animals, and wildlife. We present a novel, empirically based, predictive model for the impact of climate warming on development rates and availability of an important parasitic nematode of muskoxen in the Canadian Arctic, a region that is particularly vulnerable to climate change. Using this model, we show that warming in the Arctic may have already radically altered the transmission dynamics of this parasite, escalating infection pressure for muskoxen, and that this trend is expected to continue. This work establishes a foundation for understanding responses to climate change of other host–parasite systems, in the Arctic and globally.


Author(s):  
Kenneth Ofori-Boateng ◽  
Baba Insah

Purpose – The study aimed at examining the current and future impact of climate change on cocoa production in West Africa. Design/methodology/approach – A translog production function based on crop yield response framework was used. A panel model was estimated using data drawn from cocoa-producing countries in West Africa. An in-sample simulation was used to determine the predictive power of the model. In addition, an out-sample simulation revealed the effect of future trends of temperature and precipitation on cocoa output. Findings – Temperature and precipitation play a considerable role in cocoa production in West Africa. It was established that extreme temperature adversely affected cocoa output in the sub-region. Furthermore, increasing temperature and declining precipitation trends will reduce cocoa output in the future. Practical implications – An important implication of this study is the recognition that lagging effects are the determinants of cocoa output and not coincident effects. This finds support from the agronomic point of view considering the gestation period of the cocoa crop. Originality/value – Although several studies have been carried out in this area, this study modeled and estimated the interacting effects of factors that influence cocoa production. This is closer to reality, as climatic factors and agricultural inputs combine to yield output.


2021 ◽  
Author(s):  
Philip Kuriachen ◽  
Asha Devi ◽  
Anu Susan Sam ◽  
Suresh Kumar ◽  
Jyoti Kumari ◽  
...  

Abstract Climate change and consequent variations in temperature pose a significant challenge for sustaining wheat production systems globally. In this study, the potential impact of rising temperature on wheat yield in the north Indian plains, India's major wheat growing region, was analyzed using panel data from the year 1981 to 2009. This study deviates from the majority of the previous studies by including non-climatic factors in estimating the impact of climate change. Two temperature measures were used for fitting the function, viz., Growing Season Temperature (GST) and Terminal Stage Temperature (TST), to find out the differential impact of increased temperature at various growth stages. Analysis revealed that there was a significant rise in both GST as well as TST during the study period. The magnitude of the annual increment in TST was twice that of GST. Wheat yield growth in the region was driven primarily by increased input resources such as fertilizer application and technological development like improved varieties and management practices. Most importantly, the study found that the extent of yield reduction was more significant for an increase in temperature at terminal crop growth stages. The yield reduction due to unit increase in TST was estimated to be 2.26 % while rise in GST by 1◦C resulted in yield reduction of 2.03%.


Author(s):  
Rajesh Bajpai ◽  
Manoj Semwal ◽  
C. P. Singh

The lichens are one of the most sensitive organism in nature among the different elements of biodiversity and can be affected more due to climate change. Lichens fulfil their water need from rain, fog and dew present in the atmosphere. The change in atmospheric temperature influence, to a greater extent, the thallus temperature and physiology of lichens which leads to emergence of new ecotype and finally the shift in a species. The impact of climatic factors on lichens ecophysiology, is different from higher plantsis due to the poikilohydric nature. The lichen bioindicator communities have been shown to exhibit correlation with climatic factors of an area. The changes in lichen biomass, frequency, diversity and indicatorcommunity indices, indicate changes in environmental gradients (temperature, humidity and UV radiation). A number of techniques regarding study the environmental and climatic change are available. However, the present correspondence hypothesized about some easy and low cost techniques to monitor climate change utilizing lichens. The overview will also leads to assess patterns of lichens responses with species representation and towards its understanding the current and future changes in climate of an area.


Author(s):  
Opeyemi Gbenga ◽  
H. I. Opaluwa ◽  
Awarun Olabode ◽  
Olowogbayi Jonathan Ayodele

Aim: Agriculture entails majorly crop and animal production. Crop and Livestock production provide the major human caloric and nutrition intake. Assessing the impact of climate change on crop and livestock productivity, is therefore critical to maintaining food supply in the world and particularly in Nigeria. Different studies have yielded different results in other parts of the world, it is therefore, very important to examine the linkage between climate change and agricultural productivity in Nigeria. Study Design: The study utilized secondary data. The study utilize climate data from Nigerian Meteorology Station and Carbon emission, Crop and Livestock production data from FOASTAT. Place and Duration of Study: The study was carried in Nigeria and it covers the period between 1970-2016. Methodology: The data were used to estimate the empirical models. Data were analyzed using descriptive statistics, trend analysis, stationarity, Co-integration and Fully-Modified Least Squares regression. Results: The result of the research reveals that there is variation in the trend of the climatic factors examined and also variation in crop and livestock production over the period covered by the study in Nigeria. The finding also shows that rainfall, temperature and Carbon emission are the climatic factors that significantly affect crop and livestock production in Nigeria. Long term adverse impact of climate change on crop and livestock production index indicates threat to food availability to the country. Conclusion: The study concluded that climatic variables have significant effect on agricultural productivity in Nigeria. The study recommended the need to put in place measures that will reduce the negative effects of climate on agricultural production.


Hydrology ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 117
Author(s):  
Manisha Maharjan ◽  
Anil Aryal ◽  
Rocky Talchabhadel ◽  
Bhesh Raj Thapa

It is unambiguous that climate change alters the intensity and frequency of precipitation and temperature distribution at the global and local levels. The rate of change in temperature in the northern latitudes is higher than the worldwide average. The annual distribution of precipitation over the Himalayas in the northern latitudes shows substantial spatial and temporal heterogeneity. Precipitation and temperature are the major driving factors that impact the streamflow and water availability in the basin, illustrating the importance of research on the impact of climate change on streamflow by varying the precipitation and temperature in the Thuli Bheri River Basin (TBRB). Multiple climate models were used to project and evaluate the precipitation and temperature distribution changes in temporal and spatial domains. To analyze the potential impact of climate change on the streamflow in the basin, the Soil and Water Assessment Tool (SWAT) hydrological model was used. The climate projection was carried out in three future time windows. The result shows that the precipitation fluctuates between approximately +12% and +50%, the maximum temperature varies between −7% and +7%, and the minimum temperature rises from +0.7% to +5% in intermediate- and high-emission scenarios. In contrast, the streamflow in the basin varies from −40% to +85%. Thus, there is a significant trend in the temperature increase and precipitation reduction in the basin. Further, the relationship between precipitation and temperature with streamflow shows a substantial dependency between them. The variability in precipitation and streamflow is successfully represented by the water yield in the basin, which plays an important role in the sustainability of the water-related projects in the basin and downstream to it. This also helps quantify the amount of water available for hydropower generation, agricultural production, and the water ecosystem in the TBRB.


2019 ◽  
Vol 86 ◽  
pp. 00013
Author(s):  
Elżbieta Jasińska

The subject of this publication is to determine what environmental and climatic factors can significantly affect the value of real estate. As a research object, there was chosen area surrounding the Gulf of Gdansk, which, like the entire coast, is attractive for investment and constitutes an interesting object as a space with a special focus on tourism, including short-term rental. Progressing climate change is particularly affecting this sector. It is safe to assume that unfavorable environmental conditions can significantly change the attractiveness of this area. Therefore, the research hypothesis about the correlation between climate aspects distinguishing the coastal belt and the distribution of real estate prices in the selected area has been verified. The area of the Gulf of Gdansk Coast and the technical and protective belt were analyzed. The weather situation on the coast is different from that prevailing in the rest of the country. There are strong and gusty winds, local floods, but at the same time a natural landscape, proximity to the sea and clean, iodized air. Other possible climatic factors have also been tracked, i.e. temperature, sea level and possible changes that may occur over the next years. The analyzes were based on the data of the KLIMAT project entitled "The impact of climate change on the environment, economy and society", and the Government Project KLIMADA and SPA analyzes. An in-depth analysis of the problem of combining planning documents for the maritime sector influencing the Study of Spatial Development of Polish Marine Areas with Local Spatial Management Plans, introduced Flood Risk Maps and Flood Risk Maps was also conducted.


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