scholarly journals Quantifying climate change impacts emphasises the importance of managing regional threats in the endangered Yellow-eyed penguin

2016 ◽  
Author(s):  
Thomas Mattern ◽  
Stefan Meyer ◽  
Ursula Ellenberg ◽  
David M. Houston ◽  
John T. Darby ◽  
...  

AbstractClimate change is a global issue with effects that are difficult to manage at a regional scale. Yet more often than not climate factors are just some of multiple stressors affecting species on a population level. Non-climatic factors - especially those of anthropogenic origins - may play equally important roles with regard to impacts on species and are often more feasible to address. Here we assess the influence of climate change on population trends of the endangered Yellow-eyed penguin (Megadyptes antipodes) over the last 30 years, using a Bayesian model. Sea surface temperature (SST) proved to be the dominating factor influencing survival of both adult birds and fledglings. Increasing SST since the mid-1990s was accompanied by a reduction in survival rates and population decline. The population model showed that 33% of the variation in population numbers could be explained by SST alone, significantly increasing pressure on the penguin population. Consequently, the population becomes less resilient to non-climate related impacts, such as fisheries interactions, habitat degradation and human disturbance. However, the extent of the contribution of these factors to declining population trends is extremely difficult to assess principally due to the absence of quantifiable data, creating a discussion bias towards climate variables, and effectively distracting from non-climate factors that can be managed on a regional scale to ensure the viability of the population.

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3272 ◽  
Author(s):  
Thomas Mattern ◽  
Stefan Meyer ◽  
Ursula Ellenberg ◽  
David M. Houston ◽  
John T. Darby ◽  
...  

Climate change is a global issue with effects that are difficult to manage at a regional scale. Yet more often than not climate factors are just some of multiple stressors affecting species on a population level. Non-climatic factors—especially those of anthropogenic origins—may play equally important roles with regard to impacts on species and are often more feasible to address. Here we assess the influence of climate change on population trends of the endangered Yellow-eyed penguin (Megadyptes antipodes) over the last 30 years, using a Bayesian model. Sea surface temperature (SST) proved to be the dominating factor influencing survival of both adult birds and fledglings. Increasing SST since the mid-1990s was accompanied by a reduction in survival rates and population decline. The population model showed that 33% of the variation in population numbers could be explained by SST alone, significantly increasing pressure on the penguin population. Consequently, the population becomes less resilient to non-climate related impacts, such as fisheries interactions, habitat degradation and human disturbance. However, the extent of the contribution of these factors to declining population trends is extremely difficult to assess principally due to the absence of quantifiable data, creating a discussion bias towards climate variables, and effectively distracting from non-climate factors that can be managed on a regional scale to ensure the viability of the population.


Author(s):  
Jeffrey D Shields

Abstract Climate change has resulted in increasing temperature and acidification in marine systems. Rising temperature and acidification act as stressors that negatively affect host barriers to infection, thus enhancing disease processes and influencing the emergence of pathogens in ecologically and commercially important species. Given that crustaceans are ectotherms, changes in temperature dominate their physiological and immunological responses to microbial pathogens and parasites. Because of this, the thermal ranges of several crustacean hosts and their pathogens can be used to project the outcomes of infections. Host factors such as molting, maturation, respiration, and immune function are strongly influenced by temperature, which in turn alter the host’s susceptibility to pathogens, further amplifying morbidity and mortality. Microbial pathogens are also strongly influenced by temperature, arguably more so than their crustacean hosts. Microbial pathogens, with higher thermal optima than their hosts, grow rapidly and overcome host immune defenses, which have been weakened by increased temperatures. Pathogen factors such as metabolic rates, growth rates, virulence factors, and developmental rates are often enhanced by rising temperature, which translates into increased transmission, dispersal, and proliferation at the population level, and ultimately emergence of outbreaks in host populations. Less well known are the effects of acidification and salinity intrusion on host-pathogen processes, but they operate alongside temperature, as multiple stressors, that impose significant metabolic and physiological demands on host homeostasis.


2018 ◽  
Vol 40 (2) ◽  
pp. 205
Author(s):  
Xu-Juan Cao ◽  
Qing-Zhu Gao ◽  
Ganjurjav Hasbagan ◽  
Yan Liang ◽  
Wen-Han Li ◽  
...  

Climate change will affect how the Normalised Difference Vegetation Index (NDVI), which is correlated with climate factors, varies in space and over time. The Mongolian Plateau is an arid and semi-arid area, 64% covered by grassland, which is extremely sensitive to climate change. Its climate has shown a warming and drying trend at both annual and seasonal scales. We analysed NDVI and climate variation characteristics and the relationships between them for Mongolian Plateau grasslands from 1981 to 2013. The results showed spatial and temporal differences in the variation of NDVI. Precipitation showed the strongest correlation with NDVI (43% of plateau area correlated with total annual precipitation and 44% with total precipitation in the growing season, from May to September), followed by potential evapotranspiration (27% annual, and 30% growing season), temperature (7% annual, 16% growing season) and cloud cover (10% annual, 12% growing season). These findings confirm that moisture is the most important limiting factor for grassland vegetation growth on the Mongolian Plateau. Changes in land use help to explain variations in NDVI in 40% of the plateau, where no correlation with climate factors was found. Our results indicate that vegetation primary productivity will decrease if warming and drying trends continue but decreases will be less substantial if further warming, predicted as highly likely, is not accompanied by further drying, for which predictions are less certain. Continuing spatial and temporal variability can be expected, including as a result of land use changes.


2019 ◽  
Vol 110 (1) ◽  
pp. 68-76 ◽  
Author(s):  
S. Rocha ◽  
M.C. Caldeira ◽  
C. Burban ◽  
C. Kerdelhué ◽  
M. Branco

AbstractIn the Mediterranean and temperate regions, an increase in the frequency and intensity of drought events has been recorded, probably due to climate change. In consequence, trees will more frequently experience hydric stress, a condition that can be expected to affect insect–tree interactions, while adaptation mechanisms may be further in course. The effect of tree water stress on the performance of two allochronic populations of Thaumetopoea pityocampa was here studied. Namely, we compared a unique population of this insect, in which the larvae develop in the summer (SP), with the typical population having winter larval development (WP), to test the adaptation hypothesis to host plant status. Larvae of each population were fed on needles of young potted Pinus pinaster plants under two water supply regimes: (i) well-watered (control) and (ii) subjected to 3 months of drought stress. Compared to control, stressed plants had higher amounts of soluble sugars, phenols, and higher C/N ratio, whereas water content and chlorophylls concentrations were lower. In general, T. pityocampa larvae had lower performances on water-stressed plants, as shown by lower survival rates, lower needle consumption, and longer development times. Yet, the detrimental effects of tree stress were only significant for the WP larvae, while SP larvae were able to overcome such conditions. Results demonstrate that tree water stress can negatively affect T. pityocampa populations. Furthermore, the evidence is also provided that responses to the physiological condition of the host trees may occur at the population level, as a result of adaptation mechanisms driven by climate change.


Author(s):  
Jun-Ming Zhang ◽  
Xiang-Yong Peng ◽  
Min-Li Song ◽  
Zhen-Jian Li ◽  
Xin-Qiao Xu ◽  
...  

Understanding the impacts and constraints of climate change on the potential geographic distribution of wild Akebia trifoliata is crucial for its sustainable management and economic development as a medicinal material or fruit. In this study, according to the first-hand information obtained on-the-spot investigation, the geographic distribution and response to climate factors of Akebia trifoliata were studied by the MaxEnt model and ArcGIS. The genetic diversity and population structure of 21 natural populations of Akebia trifoliata were studied by SSR markers. The results showed that precipitation and temperature were the two most important climatic factors that restrict the geographic distribution of Akebia trifoliata. Under the current climate scenario, the suitable growth regions of Akebia trifoliata in China were 91.7-121.9 °E and 21.6-37.5 °N. Combined with the evolutionary relationship and prediction results, 21 populations of Akebia trifoliata tended to migrate to the north. In the scenarios (SSP2-4.5, SSP3-7.0, and SSP5-8.5) of higher greenhouse gas emission concentration, the distribution area of Akebia trifoliata continued to expand, while in the low concentration greenhouse gas emission scenario (SSP1-2.6), the distribution area of Akebia trifoliata remained stable. The distribution center of Akebia trifoliata in China will shift to high latitude regions with the increase of temperature in the future. The results evaluated the impact of climate factors on the spatial distribution of wild Akebia trifoliata, displayed the possible changes of geographical distribution of Akebia trifoliata under different climate scenarios, and provided scientific evidence for durative protection and supervise of Akebia trifoliata.


2021 ◽  
Vol 13 (18) ◽  
pp. 3746
Author(s):  
Shanshan Chen ◽  
Zhaofei Wen ◽  
Maohua Ma ◽  
Shengjun Wu

Forest ecosystem plays a vital role in the global carbon cycle and maintaining climate stability. However, how net primary productivity (NPP) dynamics of different stand ages of forest respond to climatic change and residual (being other climate factors or human activities) still remain unclear. In this study, firstly, forests are divided into two categories based on their stand age: forests appeared before appeared before the research period (Fold), and forests appeared during the research period (Fnew). Secondly, we improved a quantitative method of basic partial derivatives to disentangle the relative contributions of climatic factors, other climate factors, and human activities to the NPP of Fold and Fnew. Then, different scenarios were simulated to identify the dominant drivers for forest restoration and degradation. In this study, we hypothesized the residual of Fold was other climate factors rather than human activities. Our results revealed that from 2000 to 2019, Fold and Fnew of NPP in Yangtze River Basin showed a significant increment trend and precipitation was the major positive contributor among all of the climatic factors. We found that, in Fold, climate change and other climate factors contributed 9.77% and 28.33%, respectively, in explaining NPP. This finding unsupported our initial hypothesis and implied that residuals should be human activities for Fold. Furthermore, we found that human activities dominate either restoration or degradation of Fnew. This result may be due to the attenuated human disturbances and strengthened forest management, such as ecological policies, forest tending, closing the land for reforestation, etc. Therefore, based on disentangling the two types of factors, we concluded that human activities govern the forest change, and imply that the environment-friendly forest managements may favorite to improving the forest NPP against the impacts of climate change. Thus, effective measures and policies are suggested implement in controlling forest degradation in facing climate change.


2018 ◽  
Vol 40 (2) ◽  
pp. 91 ◽  
Author(s):  
Xu-Juan Cao ◽  
Qing-Zhu Gao ◽  
Ganjurjav Hasbagan ◽  
Yan Liang ◽  
Wen-Han Li ◽  
...  

Climate change will affect how the Normalised Difference Vegetation Index (NDVI), which is correlated with climate factors, varies in space and over time. The Mongolian Plateau is an arid and semi-arid area, 64% covered by grassland, which is extremely sensitive to climate change. Its climate has shown a warming and drying trend at both annual and seasonal scales. We analysed NDVI and climate variation characteristics and the relationships between them for Mongolian Plateau grasslands from 1981 to 2013. The results showed spatial and temporal differences in the variation of NDVI. Precipitation showed the strongest correlation with NDVI (43% of plateau area correlated with total annual precipitation and 44% with total precipitation in the growing season, from May to September), followed by potential evapotranspiration (27% annual, and 30% growing season), temperature (7% annual, 16% growing season) and cloud cover (10% annual, 12% growing season). These findings confirm that moisture is the most important limiting factor for grassland vegetation growth on the Mongolian Plateau. Changes in land use help to explain variations in NDVI in 40% of the plateau, where no correlation with climate factors was found. Our results indicate that vegetation primary productivity will decrease if warming and drying trends continue but decreases will be less substantial if further warming, predicted as highly likely, is not accompanied by further drying, for which predictions are less certain. Continuing spatial and temporal variability can be expected, including as a result of land use changes.


2016 ◽  
Author(s):  
Xiaoqing Peng ◽  
Oliver W. Frauenfeld ◽  
Tingjun Zhang ◽  
Kang Wang ◽  
Bin Cao ◽  
...  

Abstract. Abstract. The response of seasonal soil freeze depth to climate change has repercussions for the surface energy and water balance, ecosystems, the carbon cycle, and soil nutrient exchange. In this study, we use data from 845 meteorological stations to investigate the response of variations in soil freeze depth to climate change across China. Observations include daily air temperature, daily soil temperatures at various depths, mean monthly gridded air temperature, and Normalized Difference Vegetation Index. Results show that soil freeze depth decreased significantly at a rate of −0.18 cm/year, resulting in a net decrease of 8.05 cm over 1967–2012 across China. On the regional scale, soil freeze depth decreases varied between 0.0 and 0.4 cm/year in most parts of China from 1950 to 2009. Combining climatic and non-climatic factors with soil freeze depth, we conclude that air temperature increases are responsible for the decrease in soil seasonal freeze depth during this period. Changes in snow depth and vegetation are negatively correlated with soil freeze depth. These results are important for understanding the soil freeze/thaw dynamics and the impacts of soil freeze depth on ecosystem and hydrological process.


Author(s):  
Charles Nhemachena ◽  
Reneth Mano ◽  
Shakespear Mudombi ◽  
Virginia Muwanigwa

This study investigated perceptions of rural communities on climate change and its impacts on livelihoods. The research was conducted in the semi-arid Hwange district in Matebelel and North province of Zimbabwe. The perceptions were compared with empirical evidence from climatic studies on trends on temperature and rainfall, and impacts on livelihoods in the country and region. The findings from the current study are generally in agreement with those of other studies that indicate changes in the climate, especially in terms of rainfall. This largely applies to short-term periods; however, for long-term periods it is difficult to accurately relate rural community perceptions to changes in rainfall over time. Despite perceived changes and impacts of climate change on local livelihood activities, mainly agriculture, there are multiple stressors that the communities face which also affect their livelihoods. Further evidence-based research is required to disentangle climate change impacts on livelihoods, including livelihood impacts arising from interactions of climate and non-climatic factors.


2019 ◽  
Author(s):  
Tyson Wepprich ◽  
Jeffrey R. Adrion ◽  
Leslie Ries ◽  
Jerome Wiedmann ◽  
Nick M. Haddad

AbstractSevere insect declines make headlines, but they are rarely based on systematic monitoring outside of Europe. We estimate the rate of change in total butterfly abundance and the population trends for 81 species using 21 years of systematic monitoring in Ohio, USA. Total abundance is declining at 2% per year, resulting in a cumulative 33% reduction in butterfly abundance. Three times as many species have negative population trends compared to positive trends. The rate of total decline and the proportion of species in decline mirror those documented in three comparable long-term European monitoring programs. Multiple environmental changes such as climate change, habitat degradation, and agricultural practices may contribute to these declines in Ohio and shift the makeup of the butterfly community by benefiting some species over others. Our analysis of life-history traits associated with population trends shows an impact of climate change, as species with northern distributions and fewer annual generations declined more rapidly. However, even common and invasive species associated with human-dominated landscapes are declining, suggesting widespread environmental causes for these trends. Declines in common species, although they may not be close to extinction, will have an outsized impact on the ecosystem services provided by insects. These results from the most extensive, systematic insect monitoring program in North America demonstrate an ongoing defaunation in butterflies that on an annual scale might be imperceptible, but cumulatively has reduced butterfly numbers by a third over 20 years.


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