Modelling the Environmental Niche of Plants: Implications for Plant Community Response to Elevated CO2 Levels.

1992 ◽  
Vol 40 (5) ◽  
pp. 615 ◽  
Author(s):  
MP Austin
Keyword(s):  
Climate Change ◽  
Elevated Co2 ◽  
Temperature Response ◽  
Nutrient Status ◽  
Community Response ◽  
Process Models ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Environmental Niche ◽  
Response Curves

No simple natural gradients in CO2 concentration exist for testing predictions about changes in plant communities in response to elevated CO2. However indirect effects of CO2 via temperature increases can be tested by reference to natural analogues. Physiologists, vegetation modellers of climate change and community ecologists assume very different temperature responses for plants. Physiologists often assume a skewed non-monotonic curve with a tail towards low temperatures, forest modellers using FORET type models, a symmetric curve, and community ecologists a skewed response with a tail towards high temperatures. These assumptions are reviewed in relation to niche theory, and recent propositions concerning the continuum concept. Confusion exists between the different approaches over the shape of response curves to temperature. Distinctions need to be made between responses due to growth (physiological response), potential fitness (fundamental niche) and observed performance (realized niche). These types of response should be quantified and related to each other if process-models are to be tested for predictive success by reference to naturally occurring communities and temperature gradients. An example of a statistical method for quantifying the realized environmental niche response of a species to temperature is provided. It is based on generalised linear modelling (GLM) of presence/absence data on Eucalyptus fastigata for 8377 sites in southern New South Wales, Australia. Seven environmental variables or factors are considered: mean annual temperature, mean annual rainfall, mean monthly solar radiation, topographic position, rainfall seasonality, lithology, and soil nutrient status. The temperature response is modelled with a β-function, logy = a + α log ( t - a ) + δ log ( b - t), where t is temperature and letters are parameters. The probability of occurrence is shown to be a skewed function of mean annual temperature. Any process-models of climate change for vegetation incorporating temperature changes due to elevated CO2 must be capable of generating such realised environmental niche responses for species.

scholarly journals Agro-pastoralists’ determinants of adaptation to climate change

2018 ◽  
Vol 10 (3) ◽  
pp. 488-500 ◽  
Author(s):  
Keneilwe Ruth Kgosikoma ◽  
Phatsimo Cotildah Lekota ◽  
Olaotswe Ernest Kgosikoma
Keyword(s):  
Climate Change ◽  
Agricultural Sector ◽  
Smallholder Farmers ◽  
Adaptation Strategies ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Adaptation To Climate Change ◽  
Content Type ◽  
Household Level ◽  
Agricultural Diversification

Purpose The purpose of this study is to analyze smallholder farmers’ perceptions on climate change and its stressors, their adaptation strategies and factors that influence their adaptation to climate change. Design/methodology/approach The study was conducted in Kweneng district, located in the south eastern part of Botswana. Multi-stage sampling was used to obtain a representative sample from three sub-districts in the district. A structured questionnaire was used to collect data by using face-to-face interviews. Findings Majority of farmers perceived an increase in mean annual temperature and the number of hot days and a decrease in mean annual rainfall and the number of rainfall days over the past 10 years as indicators of climate change. The prominent adaptation strategies included changes in planting dates for crops and supplementary feeding for livestock. The logistic regression results show that gender, age, household size, poverty, shortage of land, mixed farming and knowledge about climate change significantly influence adaptation. Practical implications The findings indicate that climate change policy should target agricultural diversification at the household level and dissemination of information on climate change and adaptation strategies. Originality/value Policy recommendations can be suggested: government climate change interventions should target agricultural diversification at the household level, and this study provides insights on what influences adaptation strategies and what should be targeted to build resilience in the agricultural sector.

scholarly journals Thermal Acclimation of Foliar Carbon Metabolism in Pinus taiwanensis Along an Elevational Gradient

2022 ◽  
Vol 12 ◽  
Author(s):  
Min Lyu ◽  
Mengke Sun ◽  
Josep Peñuelas ◽  
Jordi Sardans ◽  
Jun Sun ◽  
...  
Keyword(s):  
Climate Change ◽  
Temperature Response ◽  
Elevational Gradient ◽  
Thermal Acclimation ◽  
Optimal Conditions ◽  
Climatic Warming ◽  
Response Curves ◽  
Respiration Rates ◽  
Time Substitution ◽  
Photosynthesis And Respiration

Climate change could negatively alter plant ecosystems if rising temperatures exceed optimal conditions for obtaining carbon. The acclimation of plants to higher temperatures could mitigate this effect, but the potential of subtropical forests to acclimate still requires elucidation. We used space-for-time substitution to determine the photosynthetic and respiratory-temperature response curves, optimal temperature of photosynthesis (Topt), photosynthetic rate at Topt, temperature sensitivity (Q10), and the rate of respiration at a standard temperature of 25°C (R25) for Pinus taiwanensis at five elevations (1200, 1400, 1600, 1800, and 2000 m) in two seasons (summer and winter) in the Wuyi Mountains in China. The response of photosynthesis in P. taiwanensis leaves to temperature at the five elevations followed parabolic curves, and the response of respiration to temperature increased with temperature. Topt was higher in summer than winter at each elevation and decreased significantly with increasing elevation. Q10 decreased significantly with increasing elevation in summer but not winter. These results showed a strong thermal acclimation of foliar photosynthesis and respiration to current temperatures across elevations and seasons, and that R25 increased significantly with elevation and were higher in winter than summer at each elevation indicating that the global warming can decrease R25. These results strongly suggest that this thermal acclimation will likely occur in the coming decades under climate change, so the increase in respiration rates of P. taiwanensis in response to climatic warming may be smaller than predicted and thus may not increase atmospheric CO2 concentrations.

scholarly journals Examining the Economic Impacts of Climate Change on Net Crop Income in the Ethiopian Nile Basin: A Ricardian Fixed Effect Approach

2021 ◽  
Vol 13 (13) ◽  
pp. 7243
Author(s):  
Melese Mulu Baylie ◽  
Csaba Fogarassy
Keyword(s):  
Climate Change ◽  
Economic Impacts ◽  
Fixed Effect ◽  
Least Square ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Nile Basin ◽  
Household Heads ◽  
Crop Income ◽  
Impacts Of Climate Change

Climate change affects crop production by distorting the indestructible productive power of the land. The objective of this study is to examine the economic impacts of climate change on net crop income in Nile Basin Ethiopia using a Ricardian fixed effect approach employing the International Food Policy Research Institute (IFPRI) household survey data for Ethiopia in 2015 and 2016. The survey samples were obtained through a three-stage stratified sampling technique from the five regions (Amhara, Tigray, Benishangul Gumuz, Oromia, and Southern Nation Nationality and People (SNNP) along the Nile basin Ethiopia. There are only 12–14% female household heads while there are 80–86% male households in the regions under study. In the regions, more than half of (64%) the household heads are illiterate and almost only one-tenth of them (12%) had received remittance from abroad from their relatives or children. Crop variety adoption rate is minimal, adopted by the 31% of farmers. Only 30% of the surveyed farmers mentioned that they planted their crop seeds in row whereas the rest 70% had not applied this method. The regression results from the fixed effect least square dummy variable model showed that literacy, household size, remittance, asset value, and total land holdings have significant and positive impacts on the net crop income per hectare. The regional dummy variables estimate indicated that all the regions are negatively affected by climate change at varying levels. Strategies to climate change adaptation have significant and positive contributions in leveraging the damaging effects of climate change. The results also showed that increased winter and summer temperature and rainfall increase net crop income per hectare. The estimated coefficient of the interaction term of spring temperature and rainfall is significant and negative. On the other hand, while the mean annual temperature is damaging to crops, annual rainfall is beneficial. It can be deduced that, while increased temperature and rainfall in summer and winter increase the net crop income, the converse is true for winter and spring seasons. The study also proposes a specific, context-dependent, farm-level adaptation analysis of how farmers cope with the different climatic impacts of the Nile Basin and maintain the income levels that they have previously enjoyed.

Climatic change effects on seasonal patterns of pasture production in New Zealand

1990 ◽  
pp. 43-46 ◽  
Author(s):  
J.A. Baars ◽  
J.E. Radcliffe ◽  
M.D. Rollo
Keyword(s):  
Climate Change ◽  
New Zealand ◽  
Rainfall Variability ◽  
Seasonal Pattern ◽  
Regional Climate ◽  
Production Model ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Pasture Production ◽  
The Impact

The performance of livestock industries in New Zealand is affected by a large spatial and seasonal variability in patterns of pasture production. A software package of a database and a predictive pasture production model has been used to make an initial evaluation of the impact of climate change expected around 2030, on the average seasonal pattern of pasture growth at four sites in New Zealand. Mean annual temperature is expected to be 1.2-1.8" C warmer and annual rainfall 510% less. On two cooler/ wetter sites in Southland and Canterbury (irrigated) the predicted pasture production, compared with present, was substantially better in winter (+80%, +50% respectively), better in spring and autumn (+20 to 40%), and unchanged in summer. On two warmer/ drier sites in East Coast (North Island) and Waikato, similar analyses showed improved autumn and winter growth (20-40%) with production unchanged in spring and slightly depressed in summer. Annual production was increased by 20% at South Island sites and about 5% at North Island sites. The onset of spring growth was 2-4 weeks earlier at all sites. Present technology would be expected to be able to formulate management strategies to cope with pasture changes of this magnitude. More reliable predictions of pasture growth will depend on improved climate models which can predict seasonal change in regional climate throughout New Zealand, especially rainfall variability. Keywords climate change, pasture production, mathematical modelling, regional climate

scholarly journals Farmers’ Perceptions of Climate Change Trends and Adaptation Strategies in Semiarid Highlands of Eastern Tigray, Northern Ethiopia

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hailay Tsigab Kahsay ◽  
Dawit Diriba Guta ◽  
Belay Simane Birhanu ◽  
Tagel Gebrehiwot Gidey
Keyword(s):  
Climate Change ◽  
Water Conservation ◽  
Local Governments ◽  
Smallholder Farmers ◽  
Adaptation Strategies ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Northern Ethiopia ◽  
Perceived Impacts ◽  
Impacts Of Climate Change

This study examined smallholder farmers’ perception about climate change and variability compared with the observed metrological data and their adaptation strategies in response to the perceived impacts of climate change. The multistage sampling method was employed to select 358 rural farmers in Hawzen and Irob districts located in semiarid highlands of Eastern Tigray, northern Ethiopia. Moreover, areal gridded surface monthly rainfall and temperature data between 1983 and 2015 were collected from National Meteorology Agency of Ethiopia. The results revealed that about 98.56 and 92 percent of farmers perceived a decrease in annual rainfall. In addition, 87 and 90 percent of farmers noticed that temperature was increased in Hawzen and Irob districts, respectively. Harmoniously, the modified Mann–Kendall trend test confirmed that annual rainfall was decreased by 32.38 mm and 121.33 mm during the period of analysis. Furthermore, mean annual temperature increased statistically significant (p<0.001) by about 0.40°C and 0.39°C per decade during the period of analysis cognate with the farmers’ perception. To reduce the perceived impacts of climate change, farmers adopted various farm-level adaptation strategies that vary significantly between the two groups. Soil and water conservation, planting trees, crop varieties, changing crop calendar, biological conservation, and irrigation were among the dominant adaptation strategies, respectively, in the study area. The results of this study provide baseline information for local governments, subsequent researchers, and policy-makers in terms of farmers’ perception of climate change and adaptation strategies.

scholarly journals Climate change effects on pasture systems in south-eastern Australia

2009 ◽  
Vol 60 (10) ◽  
pp. 933 ◽  
Author(s):  
B. R. Cullen ◽  
I. R. Johnson ◽  
R. J. Eckard ◽  
G. M. Lodge ◽  
R. G. Walker ◽  
...  
Keyword(s):  
Climate Change ◽  
Elevated Co2 ◽  
Future Climate ◽  
Annual Rainfall ◽  
Wagga Wagga ◽  
Climate Scenarios ◽  
Climate Change Projections ◽  
Pasture Production ◽  
South Eastern ◽  
Cool Temperate

Climate change projections for Australia predict increasing temperatures, changes to rainfall patterns, and elevated atmospheric carbon dioxide (CO2) concentrations. The aims of this study were to predict plant production responses to elevated CO2 concentrations using the SGS Pasture Model and DairyMod, and then to quantify the effects of climate change scenarios for 2030 and 2070 on predicted pasture growth, species composition, and soil moisture conditions of 5 existing pasture systems in climates ranging from cool temperate to subtropical, relative to a historical baseline. Three future climate scenarios were created for each site by adjusting historical climate data according to temperature and rainfall change projections for 2030, 2070 mid- and 2070 high-emission scenarios, using output from the CSIRO Mark 3 global climate model. In the absence of other climate changes, mean annual pasture production at an elevated CO2 concentration of 550 ppm was predicted to be 24–29% higher than at 380 ppm CO2 in temperate (C3) species-dominant pastures in southern Australia, with lower mean responses in a mixed C3/C4 pasture at Barraba in northern New South Wales (17%) and in a C4 pasture at Mutdapilly in south-eastern Queensland (9%). In the future climate scenarios at the Barraba and Mutdapilly sites in subtropical and subhumid climates, respectively, where climate projections indicated warming of up to 4.4°C, with little change in annual rainfall, modelling predicted increased pasture production and a shift towards C4 species dominance. In Mediterranean, temperate, and cool temperate climates, climate change projections indicated warming of up to 3.3°C, with annual rainfall reduced by up to 28%. Under future climate scenarios at Wagga Wagga, NSW, and Ellinbank, Victoria, our study predicted increased winter and early spring pasture growth rates, but this was counteracted by a predicted shorter spring growing season, with annual pasture production higher than the baseline under the 2030 climate scenario, but reduced by up to 19% under the 2070 high scenario. In a cool temperate environment at Elliott, Tasmania, annual production was higher than the baseline in all 3 future climate scenarios, but highest in the 2070 mid scenario. At the Wagga Wagga, Ellinbank, and Elliott sites the effect of rainfall declines on pasture production was moderated by a predicted reduction in drainage below the root zone and, at Ellinbank, the use of deeper rooted plant systems was shown to be an effective adaptation to mitigate some of the effect of lower rainfall.

scholarly journals Continental vs. Global Niche-Based Modelling of Freshwater Species’ Distributions: How Big Are the Differences in the Estimated Climate Change Effects?

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 816
Author(s):  
Danijela Markovic ◽  
Jörg Freyhof ◽  
Oskar Kärcher
Keyword(s):  
Climate Change ◽  
Thermal Properties ◽  
Safety Margin ◽  
Thermal Response ◽  
Future Climate Change ◽  
Freshwater Species ◽  
Response Curves ◽  
Preferred Temperature ◽  
Continental Scale ◽  
Management Actions

Thermal response curves that depict the probability of occurrence along a thermal gradient are used to derive various species’ thermal properties and abilities to cope with warming. However, different thermal responses can be expected for different portions of a species range. We focus on differences in thermal response curves (TRCs) and thermal niche requirements for four freshwater fishes (Coregonus sardinella, Pungitius pungitius, Rutilus rutilus, Salvelinus alpinus) native to Europe at (1) the global and (2) European continental scale. European ranges captured only a portion of the global thermal range with major differences in the minimum (Tmin), maximum (Tmax) and average temperature (Tav) of the respective distributions. Further investigations of the model-derived preferred temperature (Tpref), warming tolerance (WT = Tmax − Tpref), safety margin (SM = Tpref − Tav) and the future climatic impact showed substantially differing results. All considered thermal properties either were under- or overestimated at the European level. Our results highlight that, although continental analyses have an impressive spatial extent, they might deliver misleading estimates of species thermal niches and future climate change impacts, if they do not cover the full species ranges. Studies and management actions should therefore favor whole global range distribution data for analyzing species responses to environmental gradients.

scholarly journals Projection of Hydro-Climatic Extreme Events under Climate Change in Yom and Nan River Basins, Thailand

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 665
Author(s):  
Chanchai Petpongpan ◽  
Chaiwat Ekkawatpanit ◽  
Supattra Visessri ◽  
Duangrudee Kositgittiwong
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Extreme Events ◽  
River Basins ◽  
Annual Rainfall ◽  
Extreme Floods ◽  
Extreme Flood ◽  
Rcp 8.5 ◽  
Near Future ◽  
Far Future

Due to a continuous increase in global temperature, the climate has been changing without sign of alleviation. An increase in the air temperature has caused changes in the hydrologic cycle, which have been followed by several emergencies of natural extreme events around the world. Thailand is one of the countries that has incurred a huge loss in assets and lives from the extreme flood and drought events, especially in the northern part. Therefore, the purpose of this study was to assess the hydrological regime in the Yom and Nan River basins, affected by climate change as well as the possibility of extreme floods and droughts. The hydrological processes of the study areas were generated via the physically-based hydrological model, namely the Soil and Water Assessment Tool (SWAT) model. The projected climate conditions were dependent on the outputs of the Global Climate Models (GCMs) as the Representative Concentration Pathways (RCPs) 2.6 and 8.5 between 2021 and 2095. Results show that the average air temperature, annual rainfall, and annual runoff will be significantly increased in the intermediate future (2046–2070) onwards, especially under RCP 8.5. According to the Flow Duration Curve and return period of peak discharge, there are fluctuating trends in the occurrence of extreme floods and drought events under RCP 2.6 from the future (2021–2045) to the far future (2071–2095). However, under RCP 8.5, the extreme flood and drought events seem to be more severe. The probability of extreme flood remains constant from the reference period to the near future, then rises dramatically in the intermediate and the far future. The intensity of extreme droughts will be increased in the near future and decreased in the intermediate future due to high annual rainfall, then tending to have an upward trend in the far future.

Response of microalgae to elevated CO2 and temperature: impact of climate change on freshwater ecosystems

2016 ◽  
Vol 23 (19) ◽  
pp. 19847-19860 ◽  
Author(s):  
Wei Li ◽  
Xiaoguang Xu ◽  
Megumu Fujibayashi ◽  
Qigui Niu ◽  
Nobuyuki Tanaka ◽  
...  
Keyword(s):  
Climate Change ◽  
Elevated Co2 ◽  
Freshwater Ecosystems ◽  
Impact Of Climate Change ◽  
Temperature Impact ◽  
Elevated Co2 And Temperature
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