Long term and Short term projections of climate change effects on natu

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Long term and Short term projections of climate change effects on natural vegetations and ecosystems:

Long term and Short term projections of climate change effects on natural vegetations and ecosystems Kirpa Ram Jangra Department of Botany and Plant Physiology


Introduction In recent years there has been heightened awareness about potential impacts of climate change due to consequences of human activities Particularly on the role of increased GHGs, but other important forcings include deforestation, ozone depletion, and the effects of natural and anthropogenic aerosols The effects are felt on earth’s land surface and this is intuitive because majority of food production depends on the quality of surface vegetation In order to assess the impacts of climate change on ecosystems and on natural vegetation one has to look at regional and local scale


Condt.. The fluxes of energy, water, momentum and trace gases between land surface and atmosphere are largely regulated by biological processes A change in the vegetation type and/or properties of an area may be due to natural climatic variations of different time periods such as those associated with ice ages or seasonal draughts Changes may also be due to anthropogenic causes such as deforestation or agricultural practices

What is Climate Change?:

What is Climate Change? Any change in climate over time due to natural variability or as result of human activity (IPCC 2001) The observed increase in temperature on earth is due to the emission of GHGs

PowerPoint Presentation:

Causes of climate change Natural Causes Anthropogenic Causes Continental drift Volcanoes The Earth’s Tilts Ocean Currents Intensity of Solar Radiation 1) Green Houses Gases Carbon dioxide (CO 2 ) Methane (CH 4 ) Nitrous oxide (NO 2 ) Chloro floro carbons (CFCs) Ozone (O 3 ) Water Vapors (H 2 O) 2) Land Use Change Deforestation Urbanization 5

Likely Impacts of Climate Change :

Likely Impacts of Climate Change 6 IPCC, 2001

Short term and Long term predictions:

Short term and Long term predictions Predictions are based on models Short term models : RCM- Regional Climatic Model GCM- Global Climatic Model Long term models: based on economic and ecological development


Models Climate models use quantitative methods to simulate the interactions of the  atmosphere , oceans , land surface and ice They are used in the study of the dynamics of the weather and climate system for the projections of future climate The applications of these models to infer the consequences of increasing greenhouse gases (CO2) in the atmosphere These models predict an upward trend in the  global mean surface temperature Models can range from relatively simple to quite complex

Where they are used?:

Where they are used? Short term predictions are used in: Surface temperature Evapotranspiration Flood forecasting Summer rainfall Sea surface temperature and sea level pressure Drought Geography of species Quantitative precipitation Inter seasonal variability in the atmosphere –ocean climate system Hurricane intensity Wind power Water demand forecast


Condt.. Continental phenology for monitoring vegetative responses to interannual climate variability Ground hydrology Precipitation-runoff Alpine lee cyclogenesis Monsoon rainfall and river discharge Tropical cyclones Ecosystems responses Climetological precipitation over mountains


Condt.. Long term prediction are used in : Distribution of species and bioclimates Soil moisture Natural systems Ocean circulation –Atmospheric circulation, hydrology Terrestrial ecosystems & function of Co2 Land surface fluxes Aridity changes Soil carbon turnover to warming Mass loss, Nitrogen dynamics Monsoon processes


Condt.. Geography of species Long lead seasonal forecast Water availability Land surface water & Energy fluxes Radiation& radiative properties Destructiveness of tropical cycle Responses of photosynthetic productivity to rising temperature by Co2 conc. Cloud predation Hydrological cycle Global monthly precipitation Tectonic forces Carbon cycle feedbacks Risks for terrestrial & marine biota GHG induced changes Biomass & Soil organic matter dynamics Thermohaline circulation

Few Predictions :

Few Predictions

PowerPoint Presentation:

IPCC, 2007 Figure 2- IPCC Scenarios of temperature change 14

PowerPoint Presentation:

Precipitation increases very likely in high latitudes Decreases likely in most subtropical land regions IPCC, 2007 15 Figure 7-

PowerPoint Presentation:

Stern (2006) Cambridge University (UK) 16

PowerPoint Presentation:

Temperature Rise Rainfall Projections 17 IIS, Bangalore Ravindranath (2007) Figure 10- Projections of temperature and rainfall in India in 2071-2100 .

Potential effects of climate change on ecosystem and natural vegetation:

Potential effects of climate change on ecosystem and natural vegetation Global climate change affects a wide range of species and ecosystems Biological response is particularly prevalent in the northern sub-boreal, boreal and subarctic ecosystems where climate change signal is strongest Over the past decade a warming trend that approximately matches climate change predictions Relatively small increase in mean temperature, ~o.7 o C have had remarkable economic and ecological impacts Pine beetle epidemic may be partially caused by lack of low winter minimum temperatures


Condt.. Dothistroma needle blight cause wide spread damage is linked to increased frequency of warm and moist conditions In southern and British Columbia, substantial reforestation failures and high frequency of wildfires were attributed to draught in combination with recorded temperatures Natural variability in climate and non climatic factors may play a role in these incidents The current continued climate change may threat ecosystems and natural vegetations

Effects on natural vegetation:

Effects on natural vegetation Through bioclimate envelop studies… GLM-Generalized Linear Model GAM-Generalized Additive Models RTAM-Regression Tree Analysis Models ANN-Artificial Neural Networks Temperate tree species will expand their range northward and into higher elevations and they will loose suitable habitat at the southern end of their original distribution Shifts in vegetation zones are not entirely determined by shifts in climate Soil local topography, ground water level , and other factors may influence plant species distribution Elevated atmospheric Co2 levels could significantly increase growth rates of species under draught stress


Condt.. Different tree species or populations may have different potentials to respond to climate change through plasticity and genetic adaptation Species also have different capabilities of migrating through complex landscapes to favorable habitats Deceased vegetation reduces evapotranspiration, leading to a net increase in heat flux and higher surface temperatures Overgrazing cause shorter grass, more bare soil and a higher albedo Vegetation removal leads to increased albedo and decreased surface temperature

Changes in tree species distribution:

Changes in tree species distribution

Observed and predicted range :

Observed and predicted range

Observed and predicted range:

Observed and predicted range

Effect of climate change on ecosystems:

Effect of climate change on ecosystems As per general circulation model CCGA 1 gax Many zones that are partially or entirely in mountainous areas shift upward The mountain Hemlock zone, which consists of a narrow band on the east side of the cost mountains, appears to be particularly vulnerable By 2055 there is almost no spatial overlap with the zones current climatic envelop Exception.. Montane Spruce ecosystem, which only shows minor changes in average elevation but is largely reduced in extent by changing climates


Condt.. The predicted spatial redistribution of realized climate space for British Columbia ‘s ecosystems appears to be considerable even at the zone level, which represents major forest types Ecosystems in mountain areas appears to be vulnerable, spatial shifting out of their current climate envelop with in 50 years Other notable predictions are the initial expansion of the climatic envelop for the Interior Cedar Hemlock with in ~25 years Followed by the expansion of the Interior Douglas-fir and Ponderosa Pine climate regions throughout the interior plateau replacing the current climate space of sub-boreal and boreal ecosystems

Changes in biogeoclimatic ecological zone distribution:

Changes in biogeoclimatic ecological zone distribution

Shift of climatic envelop of ecological zones:

Shift of climatic envelop of ecological zones

Shift of climatic envelop of ecological zones based on CGC m1gax:

Shift of climatic envelop of ecological zones based on CGC m1gax

Other effects on ecosystems:

Other effects on ecosystems Changes in climate affect photosynthesis, plant respiration, and organic matter decomposition All of which influence the global land atmosphere carbon flux The increase in photosynthetic uptake due to higher atmospheric Co2 is larger than the increase in ecosystem respiration due to the warming However Co2 fertilization effect saturates at higher Co2 levels and is then partly offset by higher degrees of global warming Wide spread increase in runoff – In some regions have a high risk of reduced runoff Risks of changes in fire frequency are also widespread and its relationship to runoff is not straight forward


Condt.. Reduced fire frequency, reflecting wetter conditions is indicated for some parts but increased tree cover in some other parts promotes fire Fire is a major factor in structuring vegetation and some biome shifts follow these changes in fire regime, whereas others are forced directly by climate Forests extends into the Arctic and into semiarid savannas Extant forests are destroyed


Condt.. Climate model simulations beyond 2100 examine the ‘ committed’ climate change-which means climate change associated with changes in atmospheric composition according to the chosen scenario (A1B,A2 or B1) to 2100 and Then held constant from 2100 and the associated trends in ocean temperature and ocean volume due to the ocean thermal inertia LPJ run shows-Delay in vegetation changes to climate change


Condt.. Globally, risks of change in forest to nonforest biome or vice versa to some ecosystems are less than 43% for ˂2 o c and increasing up to 75% and 88% for 2-3 o c respectively A probability of climate change affecting a larger fraction of the world’s ecosystems (>10% land area) shifting from forest to grasslands or vice versa is only apparent

Thank you :

Thank you 34 58 Thank you

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