environmental challenge, which has enormous impacts on biodiversity patterns in
the past and is seen as having significant contemporary impacts (Sahney et al.
2010). It is predicted that it will remain one of the major drivers of biodiversity patterns in the future also (Sala et al. 2000). A thickening layer of carbon
dioxide pollution, mostly from power plants and automobiles that traps heat in the
lower atmosphere, is considered as the main reason of climate change. It has a
direct impact on biodiversity (Chapin et al. 2000) influencing the reduction in
species’ diversity (Franco et al. 2006) which ultimately affect the ability of biological systems to support human needs (Vitousek et al. 1997). The industrialization, urbanization, and agricultural intensification has led to a significant change in
land use and associated land cover (Kumar et al. 2011), which intensified the
pressures on habitats and landscapes and biodiversity in general (Stanners and
Bordeaux 1995). The steady decline of habitats and landscapes demonstrates the
need for protection, which has also been addressed in Convention on Biological
Diversity (CBD) in order to identify and monitor ecosystems, habitats, species,
communities, genomes, and genes. Global climatic changes also affect agriculture
through their direct and indirect effects on crops, soils, livestock, and pests (Pathak
et al. 2012).
Forests have been influencing the gas composition in the atmosphere, which in
turn influenced temperatures and weather patterns on Earth (Zachos et al. 2001;
Sigman and Boyle 2000). The two important measures of climate change are the
variation in precipitation and temperature (Sukumar 2000). Changes in rainfall
pattern are likely to lead either to severe water scarcity or flooding and on the other
hand, rising temperature with increasing number of days having high temperature
accelerates the extinction rate of many species and also cause shifts in crop growing
seasons, which ultimately affects food security. Plant growth, flowering, animal
reproduction, and migration also depend in part on temperature. Changing environments are expected to lead to changes in species distribution (Lynch and Lande
1993) and life cycle events, which have been recorded for many plant species
(Parmesan and Yohe 2003). Phenology is being used as an indicator of species
sensitivity to climate change (Bharali and Khan 2012). Plants used to respond to
climate change in four possible ways: (a) phenotypic plasticity enabling species
survival, with alterations in eco-physiological processes in the changed climate,
(b) evolutionary adaptation to new climate, (c) emigration to favorable habitats, and
(d) extinction (Bawa and Dayanandan 1998; Saxena and Purohit 1993). Global
climate change along with continued habitat loss and fragmentation is now being
recognized as a major threat to future biodiversity (Bharali and Khan 2012).
Ongoing distributional changes may not necessarily allow the species to persist
throughout its range. There is strong evidence that plant species are shifting their
ranges in altitude and latitude as a response to changing climatic conditions
(Parmesan and Yohe 2003). Human-induced climate change impacts biodiversity
and on the other hand, biodiversity reduces the impacts of climate change on the
environment. Genetic evidence for Fagus sylvatica suggests that populations may
show some capacity for an in situ adaptive response to climate change (Jump et al.
2006).
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P. Saikia et al.
the past and is seen as having significant contemporary impacts (Sahney et al.
2010). It is predicted that it will remain one of the major drivers of biodiversity patterns in the future also (Sala et al. 2000). A thickening layer of carbon
dioxide pollution, mostly from power plants and automobiles that traps heat in the
lower atmosphere, is considered as the main reason of climate change. It has a
direct impact on biodiversity (Chapin et al. 2000) influencing the reduction in
species’ diversity (Franco et al. 2006) which ultimately affect the ability of biological systems to support human needs (Vitousek et al. 1997). The industrialization, urbanization, and agricultural intensification has led to a significant change in
land use and associated land cover (Kumar et al. 2011), which intensified the
pressures on habitats and landscapes and biodiversity in general (Stanners and
Bordeaux 1995). The steady decline of habitats and landscapes demonstrates the
need for protection, which has also been addressed in Convention on Biological
Diversity (CBD) in order to identify and monitor ecosystems, habitats, species,
communities, genomes, and genes. Global climatic changes also affect agriculture
through their direct and indirect effects on crops, soils, livestock, and pests (Pathak
et al. 2012).
Forests have been influencing the gas composition in the atmosphere, which in
turn influenced temperatures and weather patterns on Earth (Zachos et al. 2001;
Sigman and Boyle 2000). The two important measures of climate change are the
variation in precipitation and temperature (Sukumar 2000). Changes in rainfall
pattern are likely to lead either to severe water scarcity or flooding and on the other
hand, rising temperature with increasing number of days having high temperature
accelerates the extinction rate of many species and also cause shifts in crop growing
seasons, which ultimately affects food security. Plant growth, flowering, animal
reproduction, and migration also depend in part on temperature. Changing environments are expected to lead to changes in species distribution (Lynch and Lande
1993) and life cycle events, which have been recorded for many plant species
(Parmesan and Yohe 2003). Phenology is being used as an indicator of species
sensitivity to climate change (Bharali and Khan 2012). Plants used to respond to
climate change in four possible ways: (a) phenotypic plasticity enabling species
survival, with alterations in eco-physiological processes in the changed climate,
(b) evolutionary adaptation to new climate, (c) emigration to favorable habitats, and
(d) extinction (Bawa and Dayanandan 1998; Saxena and Purohit 1993). Global
climate change along with continued habitat loss and fragmentation is now being
recognized as a major threat to future biodiversity (Bharali and Khan 2012).
Ongoing distributional changes may not necessarily allow the species to persist
throughout its range. There is strong evidence that plant species are shifting their
ranges in altitude and latitude as a response to changing climatic conditions
(Parmesan and Yohe 2003). Human-induced climate change impacts biodiversity
and on the other hand, biodiversity reduces the impacts of climate change on the
environment. Genetic evidence for Fagus sylvatica suggests that populations may
show some capacity for an in situ adaptive response to climate change (Jump et al.
2006).
108
P. Saikia et al.