486
J. A. Dar et al.
150 bird species have already become extinct in the last 500 years (Mooney et al.
2009; Bhattarai 2017) and the extinction rate of the endemic species could rise up to
39–43%, under worst-possible scenarios, which in turn indicates that around 56,000
plant and 3700 vertebrate species might get lost (Malcolm et al. 2006; Rinawati
et al. 2013). The rate of extinction has been estimated to be greater than 100 species
per million species per year (Rockstrom et al. 2009; Pravalie 2018). As of now, the
extinction rate has been estimated to be greater than 100 species per million species
per year (Rockstrom et al. 2009; Pravalie 2018). In come cases, a phenomenon called
“extinction debt” occurs, where functional extinction of a species precedes the actual
physical extinction of the species (Pecl et al. 2017). With the extinction of species,
the ecosystem regulating services become disrupted and this could in turn, create a
positive feedback to climate change.
Climate plays a crucial role in regulating the distribution of populations and in
structuring the biological communities (Austin and van Niel 2011; Drielsma et al.
2017). Therefore, it is expected that changes in the temperature and precipitation
regimes would affect species’ traits, vegetation structure, and composition, ecological
and physiological processes across different vegetation types, land uses and regions
(Niu 2001; Lindner et al. 2010; Gao et al. 2016). Change in temperature influences the
insulating nature of the snow, which in turn alters the soil temperature by determining
the extent of exposure of soil to the cold air, which may alter the composition of
soil biota (Edwards et al. 2007; Rogora et al. 2018). An alteration in climate is
known to decouple plant-pollinator interactions via several ways (Hegland et al.
2009; Ramirez and Kallarackal 2018), thus affecting both pollinator diversity as well
as plant diversity. On the other hand, reduced pollinator diversity could result in poor
fruit-setting and regeneration potential of plants. This scenario is further complicated
in the case of those plant species that have obligate/specialist pollinators (Gilman
et al. 2011; Ramirez and Kallarackal 2018). Climate change also lowers genetic
diversity due to directional selection, genetic drift as well as population migration
(Rinawati et al. 2013). Since biodiversity is the fundamental unit of all ecosystem
processes and is also easily vulnerable to extinction due to climatic alteration, it
is imperative to understand the effects of different drivers of climate change, both
individually and synergistically to take proper conservation measures.
Freshwater ecosystems are particularly vulnerable and endangered ecosystems as
they are the fragmented habitats and therefore freshwater species have limited ability
to disperse (Woodward et al. 2010; Bhattarai 2017). Climate change-related drivers
are altering the community structures of freshwater ecosystems and it is further
exacerbated by eutrophication, characterized by algal blooming and hypoxia (Pesce
et al. 2018). Freshwater ecosystems are also affected by stresses such as extraction and
exploitation of resources, pollution, etc. due to their closeness to human habitations
(Woodward et al. 2010; Bhattarai 2017). On the other hand, increasing temperature
of the oceans, ocean acidification, inundation of estuarine ecosystems by sea water,
rise in sea level, changes in coastline etc. are some of the drivers that bring about
compositional and community changes in marine ecosystems, subsequently leading
to the disruption of their ecosystem services (Day et al. 2008; Ackerly et al. 2012;
Asmus et al 2017). Coral reefs act as natural protection against huge ocean and
J. A. Dar et al.
150 bird species have already become extinct in the last 500 years (Mooney et al.
2009; Bhattarai 2017) and the extinction rate of the endemic species could rise up to
39–43%, under worst-possible scenarios, which in turn indicates that around 56,000
plant and 3700 vertebrate species might get lost (Malcolm et al. 2006; Rinawati
et al. 2013). The rate of extinction has been estimated to be greater than 100 species
per million species per year (Rockstrom et al. 2009; Pravalie 2018). As of now, the
extinction rate has been estimated to be greater than 100 species per million species
per year (Rockstrom et al. 2009; Pravalie 2018). In come cases, a phenomenon called
“extinction debt” occurs, where functional extinction of a species precedes the actual
physical extinction of the species (Pecl et al. 2017). With the extinction of species,
the ecosystem regulating services become disrupted and this could in turn, create a
positive feedback to climate change.
Climate plays a crucial role in regulating the distribution of populations and in
structuring the biological communities (Austin and van Niel 2011; Drielsma et al.
2017). Therefore, it is expected that changes in the temperature and precipitation
regimes would affect species’ traits, vegetation structure, and composition, ecological
and physiological processes across different vegetation types, land uses and regions
(Niu 2001; Lindner et al. 2010; Gao et al. 2016). Change in temperature influences the
insulating nature of the snow, which in turn alters the soil temperature by determining
the extent of exposure of soil to the cold air, which may alter the composition of
soil biota (Edwards et al. 2007; Rogora et al. 2018). An alteration in climate is
known to decouple plant-pollinator interactions via several ways (Hegland et al.
2009; Ramirez and Kallarackal 2018), thus affecting both pollinator diversity as well
as plant diversity. On the other hand, reduced pollinator diversity could result in poor
fruit-setting and regeneration potential of plants. This scenario is further complicated
in the case of those plant species that have obligate/specialist pollinators (Gilman
et al. 2011; Ramirez and Kallarackal 2018). Climate change also lowers genetic
diversity due to directional selection, genetic drift as well as population migration
(Rinawati et al. 2013). Since biodiversity is the fundamental unit of all ecosystem
processes and is also easily vulnerable to extinction due to climatic alteration, it
is imperative to understand the effects of different drivers of climate change, both
individually and synergistically to take proper conservation measures.
Freshwater ecosystems are particularly vulnerable and endangered ecosystems as
they are the fragmented habitats and therefore freshwater species have limited ability
to disperse (Woodward et al. 2010; Bhattarai 2017). Climate change-related drivers
are altering the community structures of freshwater ecosystems and it is further
exacerbated by eutrophication, characterized by algal blooming and hypoxia (Pesce
et al. 2018). Freshwater ecosystems are also affected by stresses such as extraction and
exploitation of resources, pollution, etc. due to their closeness to human habitations
(Woodward et al. 2010; Bhattarai 2017). On the other hand, increasing temperature
of the oceans, ocean acidification, inundation of estuarine ecosystems by sea water,
rise in sea level, changes in coastline etc. are some of the drivers that bring about
compositional and community changes in marine ecosystems, subsequently leading
to the disruption of their ecosystem services (Day et al. 2008; Ackerly et al. 2012;
Asmus et al 2017). Coral reefs act as natural protection against huge ocean and