488
J. A. Dar et al.
to lower species diversity and affects the ecosystem functioning to a large extent
(Seehausen et al. 2008; Edwards et al. 2011; Staudinger et al. 2012).
2.3 Changes in Phenology
Climate change leads to significant phenological changes in temporal biological
events such as flowering and fruiting as it is closely linked with climate (Penuelas
and Filella 2009). Most phenological changes occur due to changes in temperature,
which critically influence the timings of leaf flushing, budding, migration of populations, nesting, egg-laying, breeding, etc. (Hannah and Bird 2018). Various life-cycle
processes depend on seasonal and inter-annual variations in the climate (Parmesan
and Yohe 2003; Visser and Both 2005; Scheffers et al. 2016) and such changes
in phenology are evidenced in several flora and fauna around the world, although
the regions in high latitudes as well as altitudes exhibited changes on a large-scale
(Canadell and Mooney 2002). Forests and other vegetation types of around 54%
of the Earth’s terrestrial surface have shown a significant alteration in phenology
from 1981 to 2012 (Buitenwerf et al. 2015; Pravalie 2018). However, phenological changes due to climate change is not uniform in all vegetation types as carbon
dioxide enrichment induced early flowering in forb species, but delayed the same in
grass species (Cleland et al. 2006; Mooney et al. 2009). Plant-pollinator interactions
become greatly disrupted due to climate change and changes in the phenology of
both plants and pollinators results in the timing mismatches (Memmott et al. 2007;
Ackerly et al. 2012; Rinawati et al. 2013). It has been reported that several plant
species have underwent flowering much early in the last 20–50 years due to increase
in temperatures, early snowmelt, altered precipitation regimes, etc. (Fitter and Fitter 2002). At the same time, the period of emergence of the insect pollinators has
also changed drastically over the years due to changes in climate (Weiss et al. 1988;
Weiss and Weiss 1998; Ackerly et al. 2012). Mismatches in phenology have been
observed in between annual plants and butterflies, where the annual host plants die
much before the insect larvae enter the diapause (Parmesan et al. 2013; Scheffers
et al. 2016). These changes also result in physiological changes, thereby, largely
alter species’ distribution patterns and their abundance (Canadell and Mooney 2002;
Bhuiyan et al. 2018).
2.4 Drought and Forest Fires
A pronounced impact of climate change that is slowly spreading out across the
globe, is the desertification caused by superheating and failed rainfall (Abrams et al.
2018). Droughts are characterized by a clear sky, high temperature and low humidity
(Corlett 2018). Water stress imposes severe pressure on forest ecosystems, especially
drylands that cover approximately 45% of the Earth’s land area (Schimel 2010;
J. A. Dar et al.
to lower species diversity and affects the ecosystem functioning to a large extent
(Seehausen et al. 2008; Edwards et al. 2011; Staudinger et al. 2012).
2.3 Changes in Phenology
Climate change leads to significant phenological changes in temporal biological
events such as flowering and fruiting as it is closely linked with climate (Penuelas
and Filella 2009). Most phenological changes occur due to changes in temperature,
which critically influence the timings of leaf flushing, budding, migration of populations, nesting, egg-laying, breeding, etc. (Hannah and Bird 2018). Various life-cycle
processes depend on seasonal and inter-annual variations in the climate (Parmesan
and Yohe 2003; Visser and Both 2005; Scheffers et al. 2016) and such changes
in phenology are evidenced in several flora and fauna around the world, although
the regions in high latitudes as well as altitudes exhibited changes on a large-scale
(Canadell and Mooney 2002). Forests and other vegetation types of around 54%
of the Earth’s terrestrial surface have shown a significant alteration in phenology
from 1981 to 2012 (Buitenwerf et al. 2015; Pravalie 2018). However, phenological changes due to climate change is not uniform in all vegetation types as carbon
dioxide enrichment induced early flowering in forb species, but delayed the same in
grass species (Cleland et al. 2006; Mooney et al. 2009). Plant-pollinator interactions
become greatly disrupted due to climate change and changes in the phenology of
both plants and pollinators results in the timing mismatches (Memmott et al. 2007;
Ackerly et al. 2012; Rinawati et al. 2013). It has been reported that several plant
species have underwent flowering much early in the last 20–50 years due to increase
in temperatures, early snowmelt, altered precipitation regimes, etc. (Fitter and Fitter 2002). At the same time, the period of emergence of the insect pollinators has
also changed drastically over the years due to changes in climate (Weiss et al. 1988;
Weiss and Weiss 1998; Ackerly et al. 2012). Mismatches in phenology have been
observed in between annual plants and butterflies, where the annual host plants die
much before the insect larvae enter the diapause (Parmesan et al. 2013; Scheffers
et al. 2016). These changes also result in physiological changes, thereby, largely
alter species’ distribution patterns and their abundance (Canadell and Mooney 2002;
Bhuiyan et al. 2018).
2.4 Drought and Forest Fires
A pronounced impact of climate change that is slowly spreading out across the
globe, is the desertification caused by superheating and failed rainfall (Abrams et al.
2018). Droughts are characterized by a clear sky, high temperature and low humidity
(Corlett 2018). Water stress imposes severe pressure on forest ecosystems, especially
drylands that cover approximately 45% of the Earth’s land area (Schimel 2010;