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Potential of herbarium records to sequence phenological pattern: A case study of Aconitum heterophyllum in the Himalaya

Authors:
  • GB Pant National Institute of Himalayan Environment
  • Guru Gobind Singh Indraprastha University, Delhi, India

Abstract and Figures

Several pieces of evidence indicate that global climate change is affecting biological systems all across the world. Phenology is one of the tools that may indicate changing patterns. The paper focuses on the phenological pattern of alpine/sub-alpine species Aconitum heterophyllum, a high-value medicinal herb of the Indian Himalayan Region (IHR), a global hotspot and known to be sensitive to climatic change. In all 117 herbarium specimens of the species collected from three provinces (Western Himalaya, North West Himalaya and Trans Himalaya) of the region were recorded. Historic herbarium records (1848–2003) were analyzed to predict the flowering patterns using Generalized Additive Model (GAM) in view of complexity in the herbarium-based data structure. GAM indicated that the flowering time responded significantly, 26days earlier per 1,000m (P<0.02). Likewise, the model showed significantly earlier flowering (17–25days) during the last 100years (P<0.01). Moreover, maximum temperature of winter (December–February) explained increasing trends at both elevations (lower and mid) and mean winter temperature influenced the early flowering time (19–27days) with an increase of 1°C. The overall early flowering of A. heterophyllum may perhaps be considered as indicator of climate change; however, more datasets of herbarium records are required to further strengthen this premise. This study was undertaken to show that herbarium records could be utilized as a potential resource for assessing climate change using GAM. Keywords Aconitum heterophyllum –Early flowering–Generalized Additive Model–Herbarium specimens–Indian Himalayan Region–Phenology–Temperature
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1 23
Biodiversity and
Conservation
ISSN 0960-3115
Volume 20
Number 10
Biodivers Conserv (2011)
20:2201-2210
DOI 10.1007/
s10531-011-0082-4
Potential of herbarium records to
sequence phenological pattern: a case
study of Aconitum heterophyllum in the
Himalaya
Kailash S. Gaira, Uppeandra Dhar &
O. K. Belwal
1 23
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ORIGINAL PAPER
Potential of herbarium records to sequence phenological
pattern: a case study of Aconitum heterophyllum
in the Himalaya
Kailash S. Gaira
Uppeandra Dhar
O. K. Belwal
Received: 27 January 2011 / Accepted: 3 June 2011 / Published online: 14 June 2011
Ó Springer Science+Business Media B.V. 2011
Abstract Several pieces of evidence indicate that global climate change is affecting
biological systems all across the world. Phenology is one of the tools that may indicate
changing patterns. The paper focuses on the phenological pattern of alpine/sub-alpine
species Aconitum heterophyllum, a high-value medicinal herb of the Indian Himalayan
Region (IHR), a global hotspot and known to be sensitive to climatic change. In all 117
herbarium specimens of the species collected from three provinces (Western Himalaya,
North West Himalaya and Trans Himalaya) of the region were recorded. Historic her-
barium records (1848–2003) were analyzed to predict the flowering patterns using
Generalized Additive Model (GAM) in view of complexity in the herbarium-based data
structure. GAM indicated that the flowering time responded significantly, 26 days earlier
per 1,000 m (P \ 0.02). Likewise, the model showed significantly earlier flowering
(17–25 days) during the last 100 years (P \ 0.01). Moreover, maximum temperature of
winter (December–February) explained increasing trends at both elevations (lower and
mid) and mean winter temperature influenced the early flowering time (19–27 days) with
an increase of 1°C. The overall early flowering of A. heterophyllum may perhaps be
considered as indicator of climate change; however, more datasets of herbarium records are
required to further strengthen this premise. This study was undertaken to show that her-
barium records could be utilized as a potential resource for assessing climate change using
GAM.
Keywords Aconitum heterophyllum Early flowering Generalized Additive Model
Herbarium specimens Indian Himalayan Region Phenology Temperature
K. S. Gaira (&)
G. B. Pant Institute of Himalayan Environment and Development, Sikkim Unit, Pangthang,
Post Box 24, Gangtok, Sikkim 737 101, India
e-mail: kailash_gaira@rediffmail.com
U. Dhar
Department of Botany, Hamdard University (Jamia Hamdard), Hamdard Nagar,
New Delhi 110 062, India
O. K. Belwal
Department of Statistics, HNB Garhwal University, Srinagar Garhwal, Uttarakhand 246 174, India
123
Biodivers Conserv (2011) 20:2201–2210
DOI 10.1007/s10531-011-0082-4
Author's personal copy
Introduction
Changes in the timing of phenological events are among the most important indicators of
global warming (Parmesan and Yohe 2003; Root et al. 2003). Among different phenological
events, flowering time is considered the most sensitive indicator in the herbaceous species
(Tilman and El Haddi 1992; Walker et al. 1999) and has a potential for predicting the effect
of climatic change patterns (Kittel 1998). Various studies have provided pieces of evidence
that plant phenology changes due to increasing of temperature (Menzel and Fabian 1999;
Bradshaw and Holzapfel 2001; Fitter and Fitter 2002). Such phenological change sequence
relies on long-term datasets (Primack et al. 2004; Miller-Rushing et al. 2006; Inouye 2008;
Gallagher et al. 2009). Unfortunately, for many regions and species including those
occurring in Indian Himalayan Region (IHR), such data sets/documentation are often not
available.
The Himalayan region, in spite of its recognition amongst 34 global biodiversity hot-
spots (Conservation International 2004) and most conspicuous mountain chain having high
sensitivity to climatic perturbation (NAPCC 2008), is among such data deficient regions.
Alpine/sub-alpine environments are rich in endemic plants (Dhar et al. 2000) and timing of
flowering plants is significantly controlled by the timing of snowfall (Inouye and
Wielgolaski 2003) and its disappearance (Kudo and Suzuki 1999). Such events determine
the sensitivity of the region towards the climatic change (Purohit 1991; Shrestha et al.
1999; Khanduri et al. 2008). These areas and the elements of biodiversity they hold could
provide useful clues of changing patterns. Not withstanding the deficiency in data sets, the
present study was undertaken to address the following issues: (i) how phenological events
in the region are changing as a result of a variety of factors including climate change and
(ii) how these trends can be utilized as indicators.
In view of the non-availability of long-term written records and field-based observa-
tional data (Robbirt et al. 2011), the use of biological collections from museums, herbaria,
zoos, botanical gardens and research stations for determining patterns of responses to
changing climate is growing in popularity (Primack et al. 2004; Miller-Rushing et al. 2006;
Gallagher et al. 2009). Herbarium data have been utilized for comparing phenological
behavior (Bolmgren and Lo
˜
nnberg 2005), reconstructing the phenology of plant species
across large area (Lavoie and Lachance 2006) and analyzing the changing pattern, if any.
Most of the herbarium-based phenological studies are based on the analysis of the group of
species (Primack et al. 2004; Bolmgren and Lo
˜
nnberg 2005; Miller-Rushing et al. 2006),
however, a suggestion to examine the effects of climate change on a particular species is
also propounded (Primack and Miller-Rushing 2009). For example, Lavoie and Lachance
(2006) evaluated the early flowering pattern of Tussilago farfara.
In the above context, the present study focuses on Aconitum heterophyllum (Ranun-
culaceae), a perennial high-value medicinal herb, which begins above-ground growth in
May and flowers (cream colour) in August (Vashistha et al. 2009) with a 20-day peak
flowering time in the alpine/sub-alpine region of IHR (Nautiyal et al. 2009). Due to
continuous exploitation and habitat destruction, the species is becoming rare (Nautiyal
et al. 2002) and is now categorized critically endangered in India (Ved et al. 2003). The
tubers of the plant contain the alkaloids aconitine, mesaconitine, hypaconitine, atisine,
heteratisine, telatisine, and atidine (Khorana and Murti 1968; Mori et al. 1989), which are
used in the treatment of dyspepsia, diarrhea, coughs, snake bites, fevers of contagious
diseases and inflammation in the intestines (Chopra et al. 1986; Tsarong 1994). The present
study was undertaken to (i) assess the usefulness of herbarium records for predicting
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changes in flowering time along the elevation and over the year and (ii) analyze the
relationship between flowering time and temperature.
Materials and methods
Herbarium records
Herbarium records of the target species were recorded from Botanical Survey of India
(BSI), Kolkata and Dehradun; Forest Research Institute (FRI), Dehradun; National
Botanical Research Institute (NBRI), Lucknow and Hemwati Nandan Bahuguna Garhwal
University, Srinagar Garhwal. These institutions are the major source of herbarium records
especially in the IHR. The herbarium specimens’ records were collected from different
provinces of IHR [i.e. Trans Himalaya (TH); North West Himalaya (NWH); and Western
Himalaya (WH)] (Rodgers and Panwar 1988) (Fig. 1). However, the other provinces of
IHR were not considered in the current study due to poor representation and incomplete
data. We also accessed an online herbarium (i.e. Kew Herbarium) and found it incom-
patible due to unspecified location of the target species. The specimen numbers, collecting
location, date of collection, habitat characteristics, elevational ranges and name of the
collector(s) were recorded.
Of the total 117 specimens of target species, only 76 specimens were observed in the
flowering condition. Specimens lacking precise information on date of collection and
locations were discarded. The available specimens were observed in different phenophases
(budding, flowering with bud, only flowering and flower with seeds). Only specimens with
flowers with recorded collection date were considered the date of flowering of the species.
For estimating and developing phenological modelling, the flowering dates were recon-
structed as day of year (DOY) (1 DOY = January 1) and determined as a response variable
(i.e. flowering time).
06001200
Km
N
PAKISTAN
AFHGANISTAN
West Himalaya
Central Himalaya
Eastern Himalaya
BHUTAN
North West Himalaya
78°
88°
80°
81°
92°
30°
33°
36°
75°
89°
96°
27°
27°
Area under study
Fig. 1 Distribution of A. heterophyllum in the IHR and three provinces (TH, NWH and WH) included in
the study
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Elevation as an important explanatory variable was also included in the study. Most of
the records showed a single value for elevation, while some included a range of elevation
with distinct units (i.e. meters and feet). Such elevational variations were rearranged by
determining the average of elevation and ensured uniformity in unit value (i.e. meter).
Temperature records
As temperature records for alpine and sub-alpine areas (elevation 2,400–4,500 m a.s.l.) of
the IHR are lacking, the flowering change responses to temperature change were deter-
mined on the basis of the presumption that 6.5°C temperature decreased with increase per
1,000 m elevation (Singh 2005) and in this context, the lower elevational temperature
records of Vivekananda Parvatiya Krishi Anusandhan Sansthan, Hawalbag Almora,
(1,250 m a.s.l.) and mid elevational of Aryabhat Research Institute of Observational
Sciences, Nainital (1,951 m a.s.l.) were utilized for comparative variability assessment.
We analyzed daily-recorded temperature (maximum and minimum) of Hawalbag for
1971–2008 and Nainital 1971–1995 in a uniform manner. The temperature of both the
stations was analyzed seasonally [i.e. winter (December–February), summer (March–
May), monsoon (June–September) and post monsoon (October–November)] (Shrestha
et al. 1999; Murty et al. 2004). Unfortunately, the temperature records for Nainital were not
available consistently for the time period 1995–2008.
Statistical applications
A long time series (i.e. 155 years from 1848 to 2003) and herbarium data representing a
wide range of elevations (2,400–4,800 m a.s.l.) of the target species was arranged for
applying appropriate statistical methods. The herbarium-based datasets on flowering time
indicated complexities due to (i) multiple data representation in a year and (ii) non-
constant data series (i.e. gaps between the year of collections) (Fig. 2). Such complexities
suggested non-normality and non-linearity in datasets.
Realizing the availability of non-linear and non-constant data structure, Generalized
Additive Model (GAM) was selected as an appropriate approach to address these issues
(McCullagh and Nelder 1989; Hastie and Tibshirani 1990; Guisan et al. 2002). Moreover,
2000
2500
3000
3500
4000
4500
5000
1840
1860
1880
1900
1920
1940
1960
1980
2000
2020
Elevation (m asl)
Year
n = 1
n = 4
n = 16
n = 6
n = 7
n = 15
n = 12
n = 14
n = 1
Fig. 2 Herbarium specimens collected from different elevational ranges with frequency. Boxes explain the
variability of collection frequency between the time interval and elevation ranges. The dotted line represents
the 5-year moving average trend for elevational variations
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Hudson et al. (2009) used a Generalized Additive Model for Location, Scale and Shape
(GAMLSS) approach to predict the phenological changes using long time series herbarium
records and found it suitable. To illustrate, in the general linear model a response variable
Y is linearly associated with values on the X explanatory variables (e.g. year, elevation and
temperature) while the relationship on the Generalized Linear Model (GLM) is assumed to
be as:
Y ¼ gb
0
þ b
1
X
1
þþb
m
X
m
ðÞ;
where g( ) is a function and gi(.) is called the link function, so that:
g
i
YðÞ¼b
0
þ b
1
X
1
þþb
m
X
m
where, Y stands for the expected value of response variable. However, the notion of
additive models with GLM is derived as GAM
g
i
YðÞ¼S
i
f
i
X
i
ðÞ
Generally, GAM allows for choosing a wide variety of distributions for the response
variable and linking functions to improve the effective quality of the prediction
(McCullagh and Nelder 1989; Hastie and Tibshirani 1990). The GAM fit model considers
the estimation of the smoothing terms in the additive model, general algorithm added in the
model using any regression-type smoothers as partial residuals (i.e. Rjth set of partial
residuals)
R
ji
¼ Y S
0
X
h6¼j
S
k
X
k
ðÞ
The partial residuals remove the effects of all the other variables from Y, therefore Y can be
used to model the effects against X
j
. Such foundation algorithm provides a way for esti-
mating each smoothing function S
j
(.) given estimates S
i
:ðÞ
^
¼ i j

for all.
Results
Herbarium-based observations showed that the collections frequency changed across the
years. The maximum collection frequency was observed during 1880–1900 as compared to
the duration from 1940 to 1960. Before the 1920s, the specimens were collected from
2,400 to 3,500 m a.s.l. elevation and after 1920s from 3,500 to 5,000 m a.s.l. Moreover, the
5-year moving average trend of collections varied towards high elevations (Fig. 2).
Considering the flowering pattern along the elevation, the model estimated a significant
(P \ 0.02) advancement in flowering (26 days) per 1,000 m elevation (Table 1) and
showed GAM-based best smooth line with 95% confidence level (Fig. 3a). Similarly, the
early-flowering trend projected (Fig. 3b), on average 17–25 days, showed flowering has
become significantly earlier in the past century (P \ 0.001).
The daily recorded temperature was analyzed (Table 2) and showed that the mean
monthly maximum temperature responded increasingly over the years in the winter season
at lower (r = 0.58) and mid (r = 0.59) elevation significantly (P \ 0.01). Also, the
maximum temperature increased significantly (P \ 0.05) in the post monsoon at lower
elevation (r = 0.40). The minimum temperature at mid elevation increased in winter—
December–February (r = 0.40) and summer—March–May (r = 0.49) significantly
Biodivers Conserv (2011) 20:2201–2210 2205
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(P \ 0.05). Realizing the high significance of winter maximum temperature of both ele-
vations, the 5-year moving average trend was calculated and found to show a warming
signal (Fig. 4).
Table 1 Predicted early flowering of A. heterophyllum across the elevation and over the year using her-
barium specimens using GAM
Parameters Explanatory variables
Elevation Year
Sample size 76 76
b -0.026 -0.21
SE (b) 0.003 0.04
R
2
28.54 14.16
P-value 0.02 0.001
The significance of the smoothing best fit model generalized the changing slope as GAM coefficient (b),
standard error (SE) and coefficient of determinant (R
2
)
1820 1860 1900 1940 1980 2020
Year
-140
-120
-100
-80
-60
-40
-20
0
20
40
60
80
100
Adjusted flowering time (DOY)
2000 2500 3000 3500 4000 4500 5000 5500
Elevation (m asl)
-140
-120
-100
-80
-60
-40
-20
0
20
40
60
80
100
Adjusted flowering time (DOY)
a
b
Fig. 3 GAM-predicted early flowering of A. heterophyllum a along the elevation and b over the year using
herbarium specimens and smoothed best fit line with 95% confidence interval
Table 2 Spearman’s correlation coefficient between seasonal temperatures (maximum and minimum) and
year at lower and mid elevation
Season Temperature (°C)
Lower elevation (n = 38) Mid elevation (n = 25)
Maximum Minimum Maximum Minimum
Winter 0.58** -0.23 0.59** 0.40*
Pre monsoon 0.07 -0.12 -0.28 0.49*
Monsoon -0.26 -0.14 -0.19 0.25
Post monsoon 0.40* -0.14 0.02 0.38
* P \ 0.05, ** P \ 0.01
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Considering the warming winter temperature, the model estimated that flowering time
of A. heterophyllum responded significantly (P \ 0.01) 19–27 days early (i.e. GAM
coefficient =-23.16; SE = 4.30; R
2
= 28.95) with increasing 1°C temperature.
Discussion
Herbarium-based phenological assessments have gained momentum in recent years.
Primack et al. (2004) utilized 372 herbarium specimens of groups of species and compared
them with living plants, and detected earlier flowering over the years. Lavoie and Lachance
(2006) used herbarium specimens of T. farfara and estimated early flowering over time.
Gallagher et al. (2009) evaluated early flowering responses with respect to increasing
temperature. Recently, Robbirt et al. (2011) investigated the flowering time responses by
spring temperature using herbarium and field observations separately. All herbarium-based
phenological studies utilized a similar response variable (i.e. flowering time) and applied
routine statistical application (i.e. linear regression model). However, as a response vari-
able, herbarium-based flowering time is beset with complexities and shows non-normality
and non-linearity so application of parametric approaches may not be appropriate. This is
largely due to data complexities, such as (i) wide elevational ranges, (ii) multiple records in
a year, (iii) non-constant series of collections and (iv) inconsistent collection frequency in
the data (Fig. 2). Therefore, GAM-based phenological modelling was found quite suitable
using herbarium collections.
Herbarium collections frequency showed that the species were collected at higher
elevation after the 1920s, indicating a possible shift in the range of species towards higher
elevations. Several studies indicate that the species distribution ranges have shifted to
higher elevations (Grabherr et al. 1994; Thuiller 2003; Pauli et al. 2007; Inouye 2008;
Kelly and Goulden 2008).
9
11
13
15
17
19
21
23
1965 1975 1985 1995 2005 2015
Lower
Mid
Year
Maximum temperature (
°
C)
Fig. 4 Increasing trend of winter maximum temperature for two stations, i.e. Hawalbag—lower elevation
from 1971 to 2008 and Nainital—mid elevation from 1971 to 1995. The bold line is the 5-year moving
average trend
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In the present study we factored in flowering pattern of the target species along the
elevation, which performs a significant role in the Himalaya especially for phenological
activities. There is a general agreement that flowering time is delayed at higher elevation.
But, we found that over the period we studied earlier flowering was observed at higher
elevation (26 days earlier per 1,000 m). This may be a consequence of winter warming
because warming winter results in early disappearance of snow in the alpine region and
provides favorable conditions for plant growth. In this context, Shrestha et al. (1999)
reports high rate of warming at higher elevation as compared to lower elevations. In
addition, the snow cover suggested as a principal factor controlling the length of the
growing season and phenology of the alpine plants and timing of snow release, signifi-
cantly affects initiation of growth and flowering of alpine species (Kudo and Suzuki 1999;
Walker et al. 1999; Inouye and Wielgolaski 2003).
Considering the flowering pattern over the year, our model reveals advancement
(17–25 days) in flowering of A. heterophyllum in the twenty-first century. Likewise,
Lavoie and Lachance (2006) observed (15–31 day) earlier flowering of T. farfara in the
twenty-first century than around 1920 using 216 herbarium specimens. Several herbarium-
based studies report earlier flowering (Bowers 2007; Miller-Rushing and Primack 2008;
Gallagher et al. 2009). The early flowering pattern of A. heterophyllum may be linked with
warming winter results, which shows that on average flowering time is earlier
(19–27 days) with an increase of 1°C mean winter temperature. However, Robbirt et al.
(2011), comparing herbarium and field records to examine the relationship between phe-
nology and spring temperature, found 6 days early flowering per 1°CinOphrys sphegodes
in the both cases. And, Fitter and Fitter (2002) indicated that the temperature of the
previous month determines the sensitivity of the flowering and most of the changes in
flowering time were due to rising winter and spring temperature (Abu-Asab et al. 2001;
Miller-Rushing and Primack 2008). However, A. heterophyllum may be considered to be
sensitive towards rising temperature of winter season, which promotes earlier flowering.
This study had two major limitations: (i) the analysis of change in flowering time was
based on available records of herbarium specimens and (ii) non-availability of climatic
time series data of the area of occurrence of the target species. In spite of these limitations,
the evidence shows that changes in winter temperature resulted in early flowering of
A. heteophyllum at high elevations and a significant advancement of flowering over the last
century. In essence, the present study opens new vistas of utilizing long-term herbarium
and historical records to assess climate change responses (Lavoie and Lachance 2006;
Miller-Rushing et al. 2006; Gallagher et al. 2009). Also, such studies need to be encour-
aged to be undertaken and we must continue survey/explorations to enrich herbarium
collections without extending any further gap between the quality of past and recent
biological records (Lavoie and Lachance 2006).
Acknowledgments UD acknowledges the support of National Academy of Sciences, India and KSG
thanks the Director GBPIHED, for necessary facilities and to DST, New Delhi for partial financial support.
We acknowledge the help rendered by BSI Kolkata and Dehradun, FRI Dehradun, NBRI Lucknow,
HNBGU Srinagar Garhwal, VPKAS Almora and ARIES Nainital in collection of data. Mr. Triloki Pant is
thanked for helping in data analysis. We thank anonymous referees for improving the manuscript.
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... Changes in phenology of plant species is a good example of climate change impact (Parmesan & Yohe, 2003;Root et al., 2003). Studies from IHR reported early flowering and fruiting in many tree and shrubs species (Gaira et al., 2011(Gaira et al., , 2014Singh et al., 2016;Tewari et al., 2016;Mamgain et al., 2017;Negi et al., 2021a;Table 5). Changes in phenology of Schima wallichi, Castanopsis tribuloides, Callicarpa arborea, Albizia procera, Castanopsis indica was reported from Mizoram , while change in phenology of Toona ciliata, Syzygium cuminii, Litchi chinensis, Azadirachta indica from Assam (Singh & Sahoo, 2019). ...
... The changes in phenological events impacted mismatch in pollination services due fluctuations in pollinators. Pollination also be affected when the timing of blooming is no longer synchronized with insect activity; this lead changes in ecosystem productivity and the species composition (Gaira et al., 2011(Gaira et al., , 2014. Advanced seed maturation due to warming is reported in Shorea robusta, Quercus floribunda and Q. semicarpifolia from western Himalaya (Devi & Garkoti, 2013;Singh et al., 2010). ...
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There are a few regions in the world, where climate change impacts are more intense than other regions of the world, and Himalaya is the case. The Himalaya, one of the biodiversity hotspot regions and provider of ecosystem services to billion of people all across the world. Present study reviewed and synthesized climate change studies in the Himalayan region in general and Indian Himalayan region (IHR) in particular. Analysis of the literature indicates exponentially increase in climate change studies 2005 onward in the IHR, and maximum are from Jammu and Kashmir (105) followed by Uttarakhand (100) and Himachal Pradesh (77). Among the subject types, maximum climate change impact was studied on water resources/glacier retreat (141 studies) followed by agriculture (113) and forests/biodiversity (86). Increasing temperature, frequent drought spells, erratic rainfall and declining snowfall are commonly reported indicators of climate change. For instance, temperature is reported to increase by 1.5 °C in the Himalaya than an average increase of 0.74 °C globally in last century; however, it varied in eastern (0.1 °C per decade and western Himalayas (0.09 °C per decade. An increase in temperature between 0.28 and 0.80 °C per decade was reported for North-western Himalaya and 0.20–1.00 °C per decade for Eastern Himalaya. The higher altitude of Himalayan and Trans-Himalayan zone are reported to be warming at higher rates. Many of the glaciers were reported to be retreating in both eastern and western Himalaya. Heavy rainfall is becoming very common in the region often accompanied by cloudbursts that aggravate flood situation many times. Perception-based studies of the region reported to provide firsthand and detailed descriptions of climate change indicators and impacts from rural and remote areas, where no instrumental data are available.
... To deal with nonparametric statistical analysis, Generalized Additive Model (GAM) was considered exceedingly suitable for ecological studies 60,61 . The GAM is a semi-parametric extension of GLM 62 and deals with highly non-linear and non-normal relationships between the response and the set of explanatory variables 63 . GAM includes the estimation of smoothing terms in the additive model and general algorithm added in the model as partial residuals (i.e. ...
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The Khangchendzonga Landscape (KL), a part of ‘Himalayan Biodiversity Hotspot’, is known for its unique biodiversity assemblage. In recent years, the KL is experiencing threats to biodiversity due to the biological overdominance of native Maling bamboo (Yushania maling). In the present study, we investigated the impacts of the overdominance of Y. maling on the forest composition of Singalila National Park (SNP), Eastern Himalaya, India. Elevational habitats 2400 to 3400 m asl were sampled by laying 69 (10 m × 10 m) forest plots including 51 bamboo plots and 18 non-bamboo plots. Bamboo plots showed signifcantly (p< 0.05) low species richness and density in both shrub and herb layers which further manifested the low seedling density. Generalized Additive Model (GAM) estimated a signifcant (p< 0.0001) decline in species richness and density with increasing bamboo density in SNP. Our study projects the overdominance of Y. maling has a signifcant negative impact on forest structure and composition. Therefore, management of invasiveness of Y. maling is essential through its optimized removal from the protected areas and utilization in making handicrafts, paper industries etc. to create ecological and economic benefits. Further long-term studies assessing the impacts of Y. maling overdominance on forest ecosystems and soil dynamics are recommended
... understand their current distribution patterns and to predict their future distributions using an ensemble of four GCMs. The bioclimatic variables adequately clarified the current distributions of the four medicinal plants across KH and, in agreement with previous studies, indicated that the habitat suitability and climate optima of these species lie at higher elevations (Gaira et al. 2011), where they grow under higher precipitation and colder temperatures in grasslands, forests and other alpine ecosystems (Dad 2019). The species' responses to predictive variables (Fig. 2) further supports this observation, corroborating reports that high-altitude, narrowrange species show greater preference towards certain temperatures and precipitation rates (Vincet et al. 2020). ...
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As natural and anthropogenic forcings impel anticipated climate change, their effects on biodiversity and environmental sustainability are evident. A fundamental question that is often overlooked is: which changes in climate will cause the redistribution or extinction of threatened species? Here, we mapped and modelled the current and future geographical distributions of the four threatened medicinal plants – Aconitum heterophyllum Wall. ex Royle, Fritillaria cirrhosa D.Don, Meconopsis aculeata Royle and Rheum webbianum Royle – in Kashmir Himalaya using maximum entropy (MaxEnt) modelling. Species occurrence records were collated from detailed field studies carried out between the years 2010 and 2020. Four general circulation models for Representative Concentration Pathway (RCP) 4.5 and RCP8.5 climate change scenarios were chosen for future range changes over periods around 2050 (average for 2041–2060) and 2070 (average of 2061–2080). Notable differences existed between species in their responses to predictive environmental variables of temperature and precipitation. Increase in the most suitable habitat, except for A. heterophyllum and R. webbianum , were evident across Himalayan Mountain regions, while the Pir Panjal mountain region exhibited a decrease for all four species under future climate change scenarios. This study exemplifies the idiosyncratic response of narrow-range plants to expected future climate change and highlights conservation implications.
... To deal with nonparametric statistical analysis, Generalized Additive Model (GAM) was considered exceedingly suitable for ecological studies 49,50 . The GAM is a semi-parametric extension of GLM 51 and deals with highly non-linear and non-normal relationships between the response and the set of explanatory variables 52 . GAM includes the estimation of smoothing terms in the additive model and general algorithm added in the model as partial residuals (i.e. ...
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The Khangchendzonga Landscape (KL), a part of ‘Himalayan Biodiversity Hotspot’, is known for its unique biodiversity. In recent years the KL experiencing threats to biodiversity due to biological overdominance of native species such as Maling bamboo ( Yushania maling ). In the present study, we investigated the impacts of the overdominance of Y. maling on the forest composition of Singalila National Park (SNP), Eastern Himalaya, India. Elevational habitats 2400 to 3400 m asl were surveyed by laying 69 (10m x 10m) forest plots including 51 bamboo plots and 18 non-bamboo plots. Bamboo plots showed significantly (p<0.05) low species richness and density in both shrub and herb layers which further manifested the low seedling density. Generalized Additive Model (GAM) estimated a significant (p<0.0001) decline in species richness and density with increasing bamboo density in SNP. Our study projects the overdominance of Y. maling has a significant negative impact on forest structure and composition. Therefore, management of invasiveness of Y. maling is essential through its optimized removal and utilization in handicrafts to create ecological and economic benefits. Further long-term studies assessing the impacts of Y. maling overdominance on forest ecosystems and soil dynamics are recommended.
... Interestingly, while herbarium studies from temperate regions were all relatively consistent, studies from other climatic regions found very different results, e.g. weaker or no phenology shifts across >1700 species in the subtropical southeastern US (Park and Schwartz 2015), or much stronger phenology shifts in some Himalayan species (up to -9 days per decade; Gaira et al. 2011Gaira et al. , 2014. ...
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... A higher rate of temperature increase (higher than the global mean of about 0.7 • C) in the Himalayas has been observed in the last hundred years (Bhutiyani et al., 2007). Moreover, a significant increase in mean maximum temperature during winter and post rainy season over four decades (1971 and 2011) in the region (Gaira et al., 2011) supports the current trend of species composition. Rai et al. (2012) have indicated that the climatic conditions in the timberline ecotone of the west Himalaya are favourable for the regeneration of forests in recent decades. ...
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The spatial distributions of plant species are results of variable environmental gradients, including climatic and edaphic factors, biotic factors, different eco-physiological processes, species-specific characteristics, and resource requirements, thus producing spatial heterogeneity. The species distribution and their rate of change across elevational gradients in nineteen forest communities were studied using the quadrat method and statistical modeling tools. Pindari-Sunderdhunga-Kafni (PSK) area of the Kumaun region and the Lata-Tolma-Phagti (LTP) area in the Garhwal region in the buffer zone of Nanda Devi Biosphere Reserve were selected as the extensive study sites. A total of 4278 individual trees belonging to 42 families in the PSK site and 6436 individual trees belonging to 25 families in the LTP site were recorded across elevational gradients between 2050 to 3800 m a.s.l. Because of the narrow elevational range and complexity in the field-based data structure, Generalized Additive Model (GAM) was used to predict the rate of change of species richness and species density. The results showed a significant decrease in density at a rate of 319–355 ind ha-1 per 100 m elevation in the Pindari-Sunderdhunga-Kafni site (P < 0.01) while increasing patterns (53–56 ind ha-1 per 100 m elevation) in the Lata-Tolma-Phagti site (p < 0.01) was recorded. The decreasing trend for species richness was observed in Lata-Tolma-Phagti site significantly (p< 0.02) across elevation. This study, for the first time in the Indian Himalayan region, underlines the rate of change in species richness (per 1000 m elevation) and density (per 100 m elevation) across elevational gradients. The overall vegetation response may perhaps be considered as an influence of boundary constraint associated with different environmental factors; however, more datasets of vegetation dynamics and responses are required to further strengthen this premise.
... Khanduri et al. (2008) had published that if temperature increase and humidity decrease during the reproductive period still result is a pre-flowering phenomenon and a shorter flowering period. Gaira et al. (2011) reported advancement flowering in Aconitum hetrophyllum over a period of the last 100 years due to increased warmth during winter months. ...
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IMPACT OF CLIMATE CHANGE ON AGRICULTURE, FOREST AND TREE SPECIES IN GARHWAL HIMALAYA UTTRAKHAND, INDIA
Article
To date, most herbarium-based studies of phenological sensitivity to climate and of climate-driven phenological shifts fall into two categories: detailed species-specific studies vs. multi-species investigations designed to explain inter-specific variation in sensitivity to climate and/or the magnitude and direction of their long-term phenological shifts. Few herbarium-based studies, however, have compared the phenological responses of closely related taxa to detect: (1) phenological divergence, which may result from selection for the avoidance of heterospecific pollen transfer or competition for pollinators, or (2) phenological similarity, which may result from phylogenetic niche conservatism, parallel or convergent adaptive evolution, or genetic constraints that prevent divergence. Here, we compare two widespread Clarkia species in California with respect to: the climates that they occupy; mean flowering date, controlling for local climate; the degree and direction of climate change to which they have been exposed over the last 115 yr; the sensitivity of flowering date to inter-annual and to long-term mean maximum spring temperature and annual precipitation across their ranges; and their phenological change over time. Specimens of C. cylindrica were sampled from sites that were chronically cooler and drier than those of C. unguiculata, although their climate envelopes broadly overlapped. Clarkia cylindrica flowers 3.5 d earlier than C. unguiculata when controlling for the effects of local climatic conditions and for quantitative variation in the phenological status of specimens. However, the congeners did not differ in their sensitivities to the climatic variables examined here; cumulative annual precipitation delayed flowering and higher spring temperatures advanced flowering. In spite of significant spring warming over the sampling period, neither species exhibited a long-term phenological shift. Precipitation and spring temperature interacted to influence flowering date: the advancing effect on flowering date of high spring temperatures was greater in dry than in mesic regions, and the delaying effect of high precipitation was greater in warm than in cool regions. The similarities between these species in their phenological sensitivity and behavior are consistent with the interpretation that facilitation by pollinators and/or shared environmental conditions generate similar patterns of selection, or that limited genetic variation in flowering time prevents evolutionary divergence between these species.
Chapter
This review summarizes current understanding of drivers for change and of the impact of accelerating global changes on mountains, encompassing effects of climate change and globalization. Mountain regions with complex human–environment systems are known to exhibit a distinct vulnerability to the current fundamental shift in the Earth System driven by human activities. We examine indicators of the mountain cryosphere and hydrosphere, of mountain biodiversity, and of land use and land cover patterns, and show that mountain environments in the Anthropocene are changing on all continents at an unprecedented rate. Rates of climate warming in the world’s mountains substantially exceed the global mean, with dramatic effects on cryosphere, hydrosphere, and biosphere. Current climatic changes result in significantly declining snow-covered areas, widespread decreases in area, length, and volume of glaciers and related hydrological changes, and widespread permafrost degradation. Complex adaptations of mountain biota to novel constellations of bioclimatic and other site conditions are reflected in upslope migration and range shifts, treeline dynamics, invasion of non-native species, phenological shifts, and changes in primary production. Changes in mountain biodiversity are associated with modified structure, species composition, and functioning of alpine ecosystems, and compromise ecosystem services. Human systems have been negatively impacted by recent environmental changes, with both inhabitants of mountain regions as well as people living in surrounding lowlands being affected. Simultaneously, accelerating processes of economic globalization cause adaptation strategies in mountain communities as expressed clearly in changing land use systems and mobility patterns, and in increasing marginalization of peripheral mountains and highlands. The current state of the world’s mountains clearly indicates that global efforts to date have been insufficient to make significant progress towards implementing the Sustainable Development Goals of the 2030 Agenda for Sustainable Development, adopted by all United Nations member states.
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Aconitum heterophyllum is a precious endemic medicinal plant of Northwestern Himalaya. It possesses a number of curative effects and is accounted for having diuretic, hepatoprotective, antipyretic, analgesic, antioxidant, alexipharmic, anodyne, anti-atrabilious, expectorant, immunostimulant, febrifuge, anthelminthic, anti- cancerous, anti-diarrhoeal, anti-emetic, anti-inflammatory, anti-flatulent, anti-periodic, anti-phlegmatic, anti-diabetic, antifungal, antimicrobial, antiviral and carminative properties. Further, it is an important ingredient of many Ayurvedic formulations. Its pharmacological potential may be attributed to of the presence of many biologically active phytochemicals like aconitine, mesaconitine, acetylaconitine, heterophylline A, and heterophylline B. Owing to its high therapeutic uses and market value, the plant is being exploited for its tubers from the wild. Further, there are some reproductive constraints due to which the population of the plant in the wild is waning at a rapid rate. Due to these factors, Aconitum heterophyllum has been categorized as critically endangered; demanding focused conservation strategies and cultivation efforts.
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Ranichauri, the hill campus of G. B. Pant University of Agriculture and Technology located in the mid Himalayan region of Uttaranchal at an altitude of 1950m above msl. The trend analysis for both maximum and minimum temperature using, 5-year and 3-year moving averages was done for the period 1982-2002. 10-year and 5- year moving average trends indicate that maximum temperature is decreasing over the period, while little increasing trend was observed in case of minimum temperature during the period 1982-2002. Seasonal trends of maximum temperature indicate decreasing trend throughout the year, while minimum was reverse. The coefficient of variation (CV) varied between 5.2 to 9.3 per cent in case of minimum temperature showing highest variability. The trends were also compared between various pentads while during other pentads it was decreasing. The maximum temperature during winter seasons was increasing during the first and last panted. In general the maximum temperature has shown increasing trend during the last pentad in all the four seasons.
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Analyses of maximum temperature data from 49 stations in Nepal for the period 1971-94 reveal warming trends after 1977 ranging from 0.06°to 0.12°C yr-1 in most of the Middle Mountain and Himalayan regions, while the Siwalik and Terai (southern plains) regions show warming trends less than 0.03°C yr-1. The subset of records (14 stations) extending back to the early 1960s suggests that the recent warming trends were preceded by similar widespread cooling trends. Distributions of seasonal and annual temperature trends show high rates of warming in the high-elevation regions of the country (Middle MOuntains and Himalaya), while low warming or even cooling trends were found in the southern regions. This is attributed to the sensitivity of mountainous regions to climate changes. The seasonal temperature trends and spatial distribution of temperature trends also highlight the influence of monsoon circulation. The Kathmandu record, the longest in Nepal (1921-94), shows features similar to temperature trends in the Northern Hemisphere, suggesting links between regional trends and global scale phenomena. However, the magnitudes of trends are much enhanced in the Kathmandu as well as in the all-Nepal records. The authors' analyses suggest that contributions of urbanization and local land use/cover changes to the all-Nepal record are minimal and that the all-Nepal record provides an accurate record of temperature variations across the entire region.
Article
Aconitum heterophyllum Wall. is a critically endangered wild medicinal herb of alpine Himalaya and cultivation is recommended owing to its large demand in the herbal market and to ensure the conservation of wild habitats. Therefore, observations on floral biology, pollen germination, pollination, and fruit and seed setting after implying different breeding systems were carried out for its successful domestication and improvement in cultivation practices. The study reveals that the plants grown in hothouse conditions showed considerable variation in the production of flowers and seeds. Flowering occurs from the second week of September to late October, with 20 days of peak flowering. Anthers dehisced longitudinally between 7:30 and 11:00 AM, strongly dependent on higher temperature. The pollen grains per anther varied between 2000 and 6000, which means an average of 80,000 pollen grains per flower. Nectar production begins at anther dehiscence and coincides with maximum stigmatic receptivity. Bees were observed as pollinators. Pollen germination and pollen tube elongation were maximum in 5% sucrose. Controlled pollination revealed that this species is self-incompatible, although few fruits developed from selfing. Such fruits were smaller than the fruits produced by open pollinated and from hand-crossed flowers and most aborted early in development.
Article
Herbarium phenology data were evaluated and then applied in a phylogenetically independent contrast study in which flowering times were compared between fleshy and nonfleshy-fruited plants growing in the north-temperate provinces of Uppland and Södermanland, southeastern Sweden (59°-60°N). To evaluate herbarium phenology data, flowering-time information taken from herbarium specimens in the Swedish Natural History Museum (S) was compared with two independent field phenology data sets. Herbarium collections and the field studies were restricted to the province of Uppland. Flowering times derived from herbarium specimens correlated equally well with each of the two field-phenology data sets as the field phenology data sets did to each other. Differences between flowering times derived from field and herbarium collections were not affected by the number of herbarium specimens used. However, these differences in flowering times were affected by flowering season such that herbarium-derived flowering times were later for early spring-flowering species and earlier for late summer-flowering species when compared with flowering times derived from field data. In the phylogenetically independent contrast study of mean flowering times in fleshy- compared with nonfleshy-fruited plants, herbarium data were compiled for 77 species in 17 phylogenetically independent contrasts. Flowering time was found to be earlier for fleshy-fruited taxa, illustrating the evolutionary interdependence between flowering and fruiting phases and the constraining effects of a north-temperate climate on phenology evolution. This study shows that herbaria are reliable and time-saving data sources for comparative phenology studies and allow for studies at large phylogenetic and geographic scales that would otherwise be impossible.