scholarly journals Treeline dynamics with climate change at Central Nepal Himalaya

2013 ◽  
Vol 9 (5) ◽  
pp. 5941-5976 ◽  
Author(s):  
N. P. Gaire ◽  
M. Koirala ◽  
D. R. Bhuju ◽  
H. P. Borgaonkar
Keyword(s):  
Climate Change ◽  
Plant Density ◽  
Elevation Gradient ◽  
Age Distribution ◽  
Recruitment Rate ◽  
Conservation Area ◽  
Nepal Himalaya ◽  
The Past ◽  
Central Nepal ◽  
Tree Ring Data

Abstract. Global climate change has multidimensional impacts with several biological fingerprints, and treeline shifting in tandem with climate change is a widely observed phenomenon in various parts of the world. In Nepal several impacts of climate change on physical environments have been observed. However, studies on the biological impacts are lacking. This dendrochronological study was carried out at the treeline ecotone (3750–4003 m a.s.l.) in the Kalchuman Lake (Kal Tal) area of the Manaslu Conservation Area in central Nepal Himalaya with the aim to study the dynamic impact of climate change at the treeline. The study provides an insight into regeneration and treeline dynamics over the past 200 yr. Two belt transect plots (size: 20 m wide, >250 m long) were laid covering forest line, treeline as well as tree species Abies spectabilis and Betula utilis was done and their tree-cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 yr old) compared to A. spectabilis (max. age 160 yr). A. spectabilis contained an overwhelmingly high population (89%) of younger plants (<50 yr) indicating its high recruitment rate. Population age structure along an elevation gradient revealed an upward shifting of A. spectabilis at the rate of 2.61 m yr−1 since 1850 AD. The upper distribution limit of B. utilis was found stagnant in the past few decades. An increment in plant density as well as upward shifting in the studied treeline ecotones was observed. Thus, two species presented species-specific responses to climate change and much wider differences anticipated in their population status as climate continues to cha spectabilis correlated negatively with the mean monthly temperature of May–August of the current year and with September of the previous year. The regeneration of A. spectabilis, on the other hand, was positively related with May–August precipitation and January–April temperature of the current year. The reconstructed average summer temperature (May–August) using tree ring data revealed alternate period of cool and warm period with warming in the 2nd half of the 20th century. Further palynological and geochronological studies of sediments of the Kalchuman Lake would advance our understanding of past climatic trends and dynamics of the associated treeline and vegetation in the area.

scholarly journals Treeline dynamics with climate change at the central Nepal Himalaya

2014 ◽  
Vol 10 (4) ◽  
pp. 1277-1290 ◽  
Author(s):  
N. P. Gaire ◽  
M. Koirala ◽  
D. R. Bhuju ◽  
H. P. Borgaonkar
Keyword(s):  
Climate Change ◽  
Minimum Temperature ◽  
Plant Density ◽  
Elevation Gradient ◽  
Age Distribution ◽  
Maximum Temperature ◽  
High Mountain ◽  
Nepal Himalaya ◽  
Central Nepal ◽  
The Impact

Abstract. Treeline shifting in tandem with climate change has widely been reported from various parts of the world. In Nepal, several impacts of climate change on the physical environment have been observed, but study on the biological impacts is lacking. This dendrochronological study was carried out at the treeline in the high mountain slope of Kalchuman Lake (3750–4003 m a.s.l.) area of Manaslu Conservation Area in the central Nepal Himalaya to explore the impact of climate change on the treeline dynamic. Two belt transect plots (size: 20 m wide, > 250 m long) were laid which included treeline as well as tree species limit. Ecological mapping of all individuals of dominant trees Abies spectabilis and Betula utilis was done and their tree cores were collected. Stand character and age distribution revealed an occurrence of more matured B. utilis (max. age 198 years) compared to A. spectabilis (max. age 160 years). A. spectabilis contained an overwhelmingly high population (89%) of younger plants (< 50 years) indicating its high recruitment rate. Population age structure along the elevation gradient revealed an upward shifting of A. spectabilis at the rate of 2.61 m year-1 since AD 1850. The upper distribution limit of B. utilis was found to be stagnant in the past few decades. An increment in plant density as well as upward shifting in the studied treeline ecotones was observed. The temporal growth of A. spectabilis was correlated negatively with the monthly mean and minimum temperature of June to September of the current and previous year. The regeneration of A. spectabilis, on the other hand, was positively correlated with August precipitation and monthly maximum temperature of the month of the current year. The growth and regeneration of A. spectabilis was more sensitive to maximum and minimum temperature rather than average temperature. The growth of the B. utilis was mainly limited by moisture stress during the pre-monsoon season. As these two species presented species-specific responses to climate change with differential pattern in regeneration condition, much wider differences are anticipated in their population status as climate continues to change throughout the century.

scholarly journals Plant density and life history traits of Aconitum spicatum in North-central Nepal: effects of elevation and anthropogenic disturbances

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7574
Author(s):  
Deep J. Chapagain ◽  
Henrik Meilby ◽  
Suresh K. Ghimire
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Plant Density ◽  
Elevation Gradient ◽  
Seed Mass ◽  
Anthropogenic Disturbances ◽  
Life Stages ◽  
Conservation Area ◽  
North Central ◽  
Central Nepal

Increasing cross-border trade of medicinal and aromatic plants (MAPs) has put heavy pressure on a considerable number of species in the Himalayas. One of the threatened species in Nepal is Aconitum spicatum. Unfortunately for this species and for many others, our knowledge on population ecology and performance across the distribution range is insufficient, hindering the formulation of species-specific management plans. We therefore studied density and population structure of A. spicatum and assessed variation in its life history traits among three populations (subalpine, lower alpine and alpine) along an elevation gradient (3,000–4,200 m a.s.l.) in Annapurna Conservation Area, north-central Nepal. The results show that human disturbances and topographic factors contributed to the variation in density and life history traits. The overall density ranged between 0.56 ± 0.09 (Mean ± SE) and 2.48 ±  0.24 plants/m2 with highest mean density in the lower alpine and lowest in the subalpine population. The subalpine population was also characterized by lower investment in reproductive structures with lowest seed mass and low seed viability and fecundity. Among the environmental variables tested, harvesting, animal droppings and fire appeared to be the most important factors affecting density of different life stages of A. spicatum. The prevailing harvesting pattern is destructive as it involves uprooting of the whole plant and this appears to be a main reason for low recruitment and reduced density of the subalpine population. The level of disturbance decreased with increasing elevation. In terms of reproductive effort, the alpine population performed best. Our results indicate that the viability of A. spicatum populations depends on controlling over-harvesting and pre-mature harvesting of tubers and protecting younger life stages from grazing, trampling and fire. We therefore recommend that when formulating management guidelines, measures aiming to mitigate such anthropogenic disturbances should be considered.

scholarly journals Assessing the Livelihood Vulnerability of Rural Indigenous Households to Climate Changes in Central Nepal, Himalaya

2019 ◽  
Vol 11 (10) ◽  
pp. 2977 ◽  
Author(s):  
Nani Maiya Sujakhu ◽  
Sailesh Ranjitkar ◽  
Jun He ◽  
Dietrich Schmidt-Vogt ◽  
Yufang Su ◽  
...  
Keyword(s):  
Climate Change ◽  
Vulnerability Index ◽  
Financial Assets ◽  
Nepal Himalaya ◽  
Mountain Communities ◽  
Farming Communities ◽  
Central Nepal ◽  
Gender Based ◽  
And Gender ◽  
Ethnicity And Gender

Climate change and related hazards affect the livelihoods of people and their vulnerability to shocks and stresses. Though research on the linkages between a changing climate and vulnerability has been increasing, only a few studies have examined the caste/ethnicity and gender dimensions of livelihood vulnerability. In this study, we attempt to explore how cultural and gender-related aspects influence livelihood vulnerability in indigenous farming mountain communities of the Nepal Himalaya in the context of climate change. We applied the Livelihood Vulnerability Index (LVI) to estimate household (social group and gender-based) vulnerability in farming communities in the Melamchi River Valley, Nepal. The results identified female-headed families, and those belonging to disadvantaged social groups as more vulnerable and in need of being preferentially targeted by policy measures. Higher exposure to climatic extremes and related hazards, dependency on natural resources, lack of financial assets, and weak social networking were identified as components that determine overall vulnerability. The study also visualizes complex adaptation pathways and analyzes the influence of gender and ethnicity on the capacities of households and communities to adapt to climate change.

scholarly journals Herpetofaunal diversity in Manaslu Conservation Area, Nepal

Our Nature ◽  
2017 ◽  
Vol 14 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Ganesh Kumar Pokhrel ◽  
Sudeep Thakuri
Keyword(s):  
Species Diversity ◽  
Extensive Study ◽  
Biodiversity Monitoring ◽  
Conservation Area ◽  
Nepal Himalaya ◽  
Creative Commons ◽  
Central Nepal ◽  
Monitoring Activities

Herpetofauna is the least studied subject in the Nepal Himalaya. Most of the studies in wildlife are focused on mammals and birds. This paper presents the results of the herpetofauna survey in Manaslu Conservation Area in the Central Nepal, conducted with the aim of establishing the baseline on herpetofauna species diversity. The study recorded 16 species of herpetofauna, indicating a highly potential abundance of herpetofauna in the region. The study is first of its kind in establishing the baseline. The information, thus, obtained can be useful for implementing a biodiversity monitoring activities, and current and future conservation efforts. The study also underlines a need of an extensive study of herpetofauna in this region.  This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. 

scholarly journals Palaeolclimatic significance of palynological assemblages from the Siwalik sediments in the Dudhaura Khola section, central Nepal

2013 ◽  
Vol 46 ◽  
Author(s):  
Khum N. Paudayal
Keyword(s):  
Temperate Forest ◽  
Vegetation Pattern ◽  
Bottom Part ◽  
Nepal Himalaya ◽  
The Past ◽  
Central Nepal ◽  
Palynological Assemblages ◽  
Palynological Study ◽  
Siwalik Group ◽  
Vegetation And Climate

The palynological study of the Rapti Formation and Amlekhganj Formation from the Siwalik Group in the Dudhaura Khola section revealed plethora of information to interpret the past vegetation and climate existed during Late Miocene in the southern margin of the Nepal Himalaya. Altogether 30 samples were collected from Rapti Formation and Amlekhganj Formations exposed in the Dudhaura Khola section for the palynological study. Palynological assemblages recovered from the upper part of Rapti Formation and lower part of Amlekhganj Formation consist of 5 families and 10 genera from monocotyledon, 8 families and 14 genera from dicotyledon, 1 family and 4 genera from Gymnosperm and 5 families from Pteridophytes. High presence of Palm pollen and Ceratopteris spores in the Rapti Formation and Amlekhganj Formation suggests that the climate was warm and humid. The riverine vegetation is documented by the presence of Alnus, Typha, Potamogeton, Liliaceae and Poaceae.The frequency of zygnemataceous spores is common in the Rapti Formation while it is decreases towards the bottom part of the Amlekhganj Formation. There is little gymnosperm pollen in the Amlekhganj Formation but their frequency and distribution is very less. This suggests change of vegetation pattern from tropical-subtropical forest to lower temperate forest during the deposition of Amlekhganj Formation and after wards.

scholarly journals Dynamics of Abies spectabilis in Relation to Climate Change at the Treeline Ecotone in Langtang National Park

2012 ◽  
Vol 12 ◽  
pp. 220-229 ◽  
Author(s):  
Narayan P Gaire ◽  
Yub R Dhakal ◽  
Harish C Lekhak ◽  
Dinesh R Bhuju ◽  
Santosh K Shah
Keyword(s):  
National Park ◽  
Age Distribution ◽  
Silver Fir ◽  
Tree Line ◽  
Climatic Response ◽  
Treeline Ecotone ◽  
Central Nepal ◽  
Tree Ring Data ◽  
Abies Spectabilis ◽  
High Level

This paper is aimed to study the tree line dynamics of Himalayan silver fir (Abies spectabilis D. Don) based on its tree-ring data and age stand distribution at Langtang National Park, Central Nepal. Climatic response on radial growth, recruitment of A. spectabilis and its age distribution are carried out. The average tree density of the species in the study area (total 48 plots of 20 m x 20 m) was 236 no/ha while that for sapling and seedling in the study area was 255 and 350 no/ha, respectively. The stand character and age distribution of the species showed a high level of recruitment in the recent decades, with decreased in average age along with increased altitude. Tree-growth climate relationship showed negative response with temperature of March-May. Upward advancement of tree line is expected in the coming recent decades though not necessarily uniform through the line.DOI: http://dx.doi.org/10.3126/njst.v12i0.6506 Nepal Journal of Science and Technology 12 (2011) 220-229 

Ecological relationships at a near-natural treeline, Rolwaling Valley, Nepal Himalaya: Implications for the sensitivity to climate change

Erdkunde ◽  
2020 ◽  
Vol 74 (1) ◽  
pp. 15-44
Author(s):  
Niels Schwab ◽  
Karolina Janecka ◽  
Ryszard J. Kaczka ◽  
Jürgen Böhner ◽  
Ram Prasad Chaudhary ◽  
...  
Keyword(s):  
Climate Change ◽  
Nepal Himalaya ◽  
Ecological Relationships

FEEDBACK OF WATER STRESS ON WOOD PROPERTIES OF TREES: EXPERIMENTS WITH MISTLETOES ON RHODODENDRON ARBOREUM SM.

1970 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohan P. Devkota ◽  
Gerhard Glatzel
Keyword(s):  
Water Stress ◽  
Wood Anatomy ◽  
Wood Properties ◽  
Vessel Diameter ◽  
Conservation Area ◽  
Rhododendron Arboreum ◽  
Central Nepal ◽  
Inhibition Of Growth ◽  
Infected Area ◽  
Anatomical Parameters

Effects of infection by the mistletoe Scurrula elata (Edgew.) Danser, on wood properties of its common host Rhododendron arboreum Sm., were studied in the Annapurna Conservation Area of Central Nepal Himalaya. Heavy infection by mistletoes invariably causes decline of the host. Infested branches show inhibition of growth, defoliation and eventual death of branch parts distal to the site of infection. Anatomical properties of wood were compared in samples of branches proximal to the infection and in uninfected branches. The hypothesis that infection induces changes in basic wood anatomy could not be proven. Vessel density, vessel area, percentage lumen area and mean vessel diameter of the wood of infested and uninfected branches did not show any significant differences. The studied anatomical parameters were not correlated to the diameter of the host branch. These results show that infection by S. elata did not cause any changes in basic wood anatomy of its host R. arboreum. It appears that the studied anatomical parameters of Rhododendron wood are fairly stable and are not changed by stress due to infection by mistletoes. The damage to the host distal to the infected area most likely results from an insufficiency of total conductive area to supply both mistletoe and host. Unfortunately we could not determine annual conductive area increment, because R arboreum does not develop usable annual tree rings in the climate of the study area. Key words: Himalayas, mistletoe. Rhododendron arboreum, Scurrula elata, water stress, wood anatomy. Ecoprint Vol.11(1) 2004.

Denouement: World Politics, Systemic Leadership, and Climate Change

2018 ◽  
Author(s):  
William R. Thompson ◽  
Leila Zakhirova
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
World Politics ◽  
First Century ◽  
Modern World ◽  
Climate Fluctuations ◽  
The Past ◽  
Agrarian Economy ◽  
Historical Processes

In this final chapter, we conclude by recapitulating our argument and evidence. One goal of this work has been to improve our understanding of the patterns underlying the evolution of world politics over the past one thousand years. How did we get to where we are now? Where and when did the “modern” world begin? How did we shift from a primarily agrarian economy to a primarily industrial one? How did these changes shape world politics? A related goal was to examine more closely the factors that led to the most serious attempts by states to break free of agrarian constraints. We developed an interactive model of the factors that we thought were most likely to be significant. Finally, a third goal was to examine the linkages between the systemic leadership that emerged from these historical processes and the global warming crisis of the twenty-first century. Climate change means that the traditional energy platforms for system leadership—coal, petroleum, and natural gas—have become counterproductive. The ultimate irony is that we thought that the harnessing of carbon fuels made us invulnerable to climate fluctuations, while the exact opposite turns out to be true. The more carbon fuels are consumed, the greater the damage done to the atmosphere. In many respects, the competition for systemic leadership generated this problem. Yet it is unclear whether systemic leadership will be up to the task of resolving it.

scholarly journals Supporting Restoration Decisions through Integration of Tree-Ring and Modeling Data: Reconstructing Flow and Salinity in the San Francisco Estuary over the Past Millennium

Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2139
Author(s):  
Paul H. Hutton ◽  
David M. Meko ◽  
Sujoy B. Roy
Keyword(s):  
San Francisco ◽  
Tree Ring ◽  
San Francisco Estuary ◽  
Salinity Intrusion ◽  
Estuarine Ecosystem ◽  
Freshwater Flow ◽  
The Past ◽  
Decadal Scale ◽  
Tree Ring Data ◽  
Past Millennium

This work presents updated reconstructions of watershed runoff to San Francisco Estuary from tree-ring data to AD 903, coupled with models relating runoff to freshwater flow to the estuary and salinity intrusion. We characterize pre-development freshwater flow and salinity conditions in the estuary over the past millennium and compare this characterization with contemporary conditions to better understand the magnitude and seasonality of changes over this time. This work shows that the instrumented flow record spans the range of runoff patterns over the past millennium (averaged over 5, 10, 20 and 100 years), and thus serves as a reasonable basis for planning-level evaluations of historical hydrologic conditions in the estuary. Over annual timescales we show that, although median freshwater flow to the estuary has not changed significantly, it has been more variable over the past century compared to pre-development flow conditions. We further show that the contemporary period is generally associated with greater spring salinity intrusion and lesser summer–fall salinity intrusion relative to the pre-development period. Thus, salinity intrusion in summer and fall months was a common occurrence under pre-development conditions and has been moderated in the contemporary period due to the operations of upstream reservoirs, which were designed to hold winter and spring runoff for release in summer and fall. This work also confirms a dramatic decadal-scale hydrologic shift in the watershed from very wet to very dry conditions during the late 19th and early 20th centuries; while not unprecedented, these shifts have been seen only a few times in the past millennium. This shift resulted in an increase in salinity intrusion in the first three decades of the 20th century, as documented through early records. Population growth and extensive watershed modification during this period exacerbated this underlying hydrologic shift. Putting this shift in the context of other anthropogenic drivers is important in understanding the historical response of the estuary and in setting salinity targets for estuarine restoration. By characterizing the long-term behavior of San Francisco Estuary, this work supports decision-making in the State of California related to flow and salinity management for restoration of the estuarine ecosystem.

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