Mohan d. Joshi
With the changing climate in Nepal Himalayas, what’s in stock for Abies
spectabilis
Climate is changing and it is changing rapidly. Rapidly in the sense that it is changing at a rate - more than we
expected. Of-course, the changing patterns is not universally same. Climate is changing at an alarming rate in
the Arctic regions and in the Himalayas. In the Himalayas, the warming trend observed ranges from 0.01 to
0.060C/yr. and the annual mean temperature is expected to increase by 2.9 0C by the middle of the century. The
thickness of climate change will bring impacts on socio-economical, biological, physical and other aspects. But
here, we are only focused on biological issues; we are interested to know what changes it will bring to plant
species? To be more specific, we want to know what changes it will bring to plant species in terms of suitable
habitat, elevation shift, relative coverage, net primary production and carbon biomass? For that we choose Abies
spectabilis - as a plant and Manaslu Conservation Area, Nepal – as a location.
To set up the climate scenario, we use the data from CCSM4 model. Models used different scenarios to project
the future climate states, for this research, we choose RCP 2.6 scenario. RCP stands for Representative
Concentration Pathways, which are greenhouse gas concentration trajectories adopted by the IPCC for its fifth
assessment report in 2014. 2.6 is a possible range of radiative forcing value in the year 2100 relative to preindustrial value (i.e an added value of 2.6 W/m2). Plant occurrence data were collected through published
literatures, online source and from the Herbarium records. Bioclimatic parameters were calculated according to
the local climate. These data were used in two vegetation modeling approaches – the empirical Maxent and
process based LPJ-GUESS. Maxent (or Maximum entropy) is a popular software package which based upon the
theory of maximum entropy predicts the distribution of a species taking the species presence records and
environmental variables as input data. Given data on climate and atmospheric CO2 concentration, LPJ-GUESS
estimates the vegetation composition and cover in terms of Plant Functional Types (PFTs), biomass, leaf area
index and Net primary Production (NPP).
The findings show that both the models are in excellent agreement with the current distribution of Abies
spectabilis. The rate of species movement is predicted to be 14 meters per decade (MaxEnt) and 30 meters of
altitude per decade (LPJ-GUESS). In terms of suitable habitat area, MaxEnt predicts reduction of 3 % of the
suitable area by the year 2050 while LPJ-GUESS predicts the area to be reduced by 20.5 %. In addition, LPJGUESS predicts reducing coverage of Abies spectabilis from the lower-temperate climatic zone (2000-2500
masl) and increasing coverage in lower-alpine climatic zone (4000-4500 masl) in the coming future. The
species will respond to climate warming by increasing its Leaf Area Index, Net Primary Production and Carbon
biomass.It is also found that annual temperature range and precipitation seasonality (MaxEnt) influence the
current distribution while in the future, mean temperature of the coldest quarter will shape the geographical
distribution of Abies spectabilis.
Keywords: Physical Geography and Ecosystem Analysis, Abies spectabilis, Manaslu conservation Area,
Maxent, LPJ-GUESS
Advisor: Paul Miller
Master Degree Project 30 credits in Geo-information Science and Earth Observation for Environmental
Modelling and Management (GEM)
Department of Physical Geography and Ecosystem Science, Lund University.
Lund University GEM thesis series
Lund University GEM thesis series nr 8