IDEAS Insights Forest Management in Nepal | Page 6

From amongst the land suitable for business harvesting in Terai districts, we input the
following data:
For S(f) – forest stock at time point (f)
Pre-earthquake
1390.081 (in 000 ha) in 2000/01
Post-earthquake 463.360 (in 000 ha), based on predicted forest loss of 66%
For Scap – forest stock capacity
Pre-earthquake
4728.512 (in 000 ha) in 1978-1986
Post-earthquake 1576.170 (in 000 ha), provided no damage occurred to forest capacity
For K – rate of regrowth
Pre-earthquake
0.31, % regrowth in 1989-2000 in 1272.200 (in 000 ha) of forest
Post-earthquake 0.1, % regrowth
After earthquakes, growth rates fall significantly due to soil erosion via landslides, as
well as the high mortality rate of manual labour. Additionally, available biomass may be
depleted.
We therefore estimated K = 0.1% based on these factors.

Growing populations increase demand for wood products, unmanaged settlements,
encroachment, and grazing. While the population grows yearly, population growth
decreased by 0.2% post-earthquake.
Within community forests, villagers are actively
protecting against encroachment, and so illegal timber harvest has decreased.
a*P[t]:

This is 2.75 per ha, wood volume removal per forest area in 2006/07

b*L[t]:

This is 3.28, % total encroachment per annum

Natural causes include forest fires, landslides, and soil erosion. Among natural causes,
forest fires are chief contributors, and so were used as a proxy for natural causes. In
affected areas, tree survival rates are predicted to be 1%.
A binary state was used, c,
where forest fires can either be present or absent. This system ignores the influence of
wind and moisture. We therefore inputted the following data.
c*H[t], where c is a binary
When c=0, the temperature is <30°C
When c=1, the temperature is >30°C

No trees are lost to forest fire.
Pre-earthquake:
200 ha lost in 2004
Post-earthquake:
67 ha lost (-66% est.)