By using parameter values from pre- and post-earthquake sources , we formed a model to examine the impact on the stability of forest resources in Nepal . Please see below for definitions of each parameter in this model :
Forests continually grow until saturation occurs . When forests saturate , no new growth can occur . The standards for commercial harvesting are assumed to be met simultaneously .
S [ t ] |
Growing stocks ( S ) of timber measured at time period t , in hectares ( ha ) |
S [ t ]+ 1 |
Growing stocks at the subsequent measuring time period , in ha |
k |
Natural growth rate of the forest , which becomes unstable beyond 1 |
S ( f ) Scap
Canopy closure and tree density measured at time period t Canopy closure and tree density when the forest is saturation
P L H
a b c
Population growth Encroachment behaviour , such as illegal extraction of timber Area destroyed by natural hazards , such as forest fires
Harvesting effect of population growth per capita Harvesting effect of encroachment behaviour Harvesting effect of natural hazards via climate
Harvesting behaviour was therefore summarized in the following equation . Here , parameter b is represented by GDP . When GDP is low and unemployment high , encroachment is expected to rise . This inverse relationship is represented in 1 / b .
Evaluation of forest resources is composed of two major factors : |
1 . |
Use values , such as land area , wood products , and non-wood products |
2 . |
Non-use values , such as recreation , biological diversity , and other services |
A lack of data on non-use values prevented their inclusion in our model . Due to the initiation of the Community Forest Programme , we expect a greater proportion of community-managed forests . As such , we excluded data on government-managed forests , leasehold forests , and religious forests .