Full text: Technical Commission VIII (B8)

   
     
ildi et al. 2006). 
cach land use, 
is the dissection 
ty weighted by 
1.2012). 
' on what has 
s of the change 
etit et al. 2001; 
31.2008). In this 
ntegrated using 
1-based change 
poral trajectory 
sponding to its 
n 1986 to 2006 
r example, the 
eaning that the 
st in 2000 and 
d 
e change 
86-2006 were 
e of the forest 
. It was found 
t two decades. 
otal land area. 
1 open forest, 
-2006.The net 
t decreased by 
2.1 per cent of 
period, loss of 
han that from 
f the total area. 
past 20 years, 
' attributed to 
  
  
  
; Closed Open Other 
period P forest Sum forest forest 
1986 area -83.16 -3.85 -20.45 49.91 
-2000 ^ rate(94) 0 0 -0.10 0.90 
pe area -1249.2 47.52 -60.68 0.34 
E rate(%) -0.50 -0.70 -0.70 0 
458 change -1332.36 5138 -81.13 50.25 
3 rate(%) -0.19 -0.25 -0.29 0.64 
  
  
  
  
Table 1. The area changes of different forest types (km?) 
  
  
RE 
asics RETR 
x 
= 
  
  
  
  
  
  
  
  
  
  
  
Figure 2. Forest in study area in 1986(a), 2000(b), 2006(c) 
In summary, forest has decreased at an annual change rate of - 
0.19% during 1986-2000. Closed forest was destroyed with 
annual loss rate of -0.5% from 2000 to 2006. The open forest 
decreased dramatically with annual rate of -0.7% in the same 
period. Shrub forest shrunk in area between 1986 and 2000 at 
loss rate of -0.25%. There was an increase of other forest land 
with annual area change rate of 0.90% (from 1986 to 2000) and 
0.64% (from 2000 to 2006) respectively. The speed of 
deforestation from 2000 to 2006 was faster. The change rates of 
various forests were relatively high showing a negative state. 
4.2 Forest Fragmentation 
Figure 3 shows the landscape metrics for forests at class level in 
different historical years. During the past 20 years, the numbers 
of forest patch increased slightly, while the average patch area 
decreased 96 ha. Forest decreased in the average size of patches 
potentially resulting from cultivation and degradation. From 
1986 to 2006, the PD of forests increased from 0.059 per 100 ha 
to 0.062 per 100 ha. Forest land in this region affected by 
human activities have lower AMWPFD values (<1.30). 
AWMPFD of forests decreased slightly indicating that forest 
patch shape tended to be regular and simpler indicating more 
human influence during 1986-2006. The averages patch area of 
closed forest decreased 2737ha resulting from logging and 
cultivation. The MPS values of shrubs and open forest 
decreased while averages patch area of other forest increased 
probably due to the afforestation encouraged by the government. 
The AWMPFD of closed forest and shrub decreased by 0.002 
and 0.003, respectively. It was concluded that forestland 
experienced the process of substantial clearing and 
fragmentation in the past 20 years. 
  
2500 
2000 
1500 
= 
1000 
500 
  
at D 
1986 2000 
  
M Closed forest CJ Shrub [S Open forest 0 Other forest E Total 
  
  
  
12000 - 
b 
10000 - 
8000 - 
6000 - 
4000 | 
2000 
a JF a. 
1986 2000 2006 
O Closed forest [1 Shrub 0 Open forest CJ Other forest C1 Total 
MPS 
  
  
  
  
$50 - 
300 - 
250 | 
200 | 
PD 
  
1986 2000 2006 
DJ Closed forest (3 Shrub &) Open forest CJ Other forest & Total 
  
  
  
   
  
    
   
   
   
    
     
    
   
    
   
   
   
   
   
   
   
  
  
  
  
   
   
    
    
   
   
  
  
   
    
   
  
     
   
   
    
    
	        
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