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close this book Measuring drought and drought impacts in Red Sea Province
close this folder 8. Changes in tree density on five sites in Red Sea Province: early 1960s to 1989. Roy Cole
View the document Summary
View the document Introduction
View the document Methods used in the study
View the document The study sites
View the document Results
View the document Conclusion
View the document Discussion
View the document Limitation of the study
View the document References
View the document Appendix 10.1. Charcoal dealers by quarter and size class, Port Sudan, August 1988.
View the document Appendix 10.2. Total stock of charcoal per class of dealer by quarter, Port Sudan, August 1988.
View the document Appendix 10.3. Some characteristics of charcoal production and trade.
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Results

Change in tree densities on the five sites varied; for three sites the change was dramatic and negative, for one site change was moderately negative, and for one site change was slightly positive. The greatest differences were for those sites closest to Port Sudan. The following table presents the counts from the aerial photographs and ground observation for all five sites.

Table 8.1. Tree counts on five sites In Red Sea Province, 1960s and 1989.

Site Percent

 

1960s

6/7 1989

 

Change

1. Khor Akwaat Site One

Line 1 293

47

-246

-84

Line 2 279

95

-184

-66

Line 3 252

136

-116

-46

2. Khor Akwaat Site Two

Line 1

274

0

-274

-100

Line 2

246

0

-246

-100

Line 3

228

123

-105

-46

3. Khor Oko

54

36

-18

-33

4. Khor Sitareb

108

112

4

4

5. Khor Nubahawayb

159

139

-20

-13

Table 8.2 below presents a summary of the site results and an additional variable, distance from Port Sudan.

Table 8.2. Percent change In tree density, early 1960s to 1989, by site and distance from Port Sudan.

Site

Percent

Distance from

 

Change

Port Sudan

Sites One and Two

-59

30

Site Five

-13

115

Site Four

+4

140

Site Three

-33

170

 

Khor Akwaat

As is evident from Table 8.1, there have been some dramatic changes in tree density and distribution in the Akwaat study area since the early 1960s. All of this change has been negative.

Average density for Site One dropped 66 percent during the 25 year period The drop in Site Two over the same period was 84 percent. The decrease in density was not distributed equally over the three lines of each site. There was an 84, a 66, and a 46 percent decrease in the tree densities of lines one, two and three respectively of Site One. The change for Site Two was dramatic for lines one and two. These lines each decreased 100 percent. Line three decreased 46 percent.

In 1963 the trees were denser near the khor and became less dense with distance from the khor. In Site One at that time density dropped 13 percent from lines one to three. In Site Two as well, density dropped 17 percent from lines one to three. In 1989 this situation was reversed. Although overall density declined throughout the transects, the relative density of trees today is greater with distance from the khor. Line one in Site One in 1989 contained 65 percent less trees than line three. In Site Two the difference between 1963 and 1989 was 100 percent less. The figures below illustrate these differences.


Figure 8.1. Tree densities on site one in 1963 and 1989.


Figure 8.2. Tree densities on site two In 1963 and 1989.

Khor Oko

The site in Khor Oko had a 33 percent decline in tree density from the 1965 to 1989. The following figure illustrates both distributions.


Figure 8.3. Tree densities on site three In 1965 and 1989.

Khor Sitareb

The pattern of vegetation change at the Khor Sitareb site was one of slight increase. The figure below presents the densities for both periods.


Figure 8.4. Tree densities on site four in 1965 and 1989.

Khor Nubahawayb

Tree density declined modestly on site five. The figure below presents the results for this site.


Figure 8.6. Tree densities on site five In 1965 and 1989.