Abstract:
Land degradation has been a major challenge of environmental problem in highlands of Ethiopia.
In East Shewa, as part of the government responses to land degradation, area closure has been
mainly implemented to improve land management and the sustainability of environmental
resources. This study was initiated with the objective of investigating the effect of area closure on
selected physicochemical properties of soils and woody species diversity in Warja watershed,
Adami Tulu Jido Kombolcha districts, East Shewa. Systematic sampling method was employed to
take vegetation and soil sample. Sampling plot of 20mx20m was established for quantitative data
for both vegetation data and soil samples. Sample of woody species, regeneration and soil were
taken from both area closure and adjacent open grazing land. The soil samples and vegetation
data were taken from 9 plots for each site. Both disturbed and undisturbed soil samples were
collected from topsoil (0-30 cm and soil laboratory analysis were done for bulk density, soil
texture, soil moisture, soil PH, Av. P, Av. K, total N, CEC, Mg+2, K+, Ca+2, Na + and EC. These
data were analyzed by using Excel spreadsheet and SPSS software. Also independent t-test was
employed to evaluate the significance level. The analyzed data of all soil physicochemical
properties were shown significant differences except soil texture class, Mg+2 and K+. The total
density of individuals woody species in the area closure and adjacent open grazing land were
938.75/ha and 352.75/ha respectively. The diversity of all woody species in area closure was
greater than in the adjacent open grazing land. The total density of regeneration in study site were
1,056.5 /ha. Out of this, the regeneration species in area closure were 867.75/ha while the density
of regeneration in adjacent open grazing land were 197.75/ha. The in area closure total mature
trees were greater > seedlings >sapling. Both species diversity and regeneration of vegetation in
adjacent open grazing land and area closure revealed significant difference. Therefore, this study
comes up with the evidence that the establishment of area closure improved woody species
diversity and soil physicochemical properties of degraded land of the study area. Thus, area
closure plays a key role to rehabilitate woody vegetation diversity and soil qualities of degraded
land. This study did not assess the status of herbaceous plant species diversity and the extent to
which enclosures in the study area could reduce soil loss compared to open grazing lands. So
other researcher can be to assess area closure will significant or not.
