Long-term dynamics of woodland vegetation with response of climate variability in the lowlands of north western part of Ethiopia

Vegetation is one of the main earth's surface resources. It serves as a bridge among some earth's components like soil, atmosphere and water cycle. It is the most sensitive indicator of seasonal change and environmental degradation. Analysis of terrestrial vegetation dynamics allows a better understanding of climate effects on terrestrial ecosystems. Vegetation growth is influenced by the climate conditions. But, there is a debate whether woodland vegetation decreases or increases in the study area. The area was selected purposely where vegetation is sensitive too much to precipitation (RF) and relative humidity (RH). LANDSAT image has been selected from United State Geological Survey website. Starting 1984-2014 period collection of LANDSAT image with TM, ETM scanner has designed for normalized difference vegetation index (NDVI) analysis. Meteorological data were collected from Ethiopian Methodological Agency. The maximum value of NDVI was computed using ERDAS 2010 and ArcGIS10.2 software. It was analyzed with meteorological data by multiple regression analysis approach using R-statistical package. Statistical analysis result showed that woodland vegetation NDVI value and RH had positive correlation with precipitation while temperature was negative. It indicated that precipitation and woodland vegetation have strong relationship. Precipitation was significant key factor for woodland vegetation. The value of R-2 = 0.71 and P < 0.05 showed us NDVI could contribute significantly for climate variability. Spatial and temporal dynamics of woodland vegetation was found greater in the semiarid area. This was due to sensitivity nature of woodland vegetation and fire experience of the study area. Therefore, woodland's vegetation was highly sensitive to climate factor's variability and seasonal change.

Automated summary

This study analyzed the dynamics of woodland vegetation and its relationship with climate factors, focusing on the impact of precipitation and relative humidity on woodland vegetation. Statistical analysis results showed that precipitation was a significant key factor for woodland vegetation, indicating a strong relationship between precipitation and woodland vegetation.