Seasonal variation of litter arthropods in some Eucalyptus plantations at the Arboretum of Ruhande in Rwanda

Abstract

The main objective of this study was to assess the seasonal variation of litter arthropods in seven Eucalyptus plantation types and native Entandrophragma excelsum stands at the Arboretum of Ruhande, Rwanda.  Arthropods were collected using the 1m² square pick–up point technique, killed using 10% formalin solution, and transported to the laboratory for identification to the class level. The results indicate that the collected arthropod individuals belong to five classes. Seasonality exerted a strong effect on the abundance and diversity of litter arthropods. In total, 2828 arthropod individuals were collected in September 2012, 3458 individuals in January 2013 and 4005 individuals in April 2013. The Class of insects was the most abundant with relative frequency of 54.8%, 77.3% and 76.6% in September 2012, January 2013, and April 2013 sampling periods. The negative effect of Eucalyptus plantations on arthropods abundance was not exclusively confirmed by the results as some stands of Eucalyptus species had arthropod abundance comparable to those under native Entandrophragma excelsum stands. It is recommended to replicate this study under forest plantations located in other ecological zones in Rwanda, which will generate general information for better conservation of arthropod diversity in Rwanda. It is also recommended to continue arthropod classification at family, genus and species levels.

Keywords: Litter arthropods; Arthropod abundance; Arthropod diversity.