Democracy, Globalization and Private Investment in Ghana

The article examines the effects of democracy and globalization on private investment in Ghana for the period 1980–2012, using the autoregressive distributed lag (ARDL) bounds test for cointegration and the error correction model (ECM). Two models are used. In Model 1, democracy is proxy by an index for institutional quality (Polity 2), while Model 2 uses an index for civil liberties as proxy for democracy. The results for Model 1 show globalization and public investment increase private investment, while exchange rate volatility and trade openness decrease private investment in both the long and short run. In addition, national income and interest rate reduce private investment in the short run. In the case of Model 2, credit to the private sector and public investment increase private investment, while exchange rate volatility and trade openness decrease private investment in both the long and short run. Finally, national income and interest rate reduce private investment in the short run. The findings and policy recommendations of the article provide vital information for policy implementation in Ghana

Tropical terrestrial model ecosystems for evaluation of soil fauna and leaf litter quality effects on litter consumption, soil microbial biomass and plant growth Efeitos de fauna de solo e qualidade de liteira sobre o consumo, biomassa microbiana e crescimento de plantas em modelo de ecossistemas terrestres tropicais

The aim of this work was to evaluate whether terrestrial model ecosystems (TMEs) are a useful tool for the study of the effects of litter quality, soil invertebrates and mineral fertilizer on litter decomposition and plant growth under controlled conditions in the tropics. Forty-eight intact soil cores (17.5-cm diameter, 30-cm length) were taken out from an abandoned rubber plantation on Ferralsol soil (Latossolo Amarelo) in Central Amazonia, Brazil, and kept at 28ºC in the laboratory during four months. Leaf litter of either Hevea pauciflora (rubber tree), Flemingia macrophylla (a shrubby legume) or Brachiaria decumbens (a pasture grass) was put on top of each TME. Five specimens of either Pontoscolex corethrurus or Eisenia fetida (earthworms), Porcellionides pruinosus or Circoniscus ornatus (woodlice), and Trigoniulus corallinus (millipedes) were then added to the TMEs. Leaf litter type significantly affected litter consumption, soil microbial biomass and nitrate concentration in the leachate of all TMEs, but had no measurable effect on the shoot biomass of rice seedlings planted in top soil taken from the TMEs. Feeding rates measured with bait lamina were significantly higher in TMEs with the earthworm P. corethrurus and the woodlouse C. ornatus. TMEs are an appropriate tool to assess trophic interactions in tropical soil ecossistems under controlled laboratory conditions.<br>O objetivo deste trabalho foi avaliar o modelo de ecossistema terrestre (TME) como ferramenta para o estudo dos efeitos da qualidade da liteira, de invertebrados do solo e da fertilização mineral na decomposição da liteira e no crescimento das plantas em condições controladas. Foram coletados quarenta e oito cilindros de solo intacto (Latossolo Amarelo) de 17,5 cm de diâmetro e 30 cm de comprimento em um seringal abandonado na Amazônia Central brasileira e mantidos a 28ºC em laboratório, por quatro meses. Folhas da liteira de Hevea pauciflora (seringueira), ou de Flemingia macrophylla (leguminosa arbustiva) ou de Brachiaria decumbens (gramínea) foram colocadas na superfície do solo em cada TME. Em seguida, foram adicionados aos TMEs, cinco espécies de minhocas: Pontoscolex corethrurus ou Eisenia fetida; isópodes: Porcellionides pruinosus ou Circoniscus ornatus, e o diplópode Trigoniulus corallinus. O tipo de liteira afetou de forma significativa o consumo, a biomassa microbiana e a concentração de nitrato no líquido percolado de todos os TMEs, mas não apresentou efeito mensurável sobre a biomassa da parte aérea de mudas de arroz, plantadas em solo retirado da superfície dos TMEs. As taxas de alimentação da fauna edáfica, medidas por meio de lâminas-isca, foram signifitivamente mais altas nos TMEs com a minhoca P. corethrurus e com o isópode C. ornatus. O método TME se mostrou uma ferramenta apropriada para avaliar intrações tróficas em ecossistemas de solo tropical sob condições controladas de laboratório