Impacts of Shade Trees on the Adjacent Cacao Rhizosphere in a Young Diversified Agroforestry System

Cacao agroforestry systems offer the potential to diversify farmer income sources, enhance biodiversity, sequester carbon, and deliver other important ecosystem services. To date, however, studies have emphasized field- and system-scale outcomes of shade tree integration, and potential impacts on the rhizosphere of adjacent cacao trees have not been fully characterized. Interactions at the root–soil interface are closely linked to plant health and productivity, making it important to understand how diverse shade tree species may affect soil fertility and microbial communities in the cacao rhizosphere. We assessed the impacts of neighboring shade tree presence and identity on cacao yields and physical, chemical, and biological components of the cacao rhizosphere in a recently established diversified agroforestry system in South Sulawesi, Indonesia. Stepwise regression revealed surprising and strong impacts of microbial diversity and community composition on cacao yields and pod infection rates. The presence of neighboring shade trees increased nitrogen, phosphorus, and pH in the rhizosphere of nearby cacao trees without yield losses. Over a longer time horizon, these increases in rhizosphere soil fertility will likely increase cacao productivity and shape microbial communities, as regression models showed nitrogen and phosphorus in particular to be important predictors of cacao yields and microbiome diversity and composition. However, neither presence nor identity of shade trees directly affected microbial diversity, community composition, or field-scale distance-decay relationships at this early stage of establishment. These results highlight locally specific benefits of shade trees in this agroecological context and emphasize the rhizosphere as a key link in indirect impacts of shade trees on cacao health and productivity in diversified systems.

PERFORMANCE OF BIOCLIMATIC ARCHITECTURE IN BUGIS VERNACULAR HOUSING: A CASE STUDY OF JIDA AND LAMMADA HOUSES

Bioclimatic architecture is composed of climate-responsive knowledge in vernacular buildings as an effort to create comfortable conditions. This study aims to evaluate the suitability of the application of bioclimatic design to the performance of the thermal environment in one type of Bugis house. The method used is visual assessment and measurement of temperature and humidity in the case studies of Jida and Lammada houses, South Sulawesi. The results of visual observations show the accuracy of the bioclimatic design on the volume and slope elements of the roof; wall type and material; floor height and shade tree layout. The performance of the thermal environment in the living room and bedroom of Lammada house is better than similar rooms at Jida house. The bioclimatic elements that affect the performance of the thermal environment are the volume of the roof, the type and material of the walls and the height of the floor.

Assessment of Coffea Shade Value through Comparison of Mountainous Area with Farm Land Coverage, in Arsi Gololcha District, Oromia, Ethiopia

Coffea cultivation with shade tree is used for improving soil health, increasing coffea production, sustaining agro ecology. The study was attended in two kebele, on 36 farmers’ fields, at Gololcha district of East Arsi zone. The study was intended to assess the influence of coffea shade trees on farm lands versus mountainous area. Household interviews were used to get imperative separately, i.e. from old farmers, middle age farmers and young farmers. Significant difference value was observed between farm land and mountainous area coverage. Based on this respondents’ idea, before 25-30 years; the ‘condition of tree coverage at mountainous’ area in Arsi Gololcha district was ‘medium condition’ but not normal that means as deforestation of mountainous area have been starting before 30 years’ time; while the condition of tree coverage at farmland area also has been starting before 30 years’ time. The third respondents’ idea was interpreted with the real situation of the district, that it gave us a constructive inspiration on the role of coffea shade tree to enable the farm land to be taken as regular natural forest. The existing coffea shade trees are Cordia africana followed by Erythrina abyssinica and Acacia senegal. Farmers accounted 95% of coffea shade users and 4.6% without shade users. The respondents said that even if the rainfall intensity is increasing at farmland rather than mountainous area occasionally due to shade tree effect. On the contrary side, mountainous area exposed to deforestation since the farmers have been shifting to hilly side for their livelihood dependency.

Growing Energy Conservation Through Residential Shade Tree Planting

Urban residential shade trees extenuate the heating of buildings in the summertime by intercepting insolation and by evapotranspirative cooling of their immediate surroundings. By modifying location-specific climate data, and tree growth characteristics, this research adapts the Sacramento Municipal Utility District’s (SMUD) Tree Benefits Estimator for application in Toronto, Canada. This tool is then put to use modeling the energy conservation savings delivered by 577 trees planted in Toronto backyards between 1997 and 2000. This study’s results estimate that the trees contributed 77,139 kWh of electricity savings as of 2009, 54.4% of which was due to shading of neighbouring houses. This study’s findings indicate that urban residential tree planting programs should not focus exclusively on location-driven strategic planting to yield large energy conservation benefits. Instead, it is argued that priority should be given to selecting planting locations that will maximize tree survival as neighbourhood energy conservation benefits of a tree that achieves mature stature often outweigh the homeowner-specific benefit of a strategically planted tree.