Quantitative and qualitative characteristics of greenery in suburban residential districts of Metro Manila

This case study was conducted to better understand the present situation of urban greenery in Marikina City, in the suburbs of metropolitan Manila, a typical large Asian city. A vegetation survey was conducted in residential districts of Marikina City, and the quantitative and qualitative characteristics of trees were analyzed. Lot size had some influence on the quantity of greenery in residential lots. In smaller lots, however, quantity did not increase in proportion to lot size. It appears, then, that the land-use controls for individual lots did not function effectively. Quantitative differences of greenery were related to qualitative differences, depending on the year or period of development of the residential area. In the newly developed residential lots, the greenery is comprised mostly of ornamental trees. Under the present circumstances, there is no assurance of sustaining the desired quantity of greenery in smaller residential lots. From these results, we proposed that regulations on lot size/coverage and promotion of tree planting involving local residents are needed to sustain urban greenery in residential districts

Improving crop productivity in agroforestry systems: low leaf respiration is a key trait

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ENVIRONMENTAL VARIABLES ASSOCIATED WITH INVASIVE GLOSSY BUCKTHORN (FRANGULA ALNUS MILL.) AND INDIRECT CONTROL STRATEGIES FOR FOREST MANAGERS

Glossy buckthorn (Frangula alnus Mill.) is one of the most prominent non-native invasive plant species affecting New England forests. It quickly invades a forest and can create a dense understory effectively altering the species composition and dynamics of that forest. To gain a better understanding of the environmental variables associated with glossy buckthorn density we sampled forests across New Hampshire with varying degrees of buckthorn invasion. The effect on tree regeneration was analyzed with measurements of height and abundance of glossy buckthorn and native regeneration. Glossy buckthorn was found to be at its highest densities in disturbed softwood forests that were historically old fields, specifically eastern white pine (Pinus strobus L.), with a thin organic layer and low herbaceous cover on drained loam and clay soils. The data show there is direct competition between glossy buckthorn and forest tree regeneration, although no relationship with regeneration shade tolerance was found. This information was used to create a prescription risk tree to aid forest managers in assessing the risk of buckthorn invasion and inhibition of tree regeneration associated with harvesting and suggests how to adapt their silvicultural prescriptions