Browsing by Author "Salamanca, Eric F."

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    Agroforestry practices in a critical watershed
    (Journal of Agriculture and Rural Development in the Tropics and Subtropics, Supplement, 2005-08) Salamanca, Eric F.; Muuss, Uwe
    Agroforestry involves the systematic integration of tree crops and agricultural/food crops under one management scheme. This land-use system is practiced in the hillsides of the tropics but thought in the past to be inappropriate in critical watersheds. This paper aims to present various agroforestry practices in the Kaliwa watershed in the Philippines which is considered as critical. It is located in the municipalities of Tanay and Gen. Nakar in the provinces ofRizal and Quezon, respectively. It covers an area of 27,608 hectares. The area is characterized by various land uses, landscapes, vegetation and rivers. About 7000 poor rural households or approximately 37,868 individuals in the eight villages inhabit inside in the watershed. To improve the ecological well being of the watershed while enhancing the socio-economic status of the forest occupants, the government adopted a land-use system called agroforestry. It focuses on the integration of forest tree crops, agricultural crops, small-ruminants, native chicken, fish and other components in one management system. The land use system is designed to allow the production of crops to meet their immediate needs of a family without sacrificing environmental sustainability. Various agroforestry farming systems were set up in different villages. Nitrogen fixing tree species, botanical pesticide tree, vetiver grass (for erosion control) horticultural fruit trees were planted. The alleys were planted with mungbean, soybean, pineapple rice and corn. Goat and sheep were raised using the concept of cut-and-carry system. Native chicken are raised to provide egg and meat for the farmers. The integration of fish production and tree growing are established Nitrogen trees were planted around the aqua-silviculture pond. Other crops such as Tiger grass are planted in the alley to reduce soil erosion and the flowers can be made into soft brooms, thus augmenting farm income while minimizing soil erosion. All organic materials such as litter fall, trimmings, weeds and the like are chopped/shredded and decomposed with the help of native surface-earthworms. The vermin-composts were applied to the vegetables or other crops. The agroforestry practices that were introduced in the watershed are adopted by the farmers with great enthusiasm.
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    Mixed leaf litter effects on decomposition rates and soil microarthropod communities in an oak-pine stand in Japan
    (Ecological Research, 1999) Kaneko, Nobuhiro; Salamanca, Eric F.
    Rates of decomposition, and soil faunal abundance and diversity associated with single‐species and mixed‐species litters were studied in a litter bag experiment in an oak–pine forest. We used two canopy species of leaf litter, pine and oak, and one shrub species, Sasa , and compared decomposition rates, and soil microarthropod abundance and community structure of oribatid mites in the litter bags. Mass loss of single species decreased in the order: oak > pine > Sasa . While the total mass loss rates of mixed litter were intermediate between those of the constituent species, enhancement of mass loss from the three‐species mixture and from mixed slow‐decomposing litters (pine and Sasa ) was observed. Faunal abundance in litter bags was higher in mixed‐species litter than in those with single‐species litter, and species richness of oribatid mites was also higher in the three‐species mixed litter. Faunal abundance in single‐species litter bags was not correlated with mass loss, although enhancement of mass loss in mixed litter bags corresponded with higher microarthropod abundance. Habitat heterogeneity in mixed litter bags seemed to be responsible for the more abundant soil microarthropod community.
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    Rainfall manipulation effects on litter decomposition and the microbial biomass of the forest floor
    (Applied Soil Ecology, 2003) Salamanca, Eric F.; Kaneko, Nobuhiro; Katagiri, Shigeo
    Simple structures aimed at regulating the amount of rain water dropping into the forest floor were installed to determine the impact of rainfall on leaf litter mass loss, respiration rates, microbial biomass C (Cmic) and metabolic quotient (qCO2). The rainfall manipulation treatments were (I) fully covered (100% reduction); (II) partially covered (50% reduction) and (III) control (fully exposed). Using the litterbag technique, the mass losses of covered Quercus serrata, Quercus acutissima, Acer rufinerve and Pinus densiflora leaf litter were reduced (P < 0.01) by 19–26% compared to fully exposed litter. A positive linear relationship (r = 0.90; P < 0.0001) between litter Cmic and mass loss was noted across all litter types and covering regimes. The mass losses in fully exposed litter were attributed to the leaching effect of rainfall coupled with the synergistic actions of microbes and soil fauna, as suggested by their respiration and microbial biomass. In the covered litter, Cmic was generally reduced (P < 0.01) while fully and partially exposed litter were comparable (P > 0.05). On the other hand, respiration rates and qCO2 were variable and showed no consistent treatment effect except for respiration rates at 3 months. Similarly, soil respiration rates and Cmic were not consistently affected by cover treatments. Evidently, the zero-rainfall condition negatively affected some biological processes in the litter layer but sporadically affected soil processes. The absence of rainfall, even if the soil moisture content was maintained, could affect organic matter turnover in the forest floor.