Biomass Equations for Tropical Tree Plantation Species Using Secondary Data from the Philippines

Estimation of the magnitude of sinks and sources of carbon requires reliable estimates of the biomass of forests and of individual trees. Equations for predicting tree biomass have been developed using secondary data involving destructive sampling in plantations in several localities in the Philippines. These equations allow estimates of carbon sequestration to be made at much lower cost than would be incurred if detailed stand inventories were undertaken. The species included in the study reported here include Gmelina arborea, Paraserianthes falcataria, Swietenia macrophylla and Dipterocarp species in Mindanao; Leucaena leucocephala from Laguna, Antique, Cebu, Iloilo, Rizal, and Ilocos Sur, and Acacia mangium, Acacia auriculiformis and G. arborea in Leyte. Non-linear regression was used to derive species-specific, site-specific and generic equations between yield and diameter of the form y = aDb. Equations were evaluated based on the correlation coefficient, standard error of the estimate and residual plots. Regressions resulted to high r values (>0.90). In some cases, non-homogeneous variance was encountered. The generic equation improved estimates compared with models used in previous studies

Carbon Storage and Sequestration Potential of Smallholder Tree Farms on Leyte Island, the Philippines

The role of terrestrial ecosystem in mitigating the effects of climate change entails the assessment of carbon stocks in various pools. This study predicts the carbon storage and sequestration potential of common tree farm species in Leyte Island, the Philippines. Data gathered from field measurements has been used to fit the Chapman-Richards growth function to predict the volume and biomass increment of Gmelina arborea and Swietenia macrophylla tree farms until they reached their respective rotation ages. Biomass and carbon density values are found to vary with age, type of species, site conditions and silvicultural treatments applied in the stand. Although differences in year when the trees were planted had no relation with its soil carbon storage, this pool had greater storage capacity than the above-ground biomass and roots. The average maximum growth was attained after 10 years for G. arborea and 13 years for S. macrophylla. Volume growth started to slow down when the tree species reached almost half its rotation age. The same trend was observed for the biomass and carbon density of each farm. The maximum mean annual increment of both species was attained before the expected maximum growth year. Growth increment decreased as the species reached their rotation age. The total C storage capacity of a 15-year-old G. arborea tree farm was estimated at 64 MgC/ha while that of a 25-year-old S. macrophylla was estimated at 159 MgC/ha. The average carbon sequestration rate of both species was 5 MgC/ha/yr which is lower than the average rate of most tree plantation species in the Philippines. With almost 2 M ha of grasslands in the country, establishing tree farms is a strategy to attain the national goal on sustainable development and at the same time reduce the greenhouse gases (GHGs) emissions

Biomass equations for tropical tree plantation species in young stands using secondary data from the Philippines

Estimation of the magnitude of sinks and sources of carbon requires reliable estimates of the biomass of forests and of individual trees. Equations for predicting tree biomass have been developed using secondary data involving destructive sampling in plantations (mostly less than 10 years of age) in several localities in the Philippines. These equations allow estimates of carbon sequestration to be made at much lower cost than would be incurred if detailed stand inventories were undertaken. The species included in the study reported here include Gmelina arborea Roxb., Paraserianthes falcataria (L.) Nielsen Swietenia macrophylla King and Dipterocarp species in Mindanao, and Leucaena leucocephala de Wit from Laguna, Antique, Cebu, Iloilo, Rizal, and Ilocos Sur. Non-linear regression was used to derive species-specific, site-specific and generic equations between yield and diameter of the form y = D. Equations were evaluated based on the correlation coefficient, standard error of estimate and residual plots. Regressions resulted in high r values (>0.90). In some cases, non-homogeneous variance was encountered. The generic equation improved estimates compared with models used in previous studies

Carbon storage and sequestration potential of small holder tree farms

The role of terrestrial ecosystem in mitigating the effects of climate change entails the assessment of carbon stocks in various pools. This study predicts the carbon storage and sequestration potential of common tree farm species in Leyte Island, the Philippines. Data gathered from field measurements has been used to fit the Chapman-Richards growth function to predict the volume and biomass increment of Gmelina arborea and Swietenia macrophylla tree farms until they reached their respective rotation ages. Biomass and carbon density values are found to vary with age, type of species, site conditions and silvicultural treatments applied in the stand. Although differences in year when the trees were planted had no relation with its soil carbon storage, this pool had greater storage capacity than the above-ground biomass and roots. The average maximum growth was attained after 10 years for G. arborea and 13 years for S. macrophylla. Volume growth started to slow down when the tree species reached almost half its rotation age. The same trend was observed for the biomass and carbon density of each farm. The maximum mean annual increment of both species was attained before the expected maximum growth year. Growth increment decreased as the species reached their rotation age. The total C storage capacity of a 15-year-old G. arborea tree farm was estimated at 64 MgC/ha while that of a 25-year-old S. macrophylla was estimated at 159 MgC/ha. The average carbon sequestration rate of both species was 5 MgC/ha/yr which is lower than the average rate of most tree plantation species in the Philippines. With almost 2 M ha of grasslands in the country, establishing tree farms is a strategy to attain the national goal on sustainable development and at the same time reduce the greenhouse gases (GHGs) emissions

Marketing Benefits Derived from Clustering: the Case of Vegetable Clusters in Mindanao

One of the most limiting constraints for improving the profitability of smallholder vegetable farmers is poor marketing. With the lack of knowledge and inability to negotiate with downstream buyers, farmers have little option other than to sell their products to the traditional market. To facilitate access to technical information, credit and institutional markets, smallholder farmers are forming collaborative marketing groups. Clustering is one form of collaborative marketing in which smallholder farmers are organized into small groups within a defined territory or geographic area. Using the CRS Eight Step Plan for Agro-enterprise Development, 29 clusters were formed in three provinces in the Southern Philippines. This study explores the various marketing benefits smallholder farmers have achieved after joining the cluster. After interviewing 61 vegetable farmers from 10 clusters using a structured questionnaire, results show that upon joining the cluster, farmers became more aware of their buyer’s preference for product quality and gained knowledge on how to properly handle and package their produce. Cluster farmers increased their income from vegetable farming by selling a greater product variety, a larger volume and gaining access to high value markets

An amphitropic cAMP-binding protein in yeast mitochondria

ABSTRACT: We describe the first example of a mitochondrial protein with a covalently attached phos-phatidylinositol moiety acting as a membrane anchor. The protein can be metabolically labeled with both stearic acid and inositol. The stearic acid label is removed by phospholipase D whereupon the protein with the retained inositol label is released from the membrane. This protein is a cAMP receptor of the yeast Saccharomyces cereuisiae and tightly associated with the inner mitochondrial membrane. However, it is converted into a soluble form during incubation of isolated mitochondria with Ca2+ and phospholipid (or lipid derivatives). This transition requires the action of a proteinaceous, N-ethylmaleimide-sensitive component of the intermembrane space and is accompanied by a decrease in the lipophilicity of the cAMP receptor. We propose that the component of the intermembrane space triggers the amphitropic behavior of the mitochondrial lipid-modified CAMP-binding protein through a phospholipase activity. Only in recent years specific fatty acids have been recog-nized to play important roles in the association of proteins with membranes. Both noncovalent and covalent interactions be-tween fatty acids and proteins have been reported. Among the latter are GTP-binding proteins (Molenaar et al., 1988)