An assessment of adherence to basic ecological principles by payments for ecosystem service projects.

Programs and projects employing payments for ecosystem service (PES) interventions achieve their objectives by linking buyers and sellers of ecosystem services. Although PES projects are popular conservation and development interventions, little is known about their adherence to basic ecological principles. We conducted a quantitative assessment of the degree to which a global set of PES projects adhered to four ecological principles that are basic scientific considerations for any project focused on ecosystem management: collection of baseline data, identification of threats to an ecosystem service, monitoring, and attention to ecosystem dynamics or the formation of an adaptive management plan. We evaluated 118 PES projects in three markets-biodiversity, carbon, and water-compiled using websites of major conservation organizations; ecology, economic, and climate-change databases; and three scholarly databases (ISI Web of Knowledge, Web of Science, and Google Scholar). To assess adherence to ecological principles, we constructed two scientific indices (one additive [ASI] and one multiplicative [MSI]) based on our four ecological criteria and analyzed index scores by relevant project characteristics (e.g., sector, buyer, seller). Carbon-sector projects had higher ASI values (P < 0.05) than water-sector projects and marginally higher ASI scores (P < 0.1) than biodiversity-sector projects, demonstrating their greater adherence to ecological principles. Projects financed by public-private partnerships had significantly higher ASI values than projects financed by governments (P < 0.05) and marginally higher ASI values than those funded by private entities (P < 0.1). We did not detect differences in adherence to ecological principles based on the inclusion of cobenefits, the spatial extent of a project, or the size of a project's budget. These findings suggest, at this critical phase in the rapid growth of PES projects, that fundamental ecological principles should be considered more carefully in PES project design and implementation in an effort to ensure PES project viability and sustainability.

Response to thyroxine of lamellar bodies, peroxisomes and peroxisomal enzymes in the adult rat lung.

Adult male rats were fed a standard diet containing 25 mg/kg L-thyroxine for 2 weeks. The hyperthyreotic condition of the animals was checked by monitoring the metabolic rates and liver glycerol-3-phosphate dehydrogenase. In the postnuclear fraction of the lung the activity of fatty acyl-CoA oxidase, the enzyme responsible for the rate limiting first step of peroxisomal fatty acid beta-oxidation, showed a twofold increase. Catalase, the marker enzyme of peroxisomes, showed a similar increase. Electron microscopic examination of alveolar type II cells did not reveal changes in the number and distribution frequency of peroxisomes and lamellar bodies. Similarly the content of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (dipalmitoyl phosphatidylcholine), the main constituent of alveolar surfactant, was not altered significantly by thyroxine feeding. On the other hand the volume density of the peroxisomal compartment was found to be doubled according to the measured increase of catalase and acyl-CoA oxidase. Our data suggest that the induction of peroxisomal matrix enzymes, such as catalase and fatty acyl-CoA oxidase, does not influence the surfactant content.