A multi-method approach for the integrative assessment of soil functions: Application on a coastal mountainous site of the Philippines.

The projected increase of the world's population and the sustainability challenges the agricultural sector is facing, call for the enhancement of multi-functionality in agriculture in order to simultaneously provide food while meeting environmental targets. Here, we use the Functional Land Management (FLM) framework to assess the supply of and the demand for soil functions to inform agri-environmental policy for Udalo, a mountainous site in the Philippines. As many emerging communities in developing nations, Udalo is on the cusp of rapid development due to the construction of a major road increasing its accessibility and attractiveness for land investment. We assessed the supply of four soil functions in relation to six land-use types and four slope categories. The function "productivity" was assessed by interviews with 128 farmers, "habitat for biodiversity" by a vegetation survey, and "soil conservation" and "water conservation" via a literature review. The demand for functions was first assessed from the "top-down" policy perspective via interviews and reviews of policy targets, then complemented by integrating the local "bottom-up" demands for functions. These were assessed by applying a Q methodology, providing insights in the prioritisation of functions from the perspective of 22 local actors. Maps of supply and demands were generated for each function: supply maps by overlaying land use and slope category, top-down demand maps from administrative zoning/land-use plans, and bottom-up demand maps from local actors designation of geomorphological areas. Our results revealed contrasting demands for functions, as well as a heterogeneous spatial distribution of supply and demands. Discrepancies emerged (i) between supply and demand, (ii) between bottom-up (local) demands and the top-down (policy driven) demand, and (iii) among local actors perspectives. Our study indicates that discrepancies are not necessarily conflicting, but can uncover pathways for defining compromises, representing attainable policy entry points. Not one single development model can meet the needs of every stakeholder; however, a combination of land uses and management strategies can meet divergent interests and allow for optimisation of functions. This integrative approach of FLM provides a socially embedded biophysical analysis and is a valuable tool for the design of customized land-use and agri-environmental policies.

Using deep-belief networks to understand propensity for livelihood change in a rural coastal community to further conservation.

Overharvesting of terrestrial and marine resources may be alleviated by encouraging an alternative configuration of livelihoods, particularly in rural communities in developing countries. Typical occupations in such areas include fishing and farming, and rural households often switch livelihood activities to suit climate and economic conditions. We used a machine-learning tool, deep-belief networks (DBN), and data from surveys of a rural Philippine coastal community to examine household desire to change livelihood. This desire is affected by a variety of factors, such as income, family needs, and feelings of work satisfaction, that are interrelated in complex ways. In farming households, livelihood changes often occur to diversify resources, increase income, and lessen economic risk. The DBN, given its multilayer perceptron structure, has a capacity to model nonlinear relationships among factors while providing an acceptable degree of accuracy. Relative to a set of 34 features (e.g., education, boat ownership, and work satisfaction), we examined the binary response variables desire to change work or not to change work. The best network had a test set accuracy of 97.5%. Among the features, 7 significantly affected desire to shift work: ethnicity, work satisfaction, number of persons in a household in ill health, number of fighting cocks owned, fishing engagement, buy-and-sell revenue, and educational level. A cross-correlation matrix of these 7 features indicated households less inclined to change work were those engaged in fishing and retail buying and selling. For fishing, provision of economic and other incentives should be considered to encourage changing from this occupation to allow recovery of fishery resources.

Uso de Redes de Creencia Profunda para Entender la Predisposición por el Cambio en el Medio de Vida en una Comunidad Rural Costera para Promover la Conservación Resumen La sobrexplotación de los recursos terrestres y marinos puede ser mitigada promoviendo una configuración alternativa de los medios de vida, particularmente en las comunidades rurales de los países en desarrollo. Las ocupaciones típicas en dichas áreas incluyen la pesca y la agricultura, y los hogares rurales comúnmente alternan entre estas actividades de sustento para ajustarse a las condiciones climáticas y económicas. Usamos una herramienta de aprendizaje automático, redes de creencia profunda (RCP) y datos tomados de censos aplicados a una comunidad rural costera en las Filipinas para examinar el deseo de cada hogar por cambiar su medio de vida. Este deseo se ve afectado por una variedad de factores, como el nivel de ingreso, las necesidades familiares y la sensación de satisfacción laboral, que están interrelacionados de maneras complejas. En los hogares agricultores, los cambios en el medio de vida ocurren con frecuencia para diversificar los recursos, aumentar el ingreso y disminuir el riesgo económico. Las RCP, dada la estructura multicapa de su perceptrón, tiene una capacidad para modelar las relaciones no lineales entre los factores mientras proporciona un grado aceptable de precisión. En relación con un conjunto de 34 caracteres (p. Ej.: educación, propiedad de navíos, satisfacción laboral), examinamos las variables de respuesta binaria deseo cambiar de trabajo y no deseo cambiar de trabajo. La mejor red tuvo una precisión de conjunto de pruebas del 97.5%. Entre los caracteres, siete afectaron significativamente el deseo por cambiar de trabajo: la etnicidad, la satisfacción laboral, el número de personas con mala salud en un mismo hogar, el número de gallos de pelea en su propiedad, la participación dentro de la pesca, los ingresos por compra y venta, y el nivel educativo. Una matriz de correlación cruzada de estos siete caracteres indicó que los hogares con una menor tendencia hacia el cambio de trabajo fueron aquellos que participan en la pesca y en la compra y venta al menudeo. Para la pesca, el suministro de incentivos económicos y de otros tipos debería considerarse para promover el cambio de esta ocupación y así permitir la recuperación de los recursos pesqueros.

One-ecosystem analysis for environmental conservation and sustainable livelihood.

In order to achieve the objectives of resource conservation, it is important to recognize that habitats are connected by material and energy flows, and that humans often play a central role, directly or indirectly. Hence, ecological research should be designed that treats all interlinked habitats, including human populations, as one ecosystem. Examples would be coastal habitats that are impacted by effluent from the upland, which in turn can be generated by deforestation and harmful agricultural practices. All of these aspects, including the river systems that deliver run-off, should be included in the investigation. This approach entails a carefully articulated hypothesis or set of hypotheses drawing on the natural as well as social sciences, and an appropriate sampling and statistical design. It clearly imposes high demands on resources, financial and otherwise. But the continued compartmentalization of efforts along disciplines and specializations will likely slow down progress in environmental conservation.

Effects of multiple perturbations on the survivorship of fragments of three coral species.

Fist-sized fragments of Porites cylindrica, Porites rus and Pavona frondifera were deployed in single-species (P. cylindrica) and mixed-species (all three) plots in a shallow reef area in the northwestern Philippines. After 6 months, the corals in half of the plots were broken into smaller pieces to simulate an episodic physical disturbance. The survival of all corals was monitored from March 2000 to July 2001 during which the corals experienced 2 typhoons and episodes of algal overgrowth. For both intact and broken treatments, there was significantly higher survival in the mixed-species plots than in the single-species treatments. Fragment mortality varied between disturbances of varying frequencies and magnitudes, namely: one-time fragmentation stress, seasonal overgrowth by cyanobacteria and macroalgae, short-term (1 day) and long-term (more than 1 week) burial. The mixed-species assemblages had higher fragment survivorship than the monospecific assemblages during small-scale perturbations (e.g., algal overgrowth), but not in the face of subsequent, larger scale disturbances. This study emphasizes that coral responses to disturbance are both species- and context-specific.

Survivorship of coral juveniles in a fish farm environment.

Intensive fish farming is an emerging coastal activity that can potentially enhance sedimentation and promote eutrophication in fringing coral reefs. Here, we investigate the effect of fish farm effluent on the juvenile survivorship of the reef-building coral Seriatopora caliendrum. One-month old juvenile corals (on terracotta tiles) were deployed in fish farm and reference (reef) sites in Bolinao, the Philippines at a depth of 2m. After forty days, no survivor was recovered in the fish farm, while survivorship was low (11%) in the reference site, with the survivors' growth rate at 3.3polypsmo(-1) or 1.3mm(2)mo(-1). The fish farm deployed tiles were covered with muddy sediment and were colonized by barnacles, whereas those in the reference site were overgrown by a short stand of filamentous macroalgae. Environmental monitoring revealed higher nutrient levels (ammonia and phosphate), sedimentation rate, and organic matter flux, as well as diminished water transparency and dissolved oxygen levels in the fish farm compared to the reference site. Hence, intensive fish farming offers a suite of physical, chemical and biological modifications of the coastal marine environment which have a detrimental effect on the survivorship of coral juveniles.

Differential survival of coral transplants on various substrates under elevated water temperatures.

Closely related scleractinian coral species that exhibited similar survival patterns under relatively normal field conditions responded very differently to the occurrence of an environmental disturbance. The two species studied were Porites cylindrica and Porites rus which occur in the same reef zones in shallow reef flats. Transplants of both species were evenly distributed and attached to three different types of substrate: live coral colonies of P. cylindrica, dead coral colonies (also of P. cylindrica), and epoxy coated metal grids that were raised above the sandy substrate. With the onset of above-normal water temperatures due to the El Niño episode of 1998, P. cylindrica transplants immediately showed signs of bleaching stress and tissue necrosis, followed by algal overgrowth and mortality soon afterwards. In contrast, transplants of P. rus bleached more slowly and suffered less mortality, with a few actually showing signs of recovery at the end of the experimental period which covered a total of 14 weeks. These differences in responses could be attributed to properties of the symbiotic zooxanthellae, of the host coral tissue itself, or both. Over-all, survival was good on the metal grids (average of 35%), and on the live coral (average of 22%). It was poor on the dead coral (average of 6%). The metal grids as well as live coral tissue apparently provided a favorable substrate for the attached coral fragments, even for those of a different species. Under the conditions of this particular study, attachment of live coral fragments on already dead colonies for the purpose of increasing live coral cover on the reef did not yield favorable results. This is an area that requires further investigation.

Comparison of coral growth and survival under enclosed, semi-natural conditions and in the field.

Two closely related scleractinian coral species, Porites cylindrica and Porites rus, were transplanted to two different locations: the natural environment on the reef flat, and culture tanks on land. The use of tanks enabled the regulation of certain environmental factors, and, hence, the evaluation of specific responses of the corals to these factors. For both species, growth and survival were much better in the field than in the land-based tanks most probably due to unrestricted water circulation. Since the two species were subjected to identical experimental treatments, it was possible to distinguish inherent differences between them in terms of responses to external variables. Porites cylindrica was more susceptible than P. rus to predation by corallivores. Predators, as well as grazers, occurred in significant numbers in the field, but not in the land-based tanks. Porites rus, on the other hand, succumbed more readily to overgrowth by macroalgae which thrived in the culture tanks presumably because of significantly higher nutrient levels and the conspicuous absence of grazers. These results have broader ecological implications because of accelerated environmental changes taking place in present-day reefs due to human impact. Major examples are eutrophication and alterations in water circulation which frequently result in sub-optimal conditions for coral survival and growth.