Five challenges to reconcile agricultural land use and forest ecosystem services in Southeast Asia

Southeast Asia possesses the highest rates of tropical deforestation globally and exceptional levels of species richness and endemism. Many countries in the region are also recognized for their food insecurity and poverty, making the reconciliation of agricultural production and forest conservation a particular priority. This reconciliation requires recognition of the trade‐offs between competing land‐use values and the subsequent incorporation of this information into policy making. To date, such reconciliation has been relatively unsuccessful across much of Southeast Asia. We propose an ecosystem services (ES) value‐internalization framework that identifies the key challenges to such reconciliation. These challenges include lack of accessible ES valuation techniques; limited knowledge of the links between forests, food security, and human well‐being; weak demand and political will for the integration of ES in economic activities and environmental regulation; a disconnect between decision makers and ES valuation; and lack of transparent discussion platforms where stakeholders can work toward consensus on negotiated land‐use management decisions. Key research priorities to overcome these challenges are developing easy‐to‐use ES valuation techniques; quantifying links between forests and well‐being that go beyond economic values; understanding factors that prevent the incorporation of ES into markets, regulations, and environmental certification schemes; understanding how to integrate ES valuation into policy making processes, and determining how to reduce corruption and power plays in land‐use planning processes.     

Behavioral strategies of American kestrels during mate replacement

Summary To determine the influence of mate replacement on the behavior and reproductive success of wild American kestrels (Falco sparverius) we removed 4 female and 16 male members of breeding pairs during incubation in 1983 and 1984. Eight males and 1 female were replaced within a mean time of 43 h. Widowed females that received a replacement spent less time hunting, but incubated and performed aerial displays more frequently than females that did not receive a replacement. After replacement, widowed females continued to incubate the original clutch, yet copulated and performed other courtship behaviors with the incoming male. Overlapping of normal temporally separate behavioral cues may be a female strategy to gain assistance from a replacement mate. However, none of the original clutches was successfully hatched. Of 8 pairs with replacement males, 2 pairs abandoned their territory, two remained on territory but did not renest, and 4 renested within a mean interval of 18 days. The lone female replacement and her mate copulated and performed nest inspections but then abandoned the territory. Incubation behavior was similar between replacement and control pairs; however, replacement males fed more invertebrate prey to nestling and made many more nest visits. All 3 replacement nests that hatched young failed within 8 days.     

Optimal escapement levels in stochastic and deterministic harvesting models

A constant-escapement feedback policy is shown to be optimal in maximizing expected discounted net revenue from an animal resource whose dynamics are described by a stochastic stock-recruitment model, provided that unit harvesting costs satisfy certain conditions. The optimal escapement in this model is compared with that in the corresponding deterministic model and it is shown how the way in which unit harvesting costs vary with population abundance can be important in determining the relative sizes of the optimal escapements. In most cases, the optimal stochastic escapement is no less than the optimal deterministic escapement.     

Simulation of interactions between migrating whales and potential oil spills

A numerical model system was developed to quantify the probability of endangered bowhead and gray whales encountering spilled oil in Alaskan waters. Migration and diving-surfacing models for bowhead and gray whales, and an oil spill trajectory model comprise the system. The migration models were developed from conceptual considerations, then calibrated with and tested against observations. The distribution of whales is represented in space and time by discrete points, each of which may represent one or more whales. The movement of a whale point is governed by a random walk algorithm which stochastically follows a migratory pathway. Stochastic diving-surfacing models are used to stimulate surfacing behavior sequences for each species. The oil spill model accounts for oil transport and spreading in open water and in the presence of sea ice. Historical wind records and ice cover data sets provide the environmental conditions to generate stochastic oil spill scenarios. The oil spill, whale migration and diving-surfacing models are linked to provide quantitative estimates of whale-oil interactions. The model system was applied to the Alaskan Beaufort Sea to investigate the probability that bowhead whales would encounter oil spilled in this region.     

A parametric model of child body shape in seated postures

Objective: The shape of the current physical and computational surrogates of children used for restraint system assessments is based largely on standard anthropometric dimensions. These scalar dimensions provide valuable information on the overall size of the individual but do not provide good guidance on shape or posture. This study introduced the development of a parametric model that statistically predicts individual child body shapes in seated postures with a few given parameters.

Methods: Surface geometry data from a laser scanner of children ages 3 to 11 (n = 135) were standardized by a 2-level fitting method using intermediate templates. The standardized data were analyzed by principal component analysis (PCA) to efficiently describe the body shape variance. Parameters such as stature, body mass index, erect sitting height, and 2 posture variables related to torso recline and lumbar spine flexion were associated with the PCA model using regression.

Results: When the original scan data were compared with the predictions of the model using the given subject dimensions, the average root mean square error for the torso was 9.5 mm, and the 95th percentile error was 17.35 mm.

Conclusions: For the first time, a statistical model of child body shapes in seated postures is available. This parametric model allows the generation of an infinite number of virtual children spanning a wide range of body sizes and postures. The results have broad applicability in product design and safety analysis. Future work is needed to improve the representation of hands and feet and to extend the age range of the model. The model presented in this article is publicly available online through HumanShape.org.     

Mobile Fabric Filter System: Design and Preliminary Results

In order to study the effects of fabric filter parameters when filtering an actual industrial effluent stream, it is necessary to vary these parameters in the field. A mobile fabric filter system has been designed, fabricated and operated to provide this information. The design characteristics and some preliminary field data collected with this system are summarized.     

Nutrient movement and removal in a switchgrass biomass-filter strip system treated with dairy manure

Manure use on cropland has raised concern about nutrient contamination of surface and ground waters. Warm-season perennial grasses may be useful in filter strips to trap manure nutrients and as biomass feedstock for nutrient removal. We explored the use of 'Alamo' switchgrass (Panicum virgatum L.) in a biomass production-filter strip system treated with dairy manure. We measured changes in extractable P in the soil, NO3 -N in soil water, and changes in total reactive P and chemical oxygen demand (COD) of runoff water before and after a switchgrass filter strip. Five rates of dairy manure (target rates of 0, 50, 100, 150, and 200 kg N ha(-1) from solid manure in 1995; 0, 75, 150, 300, and 600 kg N ha(-1) from lagoon effluent in 1996 and 1997) were surface-applied to field plots of switchgrass (5.2 by 16.4 m) with a 5.2- by 16.4-m switchgrass filter strip below the manured area. Yield of switchgrass from the manured area increased linearly with increasing manure rate in each year. Soil water samples collected at 46 or 91 cm below the soil surface on 30 dates indicated < 3 mg L(-1) of NO3-N in all plots. Concentrations of total reactive P in surface runoff water were reduced an average of 47% for the 150 kg N rate and 76% for the 600 kg N rate in 1996 and 1997 after passing through the strip. Manure could effectively substitute for inorganic fertilizer in switchgrass biomass production with dual use of the switchgrass as a vegetative filter strip.