Using forest guards to protect a biological reserve in Costa Rica: one step towards linking parks to people

The paper examines a forest guard system protecting Monteverde Cloud Forest Reserve in Costa Rica. Using field observation, interviews and content analysis of records, the study determines the major threats facing the reserve from the local population. These threats, which include hunting, squatting and logging, are dealt with by the guards not just by creating barriers but by the guards as linkages among the many participants in the region. Community, institutional, legal and ecological linkages are identified, described and measured. The community linkage is recognized as particularly important because the Reserve's protection will be greatly enhanced if the community itself becomes ‘the guards’ and protects the Reserve. Policy recommendations are made based on the results.     

PERSISTING SEDIMENT YIELDS AND SEDIMENT DELWERY CHANGES1

ABSTRACT: The Buffalo River is a tributary to the Mississippi River in west-central Wisconsin that drains a watershed dominated by agricultural land uses. Since 1935, backwater from Lock and Dam 4 on the Mississippi River has inundated the mouth of the Buffalo's valley. Resurveys of a transect first surveyed across the lake in 1935 and cesium-137 dating of backwater sediments reveal that sedimentation rates at the Buffalo's mouth have remained unchanged since the mid-1940s. Study results indicate that sediment yields from the watershed have persisted at relatively high levels over a period of several decades despite pronounced trends toward less cultivated land and major efforts to control soil erosion from agricultural land. The maintenance of sediment yields is probably due to increased channel conveyance capacities resulting from incision along some tributary streams since the early 1950s. Post-1950 incision extended the network of historical incised tributary channels, enhancing the efficient delivery of sediment from upland sources to downstream sites.     

An Integrated Approach to Reservoir Management: The Williston Reservoir Case Study

/ The management of industrial reservoirs for hydroelectric energy can cause severe impacts to surrounding communities. This study examines the generation of dust along the northern foreshore zones of Williston Reservoir in northern British Columbia. The dust is generated in the spring when the reservoir levels are low and impacts a relocated First Nations' village (Tsay Keh) at the north end of the reservoir. Data were gathered to provide an overview of the physical conditions that contribute to the dust problem, including a social survey, soil analysis, and vegetation inventory. The study provides a scoping method to assess a large-scale and complex problem with respect to dust management along a large reservoir. Methods for dust control include short- and long-term solutions that integrate the use of native vegetation along the foreshore zones of the reservoir.     

Community Structure and Quality After 10 Years in Two Central Ohio Mitigation Bank Wetlands

We evaluate two 10-year-old mitigation bank wetlands in central Ohio, one created and one with restored and enhanced components, by analysis of vegetation characteristics and by comparison of the year-10 vegetation and macroinvertebrate communities with reference wetlands. To assess different measures of wetland development, we compare the prevalence of native hydrophytes with an index of floristic quality and we evaluate the predictability of these parameters in year 10, given 5 years of data. Results show that the mitigation wetlands in this study meet vegetation performance criteria of native hydrophyte establishment by year 5 and maintain these characteristics through year 10. Species richness and floristic quality, as well as vegetative similarity with reference wetlands, differ among mitigation wetlands in year 1 and also in their rate of change during the first 10 years. The prevalence of native hydrophytes is reasonably predictable by year 10, but 5 years of monitoring is not sufficient to predict future trends of floristic quality in either the created or restored wetland. By year 10, macroinvertebrate taxa richness does not statistically differ among these wetlands, but mitigation wetlands differ from reference sites by tolerance index and by trophic guild dominance. The created wetland herbivore biomass is significantly smaller than its reference, whereas detritivore biomass is significantly greater in the created wetland and smaller in the restored wetland as compared with respective reference wetlands. These analyses illustrate differences in measures of wetland performance and contrast the monitoring duration necessary for legal compliance with the duration required for development of more complex indicators of ecosystem integrity.     

The valuation of forest carbon services by Mexican citizens: the case of Guadalajara city and La Primavera biosphere reserve

Adequate demand for, and recognition of, forest carbon services is critical to success of market mechanisms for forestry-based conservation and climate change mitigation. National and voluntary carbon-offsetting schemes are emerging as alternatives to international compliance markets. We developed a choice experiment to explore determinants of local forest carbon-offset valuation. A total of 963 citizens from Guadalajara in Mexico were asked to consider a purchase of voluntary offsets from the neighbouring Biosphere Reserve of La Primavera and from two alternative more distant locations: La Michilía in the state of Durango and El Cielo in Tamaulipas. Surveys were applied in market stall sessions and online using two different sampling methods: the snowball technique and via a market research company. The local La Primavera site attracted higher participation and valuation than the more distant sites. However, groups particularly interested in climate change mitigation or cost may accept cost-efficient options in the distant sites. Mean implicit carbon prices obtained ranged from $6.79 to $15.67/tCO_2eq depending on the surveying methodology and profile of respondents. Survey application mode can significantly affect outcome of the experiment. Values from the market stall sessions were higher than those from the snowball and market research samples obtained online; this may be linked to greater cooperation associated with personal interaction and collective action. In agreement with the literature, we found that valuation of forest carbon offsets is associated with cognitive, ethical, behavioural, geographical and economic factors.     

Effect of automated versus manual emergency braking on rear seat adult and pediatric occupant precrash motion

Abstract

Objective: Emergency braking can potentially generate precrash occupant motion that may influence the effectiveness of restraints in the subsequent crash, particularly for rear-seated occupants who may be less aware of the impending crash. With the advent of automated emergency braking (AEB), the mechanism by which braking is achieved is changing, potentially altering precrash occupant motion. Further, due to anatomical and biomechanical differences across ages, kinematic differences between AEB and manual emergency braking (MEB) may vary between child and adult occupants. Therefore, the objective of this study was to quantify differences in rear-seated adult and pediatric kinematics and muscle activity during AEB and MEB scenarios.

Methods: Vehicle maneuvers were performed in a recent model year sedan traveling at 50?km/h. MEB (acceleration ～1?g) was achieved by the driver pressing the brake pedal with maximum effort. AEB (acceleration ～0.8?g) was triggered by the vehicle system. Inertial and Global Positioning System data were collected. Seventeen male participants aged 10–33 were restrained in the rear right passenger seat and experienced each maneuver twice. The subjects’ kinematics were recorded with an 8-camera 3D motion capture system. Electromyography (EMG) recorded muscle activity. Head and trunk displacements, raw and normalized by seated height, and peak head and trunk velocity were compared across age and between maneuvers. Mean EMG was calculated to interpret kinematic findings.

Results: Head and trunk displacement and peak velocity were greater in MEB than in AEB in both raw and normalized data (P?≤?.01). No effect of age was observed (P?≥?.21). Peak head and trunk velocities were greater in repetition 1 than in repetition 2 (P?≤?.006) in MEB but not in AEB. Sternocleidomastoid (SCM) mean EMG was greater in MEB compared to AEB, and muscle activity increased in repetition 2 in MEB.

Conclusions: Across all ages, head and trunk excursions were greater in MEB than AEB, despite increased muscle activity in MEB. This observation may suggest an ineffective attempt to brace the head or a startle reflex. The increased excursion in MEB compared to AEB may be attributed to differences in the acceleration pulses between the 2 scenarios. These results suggest that AEB systems can use specific deceleration profiles that have potential to reduce occupant motion across diverse age groups compared to sudden maximum emergency braking applied manually.     

Unexpected toxicity decrease during photoelectrochemical degradation of atrazine with NaCl

This report shows an unexpected toxicity decrease during atrazine photoelectrodegradation in the presence of NaCl. Atrazine is a pesticide classified as endocrine disruptor occurring in industrial effluents and agricultural wastewaters. We therefore studied the effects of the degradation method, electrochemical and electrochemical photo-assisted, and of the supporting electrolyte, NaCl and Na₂SO₄, on the residual toxicity of treated atrazine solutions. We also studied the toxicity of treated atrazine solutions using Artemia nauplii. Results show that at initial concentration of 20 mg L⁻¹, atrazine was completely removed in up to 30 min using 10 mA cm⁻² electrolysis in NaCl medium, regardless of the electrochemical method used. The total organic carbon removal by the photo-assisted method was 82% with NaCl and 95% with Na₂SO₄. The solution toxicity increased during sole electrochemical treatment in NaCl, as expected. However, the toxicity unexpectedly decreased using the photo-assisted method. This finding is a major discovery because electrochemical treatment with NaCl usually leads to the formation of toxic chlorine-containing organic degradation by-products.