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Estimating coffee yield by measuring components of yield rather than complete harvests can improve the ability to account for heterogeneous conditions common in shade-grown farms and other agroforestry systems. We developed a rapid estimation technique that predicts yield per plant from (1) a visual estimation of the number of fruits per lateral summed across all laterals per plant, and (2) an average fruit dry mass derived from the random harvest of 50 fruits per plant. The technique was then applied to an experiment investigating three levels of managed tree shade (0, 40, and 60%) on Arabica coffee yield. Visual estimates of fruits per lateral proved to be good predictors of counts of fruits summed for each vertical (R2 = 0.97) and yield of the whole plant (R2 = 0.90). Simulations showed this was potentially better than existing methods to account for variable yield per vertical shoot at the whole-plant level and took less time or effort when applied to the plants in our study. We propose that fruits per lateral is an effective alternative component of yield that can account for heterogeneity in shade level, other environmental variables or management practices that can affect yield at small spatial scales in agroforestry systems. [ABSTRACT FROM AUTHOR]

An 8-year-old dense monotypic stand of naturally regenerated koa ( Acacia koa A. Gray) on the Island of Hawaii was selected to determine the effects of precommercial release thinning, phosphorous (P) fertilization and herbaceous weed control on growth of potential crop trees over approximately 30 months. Thinning consisted of cutting down all stems within a 4.5-m radius of the crop tree. Phosphorus was added at a rate of 300 kg ha −1 over two years. Herbaceous weeds were sprayed once with imazapyr, a broad-spectrum herbicide. Thinning alone or in combination with P fertilization significantly increased stem diameter increment and allometric estimates of the growth of leaf area and aboveground biomass. There was no significant increase in stem diameter, leaf area or biomass in the absence of thinning. Within the thinned treatment, P fertilization resulted in significant increases in tree height over time. Herbaceous weed control had no effect on tree growth. The atmospherically resistant vegetation index (ARVI), which was derived from spectral analyses of high-resolution satellite imagery (GeoEye1), was significantly higher for thinned than unthinned trees 25 months after study initiation, suggesting greater light absorbance and a possible explanation for overall greater growth of thinned trees. When considered with results from previous studies, these findings indicated that crop tree selection and precommercial release thinning in dense, even-aged koa stands should be done early in stand development to prevent loss of crown vigor and growth potential. Additional interventions like P fertilization or herbaceous weed control may not be necessary until trees are older or site conditions suggest important soil resource limitations. [ABSTRACT FROM AUTHOR]

The objective of this review was to summarize the epidemiological literature for extreme hikers in volcanic environments and describe the incidence, nature and severity of injuries, the factors contributing to the injuries, and strategies for preventing injuries. Due to the relative newness of extreme hiking in volcanic environments, there are only a small handful of studies addressing the topic. Moreover, these studies are primarily focused on extreme hikers in Hawaii Volcanoes National Park. These studies found that the majority of extreme hikers in volcanic environments are inexperienced and unfamiliar with the potential hazards present in volcanic environments. The studies found that upper respiratory irritation resulting from exposure to volcanic gases and dehydration and scrapes, abrasions, lacerations, and thermal burns to the extremities were common injuries. The severity of the injuries ranged from simple on-site treat-and-release incidents to more severe incidents and even death. This review reveals a need for well-designed epidemiologic research from volcanic destinations outside of Hawaii that identify the nature and severity of injuries along with the factors contributing to injury incidents. There is also a demonstrated need for studies identifying preventive measures that reduce both the occurrence and severity of extreme hiking incidents in volcanic environments., (Copyright © 2012 S. Karger AG, Basel.)

Objective: To report the injuries and illnesses encountered by wilderness hikers in Hawaii Volcanoes National Park attempting to hike to active lava flows and to investigate the roles that demographics, prior hiking experience, hiking behavior, and preparedness play in hiker vulnerability to injury and illness., Methods: During an 8-week period, daily on-site exit interviews of lava hikers were conducted by a uniformed park ranger and park volunteer. Information about the hiker's home residence, wilderness hiking experience, preparedness, health status, and health problems encountered during the hike was collected from a total of 804 hikers., Results: A high rate of injury and illness was found among the study population. Scrapes and abrasions (59%), blisters (51%), and muscle strains and sprains (47%) were the most common injuries. Dehydration (77%) and respiratory irritation (46%) were the most common illnesses. Lower extremities were the most common site of injuries, and beginning hikers were the most vulnerable to injury and illness. Many hikers were inexperienced tourists willing to disregard warning signs and enter high-risk areas., Conclusions: Hawaii Volcanoes National Park is one of 22 US national park units with volcanic resources. The injuries and illnesses reported by the study group identify the impact that this type of environment can have on the safety of wilderness users in areas with similar resources. Recreating in remote and severe areas has inherent risks, but the high rate of injuries and illnesses sustained by the hikers of this study can potentially be reduced through the development of more direct risk management methods.