A framework for considering ecological interactions for common non-timber forest product species: a case study of mountain date palm (Phoenix loureiroi Kunth) leaf harvest in South India

Introduction: Many economically important non-timber forest products (NTFPs) come from widespread and common plant species. Harvest of these species often is assumed to be sustainable due to their commonness. However, because of the ecological roles of common species, harvest may affect and be affected by ecological interactions at broader scales, which are rarely considered when evaluating the sustainability of harvest. We use a case study of the mountain date palm (Phoenix loureiroi Kunth), harvested in South India to produce brooms, to present a conceptual framework illustrating how intensive harvest of a common species interacts with other anthropogenic management practices, plant-animal interactions and surrounding environmental conditions. Methods: We apply this framework to understanding the impacts of mountain date palm harvest in the southern Western Ghats regions of the Indian states of Tamil Nadu and Karnataka. We integrate data on the extent and levels of commercial harvest, local management practices, the ecological context in which harvest occurs, and research on harvest effects. We use this information to document the intensity and extent of mountain date palm harvest in the study area, identify the ecological implications of harvest, and demonstrate how a framework that considers harvest in the context of ecological communities and ecosystems is important for assessing the impacts of harvest of common NTFP species.Results: We show that mountain date palm leaves are heavily harvested from natural areas in the southern Western Ghats but that harvest levels have declined in recent years. Mountain date palm management and harvest occur within a network of ecological interactions, linking human activities to population-, community-, and ecosystem-level processes. We demonstrate that understanding the effects of return interval of anthropogenic fire, herbivory by wild animals and livestock, as well as the light environment in which harvest occurs are critical to assessing the sustainability of mountain date palm harvest. Conclusions: By considering mountain date palm leaf harvest in the context of ecological interactions at multiple scales, our findings show that sustainability cannot be assessed only from a population-level perspective. This general framework highlights the need to incorporate ecosystem- and community-level properties and processes more frequently into assessments of the sustainability of NTFP harvest—especially for widespread and common species—to ensure that their important economic and ecological roles are maintained

Workmen\u27s Compensation Denied: A Reply

A reader of the January 1968 Symposium on Workmen\u27s Compensation in the Cleveland-Marshall Law Review would be badly misled if he took the titles of the two articles by Messrs. Krise and Keller at face value.\u27 While purportedly about appeals and recommended changes in the Ohio Workmen\u27s Compensation law, these articles are in fact attacks on attorneys who represent claimants in workmen\u27s compensation controversies

Where ethics and politics meet

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74831/1/ae.2006.33.1.33.pd

Resource-Constrained Project Scheduling with Autonomous Learning Effects

It\u27s commonly assumed that experience leads to efficiency, yet this is largely unaccounted for in resource-constrained project scheduling. This thesis considers the idea that learning effects could allow selected activities to be completed within reduced time, if they\u27re scheduled after activities where workers learn relevant skills. This paper computationally explores the effect of this autonomous, intra-project learning on optimal makespan and problem difficulty. A learning extension is proposed to the standard RCPSP scheduling problem. Multiple parameters are considered, including project size, learning frequency, and learning intensity. A test instance generator is developed to adapt the popular PSPLIB library of scheduling problems to this model. Four different Constraint Programming model formulations are developed to efficiently solve the model. Bounding techniques are proposed for tightening optimality gaps, including four lower bounding model relaxations, an upper bounding model relaxation, and a Destructive Lower Bounding method. Hundreds of thousands of scenarios are tested to empirically determine the most efficient solution approaches and the impact of learning on project schedules. Potential makespan reduction as high as 50% is discovered, with the learning effects resembling a learning curve with a point of diminishing returns. A combination of bounding techniques is proven to produce significantly tighter optimality gaps