137 research outputs found
The Effects of Postfire Salvage Logging on Aquatic Ecosystems in the American West
Recent changes in the forest policies, regulations, and laws affecting public lands encourage postfire salvage logging, an activity that all too often delays or prevents recovery. In contrast, the 10 recommendations proposed here can improve the condition of watersheds and aquatic ecosystems
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Reducing Livestock Effects on Public Lands in the Western United States as the Climate Changes: A Reply to Svejcar et al.
Beschta et al. (2013) synthesized the ecological effects 41 of climate change and ungulate
grazing on western public lands, grounding their recommendations in ecological considerations
and federal agency legal authority and obligations. Svejcar et al. (2014) suggest that Beschta et
al. (2013) neither âpresent a balanced synthesis of the scientific literatureâ nor âreflect the
complexities associated with herbivore grazing.â Svejcar et al. (2014) âdispute the notion that
eliminating [livestock] grazing will provide a solution to problems created by climate change,â
although we made no such claim. Instead, Beschta et al. (2013: p. 474) indicate that removal or
reduction of livestock across large areas of public land will reduce a pervasive ecological stress,
diminishing cumulative impacts on these ecosystems under climate change. We respond to three
livestock grazing issues raised by Svejcar et al. (2014): (1) legacy vs. contemporary effects, (2)
fuels reduction and fire effects, and (3) grazing complexity and restoration.Keywords: Climate change, Public lands, Restoration, Ungulates, Livestock grazing, Biodiversit
Can forest management based on natural disturbances maintain ecological resilience?
Given the increasingly global stresses on forests, many ecologists argue that managers must maintain ecological resilience: the capacity of ecosystems to absorb disturbances without undergoing fundamental change. In this review we ask: Can the emerging paradigm of natural-disturbance-based management (NDBM) maintain ecological resilience in managed forests? Applying resilience theory requires careful articulation of the ecosystem state under consideration, the disturbances and stresses that affect the persistence of possible alternative states, and the spatial and temporal scales of management relevance. Implementing NDBM while maintaining resilience means recognizing that (i) biodiversity is important for long-term ecosystem persistence, (ii) natural disturbances play a critical role as a generator of structural and compositional heterogeneity at multiple scales, and (iii) traditional management tends to produce forests more homogeneous than those disturbed naturally and increases the likelihood of unexpected catastrophic change by constraining variation of key environmental processes. NDBM may maintain resilience if silvicultural strategies retain the structures and processes that perpetuate desired states while reducing those that enhance resilience of undesirable states. Such strategies require an understanding of harvesting impacts on slow ecosystem processes, such as seed-bank or nutrient dynamics, which in the long term can lead to ecological surprises by altering the forest's capacity to reorganize after disturbance
Saving the worldâs terrestrial megafauna
From the late Pleistocene to the Holocene, and now the so called Anthropocene, humans have been driving an ongoing series of species declines and extinctions (Dirzo et al. 2014). Large-bodied mammals are typically at a higher risk of extinction than smaller ones (Cardillo et al. 2005). However, in some circumstances terrestrial megafauna populations have been able to recover some of their lost numbers due to strong conservation and political commitment, and human cultural changes (Chapron et al. 2014). Indeed many would be in considerably worse predicaments in the absence of conservation action (Hoffmann et al. 2015). Nevertheless, most mammalian megafauna face dramatic range contractions and population declines. In fact, 59% of the worldâs largest carnivores (â„ 15 kg, n = 27) and 60% of the worldâs largest herbivores (â„ 100 kg, n = 74) are classified as threatened with extinction on the International Union for the Conservation of Nature (IUCN) Red List (supplemental table S1 and S2). This situation is particularly dire in sub-Saharan Africa and Southeast Asia, home to the greatest diversity of extant megafauna (figure 1). Species at risk of extinction include some of the worldâs most iconic animalsâsuch as gorillas, rhinos, and big cats (figure 2 top row)âand, unfortunately, they are vanishing just as science is discovering their essential ecological roles (Estes et al. 2011). Here, our objectives are to raise awareness of how these megafauna are imperiled (species in supplemental table S1 and S2) and to stimulate broad interest in developing specific recommendations and concerted action to conserve them
Pathways towards coexistence with large carnivores in production systems
Coexistence between livestock grazing and carnivores in rangelands is a major challenge in terms of sustainable agriculture, animal welfare, species conservation and ecosystem function. Many effective non-lethal tools exist to protect livestock from predation, yet their adoption remains limited. Using a social-ecological transformations framework, we present two qualitative models that depict transformative change in rangelands grazing. Developed through participatory processes with stakeholders from South Africa and the United States of America, the models articulate drivers of change and the essential pathways to transition from routine lethal management of carnivores towards mutually beneficial coexistence. The pathways define broad actions that incorporate multiple values in grazing systems including changes to livestock management practices, financial support, industry capacity building, research, improved governance and marketing initiatives. A key fnding is the new concept of âPredator Smart Farmingâ, a holistic and conscientious approach to agriculture, which increases the resilience of landscapes, animals (domesticated and wild) and rural livelihoods. Implementation of these multiple pathways would lead to a future system that ensures thriving agricultural communities, secure livelihoods, reduced violence toward animals, and landscapes that are productive and support species conservation and coexistence
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