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We evaluated the application of using an additive harvest mortality model (AHMM) as a harvest management strategy for northern bobwhites Colinus virginianus during the 2007/08 and 2008/09 hunting seasons in two ecoregions of Texas: the Rolling Plains (RP) and the South Texas Plains (STP). We collected field data on three study sites/ecoregion (of 400-1,900 ha each; two treatment and one control) to estimate four demographic parameters (i.e. fall and spring density, overwinter survival in the absence of hunting and harvest rate). We used these data to parameterize an AHMM (a theoretical component of sustained-yield harvest; SYH) for bobwhites and compare model-based predictions of spring bobwhite populations with field estimates. Our goal was to compare predictions from the AHMM to field estimates of spring density based on known rates of harvest. Compared to field estimates, the AHMM consistently underestimated spring population density (mean % ± SE) by 55.7 ± 17.8% (2007/08) and 34.1 ± 4.9% (2008/09) in the RP and by 26.4 ± 25.3% (2007/08) and 49.1 ± 2.1% (2008/09) in the STP. Prescribing a fall bobwhite harvest to achieve a specific, target spring density may be difficult given the wide variation in the model parameters (i.e. fall and spring density, and natural mortality) that we observed.

Identifying the rates of recovery of fish in no-take areas is fundamental to designing protected area networks, managing fisheries, estimating yields, identifying ecological interactions, and informing stakeholders about the outcomes of this management. Here we study the recovery of coral reef fishes through 37 years of protection using a space-for-time chronosequence of four marine national parks in Kenya. Using AIC model selection techniques, we assessed recovery trends using five ecologically meaningful production models: asymptotic, Ricker, logistic, linear, and exponential. There were clear recovery trends with time for species richness, total and size class density, and wet masses at the level of the taxonomic family. Species richness recovered rapidly to an asymptote at 10 years. The two main herbivorous families displayed differing responses to protection, scarids recovering rapidly, but then exhibiting some decline while acanthurids recovered more slowly and steadily throughout the study. Recovery of the two invertebrate-eating groups suggested competitive interactions over resources, with the labrids recovering more rapidly before a decline and the balistids demonstrating a slower logistic recovery. Remaining families displayed differing trends with time, with a general pattern of decline in smaller size classes or small-bodied species after an initial recovery, which suggests that some species-and size-related competitive and predatory control occurs in older closures. There appears to be an ecological succession of dominance with an initial rapid rise in labrids and scarids, followed by a slower rise in balistids and acanthurids, an associated decline in sea urchins, and an ultimate dominance in calcifying algae. Our results indicate that the unfished \"equilibrium\" biomass of the fish assemblage >10 cm is 1100-1200 kg/ha, but these small parks (<10 Km²) are likely to underestimate prehuman influence values due to edge effects and the rarity of taxa with large area requirement, such as apex predators, including sharks.

Harvesting on nonindustrial private forestland (NIPF) has increased dramatically in recent years, and projections suggest the trend will continue. Working NIPFs in New York State are not immune to this pressure. Managing these stands to supply a sustained yield of high-quality sawtimber into the future is necessary if working NIPFs are to avoid significant timber stock depletion. In large part, this outcome depends on the intentions of owners and productive potential of their stands. Combining these aspects helps assess whether and how sustained-yield management can be achieved. To demonstrate, we present a case study that used Ajzen's (2005) theory of planned behavior to explain sustained-yield management intentions and Fajvan et al.'s (1998) silviculture classification chart to describe potential yield on 50 recently harvested NIPFs in New York. Predictors of an owner's intention were modeled, and intentions and silviculture classifications were cross-tabulated. Nearly all owners plan to manage for a sustained yield of sawtimber, but previous cutting will force most to regenerate or convert to uneven-age management to achieve this goal.

A fishery for brine shrimp (Artemia franciscana) cysts to supply the aquaculture industry considerably expanded in the late 1980s in the Great Salt Lake, Utah, USA. With this expansion, concerns emerged in the 1990s about the fishery’s sustainability, especially its impact on the abundant western North American waterbirds that use the lake and feed on brine shrimp. We track the development of management strategies using adaptive management by the Utah Division of Wildlife Resources (UDWR), which focused on the biology of the system and development of biology-based harvesting models. The models and their rationale are presented, their success in forecasting is evaluated, and implications for managing the harvest and conserving waterbirds are examined. We view this as an interesting case study because it transpired over a short time in a relatively simple system. This permitted us to clearly track management from the onset of a harvest market, through realization that the harvest had to be managed in the absence of needed biological knowledge, to the adaptive development of management strategies as biological knowledge was accumulated. The outcome illustrates the success that harvest management can attain with careful monitoring of the resource and terminating the harvest when a necessary escapement stock is attained.

The US dairy sector is facing structural changes including a geographical shift in dairy production and a tendency toward the implementation of more intensive production systems. These changes might significantly affect farm efficiency, profitability, and the long-term economic sustainability of the dairy sector, especially in more traditional dairy production areas. Consequently, the goal of this study was to examine the effect of practices commonly used by dairy farmers and the effect of intensification on the performance of the farms. We used a sample of 273 Wisconsin dairy farms to estimate a stochastic production frontier simultaneously with a technical inefficiency model. The empirical analysis showed that at a commercial level the administration of bovine somatotropin hormone to lactating cows increased milk production. In addition, we found that production exhibits constant returns to scale and that farm efficiency is positively related to farm intensification, the level of contribution of family labor in the farm activities, the use of a total mixed ration feeding system, and milking frequency.

The policy term green infrastructure highlights the need to maintain functional ecosystems as a foundation for sustainable societies. Because forests are the main natural ecosystems in Europe, it is crucial to understand the extent to which forest landscape management delivers functional green infrastructures. We used the steep west–east gradient in forest landscape history, land ownership, and political culture within northern Europe's Baltic Sea Region to assess regional profiles of benefits delivered by forest landscapes. The aim was to support policy‐makers and planners with evidence‐based knowledge about the current conditions for effective wood production and biodiversity conservation. We developed and modeled four regional‐level indicators for sustained yield wood production and four for biodiversity conservation using public spatial data. The western case study regions in Sweden and Latvia had high forest management intensity with balanced forest losses and gains which was spatially correlated, thus indicating an even stand age class distribution at the local scale and therefore long‐term sustained yields. In contrast, the eastern case study regions in Belarus and Russia showed spatial segregation of areas with forest losses and gains. Regarding biodiversity conservation indicators, the west–east gradient was reversed. In the Russian, Belarusian, and Latvian case study regions, tree species composition was more natural than in Sweden, and the size of contiguous areas without forest loss was larger. In all four case study regions, 54–85% of the total land base consisted of forest cover, which is above critical fragmentation thresholds for forest landscape fragmentation. The results show that green infrastructures for wood production and biodiversity conservation are inversely related among the four case study regions, and thus rival. While restoration for biodiversity conservation is needed in the west, intensified use of wood and biomass is possible in the east. However, a cautious approach should be applied because intensification of wood production threatens biodiversity. We discuss the barriers and bridges for spatial planning in countries with different types of land ownership and political cultures and stress the need for a landscape approach based on evidence‐based collaborative learning processes that include both different academic disciplines and stakeholders that represent different sectors and levels of governance.

Enthusiasm for the use of forest biomass as an energy resource is growing as a result of increased energy costs and a desire to reduce the greenhouse gas emissions responsible for climate change. Although the opportunity exists for forests to have a significant role in the development and use of bioenergy technologies, justifiable concerns regarding the long-term sustainability of using forest-based energy feedstocks have emerged. In this article, we review the state of our knowledge regarding the impacts of intensive forestry with respect to issues relevant to bioenergy production, including soil and site productivity, hydrologic quality, and biodiversity. We then present guiding principles intended to aid with sustainable forest management decisions.

Early efforts in wildlife management focused on reducing population variability and maximizing yields of selected species. Later, Aldo Leopold proposed the concept of habitat management as superior to population management, and more recently, ecosystem management, whereby ecological processes are conserved or mimicked, has come into favour. Managing for resilience builds upon these roots, and focuses on maintaining key processes and relationships in social-ecological systems so that they are robust to a great variety of external or internal perturbations at a range of ecological and social scales. Managing for resilience focuses on system-level characteristics and processes, and the endurance of system properties in the face of social or ecological surprise. Managing for resilience consists of actively maintaining a diversity of functions and homeostatic feedbacks, steering systems away from thresholds of potential concern, increasing the ability of the system to maintain structuring processes and feedbacks under a wide range of conditions, and increasing the capacity of a system to cope with change through learning and adaptation. The critical aspect of managing for resilience, and therefore ecosystem management, is undertaking adaptive management to reduce uncertainty and actively managing to avoid thresholds in situations where maintaining resilience is desired. Managing adaptively for resilience is the approach best suited for coping with external shocks and surprises given the non-linear complex dynamics arising from linked social-ecological systems.

Many fisheries management systems, even when based on apparently sound science, have failed to prevent severe overfishing. And even when successful in this sense, such systems have frequently resulted in a large degree of excess fishing capacity. The reason for these failures can often be found in a lack of consideration of the economic incentives affecting fishermen. Specifically, when forced to compete for a fixed total annual catch quota (TAC), fishermen are motivated to fish at high intensity, and to expand the fishing power of their vessels. Individual fishing quotas (IFQs) are being increasingly used as a method of altering economic incentives in a desirable way. IFQ systems, however, can also suffer severe shortcomings, unless substantial fees are extracted for the exclusive right to exploit a publicly owned resource. When combined with appropriate fees, or royalties, IFQs can indeed result in sustainable, profitable fisheries. There still remains the fundamental question of risk management, but this is also now beginning to be addressed. Thus there is now a strong hope for the future success of marine fisheries, at least within 200‐mile coastal zones.

Cordyceps sinensis is a mushroom that parasitizes larvae of Thitarodes (Hepialus) moths, which inhabit the alpine grasslands of the Tibetan Plateau. Tibetans have used the mushroom, which they call yartsa gunbu (\"summer-grass, winter-worm\") for many centuries, if not millennia. A 350% increase in the price paid to pickers between 1997 and 2004 has turned this tiny mushroom into the single most important source of cash for rural households in contemporary Tibet. On average, 40% of the rural cash income in the Tibet Autonomous Region is derived from its collection, which government statistics figured at 50,000 kg in 2004, contributing at least CNY (Chinese yuan) 1.8 billion (USD 225 million) to the Tibet Autonomous Region's GDP. A dramatic fungal commodification of the rural Tibetan economy is occurring, as the income from sale of Cordyceps often accounts for 70%-90% of a family's annual cash income in areas where it grows. The ever-increasing harvesting pressure raises the question of sustainability. The fact that Cordyceps has been collected for centuries and is still common argues for its resilience, but the lack of harvest studies for C sinensis precludes a definite answer as to whether the harvest can be sustained at its current level.