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Over the past 5 decades, scientists have been documenting negative anthropogenic environmental change, expressing increasing alarm, and urging dramatic socioecological transformation in response. A host of international meetings have been held, but the erosion of biological diversity continues to accelerate. Why, then, has no effective political action been taken? We contend that part of the answer may lie in the anthropocentric ethical premises and moral rhetoric typically deployed in the cause of conservation. We further argue that it is essential to advance moral arguments for biodiversity conservation that are not just based on perceived human interests but on ecocentric values, namely, convictions that species and ecosystems have value and interests that should be respected regardless of whether they serve human needs and aspirations. A broader array of moral rationales for biodiversity conservation, we conclude, would be more likely to lead to effective plans, adopted and enforced by governments, designed to conserve biological diversity. A good place to start in this regard would be to explicitly incorporate ecocentric values into the recommendations that will be made at the conclusion of the 15th meeting of the parties to the Convention on Biological Diversity, scheduled to be held in October 2020.La Necesidad del Ecocentrismo en la Conservación de la Biodiversidad Resumen Durante las últimas cinco décadas, los científicos han estado documentando el cambio ambiental negativo causado por la actividad humana, expresando cada vez una mayor alarma e insistiendo por una transformación socio-ecológica dramática como respuesta. Se han realizado un número de reuniones internacionales pero la erosión de la diversidad biológica se sigue acelerando. Entonces, ¿por qué no se han tomado acciones políticas efectivas? Sostenemos que parte de la respuesta a esta pregunta puede estar en las premisas éticas antropocéntricas y en la retórica moral que típicamente se despliega para la causa de la conservación. Además, argumentamos que es esencial promover argumentos morales para la conservación de la biodiversidad que no estén solamente basados en los intereses humanos percibidos sino en los valores ecocéntricos, principalmente la convicción de que las especies y los ecosistemas tienen valor e intereses que deberían respetarse sin importar si sirven a las necesidades y aspiraciones humanas. Concluimos que un conjunto más amplio de justificaciones morales para la conservación de la biodiversidad tendría mayor probabilidad de guiar planes efectivos, adoptados y aplicados por los gobiernos, diseñados para conservar la diversidad biológica. Un buen punto de partida al respecto sería la incorporación explícita de los valores ecocéntricos dentro de las recomendaciones que se harán al concluir la decimoquinta reunión de las partes que forman al Convenio sobre la Diversidad Biológica, programada para octubre 2020.在过去的半个世纪中, 科学家们报道了许多人类对环境的负面影响, 同时越来越多地发出警告, 并大力呼吁推动社会生态的巨大变革来作出响应。目前已经举行了许多相关的国际会议, 但生物多样性受到的侵蚀仍在加剧。为什么人们还没有采取有效的政治行动呢？我们认为部分原因可能在于保护工作中惯用的以人类为中心的伦理前提和道德修辞。我们还认为, 推进生物多样性保护的道德论证至关重要, 它不仅要基于人类的利益, 还应基于生态中心主义的价值观, 即无论物种和生态系统是否满足人类的需求和愿望, 都应尊重它们的价值和利益。本文的结论是, 在生物多样性保护中引入更广泛的道德理论才更有可能推动政府为保护生物多样性而通过和执行的有效计划。在这方面, 一个很好的起点是明确地将生态中心价值观纳入 2020 年 10 月即将举行的《生物多样性公约》第十五次缔约方会议在结论部分提出的建议之中。翻译: 胡怡思; 审校: 聂永刚.

Natura 2000 (N2k) is a multinational and coordinated conservation network designated to support the long-term survival of Europe's most valuable species and habitats. It is the key conservation tool in the European Union. We reviewed 510 peer-reviewed publications (period 1998–2014) focusing on ecological aspects of N2k, with the aims of identifying key research gaps and proposing future research priorities for improved conservation success. We categorized the articles by spatial scale, biogeographical regions, taxonomic groups, habitat types, and the analytical methods used. The majority of studies were performed in single N2k sites or at the regional level within countries. The Mediterranean region had the greatest number of publications and the terrestrial Black Sea, Macaronesia, Pannonian and Steppic regions were overrepresented in relation to their total area and to the area of N2k sites that they comprised. Grasslands, freshwater and wetland habitats were overrepresented in comparison to their area within N2k. Plants were the most commonly studied taxonomic group and quantitative empirical studies dominated. Future N2k research should address knowledge gaps by directing more efforts towards: 1) the Boreal region, 2) alpine, agricultural, forest and marine habitats, and 3) underrepresented taxonomic groups such as reptiles, amphibians, lichens and fungi. For enhanced evaluation and realization of the conservation potential of N2k, more studies will need to encompass large spatial scales and utilize modelling approaches to effectively address future climate and land-use changes.

There is worldwide interest in managing forests to improve biodiversity, enhance ecosystem services and assure long-term sustainability of forest resources. An increasingly important goal of forest management is to increase stand diversity and improve wildlife and aquatic habitat. Well-planned silvicultural systems containing a mixture of broadleaf-conifer species have potential to enhance stand diversity and provide other ecosystem services earlier than typical even-aged conifer plantations. Here, we use the example of mixed Sitka spruce/western hemlock and red alder in young, managed stands in southeast Alaska to achieve these goals. We briefly describe the silvics of Sitka spruce, western hemlock and red alder plantations as pure conifer stands or pure broadleaf stands. Then, we synthesize studies of mixed red alder-Sitka spruce/western hemlock stands in southeast Alaska and present their potential for improving stand structural complexity, biodiversity and other ecosystem services over pure conifer forests. Finally, we discuss some of the opportunities and potential tradeoffs for managing mixed broadleaf-conifer stands for providing a number of natural resources and the influence of these broadleaf-conifer forests on ecosystem linkages and processes.

We present an event-tree biological risk assessment for a non-native Atlantic salmon (Salmo salar) invasion into Alaskan waters. Atlanticsalmon farming is prohibited in Alaska, USA, but large numbers of them are reared in ocean net-pens in Washinton (WA) USA, and BritishColumbia (BC), Canada. Large numbers of Atlantic salmon escape each year, and they have been recovered in both saltwater and freshwaterin WA, BC, and Alaska. There is limited evidence of successful spawning and rearing in BC, but none from Alaska. No stream-reared smoltsare known to have returned successfully from ocean migrations, but survey efforts for escaped adults and reared juveniles in streams havebeen very limited in time and space. Given recurring, large-scale escape events, propagule pressure could be great enough in any given yearfor a successful invasion. To date, such large numbers of adults have not been recorded ascending Alaskan streams, but again, monitoring isvery limited. Atlantic salmon could most likely successfully spawn and rear in Alaskan streams, so successful ocean migration appears to bethe factor most likely to limit their success. Successful invasion of BC waters, where propagule pressure is greater, followed by a subsequentinvasion of a pre-adapted stock by straying to Alaskan waters, may pose the greatest risk. The lack of adequate surveys, under-reporting ofescapes and recoveries, and inherent ecosystem variation, make it impossible to assign meaningful probabilities to the risk of an invasion ofAlaskan waters. We conclude that the short-term risk of invasion generally appears low, but that it might increase over time. We also notethat invasion is only part of the ecological risk of Atlantic salmon farming in Pacific waters. Disease, parasites, and pollution may also poserisks to local ecosystems – we do not assess these risks here.

The management of stock quality; control of competition from herbs, shrubs, and conifers; and protection from browsing will be important components in a successful regeneration program. Hennon (1992) conducted a small planting of yellow-cedar seedlings on Etolin Island in Alaska and reported good survival (>85%) and growth (heights of approximately 110 cm) after 5 years on productive, well-drained soils. Competing vegetation was noted as limiting survival and growth, particularly where planting was not performed promptly after harvest. There are no other reports in the literature of yellow-cedar planting results in Alaska; however, the T ongass National Forest did have an active yellow-cedar planting program in the 1990s. Research and operational experience with yellow-cedar artificial regeneration in British Columbia is probably applicable in southeast Alaska, Difficulty in collecting cones and low seed germination rate due to seed-coat-imposed dormancy (Pawlik 1993, Raimondi and Kermode 2004, Bonner and Karrfalt 2008) led to the development of yellow-cedar stecldings-planting stock produced by rooted cuttings rather than from seed (Karlsson 1974, 1981). Interestingly, vegetative reproduction is common for yellow-cedar in unmanaged forests. Parish and Antos (2006) contend that many mature yellowcedar trees in natural stands originate from layering, the rooting of lower branches. Antos and Zobel (1986) noted the occurrence of layering in natural stands of the Cascade Mountains in Oregon and Washington. Hennon et al. (1990) reported the same phenomenon in Alaska and suggested that vegetative reproduction occurred more • Paul E. Hennonl Michael H. McClellanl Sheila R. Sporesl and Ewa H. Orlikowska

Interest in mixed red alder (Alnus rubra Bong.) – conifer young-growth stands has grown in southeast Alaska, USA, because they appear to provide much more productive understory vegetation and wildlife habitat than do similar-aged pure conifer stands. We studied understory vegetation in nine even-aged young-growth stands (38–42 years old) comprising a gradient of red alder – conifer overstory composition, with red alder ranging from 0% to 86% of stand basal area. Conifers were Sitka spruce (Picea sitchensis (Bong.) Carr.), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don). We measured understory biomass and net production (current annual growth) in each stand by species and plant part and estimated carrying capacity for black-tailed deer (Odocoileus hemionus sitkensis Cowan) with a food-based habitat model. Highly significant positive relations (P < 0.002) were found between red alder basal area and all of the following: total understory biomass (r2 = 0.743), net production of shrubs (r2 = 0.758) and herbs (r2 = 0.855), and summer carrying capacity for deer (r2 = 0.846). The high correlation between red alder and herbaceous production is especially important, because herbs are least abundant and most difficult to maintain in young-growth conifer forests of this region. Red alder offers prospects for increasing understory vegetation biomass and its food value for deer and other wildlife when included as a hardwood overstory species in mixed hardwood–conifer young-growth forests.

Factors (riparian stand condition, management regimes, and channel properties) affecting distributions of wood, detritus (leaves and branches), and sediment were examined in headwater streams draining young-growth red alder (Alnus rubra Bong.) – conifer riparian forests (< 40 years old) in southeast Alaska. More riparian red alder were found along streams affected by both timber harvesting and mass movement than in streams affected by timber harvesting alone. Young-growth stands produced little large wood material (diameter ≥10 cm) and had little effect on altering the size distribution of functional large wood in channels, although more alder wood pieces were found in streams with greater numbers of riparian alder trees. Legacy wood pieces (>40 years old) remained in channels and provided sites for sediment and organic matter storage. Despite various alder–conifer mixtures and past harvesting effects, the abundance of large wood, fine wood, and detritus accumulations significantly decreased with increasing channel bank-full width ( 0.5–3.5 m) along relatively short channel distances (up to 700 m). Changes in wood, detritus, and sediment accumulations together with changes in riparian stand characteristics create spatial and temporal variability of in-channel conditions in headwater systems. A component of alder within young-growth riparian forests may benefit both wood production and biological recovery in disturbed headwater stream channels.

Stand structure and dynamics were evaluated in mixed red alder (Alnus rubra Bong.) – conifer forests of southeast Alaska. We assessed stand development, tree density, total basal area, diameter distribution of live and dead trees, height distribution of live trees, and mean diameter of all and largest conifers in 40-year-old red alder – conifer stands that developed following logging. Forty-five plots were established in nine stands sampled across a com po si tional range of 0%–86% alder. Alder height growth was initially rapid then slowed considerably, whereas conifer height growth was initially slow then rapidly increased with conifers now being 4–9 m taller than associated alders. Most alder diameters were 20–30 cm and conifer diameters were more variable with numerous small (3–10 cm) and a few large (>25 cm) trees. Total stand basal area significantly decreased (p = 0.013) with increasing proportions of alder, but density of live and dead trees was not closely associated with alder composition. More than 60% of all dead trees died standing regardless of size or species. Overall, these mixed red alder – conifer stands provided more heterogeneous structures than pure conifer stands, with more even diameter distributions, multiple canopy layers, and similar numbers of large diameter conifers.

Forest clearcutting has been the primary timber management practice in forests of southeastern Alaska since commercial timber harvesting began in the 1950s, and the dense, even-aged conifer stands that subsequently developed have broad and undesirable consequences for some nontimber resources-most notably, fish and wildlife. Because a few earlier reports suggested that red alder (Alnus rubra Bong.) helps mitigate some negative effects of timber harvesting (Deal 1997, Wipfli 1997, Hanley and Barnard 1998), we studied the influence of red alder on a broad set of nontimber resources in young conifer forests (40-year-old; equivalent to early third stage of Appendix 1, Chapter 1) in southeastern Alaska (Figure 1). It is unclear what the ecological functions of red alder are in young forested ecosystems in southeastern Alaska. Key questions include: Does red alder affect forest understory development, tree growth, and timber production? How does red alder influence food and habitat for fish and wildlife? How does red alder function in stream and riparian habitats? Does red alder influence forest ecosystem diversity and productivity? Open image in new window