Combined Effects of Climate Change and Bank Stabilization on Shallow Water Habitats of Chinook Salmon

Significant challenges remain in the ability to estimate habitat change under the combined effects of natural variability, climate change, and human activity. We examined anticipated effects on shallow water over low‐sloped beaches to these combined effects in the lower Willamette River, Oregon, an area highly altered by development. A proposal to stabilize some shoreline with large rocks (riprap) would alter shallow water areas, an important habitat for threatened Chinook salmon (Oncorhynchus tshawytscha), and would be subject to U.S. Endangered Species Act‐mandated oversight. In the mainstem, subyearling Chinook salmon appear to preferentially occupy these areas, which fluctuate with river stages. We estimated effects with a geospatial model and projections of future river flows. Recent (1999–2009) median river stages during peak subyearling occupancy (April–June) maximized beach shallow water area in the lower mainstem. Upstream shallow water area was maximized at lower river stages than have occurred recently. Higher river stages in April–June, resulting from increased flows predicted for the 2080s, decreased beach shallow water area 17–32%. On the basis of projected 2080s flows, more than 15% of beach shallow water area was displaced by the riprap. Beach shallow water area lost to riprap represented up to 1.6% of the total from the mouth to 12.9 km upstream. Reductions in shallow water area could restrict salmon feeding, resting, and refuge from predators and potentially reduce opportunities for the expression of the full range of life‐history strategies. Although climate change analyses provided useful information, detailed analyses are prohibitive at the project scale for the multitude of small projects reviewed annually. The benefits of our approach to resource managers include a wider geographic context for reviewing similar small projects in concert with climate change, an approach to analyze cumulative effects of similar actions, and estimation of the actions’ long‐term effects. Efectos Combinados del Cambio Climático y la Estabilización de Bordes de Ríos Hábitats de Aguas Poco Profundas del Salmón Chinook     

Obstruction of biodiversity conservation by minimum patch size criteria

Minimum patch size criteria for habitat protection reflect the conservation principle that a single large (SL) patch of habitat has higher biodiversity than several small (SS) patches of the same total area (SL > SS). Nonetheless, this principle is often incorrect, and biodiversity conservation requires placing more emphasis on protection of large numbers of small patches (SS > SL). We used a global database reporting the abundances of species across hundreds of patches to assess the SL > SS principle in systems where small patches are much smaller than the typical minimum patch size criteria applied for biodiversity conservation (i.e., ∼85% of patches <100 ha). The 76 metacommunities we examined included 4401 species in 1190 patches. From each metacommunity, we resampled species–area accumulation curves to evaluate how biodiversity responded to habitat existing as a few large patches or as many small patches. Counter to the SL > SS principle and consistent with previous syntheses, species richness accumulated more rapidly when adding several small patches (45.2% SS > SL vs. 19.9% SL > SS) to reach the same cumulative area, even for the very small patches in our data set. Responses of taxa to habitat fragmentation differed, which suggests that when a given total area of habitat is to be protected, overall biodiversity conservation will be most effective if that habitat is composed of as many small patches as possible, plus a few large ones. Because minimum patch size criteria often require larger patches than the small patches we examined, our results suggest that such criteria hinder efforts to protect biodiversity.     

Rabbit biocontrol and landscape‐scale recovery of threatened desert mammals

Funding for species conservation is insufficient to meet the current challenges facing global biodiversity, yet many programs use expensive single‐species recovery actions and neglect broader management that addresses threatening processes. Arid Australia has the world's worst modern mammalian extinction record, largely attributable to competition from introduced herbivores, particularly European rabbits (Oryctolagus cuniculus) and predation by feral cats (Felis catus) and foxes (Vulpes vulpes). The biological control agent rabbit hemorrhagic disease virus (RHDV) was introduced to Australia in 1995 and resulted in dramatic, widespread rabbit suppression. We compared the area of occupancy and extent of occurrence of 4 extant species of small mammals before and after RHDV outbreak, relative to rainfall, sampling effort, and rabbit and predator populations. Despite low rainfall during the first 14 years after RHDV, 2 native rodents listed by the International Union for Conservation of Nature (IUCN), the dusky hopping‐mouse (Notomys fuscus) and plains mouse (Pseudomys australis), increased their extent of occurrence by 241–365%. A threatened marsupial micropredator, the crest‐tailed mulgara (Dasycercus cristicauda), underwent a 70‐fold increase in extent of occurrence and a 20‐fold increase in area of occupancy. Both bottom‐up and top‐down trophic effects were attributed to RHDV, namely decreased competition for food resources and declines in rabbit‐dependent predators. Based on these sustained increases, these 3 previously threatened species now qualify for threat‐category downgrading on the IUCN Red List. These recoveries are on a scale rarely documented in mammals and give impetus to programs aimed at targeted use of RHDV in Australia, rather than simply employing top‐down threat‐based management of arid ecosystems. Conservation programs that take big‐picture approaches to addressing threatening processes over large spatial scales should be prioritized to maximize return from scarce conservation funding. Further, these should be coupled with long‐term ecological monitoring, a critical tool in detecting and understanding complex ecosystem change.     

Conserving spawning stocks through harvest slot limits and no-take protected areas

The key to the conservation of harvested species is the maintenance of reproductive success. Yet for many marine species large, old, individuals are targeted despite their disproportionate contribution to reproduction. We hypothesized that a combination of no-take marine protected areas (MPAs) and harvest slot limits (maximum and minimum size limits) would result in the conservation of large spawning individuals under heavy harvest. We tested this approach under different harvest intensities with a 2-sex, stage-structured metapopulation model for the Caribbean spiny lobster (Panulirus argus). P. argus is intensively harvested in the Caribbean, and in many localities large, mature individuals no longer exist. No-take MPAs and harvest slot limits combined, rebuilt and maintained large mature individuals even under high harvest pressure. The most conservative model (a 30% MPA and harvest slot limit of 75–105 mm) increased spawner abundance by 5.53E¹² compared with the fishing status quo at the end of 30 years. Spawning stock abundance also increased by 2.76–9.56E¹² individuals at a high harvest intensity over 30 years with MPAs alone. Our results demonstrate the potential of MPAs and harvest slot limits for the conservation of large breeding individuals in some marine and freshwater environments. Decisions on which management strategy best suits a fishery, however, requires balancing what is ecologically desirable with what is economically and socially feasible.     

Rapidly Shifting Baselines in Yangtze Fishing Communities and Local Memory of Extinct Species

Abstract: Local ecological knowledge can provide a unique source of data for conservation, especially in efforts to investigate the status of rare or possibly extinct species, but it is unlikely to remain constant over time. Loss of perspective about past ecological conditions caused by lack of communication between generations may create “shifting baseline syndrome,” in which younger generations are less aware of local species diversity or abundance in the recent past. This phenomenon has been widely discussed, but has rarely been examined quantitatively. We present new evidence of shifting baselines in local perception of regional species declines and on the duration of “community memory” of extinct species on the basis of extensive interviews with fishers in communities across the middle‐lower Yangtze basin. Many Yangtze species have experienced major declines in recent decades, and the Yangtze River dolphin or baiji (Lipotes vexillifer) and Yangtze paddlefish (Psephurus gladius) may have become extinct during the 21^st century. Although informants across all age classes were strongly aware of the Yangtze ecosystem's escalating resource depletion and environmental degradation, older informants were more likely to recognize declines in two commercially important fish species, Reeves’ shad (Tenualosa reevesii) and Yangtze pufferfish (Takifugu fasciatus), and to have encountered baiji and paddlefish in the past. Age was also a strong predictor of whether informants had even heard of baiji or paddlefish, with younger informants being substantially less likely to recognize either species. A marked decrease in local knowledge about the Yangtze freshwater megafauna matched the time of major population declines of these species from the 1970s onwards, and paddlefish were already unknown to over 70% of all informants below the age of 40 and to those who first started fishing after 1995. This rapid rate of cultural baseline shift suggests that once even megafaunal species cease to be encountered on a fairly regular basis, they are rapidly forgotten by local communities.     

Connectivity Planning to Address Climate Change

As the climate changes, human land use may impede species from tracking areas with suitable climates. Maintaining connectivity between areas of different temperatures could allow organisms to move along temperature gradients and allow species to continue to occupy the same temperature space as the climate warms. We used a coarse‐filter approach to identify broad corridors for movement between areas where human influence is low while simultaneously routing the corridors along present‐day spatial gradients of temperature. We modified a cost–distance algorithm to model these corridors and tested the model with data on current land‐use and climate patterns in the Pacific Northwest of the United States. The resulting maps identified a network of patches and corridors across which species may move as climates change. The corridors are likely to be robust to uncertainty in the magnitude and direction of future climate change because they are derived from gradients and land‐use patterns. The assumptions we applied in our model simplified the stability of temperature gradients and species responses to climate change and land use, but the model is flexible enough to be tailored to specific regions by incorporating other climate variables or movement costs. When used at appropriate resolutions, our approach may be of value to local, regional, and continental conservation initiatives seeking to promote species movements in a changing climate. Planificación de Conectividad para Atender el Cambio Climático     

Foundations of Resilience Thinking

Through 3 broad and interconnected streams of thought, resilience thinking has influenced the science of ecology and natural resource management by generating new multidisciplinary approaches to environmental problem solving. Resilience science, adaptive management (AM), and ecological policy design (EPD) contributed to an internationally unified paradigm built around the realization that change is inevitable and that science and management must approach the world with this assumption, rather than one of stability. Resilience thinking treats actions as experiments to be learned from, rather than intellectual propositions to be defended or mistakes to be ignored. It asks what is novel and innovative and strives to capture the overall behavior of a system, rather than seeking static, precise outcomes from discrete action steps. Understanding the foundations of resilience thinking is an important building block for developing more holistic and adaptive approaches to conservation. We conducted a comprehensive review of the history of resilience thinking because resilience thinking provides a working context upon which more effective, synergistic, and systems‐based conservation action can be taken in light of rapid and unpredictable change. Together, resilience science, AM, and EPD bridge the gaps between systems analysis, ecology, and resource management to provide an interdisciplinary approach to solving wicked problems. Fundamentos del Pensamiento sobre Resiliencia     

The challenge of biased evidence in conservation

Efforts to tackle the current biodiversity crisis need to be as efficient and effective as possible given chronic underfunding. To inform decision-makers of the most effective conservation actions, it is important to identify biases and gaps in the conservation literature to prioritize future evidence generation. We used the Conservation Evidence database to assess the state of the global literature that tests conservation actions for amphibians and birds. For the studies in the database, we investigated their spatial and taxonomic extent and distribution across biomes, effectiveness metrics, and study designs. Studies were heavily concentrated in Western Europe and North America for birds and particularly for amphibians, and temperate forest and grassland biomes were highly represented relative to their percentage of land coverage. Studies that used the most reliable study designs—before-after control-impact and randomized controlled trials—were the most geographically restricted and scarce in the evidence base. There were negative spatial relationships between the numbers of studies and the numbers of threatened and data-deficient species worldwide. Taxonomic biases and gaps were apparent for amphibians and birds—some entire orders were absent from the evidence base—whereas others were poorly represented relative to the proportion of threatened species they contained. Metrics used to evaluate effectiveness of conservation actions were often inconsistent between studies, potentially making them less directly comparable and evidence synthesis more difficult. Testing conservation actions on threatened species outside Western Europe, North America, and Australasia should be prioritized. Standardizing metrics and improving the rigor of study designs used to test conservation actions would also improve the quality of the evidence base for synthesis and decision-making.     

WATER EXCHANGES: TOOLS TO BEAT EL NIÑO CLIMATE VARIABILITY IN IRRIGATED AGRICULTURE1

ABSTRACT: Using a case study of the Yakima River Valley in Washington State, this paper shows that relatively simple tools can be used to forecast the impact of the El Niño phenomenon on water supplies to irrigated agriculture, that this information could be used to estimate the significantly shifted probability distribution of water shortages in irrigated agriculture during El Niño episodes, and that these shifted probabilities can be used to estimate the value of exchanges of water between crops to relieve some of the adverse consequences of such shortages under western water law. Further, recently devised water‐trading tools, while not completely free under western water law to respond to forecasted El Niño episodes (ocean circulation patterns), are currently being employed during declared drought to reduce the devastating effects of water shortages in junior water districts on high valued perennial crops. Additional institutional flexibility is needed to take full advantage of climate forecasting, but even current tools clearly could prove useful in controlling the effects of climate variability in irrigated agriculture. Analysis shows the significant benefit of temporarily transferring or renting water rights from low‐value to high‐value crops, based on El Niño forecasts.     

水厂抽水对乌什地震台体应变观测数据的干扰分析

根据体应变的观测原理,从理论和实际观测中分析了水厂抽水对体应变观测分钟值曲线的影响及两者间的相关性.分析表明,应变观测值波动时间与抽水时间基本吻合,因此认为水厂抽水对体应变观测会造成一定程度的干扰.