Choice of baseline affects historical population trends in hunted mammals of North America

Establishing historical baselines of species' populations is important for contextualising present-day population trends, identifying significant anthropogenic threats, and preventing a cultural phenomenon known as ‘shifting baseline syndrome’. However, our knowledge of historical baselines is limited by a lack of direct observation data on species abundance pre-1970. We present historical data of species-specific fur harvests from the Canadian government and Hudson's Bay Company as a proxy for estimating species abundance over multiple centuries. Using stochastic stock reduction analysis originally developed for marine species, we model historical population trends for eight mammals, and assess population trends based on two different baseline years: 1850 and 1970. Results show that population declines are significantly greater when using an 1850 baseline, as opposed to a 1970 baseline, and for four species, the population trend shifted from a population increase to a decrease. Overall, the median population change of the eight species changed from a 15% decline for 1850, to a 4% increase for 1970. This study shows the utility of harvest data for deriving population baselines for hunted terrestrial mammals which can be used in addition to other historical data such as local ecological knowledge. Results highlight the need for developing historically relevant population baselines in order to track abundances over time in threatened species and common species alike, to better inform species conservation programs, wildlife management plans and biodiversity indicators

Current uses and future perspectives for conservation biology

Conservation science is a discipline which has been born in response to the simple fact that biodiversity is declining at never before seen rates (Millennium Ecosystem Assessment, 2005). Background extinction rates are being dramatically exceeded, and models of future scenarios predict that this rate will only increase (Fig 2.1), perhaps by an order of magnitude, unless preventative action is taken (Regan et al., 2001). The reasons for this decline are at least well known, if not well understood. Land clearance reduces available habitat; exploitation removes healthy animals from the population; introduced predators and diseases impact ‘naïve’ species, and, ultimately, extinction breaks down ecological networks – Diamond’s evil quartet (Diamond, 1989). Increasingly, climate change is enhancing the negative impacts of this list of threats (IPCC, 2002; Thomas et al., 2004). The problem and its effects are so pressing that it has been framed under international legislation, and more than 190 countries signed up to a target set to achieve a significant reduction in biodiversity loss by 2010 (UNEP, 2002), a target that was not met (Butchart et al., 2010). Effective action to achieve such a target requires detailed information, and Floras and Faunas often provide much of the data that underpin priority-setting decisions derived from biodiversity data. While the key taxonomic issue to be faced by biodiversity conservation remains the under-description of species (May, 1988; Wilson, 2003), a growing issue that threatens to complicate, and perhaps undermine, conservation planning is taxonomic inflation (Isaac et al., 2004; Mace, 2004)

National assessment of threatened species using sparse data: IUCN Red List classification of Anatidae in Iran

Classifying the status of threatened species using tools such as the IUCN Red List is a critical step for identifying at-risk species, and for conservation planning at global and sub-global levels. The requirement for data on population trends, geographic ranges and population sizes has proved challenging to carry out at the national level, especially in countries with unstructured and spatially limited monitoring schemes and limited conservation resources. In this study, we investigated the repeatability of risk assessments made under the IUCN Red List guidelines for assessment at the national level. Specifically, we assessed the national threat status of breeding and non-breeding populations of Anatidae in Iran using population and distribution data. The variable quality of these data led to uncertainties in decision-making. To evaluate the impact of these uncertainties on population trend estimates, we generated a range of alternative possible threat categories under three scenarios of population trend estimation. For the non-breeding populations, for which long-term population data were available, we were able to classify 93% of species, 72% of which were placed in threatened categories. For the breeding populations, 78% of the species were categorized as Data Deficient. Of those species in data-sufficient categories, 67% were classified as threatened. We conclude that effective use of the IUCN categories and criteria at the national level is hampered in situations where monitoring schemes have a short history. Therefore, available data need to be complemented with some level of standardized data collection. We further make suggestions about efficient means of data collection in such cases and the importance of the use of modeling techniques prior to Red Listing and discuss the most useful IUCN criteria for threat categorization in such circumstances

Processing of pine (Pinus sylvestris) and birch (Betula pubescens) leaf material in a small river system in the northern Cairngorms, Scotland

International audienceProcessing rates, and macroinvertebrate colonisation, of pine needles and birch leaves were studied at eight sites on the river Nethy, a small river system in the Cairngorm region of north-eastern Scotland. Throughout this river system, processing rates were slow for pine (k values 0.0015-0.0034 day-1) and medium to fast for birch (k values 0.0085-0.0331 day-1). Plecopteran shredders dominated both pine and birch leaf packs during the early part of the experiment while chironomids were more important in the latter stages. It is suggested that the slow processing rate of pine needles could adversely affect the productivity of streams, particularly where needles provide the major allochthonous energy source and retentive features are limited. Forest managers should consider this when creating new pinewoods in treeless areas as it will take many years for the trees to reach a size at which they can effectively contribute retentive features, in the form of woody debris, to streams. Keywords: leaf processing, pine needles, shredders, Pinus sylvestris, Betula pubescens, Scotland

Experimental non-equilibrium radiation measurements for low-Earth orbit return

This paper reports on absolute radiation measurements performed in synthetic air (20.78% O2, 79.22% N2) shock-heated flows. Experiments were carried out in the Oxford T6 Stalker Tunnel in Aluminium Shock Tube mode. Data is presented for velocities ranging from 5.5-7.2 km/s at a nominal 1 bar post-shock pressure, in both UV/Vis and Vis/NIR spectral ranges. Simulations of the equilibrium radiance using NASA CEA and NEQAIR codes underpredict that obtained from the experimental data. An analysis using the newly developed LASTA code removes shock deceleration from consideration as a cause for this discrepancy. Non-equilibrium data is analysed in the form of spectral and absolute non-equilibrium metrics, and the effects of shock speed and post-shock pressure on the non-equilibrium radiance isolated. Finite-rate one-dimensional two-temperature simulations using POSHAX3 with Park 1993 rates are performed, which significantly underpredict the experimentally acquired data

Complex long-term biodiversity change among invertebrates, bryophytes and lichens

Large-scale biodiversity changes are measured mainly through the responses of a few taxonomic groups. Much less is known about the trends affecting most invertebrates and other neglected taxa, and it is unclear whether well-studied taxa, such as vertebrates, reflect changes in wider biodiversity. Here, we present and analyse trends in the UK distributions of over 5,000 species of invertebrates, bryophytes and lichens, measured as changes in occupancy. Our results reveal substantial variation in the magnitude, direction and timing of changes over the last 45 years. Just one of the four major groups analysed, terrestrial non-insect invertebrates, exhibits the declining trend reported among vertebrates and butterflies. Both terrestrial insects and the bryophytes and lichens group increased in average occupancy. A striking pattern is found among freshwater species, which have undergone a strong recovery since the mid-1990s after two decades of decline. We show that, while average occupancy among most groups appears to have been stable or increasing, there has been substantial change in the relative commonness and rarity of individual species, indicating considerable turnover in community composition. Additionally, large numbers of species have experienced substantial declines. Our results suggest a more complex pattern of biodiversity change in the United Kingdom than previously reported

Radiation measurements of shockwaves in synthetic air and pure nitrogen

Absolute radiance measurements in synthetic air and pure nitrogen have been performed in the Oxford T6 Stalker Tunnel while operating in Aluminium Shock Tube mode. Spatially and spectrally resolved data have been attained for shock speeds from 5.7 to 8 km/s and post-shock pressures from ∼10 to ∼100 kPa. Two independent telecentric optical set ups acquire data from the UV/Vis (200 to 520 nm) and Vis/NIR (585 to 850 nm) regions. The data are presented in multiple formats. An example 2D spectral-spatial map of absolute radiance is provided. Equilibrium spectral radiance comparisons against CEA-NEQAIR demonstrate improved agreement since prior campaigns in both T6 and the Electric Arc Shock Tube at NASA Ames. Spatial radiance profiles demonstrate lower pressure conditions can improve the resolution of non-equilibrium relaxation. Finally, spectral profiles progressing through the relaxation region for a low pressure synthetic air test case are shown. The motivation of this paper is to provide reliable calibrated data that, in future work, can be used to extract thermochemical rates and upon which numerical codes and facility results can be benchmarked against

Toward equality of biodiversity knowledge through technology transfer

To help stem the continuing decline of biodiversity, effective transfer of technology from resource-rich to biodiversity-rich countries is required. Biodiversity technology as defined by the Convention on Biological Diversity (CBD) is a complex term, encompassing a wide variety of activities and interest groups. As yet, there is no robust framework by which to monitor the extent to which technology transfer might benefit biodiversity. We devised a definition of biodiversity technology and a framework for the monitoring of technology transfer between CBD signatories. Biodiversity technology within the scope of the CBD encompasses hard and soft technologies that are relevant to the conservation and sustainable use of biodiversity, or make use of genetic resources, and that relate to all aspects of the CBD, with a particular focus on technology transfer from resource-rich to biodiversity-rich countries. Our proposed framework introduces technology transfer as a response indicator: technology transfer is increased to stem pressures on biodiversity. We suggest an initial approach of tracking technology flow between countries; charting this flow is likely to be a one-to-many relationship (i.e., the flow of a specific technology from one country to multiple countries). Future developments should then focus on integrating biodiversity technology transfer into the current pressure-state-response indicator framework favored by the CBD (i.e., measuring the influence of technology transfer on changes in state and pressure variables). Structured national reporting is important to obtaining metrics relevant to technology and knowledge transfer. Interim measures, that can be used to assess biodiversity technology or knowledge status while more in-depth indicators are being developed, include the number of species inventories, threatened species lists, or national red lists; databases on publications and project funding may provide measures of international cooperation. Such a pragmatic approach, followed by rigorous testing of specific technology transfer metrics submitted by CBD signatories in a standardized manner may in turn improve the focus of future targets on technology transfer for biodiversity conservation