The smell of desperadoes? Beavers distinguish between dominant and subordinate intruders

Olfactory signals can contain information, such as age and social status, and play a vital role in competitor assessment. In many territorial species, subordinates must leave their natal colony to obtain their own territory and mate. These individuals could be aggressive opponents in agonistic encounters, as they will have little to lose (the desperado effect). In this study, we tested the hypothesis that dominance and age are coded in the anal gland secretion (AGS) of the monogamous and highly territorial Eurasian beaver (Castor fiber), and if this information is used by conspecifics to evaluate the potential threat posed by an intruder. Territorial intrusions were simulated by presenting residents with a two-way choice test of AGS from an unknown male territory owner (i.e., dominant) and his son (i.e., subordinate; either 1 or ≥2 years old). Residents spent more time investigating AGS from subordinates than their fathers and responded more aggressively to subordinates than their fathers when subordinates were ≥2 years old. Chemical analyses gas chromatography and multivariate data analysis supported our behavioral findings and revealed differences between chemical profiles of territory owners and subordinates, as well as between the subordinates in different age classes. This study reveals that information about age and social status is coded in AGS of beavers and that this information is used to determine the level of an eventual future response to the signaler.     

Future ocean acidification will be amplified by hypoxia in coastal habitats

Ocean acidification is elicited by anthropogenic carbon dioxide emissions and resulting oceanic uptake of excess CO₂ and might constitute an abiotic stressor powerful enough to alter marine ecosystem structures. For surface waters in gas-exchange equilibrium with the atmosphere, models suggest increases in CO₂ partial pressure (pCO₂) from current values of ca. 390 μatm to ca. 700–1,000 μatm by the end of the century. However, in typically unequilibrated coastal hypoxic regions, much higher pCO₂ values can be expected, as heterotrophic degradation of organic material is necessarily related to the production of CO₂ (i.e., dissolved inorganic carbon). Here, we provide data and estimates that, even under current conditions, maximum pCO₂ values of 1,700–3,200 μatm can easily be reached when all oxygen is consumed at salinities between 35 and 20, respectively. Due to the nonlinear nature of the carbonate system, the approximate doubling of seawater pCO₂ in surface waters due to ocean acidification will most strongly affect coastal hypoxic zones as pCO₂ during hypoxia will increase proportionally: we calculate maximum pCO₂ values of ca. 4,500 μatm at a salinity of 20 (T = 10 °C) and ca. 3,400 μatm at a salinity of 35 (T = 10 °C) when all oxygen is consumed. Upwelling processes can bring these CO₂-enriched waters in contact with shallow water ecosystems and may then affect species performance there as well. We conclude that (1) combined stressor experiments (pCO₂ and pO₂) are largely missing at the moment and that (2) coastal ocean acidification experimental designs need to be closely adjusted to carbonate system variability within the specific habitat. In general, the worldwide spread of coastal hypoxic zones also simultaneously is a spread of CO₂-enriched zones. The magnitude of expected changes in pCO₂ in these regions indicates that coastal systems may be more endangered by future global climate change than previously thought.     

Behaviour of Dioxins,Furans and Metals Associated with Stabilized Msw Combustor Ash in Sea Water

This report presents the results of a research programme designed to examine the engineering and environmental acceptability of stabilizing municipal solid waste (MSW) combustor ash for artificial reef construction. Municipal solid waste combustor ash was combined with Portland cement to form solid blocks using conventional construction block making technology. the resultant stabilized combustor ash (SCA) blocks were used to construct an artificial habitat in Conscience Bay, Long Island Sound, New York and compared to identical concrete blocks, fabricated using natural aggregates. Over a 4.5 year period divers periodically returned to the site to monitor the interaction of SCA blocks with the marine environment and compare the performance of these blocks with the concrete control blocks. Results show that the SCA blocks retain their strength after prolonged sea water exposure. Contaminants of environmental concern, including metals, dioxins and furans, were retained within the cementitious matrix of the SCA blocks after prolonged sea water submersion. in addition, organisms growing on the surfaces of the SCA blocks did not accumulate contaminants from the blocks.     

Generalists and specialists along a latitudinal transect: patterns of thermal adaptation in six species of damselflies

Tropical organisms colonizing temperate environments face reduced average temperatures and dramatic thermal fluctuations. Theoretical models postulate that thermal specialization should be favored either when little environmental variation is experienced within generations or when among-generation variation is small relative to within-generation variation. To test these predictions, we studied six temperate species of damselflies differing in latitudinal distribution. We developed a computer model simulating how organisms experience environmental variation (accounting for diapause and voltinism) and performed a laboratory experiment assaying thermal sensitivities of growth rates. The computer model showed opposing latitudinal trends in among- and within-generation thermal variability: within-generation thermal variability decreased toward higher latitudes, whereas relative levels of among-generation thermal variability peaked at midlatitudes (where a shift in voltinism occurred). The growth experiment showed that low-latitude species were more thermally generalized than mid- and high-latitude species, supporting the prediction that generalists are favored under high levels of within-generation variation. Northern species had steeper, near-exponential reaction norms suggestive of thermal specialization. However, they had strikingly high thermal optima and grew very slowly over most of the thermal range they are expected to experience in the field. This observation is at present difficult to explain. These results highlight the importance of considering interactions between life history and environmental variation when deriving expectations of thermal adaptation.     

Temporal patterns of populations in a warming world: a modelling framework

In this paper, we present an approach for describing the environmentally induced temporal pattern of structured populations by partial integro-differential equations. Populations are structured according to size or stage. Growth, energy allocation and stage transitions are affected by environmental conditions of which temperature, photoperiod, water depth and food supply were taken into account. The resulting modelling framework was applied to describe, analyse and predict alterations in populations with continuous development, populations with distinct state structures and interacting populations. Our exemplary applications consider populations of freshwater Amphipoda, Isopoda and Odonata. The model was capable of simulating life cycle alterations in dependence on temperature in interaction with other environmental factors: (1) population dynamics, (2) seasonal regulation, (3) water depth-dependent dispersal, (4) intraguild predation and (5) consumer-resource dynamics.     

Retention of estrogenic steroid hormones by selected New Zealand soils

We performed batch sorption experiments for 17beta-estradiol (E2) and 17alpha-ethynylestradiol (EE2) on selected soils collected from dairy farming regions of New Zealand. Isotherms were constructed by measuring the liquid phase concentration and extracting the solid phase with dichloromethane, followed by an exchange step, and analysis by HPLC and UV detection. The corresponding metabolite estrone, (E1) formed during equilibration of E2 with soil was taken into account to estimate the total percentage recoveries for the compounds, which ranged from 47-105% (E2 and E1) and 83-102% (EE2). Measured isotherms were linear, although some deviation from linearity was observed in a few soils, which was attributed to the finer textured particles and/or the allophanic nature of the soils having high surface area. There was a marked difference in K(d)(eff) (effective distribution coefficient) values for E2 and EE2 among the soils, consistent with the soils organic carbon content and ranged from 14-170 L kg(-1) (E2), and 12-40 L kg(-1) (EE2) in the soils common for both compounds. The sorption affinity of hormones in the soils followed an order: EE2相似文献   

Sustainable forest management in Iran: a factor analysis

Since 1996, several Forest Resources Management Plans (FRMPs) have been launched by the Iranian government in order to approach sustainable forest management in the Zagros area in west and south-west Iran. This survey study aimed to provide some policy recommendations in order to launch more successful FRMPs. Using a proportional cluster random sampling method, data were collected from 208 forest-dwellers (beneficiaries) and 90 practitioners. The results showed that the FRMPs are far from satisfactory. There are several reasons for this failure. First, the financial resources allocated to these plans are being used for other purposes. Second, the inputs and supplies needed for effective forest management interventions were not in place in a timely manner. Third, the forest management in the area is far from being decentralized. Both the beneficiaries and practitioners believe that forest-dwellers play a weak role in forest management interventions. Factor analysis revealed that three main factors influencing the Zagros management effectiveness are “the management capabilities of forest-dwellers”, “the professional capabilities of practitioners in forest management”, and “public support for forest-dwellers”. The correlation analysis revealed that all the three factors are also positively and significantly associated with the success of the government’s forestry programs. Accordingly, the main recommendation of this study was to reformulate forest management policies in the Zagros area by highlighting participatory approaches, not only as a tool, but also as a goal of FRMPs.     

Geographic Profiling to Assess the Risk of Rare Plant Poaching in Natural Areas

We demonstrate the use of an expert-assisted spatial model to examine geographic factors influencing the poaching risk of a rare plant (American ginseng, Panax quinquefolius L.) in Shenandoah National Park, Virginia, USA. Following principles of the analytic hierarchy process (AHP), we identified a hierarchy of 11 geographic factors deemed important to poaching risk and requested law enforcement personnel of the National Park Service to rank those factors in a series of pair-wise comparisons. We used those comparisons to determine statistical weightings of each factor and combined them into a spatial model predicting poaching risk. We tested the model using 69 locations of previous poaching incidents recorded by law enforcement personnel. These locations occurred more frequently in areas predicted by the model to have a higher risk of poaching than random locations. The results of our study can be used to evaluate resource protection strategies and to target law enforcement activities.     

Overview of Contemporary Issues of Forest Research and Management in China

With 207 million ha of forest covering 22% of its land area, China ranks fifth in the world in forest area. Rapid economic growth, climate change, and forest disturbances pose new, complex challenges for forest research and management. Progress in meeting these challenges is relevant beyond China, because China’s forests represent 34% of Asia’s forests and 5% of the worlds’ forests. To provide a broader understanding of these management challenges and of research and policies that address them, we organized this special issue on contemporary forest research and management issues in China. At the national level, papers review major forest types and the evolution of sustainable forestry, the development of China’s forest-certification efforts, the establishment of a forest inventory system, and achievements and challenges in insect pest control in China. Papers focused on Northern China address historical, social, and political factors that have shaped the region’s forests; the use of forest landscape models to assess how forest management can achieve multiple objectives; and analysis and modeling of fuels and fire behavior. Papers addressing Central and South China describe the “Grain for Green” program, which converts low productivity cropland to grassland and woodland to address erosion and soil carbon sequestration; the potential effects of climate change on CO₂ efflux and soil respiration; and relationships between climate and net primary productivity. China shares many forest management and research issues with other countries, but in other cases China’s capacity to respond to forest management challenges is unique and bears watching by the rest of the world.     

An innovative computer design for modeling forest landscape change in very large spatial extents with fine resolutions

Although forest landscape models (FLMs) have benefited greatly from ongoing advances of computer technology and software engineering, computing capacity remains a bottleneck in the design and development of FLMs. Computer memory overhead and run time efficiency are primary limiting factors when applying forest landscape models to simulate large landscapes with fine spatial resolutions and great vegetation detail. We introduce LANDIS PRO 6.0, a landscape model that simulates forest succession and disturbances on a wide range of spatial and temporal scales. LANDIS PRO 6.0 improves on existing forest landscape models with two new data structures and algorithms (hash table and run-length compression). The innovative computer design enables LANDIS PRO 6.0 to simulate very large (>10⁸ ha) landscapes with a 30-m spatial resolution, which to our knowledge no other raster forest landscape models can do. We demonstrate model behavior and performance through application to five nested forest landscapes with varying sizes (from 1 million to 100 million 0.09-ha cells) in the southern Missouri Ozarks. The simulation results showed significant and variable effects of changing spatial extent on simulated forest succession patterns. Results highlighted the utility of a model like LANDIS PRO 6.0 that is capable of efficiently simulating large landscapes and scaling up forest landscape processes to a common regional scale of analysis. The programming methodology presented here may significantly advance the development of next generation of forest landscape models.