Soil quality index as a tool for Scots pine （Pinus sylvestris） monoculture conversion planning on afforested,reclaimed mine land

In Central Europe,a large portion of post-mining sites were afforested with Scots pine,which is characterized by good adaptability and a tolerance for poor habitat at the beginning of forest ecosystem development.Conversion of monoculture on mine sites into more biodiverse mixed hardwood forests,especially on more fertile deposits,can be an emerging need in this part of Europe in next decades.The ability to classify the forests at these post-mining sites will facilitate proper species selection as well as the management and formation of the developed ecosystem’s stability.This work describes the guidelines that can be followed to assess reclaimed mine soil(RMS)quality,using the mine soil quality index(MSQI)and a classification of developed forest sites as a basis of tree-stand species selection and conversion of pine monocultures.The research was conducted on four post-mining facilities(lignite,hard coal,sulphur,and sand pit mining areas)on different RMS substrates dominant in Central Europe.Soil quality assessment takes into account the following features of the soil:texture soil nutrients(Ca,Mg,K,Na,P);acidity(pH KCl);and Corg-to-Nt ratio in the initial organic horizon.An analysis was conducted of classification systems using the MSQI validation correlation(at p=0.05)with vegetation features affected by succession:aboveground biomass of forest floor and ecological indicators of vascular plants(calculated on the basis of Ellenberg’s(2009)system).Eventually,in the analysed data set,the MSQI ranged from0.270 for soils on quaternary sands to 0.720 for a mix of quaternary loamy sands with neogene clays.Potential forest habitat types and the role of the pine in the next generation of tree stands on different RMS parent rock substrate were proposed.     

Gharial (Gavialis gangeticus) populations and human influences on habitat on the River Chambal,India

相似文献   

Effects of predation and intraspecific interactions on habitat use and foraging by brown trout in artificial streams

Abstract— We studied habitat use, foraging rates and behavior of 10 cm and 12 cm long brown trout, Salmo trutta , at two densities, 1.5 and 3.0 fish. m⁻², in artificial streams that contained either the amphipod, Gammarus pulex , alone or G. pulex together with the piscivore, northern pike, Esox lucius. Gammarus were stocked in and largely restricted to the pools at a density of 128 Gammurus. m⁻² . pool⁻¹ Large trout (12 cm) used pools more and riffles less when small trout (10 cm) were present than when small trout were absent. Small trout consumed fewer Gammarus when together with large trout than when alone, but showed no difference in habitat use in the presence and abscnce of large trout. Habitat use and number of Gammarus consumed per trout were not affected by trout density for either size-class when alone. For both size-classes of trout, use of pools and foraging rates were higher in the absence than in the presence of pike, and pike primarily resided in the pools. The number of aggressive interactions by both size-classes of trout decreased when pike was present. Our results indicate that for habitats that differ in food resources and predation risk, size structure may affect habitat use and foraging by brown trout.     

Beware of changes: Conservation of Indo‐Pacific humpback dolphins in disturbed habitats

1. Protecting critical habitats of the Indo‐Pacific humpback dolphin, Sousa chinensis, is a hot topic of discussion for marine biodiversity conservation in China and many Southeast Asian countries. In practice, sound habitat protection action (HPA) planning often suffers from information gaps in macroscopic habitat configurations and changes in the habitat conditions of humpback dolphins.
2. Recent publications in the journal Aquatic Conservation: Marine and Freshwater Ecosystems (AQC) have served to advance humpback dolphin conservation in Chinese waters by resolving such habitat configurations and indicating significant changes in distribution patterns and habitat characteristics under intense coastal anthropogenic activity.
3. We highlight an integrative research framework to investigate habitat configuration and long‐term habitat changes when planning a holistic HPA programme for humpback dolphins. When constructing habitat configuration baselines, field surveys should be designed and conducted in a systematic manner to ensure survey efforts cover diverse environments equally, in either a spatially stratified or gridded pattern, to minimize potential spatial sampling biases. Long‐term habitat changes can be revealed by comparing satellite images from different decades. Changes in habitat preferences and habitat characteristics can be explored through questionnaire surveys on local ecological knowledge, associating historical occurrences with coastline features and projecting historical habitat configuration by species distribution modelling exercises.
4. A lack of good communication and sharing of information between research and management sectors can still be an obstacle to the implementation of sound conservation practices, however, even though there is robust scientific evidence to fill knowledge gaps in distribution and habitat baselines. We have addressed the need to establish a mechanism to improve and streamline information sharing between research teams, management sectors, and stakeholder groups.

     

Hypoxia-based habitat compression of tropical pelagic fishes

Large areas of cold hypoxic water occur as distinct strata in the eastern tropical Pacific (ETP) and Atlantic oceans as a result of high productivity initiated by intense nutrient upwelling. We show that this stratum restricts the depth distribution of tropical pelagic marlins, sailfish, and tunas by compressing the acceptable physical habitat into a narrow surface layer. This layer extends downward to a variable boundary defined by a shallow thermocline, often at 25 m, above a barrier of cold hypoxic water. The depth distributions of marlin and sailfish monitored with electronic tags and average dissolved oxygen (DO) and temperature profiles show that this cold hypoxic environment constitutes a lower habitat boundary in the ETP, but not in the western North Atlantic (WNA), where DO is not limiting. Eastern Pacific and eastern Atlantic sailfish are larger than those in WNA, where the hypoxic zone is much deeper or absent. Larger sizes may reflect enhanced foraging opportunities afforded by the closer proximity of predator and prey in compressed habitat, as well as by the higher productivity. The shallow band of acceptable habitat restricts these fishes to a very narrow surface layer and makes them more vulnerable to over‐exploitation by surface gears. Predictably, the long‐term landings of tropical pelagic tunas from areas of habitat compression have been far greater than in surrounding areas. Many tropical pelagic species in the Atlantic Ocean are currently either fully exploited or overfished and their future status could be quite sensitive to increased fishing pressures, particularly in areas of habitat compression.     

Changes in rhodopsin-porphyropsin ratio of chum and pink salmon

ABSTRACT:   In order to investigate the changes in rhodopsin-porphyropsin ratio of chum salmon and pink salmon in relation to the change in their habitat, the ratios were analyzed in individual fish prior to stocking, during the sea run, homing, and upstream migration. The ratio in both the species gradually increased during the sea run. However, the ratio decreased after upstream river migration. Moreover, in the sea, the rhodopsin-porphyropsin ratio of chum salmon was always slightly higher than that of pink salmon. The largest difference in the individual variation was observed in the individuals caught with a set net placed near the mouth of a home river.     

The yellow European eel (Anguilla anguilla L.) may adopt a sedentary lifestyle in inland freshwaters

Abstract – We analysed the movements of the growing yellow phase using a long-term mark–recapture programme on European eels in a small catchment (the Frémur, France). The results showed that of the yellow eels (>200 mm) recaptured, more than 90% were recaptured at the original marking site over a long period before the silvering metamorphosis and downstream migration. We conclude that yellow European eels >200 mm may adopt a sedentary lifestyle in freshwater area, especially in small catchment.     

The potential of temporary shelters to increase survival of the endangered Mexican axolotl

1. Amphibian populations worldwide are in decline. Proactive conservation techniques such as translocations into created and restored wetlands have gained popularity in recent years but may fail owing to high predation and low environmental adaptability.
2. The Mexican axolotl (Ambystoma mexicanum), affected by rapid urbanization, is now possibly extinct in the wild despite millions living in captivity throughout the world.
3. The aim of this study was to explore whether ponds from an artificial wetland can function as temporary shelters for a viable population of axolotls that could be re-introduced into their native ecosystem in Xochimilco once it is restored.
4. Egg-laying and hatching of 11 unique axolotl pairs placed into reproductive enclosures and larval survival to 7 weeks and up to 12 months were examined. Physicochemical and biological parameters were estimated and compared among ponds.
5. The results from this study are encouraging as they suggest that two ponds have adequate conditions for axolotls to reproduce and for larvae and juveniles to survive.

     

Machine learning highlights the importance of primary and secondary production in determining habitat for marine fish and macroinvertebrates

1. Species distribution models for marine organisms are increasingly used for a range of applications, including spatial planning, conservation, and fisheries management. These models have been constructed using a variety of mathematical forms and drawing on both physical and biological independent variables; however, what might be called first-generation models have mainly followed the form of linear models, or smoothing splines, informed by data collected in the context of fish surveys.
2. The performance of different classes of variables were tested in a series of species occurrence models built with machine learning methods, specifically evaluating the potential contribution of lower trophic level data. Random forest models were fitted based on the classification of the absence/presence for fish and macroinvertebrates surveyed on the US Northeast Continental Shelf.
3. The potential variables included physical, primary production, secondary production, and terrain variables. For accepted model fits, six variable importance measures were computed, which collectively showed that physical and secondary production variables make the greatest contribution across all models. In contrast, terrain variables made the least contribution to these models.
4. Multivariable analyses that account for all performance measures reinforce the role of water depth and temperature in defining species presence and absence; however, chlorophyll concentration and some specific zooplankton taxa, such as Metridia lucens and Paracalanus parvus, also make important contributions with strong seasonal variations.
5. Our results suggest that lower trophic level variables, if available, are valuable in the creation of species distribution models for marine organisms.

     

Biodiversity,ecology, fisheries,and use and trade of Tetraodontiformes fishes reveal their socio‐ecological significance along the tropical Brazilian continental shelf

1. Tetraodontiformes fishes play a critical role in benthic and demersal communities and are facing threats due to anthropogenic impacts and climate change. However, they are poorly studied worldwide. To improve knowledge on the socio‐ecological significance and conservation of Tetraodontiformes a review of literature addressing the diversity, ecology, use and trade, conservation, and main threats of Tetraodontiformes combined with a comprehensive in situ dataset from two broad‐range multidisciplinary oceanographic surveys performed along the Tropical Brazilian Continental Shelf was undertaken.
2. Twenty‐nine species were identified, being primarily found on coral reefs and algal ecosystems. At these habitats, tetraodontids present highly diversified trophic categories and might play an important role by balancing the marine food web
3. Coral reef ecosystems, especially those near to the shelf break, seem to be the most important areas of Tetraodontiformes fishes, concentrating the highest values of species richness, relative abundance and the uncommon and Near Threatened species.
4. Ninety per cent of species are commonly caught as bycatch, being also used in the ornamental trade (69%) and as food (52%), serving as an important source of income for artisanal local fisheries.
5. Tetraodontiformes are threatened by unregulated fisheries, overexploitation, bycatch, and habitat loss due to coral reef degradation and the potential effects of climate change. These factors are more broadly impacting global biodiversity, food security, and other related ecosystem functions upon which humans and many other organisms rely.
6. We recommend the following steps that could improve the conservation of Tetraodontiformes along the tropical Brazilian Continental shelf and elsewhere: (i) data collection of the commercial, incidental, ornamental and recreational catches; (ii) improvement of the current legislation directed at the marine ornamental harvesting; (iii) increase efforts focused on the education and conservation awareness in coastal tourism and communities; and, most important, (iv) creation of marine reserves networks in priority areas of conservation, protecting either the species and key habitats for its survival.