Problem solving in European bison (Bison bonasus): two experimental approaches

The ability to solve novel problems is crucial for individual fitness. However, studies on problem solving are usually done on few taxa, with species with low encephalization quotient being rarely tested. Here, we aimed to study problem solving in a non-domesticated ungulate species, European bison, with two experimental tasks. In the first task, five individuals were presented with a hanging barrel filled with food, which could either be directly accessed (control condition) or which could only be reached by pushing a tree stump in the enclosure below it and stepping on it (experimental condition). In the second task, five individuals were repeatedly fed by an experimenter using a novel bucket to retrieve food from a bag. Then, three identical buckets were placed in the enclosure, while the experimenter waited outside with the bag without feeding the bison, either with a bucket (control condition) or without it (experimental condition). In the first task, no bison moved the stump behind the barrel and/or stepped on it to reach the food. In the second task, two individuals solved the task by pushing the bucket within the experimenter's reach, twice in the experimental and twice in the control condition. We suggest that bison showed a limited ability to solve novel problems, and discuss the implications for their understanding of the functional aspects of the tasks.

Numerical Simulation of the Combined Slope Protection Effect of Live Stump and Bamboo Anchor

Five slope states were selected to research deep protection effect of the living tree stump-bamboo anchor supporting structure. These five states were the natural slope state,the bamboo anchor slope protection state, and the living tree stump-bamboo anchor initial supporting state,living tree stumps-bamboo bolt mid-term support status,living tree stump slope protection status. Three-dimensional numerical models are established by Midas GTS/NX finite element software, and the force characteristics and stability of the living tree stump-bamboo anchor support structure were studied. The results show that: (1) Compared with natural slopes, the relative stability and safety factors of bamboo anchor slope protection, live tree stumps-bamboo anchor initial slope protection, live tree stumps-bamboo anchor mid-term slope protection, and live tree stump slope protection have increased by 18.6%, 19.7%, and 44.0 %, 44.1%, it can be found that the living tree stump-bamboo bolt supporting structure has obvious deep protection effect. (2) In the initial supporting state of live tree stumps and bamboo anchors, the bamboo anchors have the largest stress value at the position where the bamboo anchors are buried at a depth of 5m on the slope; The bamboo anchors in the fourth row and the fifth row are below the buried depth of 6m on the slope, and the stress value of the bamboo anchors increases linearly. (3) The closer to the toe of the slope, the greater the tensile stress generated by the root system on the left side of the living tree stump, and the greater the compressive stress generated by the root system on the right side of the living tree stump. The research results can be used as an important basis for the new living tree stump-bamboo bolt support structure to effectively prevent and control deep-seated slope protection, and it is of great significance to expand the green technology for preventing and controlling deep-seated landslides.

The geochronology of a palaeolake at the Pleistocene/Holocene transition in the Muya-Kuanda Basin (Eastern Siberia, Russia)

This article presents new data on the study of preserved wood from flooded forests in the Muya-Kuanda Basin, Eastern Siberia. On the basis of the stratigraphic position of a buried tree stump horizon, the analysis of the associated alluvial deposits and a new programme of radiocarbon dating, the chronology of formation and collapse for a Late Pleistocene pal eolake in the Muya-Kuanda Basin can be precisely determined. The accuracy of dating of geological events with the radiocarbon method and the possibility of linking them to calendrical dates is discussed. As a result of this research it is possible to connect the geochronology of the lake with archaeological sites in the Vitim Basin, both upstream and downstream along the river. The reasons for the periodic formation of substantial bodies of water in the Muya-Kuanda Basin are also discussed, with implications for decision making with regard to the modern economic development of the region.

A Spatially Explicit Decision Support System for Assessment of Tree Stump Harvest Using Biodiversity and Economic Criteria

Stump harvesting is predicted to increase with future increasing demands for renewable energy. This may affect deadwood affiliate biodiversity negatively, given that stumps constitute a large proportion of the coarse deadwood in young managed forests. Spatial decision support for evaluating the integrated effects on biodiversity and production of stump harvesting is needed. We developed a spatially explicit decision support system (called MapStump-DSS), for assessment of tree stump harvesting using biodiversity and economic criteria together with different scenarios for biodiversity conservation and bioenergy market prices. Two novel key aspects of the MAPStump-DSS is that it (1) merges and utilizes georeferenced stump-level data (e.g., tree species and diameter) directly from the harvester with stand data that are increasingly available to forest managers and (2) is flexible toward incorporating both quantitative and qualitative criteria based on emerging knowledge (here biodiversity criteria) or underlying societal drivers and end-user preferences. We tested the MAPStump-DSS on a 45 ha study forest, utilizing harvester data on characteristics and geographical positions for >26,000 stumps. The MAPStump-DSS produced relevant spatially explicit information on the biodiversity and economic values of individual stumps, where amounts of “conflict stumps” (with both high biodiversity and economical value) increased with bioenergy price levels and strengthened biodiversity conservation measures. The MAPStump-DSS can be applied in practice for any forest site, allowing the user to examine the spatial distribution of stumps and to obtain summaries for whole forest stands. Information depicted by the MAPStump-DSS includes amounts, characteristics, biodiversity values and costs of stumps in relation to different scenarios, which also allow the user to explore and optimize biodiversity and economy trade-offs prior to stump harvest.