小水电代燃料工程对森林生态服务功能的影响

根据国家林业局发布的《森林生态系统服务功能评估规范》(LY/T 1721—2008),从涵养水源、保育土壤、固碳释氧和积累营养物质功能4个方面进行评价,研究小水电代燃料工程的实施对贵州省麻江县项目区森林生态服务功能的物质量及其价值的影响.结果表明: 小水电代燃料工程对森林生态系统服务功能物质量的增加有显著作用.马尾松和柏木人工林在项目区内涵养水源功能的物质量达20662.04 m³·hm^-2·a^-1,比项目区外增加20.5%,保育土壤量为119.1 t·hm^-2·a^-1,比项目区外增加29.7%,固碳释氧量为220.49 t·hm^-2·a^-1,比项目区外增加40.2%,林木营养积累量达3.49 t·hm^-2·a^-1,比项目区外增加48.5%.小水电代燃料工程对项目区森林生态系统服务功能价值增加额度表现为:固碳释氧功能(7.14 万元·hm^-2·a^-1)>涵养水源功能(6.01万元·hm^-2·a^-1)>林木营养积累功能(1.38万元·hm^-2·a^-1)>保育土壤功能(0.81万元·hm^-2·a^-1).小水电代燃料工程对提高森林生态服务功能价值和实现林区的可持续发展具有重要作用.     

Carbon pool densities and a first estimate of the total carbon pool in the Mongolian forest‐steppe

The boreal forest biome represents one of the most important terrestrial carbon stores, which gave reason to intensive research on carbon stock densities. However, such an analysis does not yet exist for the southernmost Eurosiberian boreal forests in Inner Asia. Most of these forests are located in the Mongolian forest‐steppe, which is largely dominated by Larix sibirica. We quantified the carbon stock density and total carbon pool of Mongolia's boreal forests and adjacent grasslands and draw conclusions on possible future change. Mean aboveground carbon stock density in the interior of L. sibirica forests was 66 Mg C ha^?1, which is in the upper range of values reported from boreal forests and probably due to the comparably long growing season. The density of soil organic carbon (SOC, 108 Mg C ha^?1) and total belowground carbon density (149 Mg C ha^?1) are at the lower end of the range known from boreal forests, which might be the result of higher soil temperatures and a thinner permafrost layer than in the central and northern boreal forest belt. Land use effects are especially relevant at forest edges, where mean carbon stock density was 188 Mg C ha^?1, compared with 215 Mg C ha^?1 in the forest interior. Carbon stock density in grasslands was 144 Mg C ha^?1. Analysis of satellite imagery of the highly fragmented forest area in the forest‐steppe zone showed that Mongolia's total boreal forest area is currently 73 818 km², and 22% of this area refers to forest edges (defined as the first 30 m from the edge). The total forest carbon pool of Mongolia was estimated at ~ 1.5?1.7 Pg C, a value which is likely to decrease in future with increasing deforestation and fire frequency, and global warming.     

Use of the Gibbs Sampler to Obtain Conditional Tests, with Applications

A random sample is drawn from a distribution which admits aminimal sufficient statistic for the parameters. The Gibbs sampleris proposed to generate samples, called conditionally sufficientor co-sufficient samples, from the conditional distributionof the sample given its value of the sufficient statistic. Theprocedure is illustrated for the gamma distribution. Co-sufficientsamples may be used to give exact tests of fit; for the gammadistribution these are compared for size and power with approximatetests based on the parametric bootstrap.     

Male Migration in Barbary Macaques (Macaca sylvanus) at Affenberg Salem

We analyzed male migration during a 20-year period in the free-ranging Barbary macaque population of Affenberg Salem. Most natal migrations occurred around puberty, but only one third of all males left the natal group. Secondary group transfers were rare. All males immediately transferred to other bisexual groups. Migration rates were highest during periods with high adult female/male ratios within social groups. Immigrants highly preferred groups with fewer males of their own age than in the natal group, and many males immigrated into groups that had no male their own age. These groups originated from a skewed distribution of resident males during group fissions. A comparison of emigrants with their natal peers supports the inbreeding avoidance hypothesis as cause of emigration rather than the male competition avoidance hypothesis. Emigrants had no lower individual rank position and did not come from lower-ranking matrilines. Emigrants had more female maternal relatives, especially sisters. Males without female relatives almost never emigrated. Conversely, there is virtually no indication that emigrants were evicted from the natal group. Emigrants had no increased mortality. Paternity data revealed that the reproductive success of emigrants and natal males is similar, indicating that emigration had no reproductive cost. Many similarities between emigrants and natal males that separated from female maternal kin during group fissions suggest that inner migration during fissions is an alternative way to avoid maternal inbreeding. The mating system resulted in a genetic structure within social groups that largely diminished the chances for paternal inbreeding even without recognizing paternal kin.     

Fixing Content and Function in Neurobiological Systems: The Neuroethology of Electroreception

Are attributions of content and function determinate, or is there no fact of the matter to be fixed? Daniel Dennett has argued in favor of indeterminacy and concludes that, in practice, content and function cannot be fixed. The discovery of an electrical modality in vertebrates offers one concrete instance where attributions of function and content are supported by a strong scientific consensus. A century ago, electroreception was unimagined, whereas today it is widely believed that many species of bony fish, amphibians, sharks, skates, and rays possess this non-human sensory modality. A look at the history of science related to this discovery reveals a highly interdisciplinary endeavor, encompassing ethology, behavioral analysis, neuroscience, and evolutionary biology. While each area provides important evidence, none is sufficient on its own to fix content and function. Instead, I argue that an interdisciplinary, neuroethological approach is required to carry out such determinations. Further, a detailed consideration of biological research suggests that while content and function claims are empirically underdetermined and uncertain, there is insufficient reason to believe in an additional problem of indeterminism. In particular, Dennett's indeterminism arises from a research methodology -- logical adaptationism -- that generates evidence from only one of the areas of neuroethology. However, logical adaptationism does not reflect adaptationism as it is practiced in contemporary biology. I conclude that Dennett is faced with a dilemma: On the one hand, he can hold to logical adaptationism and the indeterminism that results from it, while giving up the relevance of his arguments to biological practice. On the other, he can embrace a more accurate version of adaptationism -- one which plays a role in a larger neuroethological framework -- but from which no strong indeterminacy claims follow.     

Establishment of Transfer Functions of the Pollen-Climatic Factors in Northern China and the Quantitative Climatic Reconstruction at DJ Core

The 2.4 meter-long core was extracted from the Diaojiao lake (41º18′N, 112º21′E) at the foot of the northern part of Daqingshan Mts. Pollen analysis from collections subsampled in the laboratory at 2 cm intervals, revealed plentiful pollen and spores from over 10 arboreal genera, including Pinus, Betula, Picea, Abies, Carpinus, Quercus, Ulmus and more than 20 non-arboreal genera, mainly of Artemisia, Labiatae, Nitraria, Polygonaceae, Ranunculus, Thalictrum, Umbel- liferae, Caryophyllaceae and Cyperaceae. Fern spores, aquatic pollen and algae were also observed in some parts of the core. The transfer functions were established by the stepwise regression analysis using the climatic factors and 13 pollen taxa. The different Fl and F2 value were used as the thresh- old value of F test (i. e. used for selecting and deleting factors). Each regressed equation was obtained from 70 times of calculations with a step-wise increase of 0.1 for Fl and F2 and those having the smallest regression deviation and the largest multiple correlation coefficient were the final four transfer functions. Substituting the pre-factor obtained from the stratigraphic sampled into the regression equations, the estimates of temperature and precipitation in January and in July, and annual mean temperature values could be calculated. Some climatic stages were inferred from total pollen influx and pollen percentage from the core using a transfer function: humid-cool (from 10 000 to 7 800 a BP), arid-cold (9 200 to 7 900 a BP), arid-warm (7 900 to 7 100 a BP), humid-warm (7 100 to 4 400 a BP), arid-warm (4 400 to 3 000 a BP), arid-cold (3 000 to 2 100 a BP). The highest annual mean temperature during Holocene was ca. 4 ℃ higher and the lowest was ca. 2 ℃ lower than the present temperature. Annual precipitation was 250 mm higher and 300 mm lower than the present.