种族（Races）属于生物学范畴,但问题十分复杂,涉及到生物学、古人类学、体质人类学、解剖学等领域。民族学也研究种族,民族学教科书均列专章描述。然而,迄今人们对它的认识仍较零碎和肤浅。本文根据有关学科最新资料,试作一综合研究,...种族（Races）属于生物学范畴,但问题十分复杂,涉及到生物学、古人类学、体质人类学、解剖学等领域。民族学也研究种族,民族学教科书均列专章描述。然而,迄今人们对它的认识仍较零碎和肤浅。本文根据有关学科最新资料,试作一综合研究,分四个问题论述。 一、种族差别 人虽属同种（The human species）,但种族之间是有差别的,C·达尔文在《人类的由来》（1871）一书指出:“但各个所谓种族,如果我们把他们仔细地比较和测量一下,彼此之间也无疑地表现很多的差别,例如发的结构、身体各部分的相对比例、肺的容量、颅骨的形态和容量、乃至脑子的脑回。但体格方面的差别太多了,……在素质上,在适应气候或水土的能力上。展开更多
A field experiment was conducted in Jungar Banner,Inner Mongolia,China to study the effects of plant types on the physical structure and chemical properties of open-cast mining soils reclaimed for 15 years,and to anal...A field experiment was conducted in Jungar Banner,Inner Mongolia,China to study the effects of plant types on the physical structure and chemical properties of open-cast mining soils reclaimed for 15 years,and to analyze the triggering factors of the soil formation.Results indicate that plant types affect soil-forming process especially in the upper layer (0-20 cm),and the spatial structure of reclaimed plant is the main reason for variability of the soil-forming process.In the upper soil layer at the site reclaimed with mixed plants,the concentrations of soil organic matter (SOM) and soil organic carbon (SOC) are the highest,and they were significantly higher at the sites reclaimed with Leymus chinensis,Caragana sinica,which is mainly due to a large amount of litter fall and root exudation in herbages and shrubs.However,the concentrations of SOM and SOC in the soils at the reclaimed sites are quite low comparing with those in local primary soil,which indicates the importance of using organic amendments during the ecological restoration in the study area.展开更多
Investigation of the above-ground biomass allocation patterns on Scots pine plantations is critical for quantifying the productivity and carbon cycle of forest ecosystems. We estimated above-ground biomass and net pri...Investigation of the above-ground biomass allocation patterns on Scots pine plantations is critical for quantifying the productivity and carbon cycle of forest ecosystems. We estimated above-ground biomass and net primary production of a 25-year-old Pinus sylvestris L. （Scots pine） plantation, in a semi-arid region of Mongolia. The above-ground biomass of sample trees was divided into stem wood, stem bark, live branches, dead branches and needles. Total biomass for the stand was only 18.03 Mg ha1, of which 47.6% was found in stem wood, 25.8% in live branches and 14.8% in needles. The growth rate of the Scots pine plantation in the study region was relatively low compared with other regions. In the study area, it was observed that the rate of biomass accumulation in the plantation was very slow; this can be explained by very limited growing conditions and intensive crown closure. The results from this study indicate that it may be necessary to carry out thinning to increase biomass production by reducing competition between trees in the Scotch pine plantation.展开更多
Knowledge of the leaf anatomy of grassland plants is crucial for understanding how these plants adapt to the environment. Tibetan alpine grasslands and Inner Mongolian temperate grasslands are two major grassland type...Knowledge of the leaf anatomy of grassland plants is crucial for understanding how these plants adapt to the environment. Tibetan alpine grasslands and Inner Mongolian temperate grasslands are two major grassland types in northern China. Tibetan alpine grasslands occur in high-altitude regions where the low temperatures limit plant growth. Inner Mongolian temperate grasslands are found in arid regions where moisture is the limiting factor. Few comparative studies concerning the leaf anatomy of grassland plants of the Tibetan Plateau and Inner Mongolian Plateau have been conducted. We examined leaf characteristics at 71 sites and among 65 species, across the alpine grasslands of the Tibetan Plateau and the temperate grasslands of the Inner Mongolian Plateau. We compared the leaf structures of plants with different life forms and taxonomies, and their adaptation to arid or cold environments. We explored relationships among leaf features and the effects of climatic factors (i.e., growing season temperature and precipitation) on leaf characteristics. Our results showed that (i) there were significant differences in leaf anatomy between Tibetan alpine and Inner Mongolian temperate grasslands. Except for mesophyll cell density, the values obtained for thickness of leaf tissue, surface area and volume of mesophyll cells were larger on the Tibetan Plateau than on the Inner Mongolian Plateau. (ii) Within the same family or genus, leaf anatomy showed significant differences between two regions, and trends were consistent with those of whole species. (iii) Leaf anatomy of woody and herbaceous plants also showed significant differences between the regions. Except for mesophyll cell density, the values obtained for the thickness of leaf tissue, and the surface area and volume of mesophyll cells were larger in herbaceous than in woody plants. (iv) Leaf anatomical traits changed accordingly. Total leaf thickness, thicknesses of lower and upper epidermal cells, and surface area and volume of mesophyll cells were positively correlated, while mesophyll cell density was negatively associated with those traits. (v) Growing season temperature had stronger effects on leaf anatomy than growing season precipitation. Although the communities in Tibetan and Inner Mongolian grasslands were similar in appearance, leaf anatomy differed; this was probably due to the combined effects of evolutionary adaptation of plants to environment and environmental stress induced by climatic factors.展开更多
文摘种族（Races）属于生物学范畴,但问题十分复杂,涉及到生物学、古人类学、体质人类学、解剖学等领域。民族学也研究种族,民族学教科书均列专章描述。然而,迄今人们对它的认识仍较零碎和肤浅。本文根据有关学科最新资料,试作一综合研究,分四个问题论述。 一、种族差别 人虽属同种（The human species）,但种族之间是有差别的,C·达尔文在《人类的由来》（1871）一书指出:“但各个所谓种族,如果我们把他们仔细地比较和测量一下,彼此之间也无疑地表现很多的差别,例如发的结构、身体各部分的相对比例、肺的容量、颅骨的形态和容量、乃至脑子的脑回。但体格方面的差别太多了,……在素质上,在适应气候或水土的能力上。
基金Under the auspices of Major State Basic Research Development Program of China (No. 2007CB106801)the Seventh Framework Program of European Union (No. 226818)Testing Foundation of Northeast Normal University
文摘A field experiment was conducted in Jungar Banner,Inner Mongolia,China to study the effects of plant types on the physical structure and chemical properties of open-cast mining soils reclaimed for 15 years,and to analyze the triggering factors of the soil formation.Results indicate that plant types affect soil-forming process especially in the upper layer (0-20 cm),and the spatial structure of reclaimed plant is the main reason for variability of the soil-forming process.In the upper soil layer at the site reclaimed with mixed plants,the concentrations of soil organic matter (SOM) and soil organic carbon (SOC) are the highest,and they were significantly higher at the sites reclaimed with Leymus chinensis,Caragana sinica,which is mainly due to a large amount of litter fall and root exudation in herbages and shrubs.However,the concentrations of SOM and SOC in the soils at the reclaimed sites are quite low comparing with those in local primary soil,which indicates the importance of using organic amendments during the ecological restoration in the study area.
文摘Investigation of the above-ground biomass allocation patterns on Scots pine plantations is critical for quantifying the productivity and carbon cycle of forest ecosystems. We estimated above-ground biomass and net primary production of a 25-year-old Pinus sylvestris L. （Scots pine） plantation, in a semi-arid region of Mongolia. The above-ground biomass of sample trees was divided into stem wood, stem bark, live branches, dead branches and needles. Total biomass for the stand was only 18.03 Mg ha1, of which 47.6% was found in stem wood, 25.8% in live branches and 14.8% in needles. The growth rate of the Scots pine plantation in the study region was relatively low compared with other regions. In the study area, it was observed that the rate of biomass accumulation in the plantation was very slow; this can be explained by very limited growing conditions and intensive crown closure. The results from this study indicate that it may be necessary to carry out thinning to increase biomass production by reducing competition between trees in the Scotch pine plantation.
基金supported by the Funds for Creative Research Groups of the National Natural Science Foundation of China (Grant No. 31021001)the Funds of the Chinese Academy of Sciences for Key Topics in Innovation Engineering (Grant No. KSCX2-YW-Z-0806)
文摘Knowledge of the leaf anatomy of grassland plants is crucial for understanding how these plants adapt to the environment. Tibetan alpine grasslands and Inner Mongolian temperate grasslands are two major grassland types in northern China. Tibetan alpine grasslands occur in high-altitude regions where the low temperatures limit plant growth. Inner Mongolian temperate grasslands are found in arid regions where moisture is the limiting factor. Few comparative studies concerning the leaf anatomy of grassland plants of the Tibetan Plateau and Inner Mongolian Plateau have been conducted. We examined leaf characteristics at 71 sites and among 65 species, across the alpine grasslands of the Tibetan Plateau and the temperate grasslands of the Inner Mongolian Plateau. We compared the leaf structures of plants with different life forms and taxonomies, and their adaptation to arid or cold environments. We explored relationships among leaf features and the effects of climatic factors (i.e., growing season temperature and precipitation) on leaf characteristics. Our results showed that (i) there were significant differences in leaf anatomy between Tibetan alpine and Inner Mongolian temperate grasslands. Except for mesophyll cell density, the values obtained for thickness of leaf tissue, surface area and volume of mesophyll cells were larger on the Tibetan Plateau than on the Inner Mongolian Plateau. (ii) Within the same family or genus, leaf anatomy showed significant differences between two regions, and trends were consistent with those of whole species. (iii) Leaf anatomy of woody and herbaceous plants also showed significant differences between the regions. Except for mesophyll cell density, the values obtained for the thickness of leaf tissue, and the surface area and volume of mesophyll cells were larger in herbaceous than in woody plants. (iv) Leaf anatomical traits changed accordingly. Total leaf thickness, thicknesses of lower and upper epidermal cells, and surface area and volume of mesophyll cells were positively correlated, while mesophyll cell density was negatively associated with those traits. (v) Growing season temperature had stronger effects on leaf anatomy than growing season precipitation. Although the communities in Tibetan and Inner Mongolian grasslands were similar in appearance, leaf anatomy differed; this was probably due to the combined effects of evolutionary adaptation of plants to environment and environmental stress induced by climatic factors.
