The effect of heterogeneous spatial distribution of soil nitrogen on regeneration of Larix principis\|rupprechtii seedlings in typical naturally\|regenerated montane forests of Northen China Fractal feature of soil structure and reflection on soil properties in different regeneration patterns of Casuarina equisetifolia forest in coastal sandy soil Effects of Different Cutting and Regeneration Patterns on β Diversity of Castanopsis carlesii Communities EFFECTS OF DIFFERENT REGENERATION PATTERN OF SECONDARY BROADLEAVED FOREST ON STAND COMPOSITION AND SOIL FERTILITY Optimum fertilization for high sugar and low-nitrate pumpkin production in the Loess Plateau