| Melhania hamiltania blongs to hamiltania,Sterculiaceae.It is deciduous trees.It is only distributed in a narrow range of Yuanjiang dry vally discontinuously.This article uses the methods of sample plots and sample line in the field on April 2014,January 2015 and November 2015.Through comprehensive survey and data analysis methods to analysis the Community characteristics and population structure of Melhania hamiltania.The purpose is to analysis the resource status,the protection status and the causes of endangering.The significance is to provide theoretical support to protect wild resources.It has practical significance to afforestation in the special habitat of the dry-hot valleys and provides a certain number of reference data for further research.The results are as follows:(1)The specific location of concentrated Melhania hamiltania is Nanbachong red bridge across the dam the flood,the Red River Interchange Nanbachong red bridge and dam and flood the old walled Wing of the cement plant on the eastern side and northwest side,distributed in groups or small pieces like distribution,distribution altitude range 380 ~ 570 m,Melhania hamiltania suitable for growing in yellow soil,and with more sandstone and limestone,and is extremely drought-resistant species.(2)Field investigation into the Melhania hamiltania communities of vascular plants,74 species belonging to 28 families and 55 genera,vegetation type is savanna scrub and grass,the division of the flora,the family,genus,species,respectively 5,20,22 areal types,families,genera and species of tropical flora are the main species endemism is high,community structure is simple,Heterochronogenous significant.(3)Through the distribution area Melhania hamiltania sample survey,field investigation to the record total of 1835 Melhania hamiltania(can be measured basal diameter,height of the number of trees 620 seedlings 1215),the diameter of the base structure analysis,0.5cm? D<1.5cm and 1.5cm?D<2.5cm seedlings up to the total number of trees of 42.69%;6.5cm?D<7.5cm seedlings least 0.69%of the total number of trees.Population age structure was a typical pyramid,reasonable structure of the population as a whole.(4)Integrated distribution Melhania hamiltania,Community,population science research results,since the Melhania hamiltania seedlings and saplings in different distributions of the number of points varies greatly,so as successional communities,Melhania hamiltania uneven distribution will gradually increase the distribution area will gradually shrink further,suggesting the reason,mainly because of habitat is the Melhania hamiltania Yuanjiang dam regional development of agricultural production,the development of agriculture,resulting in Melhania hamiltania most suitable habitat loss;the other is man-made greater impact,cultivated plants too much,resulting in community canopy density,it is not conducive to the growth of Melhania hamiltania,in addition,in the laboratory Melhania hamiltania seed germination failure,so the seed germination and biological characteristics may also itself related.Therefore,to strengthen the narrow domain endemic Melhania hamiltania protection,the key is to prevent vandalism to in situ conservation,to protect the original habitat and promote natural regeneration;artificial tending measures,through artificial breeding seedlings and increase the survival rate of seedlings,rejuvenation wild population;in addition,to strengthen the study of dynamic changes of seed and seedlings of Melhania hamiltania to supervise the protection of local education. |
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