| There are significant differences between the different mountain habitats,as one of the important factors mountainous terrain, slope indirectly lead to plant species composition and distribution structure, which in turn on soil moisture, soil temperature and other ecological factors affect the light radiated by the surface redistribution can receive,reaching impacts on biodiversity the purpose of ecosystem function, productivity and plant growth and development, and so the research relationship between plant distribution and the habitat is significant. Due to the different aspect of light, temperature, moisture, soil and other factors are different, species composition within the habitat gradient will exhibit changes accordingly, understanding photosynthetic physiological characteristics of different aspect of plants that can help us explore species habitat adaptation mechanisms.In this study, in the eastern part of the Tibetan Plateau Subalpine example, analysis of the different habitat gradient plant composition and ecological factors related changes of photosynthetic physiological characteristics of plant species studied the correlation between diversity and other factors.The results showed that:From the aspect perspective(sunny- half-sunny- west- half-negative- shady slope), environmental factors have a significant change in trend, daylight illumination from 7:00 am to approximately 20:00 pm first and then increase or decrease the trend, the average light intensity showed sunny slope > half-sunny slope > west slope > half-negative slope > shady slope. Overall 0-20 cm soil moisture and soil moisture soil 20-40 cm soil have shown a half-negative slope > shady slope > west slope > half-sunny slope > sunny slope trend.Soil nutrients, the soil total phosphorus and soil organic matter content in descending order of shady slope, sunny slope, half-negative slope, west slope, half-sunny slope(0-20 cm soil), soil nitrogen and soil organic matter behave a consistent trend, shady slope > sunny slope > half-negative slope > half-sunny slope > west slope(20-40 cm soil). 20-40 cm soil with no significant differences in soil p H changes 0-20 cm soil, have shown decreasing trend after the first increase.0-20 cm soil, soil nitrogen and soil organic matter showed a significant positive correlation. Soil p H, soil organic matter and soil total phosphorus showed a significant negative correlation. Soil moisture and soil total phosphorus showed a significant positive correlation. Light intensity and soil total phosphorus showed a significant negative correlation, positively correlated with soil p H showed significant, and soil water content showed a very significant negative correlation. The remaining no significant correlation.20-40 cm soil, soil organic matter and soil nitrogen showed a very significant positive correlation. Soil p H and soil total nitrogen, total phosphorus in the soil, soil organic matter showed a significant negative correlation. Soil moisture and soil total phosphorus showed a significant correlation, and soil p H showed a significant negative correlation. Light intensity and soil total phosphorus showed a significant negative correlation, positively correlated with soil p H showed significant, and soil water content showed a very significant negative correlation. The remaining no significant correlation.Shannon Wiener index trends are consistent with species richness, emerged from the shady slope gradually decreasing trend to sunny slope. Changes Pielous evenness index is shady slope and sunny slope with respect to the other three big transition, half-sunny slope and half-negative slope uniformity is relatively small, and west slope of the peak value of individual samples, far more than other aspect.Ground biomass trends due to different locations and different, from sunny to shady slope showing the first increase after decreasing trend, sunny, half-sunny slope and west slope the biomass was not significantly different, then increases rapidly, in half negative slope reaches a maximum. Water is the major limiting factor for plant growth.Aboveground biomass and Shannon Wiener index and Margalef richness index both showed negative quadratic relationship,with evenness showed obvious negative quadratic function.0-20 cm soil, Shannon Wiener index and soil total phosphorus showed a significant positive correlation, and soil p H showed a significant negative correlation, and soil water content showed a very significant positive correlation, and illumination in 10:00 am rendered a more significant positive correlation, with the illumination in 14:00 pm showed a significant negative correlation. Margalef richness index and soil total phosphorus showed a significant positive correlation, and soil p H showed a significant negative correlation, and soil water content showed a very significant positive correlation, and illumination in 10:00 am rendered a more significant positive correlation, with the illumination in 14:00 pm showed a significant negative correlation. Pielous evenness index and soil water content showed a significant positive correlation, with the illumination in 14:00 pm showed a more significant negative correlation. Biomass and soil moisture showed a more significant positive correlation, with the illumination in 14:00 pm showed a significant negative correlation.20-40 cm soil each correlation is consistent with 0-20 cm soil.Net photosynthetic rate and chlorophyll content of the main species has no significant difference in different habitat aspect. The specific leaf area in shady slope and half-negative slope showed significantly greater than sunny slope and half-sunny slope. This is mainly due to the shady slope received weaker light radiation. Plants need to improve their ability to capture light blade unit mass by increasing leaf area. This difference reflects the different light adaptation mechanisms between species. About the plant water use efficiency, Apart from Potenti Ua fragarioides Linn, other four species in sunny slope exhibit higher water use efficiency. Soil moisture is the main factor for this difference. |
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