Reproductive Allocation And Adaptation Strategies Of Tetracentron Sinsense Oliv. Population

By setting the fixed-area sampling plot,from the component level of Tetracentron sinense Oliv.Community in Meigu Dafengding Nature Reserve,on the reproductive allocation of population and environmental adaptability.The purpose of this study is to explore the reproductive allocation(RA)of Tetracentron sinense Oliv.and the relationship between reproductive and vegetative investment,and thus investigate the life history strategies and endangered reasons for this species.Using fixed-area sampling plot in Meigu Dafengding Nature Reserve,we collected and measured the reproductive modules biomass of individuals with different DBH(diameter at breast height)class.Multiple comparison analysis was conducted to compare the differences in reproductive investment and allocation among different DBH class.Further relationships were analyzed between RA,reproductive modules biomass and the nutrient modules biomass by correlation and linear regression analysis.Based on the different slope,observation distance branch biomass of individual reproductive Tetracentron sinense Oliv.river near and far,to explore the reproductive allocation of environmental adaptability mechanism,analysis of the endangered causes and protection measures.The results are as follows:(1)Study on reproductive allocation of Tetracentron in different diameters on the level of individual components.With increasing DBH class,the reproductive and vegetative investment showing the same changing trend,and no trade off appeared between them;The nutrient inputs of Tetracentron sinense Oliv is beneficial to its reproductive inputs.At the level of modules,RA firstly increased at the beginning and then decreased with increasing DBH class;The reproductive period of Tetracentron sinense Oliv..could be divided into four periods: initial,increment,peak,and decline phases.Reproductive investment was significantly positive correlated with vegetative investment or leaf biomass.However,RA was significantly negative correlated with vegetative investment or leaf biomass;For the reproductive modules,RA was significantly and negatively correlated with the dry weight of the shaft infructescence axis biomass.In contrast,there was a significantly positive correlation between seed biomass and pericarp biomass.A trade-off existed between seed number and seed size.The seeds at different reproductive phases may have different life history strategies,reflecting the reproductive adaptation strategies during the process of evolution and development in this species.(2)The reproductive configuration of Tetracentron sinense Oliv of the same size and the adaptive strategies of environment.Tetracentron sinense Oliv.reproduction and input of nutrients are rivers with distance the distance and change in flowering and fruit showed a trend to increase with the decrease in reproductive investment,from the river near the river is far greater than the distance from the individual individual;in nutrient inputs,the distance from the river is far greater than the distance from the individual the river near the individual distance.Different river habitats distance had a significant effect on the reproductive allocation of Tetracentron member level,away from the river near the habitat is more conducive to the realization of Tetracentron reproductive process.Tetracentron sinense Oliv.reproductive and input of investment due to the slope change,flowering and fruit also showed the same trend of increase with the decrease of flowering or fruiting.Whether in flower or fruit,there is no significant difference between the nutritional inputs and reproductive inputs of the end reproductive branches of the Tetracentron sinense Oliv.of the same size.In the whole reproductive period,reproductive allocation of cloudy slope was greater than the sunny slope,may be formed on the reproductive adaptation strategies of Tetracentron sinense Oliv.damp environment.