|
P. tabulaeformis (Pinus tabulaeformis Cart.) Is one of the main afforestation tree in northern China, a windbreak and sand, and improve the ecological environment. Chestnut (Castanea mollissima Bl.) Is China's famous economic forest tree species, hi light, acidic soil, cold, drought, resistance to harmful gases, the main distribution area is more extensive, the north and south also have. Cork oak (Quercus variabilis Bl.) And chestnut belong to Fagaceae, deciduous tree, up to 25a; cork layer developed bark deep diastema, black and gray. Currently, pine and oak mixed forest afforestation mode is used mainly in the north, can make full use of fertility, but also for a variety of wood, to generate economic benefits. In recent years, the chestnut not only with its green hills and to maintain the role of soil and water, and can also increase the income of farmers, the government strongly advocated the establishment of ecological economic forest planting economic forest tree species. Chestnut and cork oak belong to Fagaceae, therefore, in order to further study the Pinus tabulaeformis Allelopathy of chestnut and cork oak seedlings to explore the feasibility of Pine and Chestnut complex plant. In this paper, through the pot experiment, select the surface soil of the pine forest land, semi-decomposition of litter state Litters gradient design test as a test material, in accordance with 1:10,1:50,1:100 three concentrations, and photosynthesis indicators and protective enzyme activities and growth indicators to study the impact the of P. tabulaeformis Litters immersion fluid on the chestnut and cork oak seedlings, and made the following conclusions: (1) pine forest land topsoil, semi-decomposition of litter, undisturbed Litters extracts of chestnut and cork oak seedling allelopathy strength of seedling age-related 0.5a the chestnut seedlings apparent than 1.5a Quercus variabilis seedlings Allelopathy significant, indicating that the smaller seedlings planted Allelopathy more obvious. (2) oil pine topsoil, half-decomposed litter material, the original form of litter extracts to promote the role of the high concentration inhibition of chestnut seedling growth index performance for low concentration, which most of topsoil, followed by semi-decomposition litter, the performance of the original form of litter is the most obvious show that the Allelopathy significant need for further research and analysis; Quercus variabilis seedlings growth parameters were measured. (3) oil pine topsoil, half-decomposed litter material, undisturbed litter material extracts Determination of the diurnal variation of chestnut and cork oak seedlings photosynthetic indicators shows half decomposition of litter, topsoil, state Litters both unimodal presented. chestnut and cork oak net photosynthetic rate and transpiration rate curves, \Topsoil, half-decomposed litter, the original form of litter on the chestnut and cork oak stomatal conductance showed an overall downward trend. (4) oil pine topsoil, half-decomposed litter material state the litter materials impregnated humoral chestnut chlorophyll fluorescence value showed strong differences. Topsoil, half-decomposed litter and the status quo of litter were shown a significant role compared to other concentration gradient 1:50; chlorophyll fluorescence value of the cork oak showed only a trend, that is, low concentration promote high the trend of the concentration inhibition. The results show: (5) oil pine topsoil, half-decomposed litter material, the original form of litter extracts of chestnut and cork oak seedlings regularly sampling (leaves) and the determination of protective enzymes chestnut on the surface soil of the pine forest land half-decomposed litter, the status quo of litter Baptist humoral Allelopathy than cork oak evident, that the surface soil of the pine forest land, semi-decomposition of litter undisturbed litter material extracts with chestnut Allelopathy than with Quercus variabilis between allelopathic obvious role. The intensity size: topsoil) semi-decomposition of litter) undisturbed litterfall, and 1:50 apparent role compared to other concentration gradient. The innovation of this study is that the use of litter Baptist humoral test allelopathy between Pinus tabulaeformis and chestnut, Quercus variabilis comparative test measurement and analysis, chestnut, cork oak and P. tabulaeformis optimize composite cropping patterns.
|