| Evergreen broad-leaved forest (EBLF) is a typical of vegetation in the east middle subtropical zone of China, The EBLF in Tiantong national forest park is the representative district. Near these decades,with the aggravation day by day of the human activity, the degradation of the vegetation and recovery question receive much concern day by day, in order to understand the ecophysiological characteristics of dominant species better and give science and technical support of the restoration and reconstruction of the degradation vegetation in the EBLF district. Using the Li-6400 portable photosynthesis system, the photosynthetical ecophysiology of the main dominant species seedlings and saplings (Castanopsis fargessi, Schima superba, Castanopsis carlesii, Lithocarpus glaber and Castanopsis Sclerophylla) in the regeneration layer in different disturbance regimes in Tiantong evergreen broad-leaved forest were measured. The experiments were carried on in four artificial plots, seven natural disturbed canopy gaps and one control plot separately in four seasons of one year. Through comparing the differences and changes of the niche factors in different disturbed plots, then comparing the ecophysiological indexes (Pn-PFD curve, daily photosynthesis rates, daily transpiration rates etc.) of the dominant species seedlings and saplings in different disturbance regimes. The result shows:Compare with the control plot, the photosynthetic active radiation (PAR) of all the disturbed plots are higher than it in every season; the air temperature (Tair) of disturbed plots are far higher than the control plots in the daytime of spring, summer and autumn, and the situation is a bit special in winter, the Tair of control plot is higher than disturbed plots before 10:00, and with the increase of PAR, the Tair of disturbed plots rises to control plot gradually; the relative humidity (RH) of disturbed plots are lower... |
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