Photosynthetic characteristics of ash and larch in mixture and pure stands

The photosynthesis of ash (Fraxinus mandshurica) and larch (Larix gmelini) in pure and mixture plantation stands was measured and the influence of the microclimate on the photosynthesis was analyzed in this study. The result shows that the net photosynthetic rate (NPR) of ash is higher in mixed stand than in pure one, 61.64% higher in the measuring day. The NPR of larch is approximately the same in the two stands. The microclimate in the mixed ash-larch stand is much different from that in the pure one. The temperature is moderate in the mixture stand, e.g., the maximum temperature in the mixture stand is lower and the minimum temperature is higher than that in the pure ash stand. The relative air moisture is higher in the mixture stand. The microclimate in the mixture stand benefits the photosynthesis of ash, considered as one of the important reasons that make the mixture stand more productive.