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Edge Effects on Tree Growth and Species Diversity in Forests of Different Types and Ages

Li J., Zhao C., Peng Y., Hu Y., Yuan X.

Polish Journal of Ecology

2018

Vol. 66, nr 3

239--249

Edge to interior gradients in forest ecosystems can influence the species composition and community structure as a result of variations in micro-environment. In this study, the edge effects on stand productivity and plant species diversity were investigated in two adjacent types of forests in central-southern China: Chinese fir adjacent with pine forests and Chinese fir adjacent with broad-leaved forests. A total of 48 sample plots for overstory and 240 sample quadrates for understory in different stand ages were set up. The tree growth parameters were measured in the overstory while the plant species diversity was measured in both overstory and understory of the examined forests. The results showed that DBH (tree diameter at the breast height), tree height and stand volume in overstory increased from the central areas (CA) of forests to the edge areas (EA), and the plant species richness and diversity in understory were greater in EA than in CA. The edge effect was greater in Chinese fir paired with broad-leaved forests than in Chinese fir paired with pine forests. The edge effect decreased in an order as young aged stands > middle aged stands > mature aged stands in the studied forests. The changes in tree growth and species diversity in the edge area compared to the interior were mainly attributed to the alteration of micro-environmental factors such as light density, temperature and moisture. Our results suggest increasing forest productivity and plant species diversity could be achieved by making more edges in the forests.

Growth and nutrition of restored Quercus castaneifolia C.A. Mey. versus native Celtis australis L. tree species : conservation perspectives of Hyrcanian forest (Iran)

Hosseini S., Raouhi-Moghaddam E., Ebrahimi E., Rahmani A., Tabari M.

Polish Journal of Ecology

2010

Vol. 58, nr 1

41-51

For native species, mixed plantation systems seem to be the most appropriate for providing a broader range of options such as production, protection, biodiversity conservation and restoration. After 11 years, growth and nutrition and soil properties were examined in young plantation of two indigenous tree species in Hyrcanian forests of Iran. Quercus castaneifolia C.A. Mey. (as target species) and Celtis australis L. (as native component species) were planted in five proportions (100Q, 70Q:30C, 60Q:40C, 50Q:50C, 40Q:60C) in Noor, Iran. Diameter at breast height of individual Quercus trees and total basal area were affected by the presence of Celtis. Percent retranslocation of nutrients in Quercus followed in order: K> P> N. Leaf-litter fall production ranged from 4.10 to 6.14 t ha[^-1] year[^-1]. Ca and Mg concentrations in fully expanded leaves of Quercus, N and K retranslocation of Quercus, concentration of available P in soil were higher in some of the mixed plantations than in monoculture of Quercus. On the other hand, N concentration in fully expanded leaves of Quercus, N fluxes and soil C/N ratio were higher in monoculture of Quercus. Within the framework of this experiment, it appeared that production was maximized when these two species were grown together in the proportion of 60% Quercus and 40% Celtis.