Spatial characteristics and change for tree species along the North East China Transect (NECT)

摘要

Spatial characteristics of sixteen tree species were analyzed by the information from 287 permanent plots in 1986 and 1994 on North East China Transect (NECT). Some species expanded and some retracted their distribution extents. Betula costata and Phellodendron amurense spread most fast toward west and east, respectively. All tolerant tree species extended their frontiers and all intolerant tree species retracted their frontiers except Betula platyphylla. The distribution area decreased for all species except Betula costata, Juglans mandshurica, Ulmus spp. and Fraxinus rhynchophylla. The patch sizes of Pinus koraiensis, Populus davidiana, Phellodendron amurense, Juglans mandshurica, Fraxinus mandshurica, Betula dahurica, Picea spp., Abies nephrolepis and Larix olgensis decreased, however, the patch sizes of Quercus mongolica, Betula costata, Acer mono, Tilia spp., Ulmus spp., Betula platyphylla and Fraxinus rhynchophylla increased. The frequency pattern of Populus davidiana, Betula platyphylla, Fraxinus rhynchophylla and Betula dahurica changed significantly (p< 0.05). The dominance pattern of Populus davidiana, Tilia spp., Juglans mandshurica, Betula platyphylla, Betula dahurica and Abies nephrolepis changed significantly (p < 0.05). The spatial correlation between species changed, such as the spatial correlation between Larix olgensis and Betula platyphylla, Acer mono and Ulmus spp. increased. The possible cause of these changes might be climate change, disturbances and habitat loss.