| The structure, biomass productivity, volume productivity, species richness,α,βdiversityindexes of natural, succession (after fire or felling disturbance) or forestation forest-swampcommunities were studied by using transect investigation method, Shannon-wiener or Codyindex methods and sample tree analysis method along the environmental gradients fromswamp to forest in Daxing'an and Xiaoxing'an Mountains, in order to assess the effects of thedifferent restoration approaches on structure, productivity and plant diversity of forestedwetlands, probe valid restoration approach for deteriorate forested wetlands, and providescientific basis for managing forested wetlands. The results showed that:①the natural orsuccession after fire or felling forest-swamp communities were all composed of 2～3 treespeciese such as Alnus sibirica, Betulaplatyphylla or Larix gmelini, and constructive species ofthe communities were replaced regularly along the environmental gradients from swamp toforest, which apears Alnus sibirica, Betula platyphylla, Larix gmelini in turns, however firedisturbance strengthened the position of constructive species in the communities, and fellingdisturbance weakened the position of constructive species in some communities. But this kindof tree species replacement did not take place in afforestation communities dominated by L.gmelini.with small amount natural regeneration trees of Alnus sibirica or Betula platyphylla.②the diameter class distributions of succession (96.8％～99.1％or 80.0～93.3％) or natural(79.4％～90.0％or 49.6～67.3％) forest-swamp communities were dominated absolutely bysmaller diameter classes trees, both of them taken on a descending law with diameter classincreasing, and the proportion of smaller or bigger diameter classes trees decreased orincreased progressively along the environmental gradients from swamp to forest. But thediameter class distributions of afforestation forest-swamp communities differed from thesuccession and natural communities, which was dominated by smaller diameterclasses(72.06％～100.00％or 84.56～93.40％) at low site and bigger diameterclasses(70.69％～71.08％or 38.67～47.74％) at middle and high sites on the planted forest-swamp ecotone environmental gradients.③biomass productivity (mean annual biomassaccumulation) of the communities changed greatly along the different disturbanceenvironmental gradients from swamp to forest in Daxing'an Mountain, that of natural(1.2320～4.4322 t.hm-2.a-1) or succession after fire (1.7102～10.7835 t.hm-2.a-1) or forestation(2.1894～6.3084 t.hm-2.a-1) forest-swamp communities took on single-peak, decreasedprogressively or fluctuate distribution law respectively along the ecotoneal environmentalgradients, and biomass productivity of succession or forstation communities increased by126.34％or 31.10％than that of natural communities separately. In Xiaoxing'an Mountain, biomass productivity of natural (3.5881～7.3503 t.hm-2.a-1), succession after fire (3.6423～11.1350 t.hm-2.a-1), succession after felling (4.1538～7.6100 t.hm-2.a-1), or forestation(3.5670～8.7925 t.hm-2.a-1) communities took on similar constant (besides higher at low site),fluctuate, approximate increasing progressively(besides lower at high site), or increasingprogressively distribution law respectively along the ecotoneal environmental gradients, andbiomass productivity of succession after fire or felling, forestation communities increased by52.16％or 58.08％and 20.10％(61.73％～89.85％at above middle sites) than that of naturalcommunities separately.④volume productivity (mean annual volume growth) of the forest-swamp communities also changed greatly along the environmental gradients from swamp toforest in Daxing'an Mountain, that of natural or succession forest-swamp communities(6.6898～1.4118 m3.hm-2.a-1or 6.0059～1.6126 m3.hm-2.a-1) decreased. progressively, but that offorestation communities (4.3497～6.9905 m3.hm-2.a-1) increased progressively, and volumeproductivity of the succession or forestation communities varied from -10.22％to 24.97％orfrom -34.67％to 395.15％by contrasting natural communities. In Xiaoxing'an Mountain,volume productivity of natural forest-swamp communities (3.5650-3.6611 m3.hm-2.a-1) keepconstant, succession forest-swamp communities (2.5452～1.3042 m3.hm-2.a-1) decreasedprogressively, forestation communities (3.3548～10.8194 m3.hm-2.a-1 increase progressively,and volume productivity of the succession or forestation communities varied from -28.61％to-64.38％or from 101.73％to 151.10％by contrasting natural communities.⑤speciese richness,species diversity, Cody indexes, and community similarity coefficient of succession after firedor forestation forest-swamp ecotone communities increased by 74.00％or 76.24％, 50.12％or12.68％, 31.91％or 16.45％, 5.00％or 85.00％than that of natural forest-swamp ecotonecommunity respectively, so succession approach had advantage in maintaining speciese andcommunity diversity in Daxing'an Mountains. But speciese richness, species diversity, Codyindexes, and community similarity coefficient of succession after fired or felling, andforestation forest-swamp ecotone communities decreased by 37.37％, 21.08％, 11.32％; 60.46％,48.92％, 14.69％; 62.64％, 42.64％, 44.00％; 74.36％, 66.67％, 74.36％than that of naturalforest-swamp ecotone community separately, so plantation approach had advantage inmaintaining speciese and community diversity in Xiaoxing'an Mountains.⑥the validrestoration approaches were probed, on the basis of evaluating effects of succession orforestation approach on the restoration of the deteriorate forested wetlands comprehensively, inDaxing'an and Xiaoxing'an Mountains, and three kinds of restoration models were suggestedfor restorating or rehabilitating vegetation on the deteriorate forested wetlands ecotones by fireor felling disturbanec, which mainly including natural succession model, afforestation model,and natural succession-afforestation model or nearly natural model.
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