Propagation of Native Tree Species to Restore Subtropical Evergreen Broad-Leaved Forests in SW China

Abstract

Subtropical evergreen broad-leaved forest (EBLF) is a widespread vegetation type throughout East Asia that has suffered extensive deforestation and fragmentation. Selection and successful propagation of native tree species are important for improving ecological restoration of these forests. We carried out a series of experiments to study the propagation requirements of indigenous subtropical tree species in Southwest China. Seeds of 21 tree species collected from the natural forest were materials for the experiment. This paper examines the seed germination and seedling growth performance of these species in a nursery environment. Germination percentages ranged from 41% to 96% and were ě50% for 19 species. The median length of germination time (MLG) ranged from 24 days for Padus wilsonii to 144 days for Ilex polyneura. Fifteen species can reach the transplant size (ě15 cm in height) within 12 months of seed collection. Nursery-grown seedlings for each species were planted in degraded site. Two years after planting, the seedling survival rate was >50% in 18 species and >80% in 12 species. Based on these results, 17 species were recommended as appropriate species for nursery production in forest restoration projects. Our study contributes additional knowledge regarding the propagation techniques for various native subtropical tree species in nurseries for forest restoration.

Selection of Native Tree Species for Subtropical Forest Restoration in Southwest China

“…The number of germinated seeds was recorded each day until no additional seeds germinated. Our previous research [50] indicated that species such as Lindera communis , Lindera thomsonii , Machilus rufipes , Myrsine semiserrata , and Ilex polyneura have dormant seeds. However, only limited information is available on seed dormancy mechanisms and pre-germination treatment techniques for the studied species.…”

“…The average planting size of seedlings was 25 cm in height. For further details of the nursery conditions, see Lu et al [50]. …”

“…However, as in other areas of the tropics, most reforestation efforts in the region have established monoculture plantations comprised of a relatively small set of fast-growing commercial species, mainly from the genera Pinus , Cunninghamia , and Eucalyptus [46–48]. This may be at least partly due to the fact that, although the use of a wider range of native species is increasingly encouraged in reforestation and restoration programs [49, 50], existing knowledge of tree species selection techniques for subtropical forests is limited. Principles of industrial forestry techniques are emphasized in the training program for the employees of the forest departments and the employees are often unaware how to incorporate native species restoration into their programs [24, 50, 51].…”

“…This may be at least partly due to the fact that, although the use of a wider range of native species is increasingly encouraged in reforestation and restoration programs [49, 50], existing knowledge of tree species selection techniques for subtropical forests is limited. Principles of industrial forestry techniques are emphasized in the training program for the employees of the forest departments and the employees are often unaware how to incorporate native species restoration into their programs [24, 50, 51]. However, some studies have investigated subtropical forest succession [26, 38, 39, 41], making it possible to assign species to successional guilds.…”

Vegetation Structure and Prioritizing Plants for Eco-Restoration of Degraded Wildlife Corridor in Dry Tropical Forest of South India

“…According to meta-population, meta-community and island-biogeography theories, degradation and fragmentation of natural wildlife habitats could lead to the extinction of many species across the globe due to loss of sub-population connectedness and inbreeding depression [4,8]. Therefore, at the time of unprecedented wildlife habitat destruction, eco-restoration of degraded forest areas particularly wildlife corridors is gaining global importance and also emerging as a practical conservation strategy [9][10][11][12]. Under the 'Green India Mission', the Indian government is planning to double afforestation efforts by 2020 [13] and also planning to buy private plantations to restore elephant corridors [14,15].…”