47 The CNFM hypothesis here can be expressed as “the present canopy of Casuarina equisetifolia will serve as protecting
layer for establishment of seedlings of other new introduced broadleaf species which do not thrive in open areas such as the tropical coastal site. A series with typical pioneer-opportunity-climax species planted under the canopy will speed the
development of the stand towards a stable coastal forest ecosystem.” Melia azedarach, Beischimiedia glauca and Mytilartia laosensis as the fast-growing group, and Homalium hainanense, Dalbergia odorifera and Calophyllum inophyllum as the
hardwood climax group were used for enrichment planting under the canopy. The first two years of observations showed very positive results by 2013, and on this basis the transformation of the coastal protection plantation can now be expanded.
The second example is the large-scale restoration of forests damaged by the extreme ice-storm in Hunan Province. Hunan Province is a subtropical climate-controlled montane region in South Central China; its natural conditions of humid sunny
climate and abundant tree species on hill and low montane areas are highly favourable for forestry. The province has a long history of conifer plantation management with Cunninghamia lanceolata and Pinus massoniana. The extreme ice-storm
of early 2008 affected about 35.28 percent of the total forest area, with loss of growing stock reaching 43.19 percent of the total growing volume in the province. This represented a direct loss to forestry of about 16.5 billion yuan US1.00 =
6.119 yuan, October 2014, further affecting the economy of the province. Notably, damage from the ice-storm was more severe and devastating in single species coniferous forest plantations and bamboo stands than in natural, mature forests
or mixed species plantations.
A few years after the event, it was clear that most of the damaged forests, in particular the plantations, would not be able to recover naturally. Therefore an FLR scheme, the Hunan Forest Restoration and Development Project, was proposed
and supported by the government to prevent further degradation and restore the ecological balance in the storm-affected landscapes of 22 counties. The project started in January 2013 and will last for six years. Its objective is to develop forest
restoration and management models that will both strengthen resilience and enhance carbon sequestration in forest areas severely damaged by the ice-storm.
3.5 Tentative results
Ten years ago conifer plantations were the main forest type in the ECTF and occupied 71 percent of the total forest area. Masson pine Pinus massoniana, 63 percent and Chinese fir Cunninghamia lanceolata, 7 percent were the two largest
tree species there. Compared with single species rotation management models of these two conifer species, CNFM has at least three advantages: 1 forming a multilayer stand structure to increase spatial availability, 2 enhancing positive
interspecies synergy between conifer and broadleaf species to increase vitality and resilience of stands, and 3 thinning to allow the target trees to be released from competition. Based on our analysis of the data from 80 plots for the two forest
types over five years 2008-2013, the yearly growth of standing volume increased to 19.3 m
3
ha for Pinus massoniana and 15.9 m
3
ha for Cunninghamia lanceolata, compared to the reference stand with 4 m
3
ha and 3.9 m
3
ha, respectively Figure 4.
Figure 4. Volume per annual increment before and post-CNFM
The observations also show that species composition had improved after eight years’ transformation from pure Pinus massoniana forest to mixed forest Figure 5, and likewise with the Cunninghamia lanceolata forest Figure 6. The species
numbers in both types of forests are clearly higher through enrichment planting and identifyingprotecting natural regeneration through the transformation process.
5 10
15 20
25
Masson pine pre-operation Masson pine post-operation
Chinese fir pre-operation Chinese fir post-operation
Periodic annual increment of standing volume m
3
ha
48 Toxicodendron verniciflum
Schima superba Ficus esquiroliana
Liquidamba formosana Schefflera minutistellata
Cunninghamia lanceolata Vernicia fordii
Mesua ferrea Styrax tonkinensis
Michelia hedyosperma Castanopsis hystrix
Erythrophleum fordii Mytilaria laosensis
Manglietia glauca Quercus griffithii
Pinus massoniana
Tree species
50 100
150 200
250 300
350 400
Tree numberha
Figure 5. Species composition of a Pinus massoniana stand showing enrichment after eight years’ transformation from pure to mixed forest through both enrichment planting Mytilaria laoensis, Castanopsis fissa, Castanopsis
hystrix and identifyingprotecting natural regeneration
Figure 6. The species composition of a Cunninghamia lanceolata stand is clearly enriched after eight years’ transformation from pure to mixed forest through both enrichment planting Mytilaria laoensis, Castanopsis
fissa, Castanopsis hystrix and identifyingprotecting natural regeneration.
Concerning all trees with diameter over 5 cm, species number reached 16 with total tree number of 902ha for Pinus massoniana forest, and 18 with total tree number of 1 438ha for Cunninghamia lanceolata forest.
Vernicia fordii Liquidamba formosana
Ficus virens Macarange deheiculata
Schima wallichii Saplum sebiferum
Schima superba Toxicodendron verniciflum
Schefflera minutistellata Alnus lanata
Mesua ferrea Manglietia glauca
Michelia hedyosperma Mytilaria laosensis
Erythrophleum fordii Castanopsis hystrix
Quercus griffithii Cunninghamia lanceolata
Tree species
100 200
300 400
500 600
700 Tree numberha