Extent and causes of forest cover changes in Vietnam’s provinces 1993–2013: a review and analysis of official data

2017 ◽  
Vol 25 (2) ◽  
pp. 199-217 ◽  
Author(s):  
Roland Cochard ◽  
Dung Tri Ngo ◽  
Patrick O. Waeber ◽  
Christian A. Kull

Within a region plagued by deforestation, Vietnam has experienced an exceptional turnaround from net forest loss to forest regrowth. This so-called forest transition, starting in the 1990s, resulted from major changes to environmental and economic policy. Investments in agricultural intensification, reforestation programs, and forestland privatization directly or indirectly promoted natural forest regeneration and the setting-up of plantation forests mainly stocked with exotic species. Forest cover changes, however, varied widely among regions due to specific socio-economic and environmental factors. We studied forest cover changes (including natural and planted forests) and associated drivers in Vietnam’s provinces from 1993–2013. An exhaustive literature review was combined with multivariate statistical analyses of official provincial data. Natural forest regrowth was highest in northern mountain provinces, especially in the period 1993–2003, whereas deforestation continued in the Central Highlands and Southeast Region. Forest plantations increased most in mid-elevation provinces. Statistical results largely confirmed case study-based literature, highlighting the importance of forestland allocation policies and agroforestry extension for promoting small-scale tree plantations and allowing natural forest regeneration in previously degraded areas. Results provide evidence for the abandonment of upland swidden agriculture during 1993–2003, and reveal that spatial competition between expanding natural forests, fixed crop fields, and tree plantations increased during 2003–2013. While we identified a literature gap regarding effects of forest management by para-statal forestry organizations, statistical results showed that natural forests increased in areas managed for protection/regeneration. Cover of other natural forests under the organizations’ management, however, tended to decrease or stagnate, especially more recently when the organizations increasingly turned to multi-purpose plantation forestry. Deforestation processes in the Central Highlands and Southeast Region were mainly driven by cash crop expansion (coffee, rubber) and associated immigration and population growth. Recent data trends indicated limits to further forest expansion, and logging within high-quality natural forests reportedly remained a widespread problem. New schemes for payments for forest environmental services should be strengthened to consolidate the gains from the forest transition, whilst improving forest quality (in terms of biodiversity and environmental services) and allowing local people to actively participate in forest management.

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 593
Author(s):  
Janet E. Nichol ◽  
Sawaid Abbas

Global trends predict a continuous increase in the proportion of forest occupied by plantations up to the end of the 21st century, while a dramatic loss of biodiversity is foreseen as a result of anthropogenic exploitation and climate change. This study compares the role and performance of plantation policies in Hong Kong, with natural regeneration of secondary forest, using detailed spatio-temporal data extracted from a previous study. The study extends over a 70-year period from 1945 to 2014 using aerial photographs and satellite images of five time periods to document spatio-temporal trends in plantation forestry and natural forest succession. Field data on species richness and woody biomass at different stages of forest succession are compared with available data from plantations in the same study area. Results indicate that plantation forests support relatively few native species in the understory, with much lower species richness than naturally regenerated forest, even after 6 to 7 decades. Time-sequential maps of habitat change show that natural forest succession from barren grassy hillsides, progressed at an annual rate of 7.8%, from only 0.2% of the landscape post WWII, to over 37% today. Plantation forestry on the other hand has been less successful, and has even acted as a barrier to natural forest regeneration, as mono-cultural plantations from the late 1960s to 1980s are still plantations today, whereas other similar areas have succeeded naturally to forest. The theory of plantations acting as a nurse crop for a woody native understory is not supported, as Pinus massoniana plantations, destroyed by two deadly nematodes during the 1970s, apparently had no woody understory, as they were seen to have reverted to grassland in 1989 and are still mainly grassland today.


2021 ◽  
Vol 25 (9) ◽  
pp. 4861-4886
Author(s):  
Aaron J. Neill ◽  
Christian Birkel ◽  
Marco P. Maneta ◽  
Doerthe Tetzlaff ◽  
Chris Soulsby

Abstract. Increasing rates of biodiversity loss are adding momentum to efforts seeking to restore or rewild degraded landscapes. Here, we investigated the effects of natural forest regeneration on water flux partitioning, water ages and hydrological connectivity, using the tracer-aided ecohydrological model EcH2O-iso. The model was calibrated using ∼ 3.5 years of diverse ecohydrological and isotope data available for a catchment in the Scottish Highlands, an area where impetus for native pinewood regeneration is growing. We then simulated two land cover change scenarios that incorporated forests at early (dense thicket) and late (old open forest) stages of regeneration, respectively. Changes to forest structure (proportional vegetation cover, vegetation heights and leaf area index of pine trees) were modelled for each stage. The scenarios were then compared to a present-day baseline simulation. Establishment of thicket forest had substantial ecohydrological consequences for the catchment. Specifically, increased losses to transpiration and, in particular, interception evaporation drove reductions in below-canopy fluxes (soil evaporation, groundwater (GW) recharge and streamflow) and generally slower rates of water turnover. The greatest reductions in streamflow and connectivity were simulated for summer baseflows and small to moderate events during summer and the autumn/winter rewetting period. This resulted from the effect of local changes to flux partitioning in regenerating areas on the hillslopes extending to the wider catchment by reducing downslope GW subsidies that help sustain summer baseflows and saturation in the valley bottom. Meanwhile, higher flows were relatively less affected, especially in winter. Despite the generally drier state of the catchment, simulated water ages suggested that the increased transpiration demands of the thicket forest could be satisfied by moisture carried over from previous seasons. The more open nature of the old forest generally resulted in water fluxes, water ages and connectivity returning towards baseline conditions. Our work implies that the ecohydrological consequences of natural forest regeneration depend on the structural characteristics of the forest at different stages of development. Consequently, future land cover change investigations need to move beyond consideration of simple forest vs. non-forest scenarios to inform sustainable landscape restoration efforts.


Biotropica ◽  
2016 ◽  
Vol 48 (6) ◽  
pp. 745-757 ◽  
Author(s):  
Miguel Martínez-Ramos ◽  
Aline Pingarroni ◽  
Jorge Rodríguez-Velázquez ◽  
Lilibeth Toledo-Chelala ◽  
Isela Zermeño-Hernández ◽  
...  

Biotropica ◽  
2016 ◽  
Vol 48 (6) ◽  
pp. 798-808 ◽  
Author(s):  
Alex C. Gilman ◽  
Susan G. Letcher ◽  
Rita M. Fincher ◽  
Ashley I. Perez ◽  
Tyler W. Madell ◽  
...  

2021 ◽  
Vol 752 ◽  
pp. 141760
Author(s):  
Sawaid Abbas ◽  
Janet E. Nichol ◽  
Jinlong Zhang ◽  
Gunter A. Fischer ◽  
Man Sing Wong ◽  
...  

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