Study on Sonneratia apetala productivity in restored forests in Leizhou Peninsula, China

The exotic Sonneratia apetala in Leizhou Peninsula, has shown outstanding fast-growing ability in restored mangrove forests, at the middle and high tide intertidal zone, with year-round fresh water input from drainage. By setting plot and selecting standard tree, investigation and measurement on height growth, diameter growth, biomass, productivity, and so on, were made in a S. apetala plantation at age of six at Lanbei, Fucheng, Leizhou Peninsula in May 2001. The investigating results showed that the mean annual height growth of plantation was 2.03 m and mean annual growth of diameter at breast height (DBH) was 2.35 cm. There exists a significant correlation between the diameter at ground surface (DGS) and DBH. The average biomass of a single standard tree in dry weight was 95.647 kg/m2. A ratio of above-ground biomass to under-ground biomass was 1.60. The stand biomass of unit area was 22.955 kg/m2, singletree wood volume was 88.23 dm3, and the annual wood volume productivity (PA) of the same year was 0.407. The forest energy accumulation was 424.851 MJ/m2, with annual solar energy fixing rate of 40.68 ×10-7%. It is concluded that S. apetala species had characteristics of outstanding high biomass accumulation and could be used as coastal planting tree species in southern China.

Biochar-Based Seed Coating as an Effective Strategy to Reduce Seed Predation When Restoring Forests on Degraded Land

As ecosystem degradation becomes more widespread, there is a growing need for efficient and effective forest restoration methods. Direct seeding is one such method that can be used to cover a relatively large area, particularly places with difficult-to-access terrain. One major obstacle hampering successful restoration via direct seeding is seed predation, as seeds are damaged or eaten. We tested the effectiveness of encrusting six species of native seeds with biochar-based coating in reducing the seeds’ chances of being predated on degraded hillsides and landslide scars in Hong Kong. The six seeded species are native trees and shrubs, including both late-successional and pioneer species that are present in forests and shrublands. Our results show that biochar-based seed coats were able to significantly reduce overall seed predation by 5.77% (SE = 1.41, p < 0.05). Additionally, we found varied effectiveness of the biochar-based seed coats across species and seed morphology. Of the six species that were included, four of them had significantly reduced seed predation after encrusting with biochar-based seed coats, while two other species were not significantly affected by the biochar-based seed coats. When we investigated seed predation against seed morphology, we found that while the species with larger seeds were more likely to be predated when sown without any biochar-based seed coat, the effectiveness of the biochar-based seed coat to reduce predation also increased with larger seeds. Our results suggest that encrusting seeds with biochar-based seed coats is an effective means of reducing seed predation.

Research advance in forest restoration on the burned blanks

How to restore the destroyed forest after forest fire is a key question that man must face. This paper reviewed the research situation and history on the forest restoration burned blanks and summed up the research methods used into four scales: seed-bank scale, community scale, ecosystem scale and landscape scale. The new technologies such as GIS & Remote Sensing used to vegetation restoration were also summarized. The strategies and developing trend of vegetation restoration research on burned blanks were discussed.

Problems and countermeasures on restoration of forest ecological environment of Jilin Province

Jilin Province is one of major forest regions of China. This paper analyzed the existing conditions and tendency in forest ecological restoration of the province and revealed the confronting problems in ecology and economy. The authors divided Jilin Province into three ecological economic zones, including nid-west farming and stockbreeding area, east hilly diversified-operation area, and Changbai Mountain national forest area, and discussed the direction and tasks of forest ecological restoration of each zone. Some Countermeasures and suggestions were put forward for restoration of forest ecology of the province.

A review of the roles of forest canopy gaps

Treefall gap, canopy opening caused by the death of one or more trees, is the dominant form of disturbance in many forest systems worldwide. Gaps play an important role in forest ecology helping to pre- serve bio- and pedo-diversity, influencing nutrient cycles, and maintain- ing the complex structure of the late-successional forests. Over the last 30 years, numerous reviews have been written describing gap dynamics. Here we synthesize current understanding on gap dynamics relating to tree regeneration with particular emphasis on gap characteristics consid- ered critical to develop ecologically sustainable forest management sys- tems and to conserve native biodiversity. Specifically, we addressed the question： how do gaps influence forest structure？ From the literature re- viewed, the size of gaps induces important changes in factors such as light intensity, soil humidity and soil biological properties that influence tree species regeneration and differ in gaps of different sizes. Shade- tolerant species can colonize small gaps; shade-intolerant species need large gaps for successful regeneration. Additionally, gap dynamics differ between temperate, boreal, and tropical forests, showing the importance of climate differences in driving forest regeneration. This review summa- rizes information of use to forest managers who design cutting regimes that mimic natural disturbances and who must consider forest structure, forest climate, and the role of natural disturbance in their designs.

Changes in leaf stomatal traits of different aged temperate forest stands

Stomata control carbon and water vapor exchange between the leaves and the atmosphere,thus infl uencing photosynthesis and transpiration.Combinations of forest patches with different stand ages are common in nature,however,information of which stomatal traits vary among these stands and how,remains limited.Here,seven different aged forest stands(6,14,25,36,45,55,and 100 years)were selected in typical temperate,mixed broadleaf-conifer forests of northeast China.Stomatal density,size and relative area of 624 species,including the same species in stands of different ages were selected.Stomatal density,size and relative area were distributed log-normally,differing across all species and plant functional groups.Stomatal density ranged from 4.2 to 1276.7 stomata mm^(–2),stomatal size ranged from 66.6 to 8315.7μm^(2),and stomatal relative area 0.1–93.3%.There was a significant negative relationship between density and size at the species and functional group levels,while the relative stomatal area was positively correlated with density and size.Stomatal traits of dominant species were relatively stable across different stand ages but were significantly different for herbs.The results suggest that stomatal traits remain relatively stable for dominant species in natural forests and therefore,spatial variation in stomatal traits across forest patches does not need to be incorporated in future ecological models.

Effects of silviculture treatments in a hurricane-damaged forest on carbon storage and emissions in central Hokkaido, Japan

Hurricanes cause abrupt carbon reduction in forests, but silviculture treatment can be an effective means of quickly regenerating and restoring hurricane-damaged sites. This study assessed how silviculture treatments affect carbon balance after hurricane damage in central Hokkaido, Japan. We examined carbon storage in trees and underground vegetation as well as carbon emissions from silviculture operations in 25-year-old stands, where scarification and plantation occurred just after hurricane damage. The amount of carbon stored varied according to silviculture treatment. Among three scarification treatments, a scarified depth of 0 cm （understory vegetation removal） led to the largest amount of carbon stored （64.7 t·ha^-1 C）. Among four plantation treatments, the largest amount of carbon was stored in a Larix hybrid （L. gmelinii var. japonica × L. kaempferi） plantation （80.3 t·ha^-1 C）. The plantation of Abies sachalinensis was not successful at accumulating carbon （40.5·ha^-1 C）. The amount of carbon emitted from silviculture operations was 0.05-0.14 t·ha^-1 C, and it marginally affected the net carbon balance of the silviculture project. Results indicate that silviculture treatments should beperformed in an appropriate way to effectively recover the ability of carbon sequestration in hurricane-damaged forests.

Soil organic carbon storage in forest restoration models and environmental conditions

The scale of forest and landscape restoration is expected to increase during the UN Decade on Ecosystem Restoration and its contribution to the provision of critical ecosystem services to society.Several models of forest restoration may improve ecosystem services,including soil organic carbon(SOC)storage.A review was carried out to access:(1)the variability of SOC storage between worldwide forest restoration models and,(2)the effects of climate,soil class,soil texture,and vegetation type on SOC storage.We reviewed 119 primary studies with information on SOC and soil texture for different forest restoration models.The restoration models were grouped into four categories:natural regeneration,monocultures,agroforestry,and mixed forest.SOC data was extracted from these four restoration models,other land uses(cropland,bare land,grassland,and natural forest),climate regimes,and soil properties.The SOC storage in the forest restoration models and other land uses at a global scale ranged between 0.1 to 514 Mg ha^(-1).The overall mean value for SOC storage was higher for natural regeneration(112 Mg ha^(-1)),followed by agroforestry(74 Mg ha^(-1)),mixed forest(73 Mg ha^(-1)),and monocultures(68 Mg ha^(-1)).However,the average SOC storage was similar among the four restoration models in the moist warm climate zone.The SOC storage mean value in the moist cool zone was 23%higher than the dry cool zone(81 and 62 Mg ha^(-1),respectively),and 50%higher for the moist warm zone when compared to the dry warm climatic zone(74 and 38 Mg ha^(-1),respectively).The SOC storage of the restoration models was positively related to soil depth(0.59;p<0.01),clay content(0.29;p<0.01),and stand age(0.17;p<0.01).Globally,the mean values of SOC storage were 26,66,and 139 Mg ha^(-1) at zero-10,zero-30,and zero-100 cm depths,respectively.In addition,sandy soils showed smaller mean values of SOC storage than medium to clay soils,especially in deeper soil layers.Furthermore,SOC storage was positively related between restoration models and other land uses(0.93;p<0.01),suggesting a prominent effect of climate and soil properties on SOC.Forest restoration models showed larger SOC storage when compared to croplands and bare land,but in general it was smaller or similar when compared to pasture and natural forest.

Tree Planting:How Fast Can It Accelerate Post-fire Forest Restoration?——A Case Study in Northern Da Hinggan Mountains,China

In 1987,a catastrophic fire burned over 1330000 ha in the densely forested area of the Da Hinggan Mountains in the northeastern China.After the fire,intensive management including burned trunk harvesting and coniferous tree planting had been conducted to accelerate forest restoration.To study the long term effect of these activities on forest recovery,we used a simulation modeling approach to study long-term(300 years) forest dynamics under current planting and natural regeneration scenarios.Results indicate that under tree planting scenario in the severely burned area,the dominant species Dahurian larch(Larix gmelinii) can reach pre-fire level(60% of the area) within 20 years and the maximum abundance can reach nearly 90% within 100 years.While under natural regeneration scenario,it needs about 250 years to reach its pre-fire level.From the perspective of timber production,tree planting can bring twice as much timber volume as that under natural regeneration within 300 years,which is the average longevity of L.gmelinii.It needs about 70 years to reach the timber volume of pre-fire level under the planting scenario,whereas it requires at least 250 years to reach the timber volume of pre-fire level under natural regeneration scenario.Another dominant species Asian White birch(Betula platyphylla) responded negatively to the planting of coniferous species.In general,tree planting of coniferous species after fire can greatly accelerate forest restoration in terms of species abundance and target timber volume,with desirable ecological and economic returns.

Aspects of forest restoration and hydrology:linking passive restoration and soil–water recovery in Brazilian Cerrado

Although the scientific knowledge about some associations between physical parameters of the soil is consolidated,studies focused on investigating the dynamics of forest restoration processes and the structure of soils remain incipient.The study area is located in Cerrado and is called as Private Natural Heritage Reserve(RPPN)Águas Perenes Forest(perennial water forest)and was selected as a“High Conservation Value Forest”,provides scope to investigate the soil physical properties recovery on passive restoration sites,with different ages but with the same land use history.So,the aim was to investigate the soil density,moisture,penetration resistance and infiltration rate with long-term from old(FA,46 year-old),medium(FB,11 year-old)and young(FC,8 year-old)passive restoration sites.It was observed differences in soil density,as well as in soil moisture,resistance to penetration and infiltration rate.Mean densities recorded for FA,FB and FC were 1.38,1.48 and 1.53 g cm^(-3),respectively.FA recorded higher mean soil moisture(14.9%)than FB(11.5%)and FC(10.0%),whereas mean soil resistance to penetration was increased from FA(0.87 MPa)to FB(0.91 MPa)and FC(1.10 MPa).The average infiltration rate was almost similar in FA and FB(FA=76.43 mm h^(-1);FB=77.48 mm h^(-1))and approximately 39%higher than FC(55.79 mm h^(-1)).Thus,although soil density and moisture were different in each passive restoration site,11 year-old passive restoration site showed similar resistance to penetration and infiltration rate to the old(46 years)passive restoration site.These features allowed seeing improvements in hydrological maintenance in the soil and revealed that passive restoration in Cerrado is able to improve the physical features on a soil presenting similar texture,climate and management history.

Integrating species and successional classes for wood production in a mixed forest restoration system in a neotropical region

As forests in neotropical regions,particularly in developing countries,are devastated,interventions to restore biodiversity and its ecological functions are needed.Rural producers have thus been encouraged to grow trees for wood production as an economic activity.The objective of this study was to quantify the increment of wood density of four forest species from different successional classes of a mixed system of restoration in a neotropical forest in Brazil.Tree discs were sampled at breast height and analyzed radially by X-ray densitometry to obtain apparent density and basic density.Three trees each of a species from the pioneer,early and late secondary successional stages and of the dominant species in the climax community.The radial profiles indicated increasing density from the pith to bark of trunks,except for some variations due to wood defects and growth.Average density was 0.576 g cm^(-3),0.655 g cm^(-3),0.706 g cm^(-3)and 0.775 g cm^(-3),respectively,for Peltophorum dubium,Schinus terebinthifolius,Cariniana estrellensis and Hymenaea courbaril.Radial profiles indicated higher amplitudes in the apparent densities for slow-growing species.X-ray densitometry generated parameters such as minimum,average and maximum densities,and radial density variations.These parameters are important for understanding the ecological functional role of successional classes of the Atlantic Forest from the Neotropical region.

Neighborhood diversity structure and neighborhood species richness effects differ across life stages in a subtropical natural secondary forest

Natural secondary forest has a strong capacity to regrow naturally and recover biodiversity rapidly on abandoned lands.However,at the neighborhood scale,which can truly reflect the facilitative or competitive interactions among individual plants,the local diversity spatial structure in secondary forest and the feedback effects of neighborhood diversity on natural regeneration remain unclear,and this may be the key to properly understand the mechanisms of natural secondary forest species diversity recovery.To this end,this study established a dynamic plot in a rehabilitated secondary forest after disturbance and conducted a comprehensive survey of 68,336 individual plants with repeated measurements at 5-year interval to assess the characteristics of neighborhood diversity structure across life history stages and link the neighborhood species richness(NSR)effect translated by species interactions at species diversity structure with individual trees recruitment/mortality in secondary forest regeneration.The results showed that,compared with tropical and temperate natural forests,a higher proportion of diversity accumulators and a lower proportion of repellers in subtropical secondary forests resulted in neighborhood diversity structures characterized by heterospecific or high-diversity patches,which are beneficial to the maintenance or restoration of biodiversity.As an important supplement to the research on the relationship between diversity and productivity,our findings show a positive diversity-survival relationship in subtropical secondary forests.Importantly,we observed that the neighborhood diversity structure exhibited a trend of accumulator-dominated to neutral-dominant changes with life stage from sapling to adult,which,in turn,determined the direction and strength of NSR effects on recruitment/mortality.Specifically,diverse local neighborhoods at a later successional stage characterized with‘neutral’species-species interactions can act as a‘welfare net’by offering favorable microhabitats for the most vulnerable recruitments or saplings,i.e.,the NSR effects that promoted individual recruitment/survival in our study.These results not only enrich our understanding of the biodiversity-productivity-survival relationship but also highlight the importance of retaining latesuccessional species of native trees in intensive forest production or in situ conservation policies.

Changing Forestry Policy by Integrating Water Aspects into Forest/Vegetation Restoration in Dryland Areas in China

Restoration forestry （forest rehabilitation） or re-vegetation is one effective measure to solve environmental problems, notably soil erosion. It may be further stimulated by the Clean Development Mechanism for carbon sequestration. However, there is an intensive and on-going debate about the adverse effects arising from afforestation in dryland areas, such as soil drying up which may cause further damage to the success of forest restoration, and the water yield reduction from watershed which may harm the regional development. On other hand, some preliminary studies showed a possibility that these adverse effects may be diminished more or less by properly designing the system structure and spatial distribution of forest/vegetation in a watershed. However, it is urgent to develop an evidence-based and sustainable new forestry policy for harmonizing forest-water interrelation. As a leading country in afforestation, China is beginning to develop a more trans-disciplinary and cross-sectoral forestry policy for harmonizing forestry development with water management. The main points of the changing new forestry policy should include： （1） Establishing a regional development strategy focusing on harmonized forest-water relations; （2） Taking forest-water interactions as an important part of evaluation; （3） Reducing the ＇eco-water＇ quota of forests through technical advancement; （4） Developing and extending water-adaptive forest management practices; （S） Strengthening forest ecohydrological research and decision support ability.

Estimating Urban Households’ Willingness-to-Pay for Upland Forest Restoration in Vietnam

Increased urbanization coupled with increased reliance of urban communities on rural areas for ecosystem service provision is a challenge faced by many nations. The ability of urban households to directly support restoration efforts in surrounding rural regions represents an underappreciated funding stream for ecological restoration. This study explored the willingness of urban households to support forest restoration in Vietnam. We surveyed 211 households (HHs) in the capital city Hanoi, Vietnam. A Maximum Likelihood Estimator (MLE) model allowed us to obtain the parameters of our model and quantify mean Willingness-to-Pay (WTP) for a program of forest restoration in addition to identifying factors influencing the decision of WTP. Generally, over forty percent of the households surveyed are willing to pay for forest restoration and the mean value of WTP is 37,830 VND ($1.73) per household per month. WTP depends on endogenous and exogenous factors including level of education, income, female-to-male ratio in the household, attitude toward payment for monthly electricity consumption, and awareness of payment for environmental service. Our results suggest that urban household’s demand for forest restoration is real, and represents an untapped source of restoration funding. Policy-makers should take actions to apply charges on water bills to turn this potential into reality for restoration projects in Vietnam if the benefits from restoration outweigh the costs based on our findings.

Conceptual models of forest dynamics in environmental education and management:keep it as simple as possible,but no simpler

Background：Conceptual models of forest dynamics are powerful cognitive tools,which are indispensable for communicating ecological ideas and knowledge,and in developing strategic approaches and setting targets for forest conservation,restoration and sustainable management.Forest development through time is conventionally described as a directional,or ＂linear＂,and predictable sequence of stages from ＂bare ground＂ to old forest representing the ＂climax-state＂.However,this simple view is incompatible with the current knowledge and understanding of intrinsic variability of forest dynamics.Hypothesis：Overly simple conceptual models of forest dynamics easily become transformed into biased mental models of how forests naturally develop and what kind of structures they display.To be able to communicate the essential features and diversity of forest dynamics,comprehensive conceptual models are needed.For this end,Kuuluvainen（2009） suggested a relatively simple conceptual model of forest dynamics,which separates three major modes of forest dynamics,and incorporates state changes and transitions between the forest dynamics modes depending on changes in disturbance regime.Conclusions：Conceptual models of forest dynamics should be comprehensive enough to incorporate both longterm directional change and short-term cyclic forest dynamics,as well as transitions from one dynamics mode to another depending on changes in the driving disturbance regime type.Models that capture such essential features of forest dynamics are indispensable for educational purposes,in setting reference conditions and in developing methods in forest conservation,restoration and ecosystem management.

Effects of Forest Restoration Techniques on Community Diversity and Aboveground Biomass on Area Affected by Mining Tailings in Mariana,Southeastern Brazil

Currently there is an urgent and special attention in actions to restore tropical forests.In this study,we evaluated the effect of different restoration methods on aboveground biomass(AGB)stock,tree community diversity and structure,in areas affected by the Fundão tailings dam collapse in Mariana,Minas Gerais state,Brazil.We measured and compiled data of the AGB,community diversity and structure attributes in 36 plots distributed in six restoration treatments and six replicas:planting of native tree seedlings with fertilization and pH correction(PSf)and without fertilization and pH correction(PS);seeding of native trees with fertilization and pH correction(SDf)and without fertilization and pH correction(SD);natural regeneration with fertilization and pH correction(NRf)and without fertilization and pH correction(NR).No significant differences in substrate properties and AGB between treatments.Although biomass storage between treatments was not statistically different,there is a clear pattern showing higher values active restoration method.The Pielou index ranged from 0.520(SDf)to 0.943(NR),except for SDf all the others treatments had values higher than 0.76.This result suggests floristic heterogeneity,without ecological dominance in the plant community.Overall,active restoration had important implications for the forest restoration where natural regeneration is limited.

Alleviating forest degradation in the Lancang-Mekong Region requires closing management—measurement gaps

Deforestation and forest degradation are having profound negative impacts on social-ecological systems in the emerging economies across the tropics.Consequently,interest in restoring and rehabilitating degraded forests has been growing.This paper explores current issues related to addressing forest degradation in the Lancang-Mekong Region(LMR)of Southeast Asia through a review of the use of criteria and indicators for forest degradation and rehabilitation.Forest degradation must be understood in the context of its underlying drivers,which are numerous and complex.Understanding these underlying drivers of degradation requires diagnosing the entwined political,social,economic,and environmental systems that aff ect forests.Landscapes are the relevant scales to diagnose and intervene for improved forests.Interventions to restore or rehabilitate forests should be process-driven,focused on the underlying social,ecological and political processes that degrade landscapes.Interventions should also include negotiation among all actors infl uencing and competing for natural resource claims in forest landscapes.Criteria and indicators for forest landscape restoration should therefore help to improve the governance of forest landscapes.Criteria and indicators provide measures of the biophysical outcomes of degradation,in addition to processes,but these should be adapted to changing contexts and emerging challenges,and should rectify any pre-existing fl awed change-logic.Restoration activities should synthesize,integrate,and build upon the rich history of pre-existing restoration guidelines,but should be adaptable in order to be applied eff ectively in the contexts of local landscapes.This project is facilitating a dialogue around the use of criteria and indicators to help solve the degradation challenge in the LMR.We will trial the use of the criteria and indicators generated through this research in the LMR to learn what works and what doesn’t.This will provide an opportunity to build consensus around the ways in which restoration investments made by governments,civil society,and the private sector can infl uence sustainability.

Observations on forest restoration in Jilin, China

This paper reviews various forestry practices in Jilin Province, China. The authors emphasize the rich natural diversity of Jilin and the need to focus research efforts on understanding the potential of native species to meet the needs of land-management agencies involved in forest resource exploitation and ecological restoration. The native species of China hold great potential, and deserve more research attention, for meeting these needs. The introduction and testing of exotic species should be dbne only under rigorous scientific testing and after comparison with native species prior to operational introduction into forestry in order to avoid unwanted ecological consequences, including potential problems with alien invasives and pest introductions. The authors also emphasize the need to maintain viable （e.g., genetically diverse and reproductively fit） natural populations of native species in order to protect China＇s valuable natural diversity and maintain the potential of native species to function as future seed sources for local forest and ecological restoration activities.

Linkage of microbial living communities and residues to soil organic carbon accumulation along a forest restoration gradient in southern China

Background:Forest restoration has been considered an effective method to increase soil organic carbon(SOC),whereas it remains unclear whether long-term forest restoration will continuously increase SOC.Such large uncertainties may be mainly due to the limited knowledge on how soil microorganisms will contribute to SOC accumulation over time.Methods:We simultaneously documented SOC,total phospholipid fatty acids(PLFAs),and amino sugars(AS)content across a forest restoration gradient with average stand ages of 14,49,70,and>90 years in southern China.Results:The SOC and AS continuously increased with stand age.The ratio of fungal PLFAs to bacterial PLFAs showed no change with stand age,while the ratio of fungal AS to bacterial AS significantly increased.The total microbial residue-carbon(AS-C)accounted for 0.95-1.66% in SOC across all forest restoration stages,with significantly higher in fungal residue-C(0.68-1.19%)than bacterial residue-C(0.05-0.11%).Furthermore,the contribution of total AS-C to SOC was positively correlated with clay content at 0-10 cm soil layer but negatively related to clay content at 10-20 cm soil layer.Conclusions:These findings highlight the significant contribution of AS-C to SOC accumulation along forest restoration stages,with divergent contributions from fungal residues and bacterial residues.Soil clay content with stand age significantly affects the divergent contributions of AS-C to SOC at two different soil layers.

A decision framework for identifying models to estimate forest ecosystem services gains from restoration

Restoring degraded forests and agricultural lands has become a global conservation priority. A growing number of tools can quantify ecosystem service tradeoffs associated with forest restoration. This evolving ＂tools landscape＂ presents a dilemma： more tools are available, but selecting appropriate tools has become more challenging. We present a Restoration Ecosystem Service Tool Selector （RESTS） framework that describes key characteristics of 13 ecosystem service assessment tools. Analysts enter information about their decision context, services to be analyzed, and desired outputs. Tools are filtered and presented based on five evaluative criteria： scalability, cost, time requirements, handling of uncertainty, and applicability to benefit-cost analysis. RESTS uses a spreadsheet interface but a web-based interface is planned. Given the rapid evolution of ecosystem services science, RESTS provides an adaptable framework to guide forest restoration decision makers toward tools that can help quantify ecosystem services in support of restoration.