Reforestation Plots Research Articles

Reassembly of ground-dwelling ant communities in reforestation plots in SW Costa Rica

Due to agriculture and logging, Costa Rica has lost many primary forests, making reforestation an important task. To judge the progress of reforestation, it is important to follow the reassembly of organismal communities within restored habitats. The COBIGA project near La Gamba, in the Golfo Dulce region of Costa Rica, aims at reforestation of lowland sites with native tree species. Ants, as ubiquitous and highly abundant terrestrial organisms, have a substantial influence on tropical ecosystems. The multiple roles include scavenging, predation, herbivory, and mutualistic interactions. We examined ant community responses to reveal the status of community regeneration and functional integrity. We compared the composition and diversity of the ant assemblages at three different age reforestation sites (2, 8, and 10 years old) with those at an old-growth forest as a reference site. By offering canned tuna fish at ground level along replicated transects, we observed 43 ant species representing six functional groups during the 2 months of sampling. Most of the observed ant species were omnivorous, but old-growth forests harbored a substantial number of other functional groups, such as generalized predators, arboreal predators, and arboreal omnivores. In contrast, the youngest reforestation site harbored a severely impoverished ant assemblage comprising mostly generalized polygynous and polydomous ant species from lower trophic levels. The within-site heterogeneity of the ant assemblages increased from the youngest to the oldest forest. In addition, our results show the importance of monitoring the progress of forest recovery to avoid the spread of invasive species into primary habitats.

Enhanced carbon, nitrogen and associated bacterial community compositional complexity, stability, evenness, and differences within the tree-soils of Inga punctata along an age gradient of planted trees in reforestation plots

Enhanced carbon, nitrogen and associated bacterial community compositional complexity, stability, evenness, and differences within the tree-soils of Inga punctata along an age gradient of planted trees in reforestation plots

Does restoring native forest restore ecosystem functioning? Evidence from a large‐scale reforestation project in the Scottish Highlands

Given the worldwide plans for extensive tree planting, we urgently need to understand how and where implementation will contribute to goals such as those for carbon sequestration. We used a long‐term, large‐scale native reforestation project in the Scottish Highlands to assess the response of carbon storage and other ecosystem functions to reforestation and grazing exclusion. We measured aboveground carbon, topsoil carbon, topsoil nitrogen, decomposition rates, soil invertebrate feeding activity, tree regeneration, and ground‐layer and moss height at 14 sites that are in the early stages of reforestation and fenced to exclude grazing. Reforestation areas were compared to unforested and mature forest areas that are both grazed and ungrazed, using 10 × 10 m plots. Aboveground carbon in the reforestation plots (1.4 kg/m2 [95% CI: 0.6, 2.6], average age 20 years since reforestation) was c. 8% of the mature forest plots (17.1 kg/m2 [13.1, 21.8]). Topsoil carbon was lower in the reforestation plots (18.78 kg/m2 [11.79, 25.78]) than in the unforested (29.82 kg/m2 [24.34, 35.29]) or mature forest (31.39 kg/m2 [22.91, 39.88]) plots. Responses of other functions to the reforestation and grazing interventions varied. Our results suggest that reforestation may trigger carbon loss from areas with high initial soil carbon even with low disturbance establishment, at least in the short term. Our work emphasizes where we lack knowledge: on the potential for long‐term re‐accumulation of soil carbon under semi‐natural native reforestation, soil carbon sequestration in the deeper soil layers, and the response of soil carbon to natural regeneration.

Plantation development and colonization of woody species in response to post-mining spoil preparation methods

Rising mineral and fossil fuel demand have accelerated the global prevalence of surface mining, resulting in adverse impacts to many forest ecosystems. Post-mining reclamation techniques, specifically spoil preparation methods, can influence reforestation success and the trajectory of future stand dynamics. Compaction is a common post-mining spoil stabilization technique but consequently creates high-density rooting media unconducive to forest succession. In the eastern USA, mine operators have traditionally attempted mine reforestation in compacted soils, achieving little success. In 1996–1997, a series of reforestation plots were created on a reclaimed surface mine in eastern Kentucky, USA, to evaluate the impacts of post-mining spoil preparation on plantation development of six native tree species. We conducted follow-up inventories 19 years after planting to elucidate the effect of three spoil preparation methods on tree growth, stand structure, and natural regeneration during the initial period of the stem exclusion stage of stand development. Low compaction reclamation techniques prior to tree planting generally resulted in higher survival and larger trees of all species nearly two decades after establishment when compared with compacted spoil. Natural recruitment and relative percentage of native colonizing species were also inversely correlated with level of grading treatment. Height and biomass growth of plantations in low-compaction treatments approximated those of naturally regenerating stands in unmined forests during similar periods. Study findings indicate that choice of spoil preparation technique during initial stages of reclamation guides forest dynamics up to two decades after planting and that loose-dump and strike-off treatments each promote favorable long-term growth trajectories.

Diversité De La Macrofaune Du Sol Dans Les Parcelles De Reboisement De La Grande Muraille Verte Au Sénégal

Objective: To assess the effect of vegetation cover on soil macrofauna, a study focused on the diversity of soil macrofauna inside and outside reforestation plots of the Great Green Wall in Senegal was carried out. Methodology: The sampling of macrofauna was performed according to the method recommended by the TSBF network (Tropical Soil Biology and Fertility). It involves isolating 10 ground plots along a transect of 50 meters chosen at random in each plot and outside of each plot. The macrofauna was sampled between February and July 2016 during the dry season Results: The results show, in order of importance Hymenoptera, Isoptera, Coleoptera, the Spiders, the isopods and springtails are the taxonomic groups of the study area. The density of each of these taxa is larger inside and outside of the plots. The vertical distribution of macrofauna shows that the 0-10 cm layer is more densely populated than the deeper layers. Conclusion: This study showed a low diversity of soil macrofauna in the area. It also shows that the vegetation cover affects the density of the macrofauna.

Landscape Factors and Restoration Practices Associated with Initial Reforestation Success in Haiti

Mountainous land in Haiti is highly degraded following decades of deforestation and erosion. Although mountainous landscapes represent an important target for forest recovery, there is a lack of empirical information to guide reforestation of sloping tropical lands. Using sapling survival data from 299 replicated reforestation plots planted with 24 dry forest species during 2007–2008 in Haiti, we examined the association of sapling survival with topographical, climatic, and landscape level variables. Our analysis indicates that the total number of surviving saplings was strongly correlated to sites with higher water availability, including sites with greater precipitation in dry months and sites with cooler (N/E) exposures. Sites with more adult remnant trees had higher sapling survival. Sapling survival was also improved by the use of best management practices of building micro-catchments and planting multiple sapling species into reforestation plots. Year effects were also significant and modified the effects of exposure, nurse trees, and soil rockiness. This temporal variation suggests sapling responses to environmental factors are sensitive to variation in rainfall.

Practices of the Great Green Wall Project in the Ferlo (Senegal): Effects on Pastoral Resilience and Development

To support the ecosystem resilience in the sylvo-pastoral area, Senegal did pioneering work by initiating, since 2008,field activities in the framework of the pan-African project of the Great Green Wall (GGW). How have theSenegalese practices contributed to the pastoral resilience and development? What are the lessons that the PanAfrican Agency and the Sahelian countries involved can draw from the Senegalese experience? To answer thesequestions, this study proposes to identify the major characteristics of the GGW practices as well as the effects onpastoralism in a comprehensive and strategic perspective, following an inductive approach.The Great Green Wall looks like a sectorial project (forest) with diversification activities (horticulture). The wayfield workers perceive it is not homogeneous. Reforestation plots have impacts on the resilience of the courses andthe populations. They modify the grazing plans and encourage private fodder banks to the detriment of traditionalpasture reserves. Several actions (distribution of food, medical consultations, employment) of the Great Green Wallcontribute to the resilience of the pastoral populations (health, food security and income). The Great Green Wall alsohas effects on social transformation and pastoral development. There is a noticeable change of mindset, adevelopment of civic awareness, as well as a breakdown of their social isolation.To become a systemic project development, the GGW could integrate production sectors such as hydraulics andeducation. To accomplish this, the agency must hire a multidisciplinary staff with a corporate culture to break awaywith participative behaviors.

Soil biochemical properties in brown and gray mine soils with and without hydroseeding

Abstract. Surface coal mining in the eastern USA disturbs hundreds of hectares of land every year and removes valuable and ecologically diverse eastern deciduous forests. Reclamation involves restoring the landscape to approximate original contour, replacing the topsoil, and revegetating the site with trees and herbaceous species to a designated post-mining land use. Re-establishing an ecosystem of ecological and economic value as well as restoring soil quality on disturbed sites are the goals of land reclamation, and microbial properties of mine soils can be indicators of restoration success. Reforestation plots were constructed in 2007 using weathered brown sandstone or unweathered gray sandstone as topsoil substitutes to evaluate tree growth and soil properties at Arch Coal's Birch River mine in West Virginia, USA. All plots were planted with 12 hardwood tree species and subplots were hydroseeded with a herbaceous seed mix and fertilizer. After 6 years, the average tree volume index was nearly 10 times greater for trees grown in brown (3853 cm3) compared to gray mine soils (407 cm3). Average pH of brown mine soils increased from 4.7 to 5.0, while gray mine soils declined from 7.9 to 7.0. Hydroseeding doubled tree volume index and ground cover on both mine soils. Hydroseeding doubled microbial biomass carbon (MBC) on brown mine soils (8.7 vs. 17.5 mg kg−1), but showed no effect on gray mine soils (13.3 vs. 12.8 mg kg−1). Hydroseeding also increased the ratio of MBC to soil organic C in both soils and more than tripled the ratio for potentially mineralizable nitrogen (PMN) to total N. Brown mine soils were a better growth medium than gray mine soils and hydroseeding was an important component of reclamation due to improved biochemical properties and microbial activity in mine soils.

Reforestation Sites Show Similar and Nested AMF Communities to an Adjacent Pristine Forest in a Tropical Mountain Area of South Ecuador

Arbuscular mycorrhizae are important for growth and survival of tropical trees. We studied the community of arbuscular mycorrhizal fungi in a tropical mountain rain forest and in neighbouring reforestation plots in the area of Reserva Biológica San Francisco (South Ecuador). The arbuscular mycorrhizal fungi were analysed with molecular methods sequencing part of the 18 S rDNA. The sequences were classified as Operational Taxonomic Units (OTUs). We found high fungal species richness with OTUs belonging to Glomerales, Diversisporales and Archaeosporales. Despite intensive sampling, the rarefaction curves are still unsaturated for the pristine forest and the reforestation plots. The communities consisted of few frequent and many rare species. No specific interactions are recognizable. The plant individuals are associated with one to ten arbuscular mycorrhizal fungi and mostly with one to four. The fungal compositions associated with single plant individuals show a great variability and variety within one plant species. Planted and naturally occurring plants show high similarities in their fungal communities. Pristine forest and reforestation plots showed similar richness, similar diversity and a significantly nested structure of plant-AMF community. The results indicate that small-scale fragmentation presently found in this area has not destroyed the natural AMF community, at least yet. Thus, the regeneration potential of natural forest vegetation at the tested sites is not inhibited by a lack of appropriate mycobionts.

Comparative water fluxes through leaf litter of tropical plantation trees and the invasive grass Saccharum spontaneum in the Republic of Panama

Summary The hydrological properties of leaf litter layers remain relatively unexplored, especially in tropical vegetation communities. In this paper we explore the hydrological dynamics of litter samples from reforestation plots of tropical hardwoods and the invasive sugar cane Saccharum spontaneum , which these trees were planted to replace. Water holding capacity (WHC) and drying rates were compared under controlled conditions, and throughfall interception, drainage and calculated evaporation were measured in two field experiments (A and B) conducted with different sets of samples. The WHC of samples varied from 3.4 to 6.5 mm in experiment A, and from 1.6 to 7.1 mm in experiment B. Drainage through the litter samples averaged 78.3 ± 34.4% and 61.2 ± 34.70% TF in experiments A and B, respectively. Daily water storage was 70.8 ± 14.25% of total WHC in experiment A and 78.6 ± 25.35% of total WHC in experiment B. Estimated evaporation averaged 34.8 ± 12.52% of WHC in experiment A and 34.3 ± 14.91% of WHC in experiment B. Although significant interspecific differences in WHC, interception of TF and evaporation were recorded, species rankings tended to be different in experiments A and B. The exception was litter from the leguminous tree Gliricidia sepium , which maintained the lowest WHC and water storage in the field in both experiments, but which evaporated water more rapidly than other species. The depth of throughfall draining through litter samples in the field was similar among all species in both experiments. Comparisons of regression slopes also showed that drainage depth increased with increasing throughfall at similar rates among species. On the other hand, both slopes and slope elevations differed among species when drainage was expressed in l kg −1 . Patterns of water storage and drainage in our samples were in broad agreement with those of other studies, although WHC and litter necromass in our young tree plantations fell into the lower end of the range reported for mature Amazonian forest.

Collembola as bioindicators of restoration in mined sand dunes of Northeastern Brazil

Opencast mining causes severe environmental impacts by removing the vegetation cover and depleting the fauna. Reforestation methods using native species and diverse pre- and post-disturbance approaches aim to recover the original richness and diversity of species found before the impact. Bioindicators are powerful tools to evaluate the restoration of the original environmental conditions in disturbed areas. We used species richness, endemism and diversity measurements of Collembola to compare successional stages in reforested sites of different ages compared with a control undisturbed area. Richness and abundance of Collembola were subjected to correlation analysis with age of plots and vegetational variables. Areas that were reforested for up to 16 years supported a much lower Collembola species richness than undisturbed areas. Both the age of reforestation plots and vegetation variables (number of trees, diameter of crowns, depth of leaf litter and tree species richness) were positively and significantly correlated to collembolan abundance and richness. The results showed that the diversity of the 16-year-old plot was significantly higher than that of younger areas, but significantly less diverse than that of the control area. Endemic species were more sensitive to disturbance than non-endemics. Thus, species richness and diversity of soil Collembola can be only partially restored with appropriate reforestation methods, and although it takes many years, to some extent even endemic species can be gradually restored. Nevertheless, the maintenance of undisturbed diversity reservoirs linked by ecological corridors to reforested plots is imperative, as only undisturbed areas can support most of the endemic species able to re-colonize reforested sites.

Small Mammal Response to Vegetation and Spoil Conditions on a Reclaimed Surface Mine in Eastern Kentucky

Abstract Ecologically effective mine reclamation is characterized by the return of pre-mining floral and faunal communities. Excessive soil compaction typically results in delayed succession and low species diversity on reclaimed mine lands. We compared small mammal abundance and diversity among three levels of compaction in reforestation plots on an eastern Kentucky surface mine during 2004 and 2005. Compaction levels included 1) no compaction (loose-dumped), 2) light compaction (strike-off), and 3) high compaction (standard reclamation). Peromyscus leucopus (White-footed Mouse) made up 98% (295 of 300) of all individuals captured. In 2004, loose-dumped plots had more White-footed Mice (n = 108, mean = 36, SE = 0.58) than high-compaction plots (n = 62, mean = 20.6, SE = 3.10). Strike-off plots had more White-footed Mice (n = 59; mean = 19.6, SE = 0.66) than loose-dumped (n = 46, mean = 15.3, SE = 1.45) or high-compaction (n = 20, mean = 6.6, SE = 2.19) plots in 2005. Canopy cover and large rocks that cre...

DISTINCT MYCORRHIZAL COMMUNITIES ON NEW AND ESTABLISHED HOSTS IN A TRANSITIONAL TROPICAL PLANT COMMUNITY

The extent to which interspecific plants share mycorrhizal fungal communities depends on the specificity of the symbiosis. For tropical forest tree seedlings, colonization by mycorrhizal fungi associated with established vegetation could have important consequences for survival and growth. I used a novel molecular technique to assess the potential for sharing of mycorrhizas in forest and pasture in southern Costa Rica, by identifying arbuscular mycorrhizal (AM) fungi in roots of the forest canopy tree species Terminalia amazonia, pasture grasses Urochloa ruziziensis and U. decumbens, and seedlings of T. amazonia planted into experimental reforestation plots. I tested the hypotheses that experimental seedlings were colonized either by the AM fungal community of the forest T. amazonia (suggesting host specificity) or of Urochloa (suggesting absence of specificity/importance of local environment). After two years, pasture-grown T. amazonia seedlings were colonized by neither community, but rather by a species of Glomus that was rarely observed on the other plants. These results suggest that conspecific seedlings planted into existing vegetation generate a distinct mycorrhizal community that may influence competitive interactions and the relative costs and benefits of the AM fungal symbiosis at early stages in the life cycle of tropical trees.

Evaluation of the economic and environmental impact of converting cropland to forest: A case study in Dunhua county, China

The Sloping Land Conversion Program (also known as “Grain for Green” or the Upland Conversion Program) for converting cropland to forest is one of China's most ambitious environmental initiatives, and is one of the world's largest land-conservation programs with a budget of RMB 337 billion (over US$ 40 billion). Although environmental impacts have played a vital role in the general reasoning and argumentation for forest plantations, environmental impact analyses have often received less attention than economic analyses in the planning of plantation forestry projects. The overall goal of this paper is to evaluate the program's environmental impact considering the farmer's interests and the potential social benefits due to carbon sequestration in different scenarios based on household and field survey data in Dunhua County. Our findings are that: (1) in many cases, the program did not give adequate consideration to land productivity and environmental heterogeneity when selecting plots; (2) more than half of the reforestation plots were on flat cropland (slopes of less than 5°); (3) in five of the eight townships, net incomes on reforested land were substantially above or below previous crop incomes, raising questions about the efficiency of the allocation of compensation to farmers participating in the program; (4) the potential carbon co-benefit increased the NPV of the program by 5954–7009 RMB/ha. In conclusion, we recommend that more attention should be paid to the quality of reforestation programs rather than just their scale and note that consideration of potential carbon sequestration co-benefits enhances the benefits of cropland conversion programs.

Re-establishment of epibiotic communities in reforested mangroves of Gazi Bay, Kenya

Recolonization of epibiotic flora and fauna in two fringing Sonneratia alba reforestation plots was investigated and compared to a natural mangrove stand and a denuded site in Gazi Bay, Kenya. The ...

Factors Limiting the Survival of Native Tree Seedlings Used in Conservation Efforts at the Edges of Forest Fragments in Upland Madagascar

Abstract We tested four reforestation techniques in tropical forest fragments that were damaged by fire in upland Madagascar. We conducted a full‐factorial experiment on the survival of transplanted seedlings of five native tree species in grassland plots adjacent to the forest fragments in the Ambohitantely Forest Reserve. The species studied were Dodonaea madagascariensis, Filicium decipiens, Olea lancea, Podocarpus madagascariensis, and Rhus taratana. A total of 480 seedlings were planted; 207 survived the 15 months of the experiment. The factors examined were distance of the reforestation plots from the forest, mixing of forest soil into the plots, application of chemical fertilizers, experimental shading of plots, and the cover of naturally establishing shrubs. Both increasing the distance of plots from the forest edge and adding chemical fertilizers significantly reduced the survival of all seedlings. The surprising negative effects of fertilization may be partly due to increased competition from naturally establishing shrubs that are adapted to exploit high nitrogen levels. Mixing soil from the forest areas into the plots did not change seedling survival. Shading reduced the survival of D. madagascariensis seedlings and did not increase the survival of any species. These findings suggest that the success of reforestation projects can be increased by planting seedlings close to the existing forest fragments. Reforestation of similar tropical forests is likely to be more successful if efforts are focused on expanding the size of existing fragments of tropical forest, rather than on establishing new fragments in grassland openings.

Efficacy of Cholecalciferol Baits for Pocket Gopher Control and Possible Effects on Non-Target Rodents in Pacific Northwest Forests

Author(s): Rizor, Suzanne E.; Arjo, Wendy M.; Bulkin, Stephan; Nolte, Dale L. | Abstract: Population reduction measures need to be implemented to reforestation plots infested with pocket gopher in the Pacific Northwest. This 1-year investigation assessed the efficacy of 0.15% cholecalciferol (vitamin D3) bait application to reduce pocket gophers and the long-term effects on non-target small rodent populations within treated plots. The study site was a reforested clear cut containing pocket gopher populations of 10 to 14 animals per ha. Six plots (2.8 ha each) were randomly selected at the study site, 3 plots of untreated controls and 3 plots baited with cholecalciferol. A trap-and-release program was used to assess non-target populations. Radio telemetry and the open hole method were used to monitor pocket gopher activity before and after the fall application of cholecalciferol bait. A 70-80% reduction of pocket gopher activity from telemetered animals occurred in the treated plots, whereas only 10-20% mortality occurred on the control plots. Pocket gopher activity in most of the plots increased by June, and by September of the following year, activity was back to original levels. Time, not treatment, had a significant effect on yellow pine chipmunk, Townsend chipmunk, and golden-mantled ground squirrel populations. We conclude that 0.15% cholecalciferol bait appears to have application for pocket gopher control. Risks to non-target species may exist.

Sacred Forests in Tibet

The treeless desertlike environments of southern Tibet are assumed to be naturally unsuitable for forests. Yet, climatic conditions do allow for the growth of indigenous trees in Lhasa and many parts of southern Tibet, even where there is no high groundwater table or irrigation. This was discovered and proven in a Sino–German research project launched in 1997. The project made an inventory of forest relics, correlated residual tree stands with climatic data, and successfully cultivated nonirrigated indigenous junipers and cypresses. The eroded semidesert landscape of southern Tibet appears to have a huge potential for reforestation. The area with a potential for tree growth was investigated using the Geographical Information System known as GRASS (Geographical Resource Analysis Support System). Reforestation measures could meet the heavy demand for timber and firewood, help combat erosion on overgrazed slopes, and restore the degraded pastures. Grazing must be excluded on reforestation plots. Simultaneously, rangelands may regenerate after overgrazing. The optimum duration of the ungrazed period varies with altitude, humidity, soil conditions, and the degree of degradation. Successional trends observed on exclosure plots suggest that the drier the climate and the lower the initial degree of herbaceous vegetation cover, the longer the ungrazed period will be beneficial for pasture regeneration. Challenges in research and practice resulting from these preliminary results are highlighted.

Farming the forest: Managing people and trees in reserved forests in Thailand

The accelerated rate of global forest depletion poses a series of complex problems for development planners and resource managers in many developing nations. Among the issues being confronted are the need for foresters to gain new skills in managing human resources, design forest use systems which are both productive and sustainable, and to insure that the benefits of these systems are disrtibuted more equitably. In the last quarter of a century reserved forest lands in Thailand have been seriously degraded through deforestation, overcutting, and the illegal encroachment of poor and landless farmers. To counter these forces the government proposed two new forest management programs in 1975 which would grant certificates of use or limited land use rights to some degraded forest land in areas of national reserved forest. This paper examines the use of this policy in the Forest Village and National Forest Land Allotment Projects in northeast Thailand. Since their implementation in the Dong Mun National Reserved Forest 8 years ago, these projects have been plagued with conflicts over de jure and de facto land rights, public misperceptions about the government's grant of amnesty to illegal forest residents, problems controlling immigration, and the small 2.4 ha land allotments given to project participants. These conditions have produced unequal access to and distribution of land, allotment of land poorly suited for agriculture, the destruction of reforestation plots, continued degradation of reserved forest, and a pronounced pattern of social and economic inequality within and between the villages participating in both projects. We argue that these problems are fundamentally caused by government failures to correctly assess population pressures on land in the northeast and to modify program design to better fit community needs, capabilities, and insure equitability in the distribution of benefits.