Intact Primary Forest Research Articles

“Hg distribution and accumulation in soil and vegetation in areas impacted by artisanal gold mining in the Southern Amazonian region of Madre de Dios, Peru.”

Artisanal and small-scale gold mining (ASGM) is the primary global source of anthropogenic mercury (Hg) emissions. It has impacted the Amazon rainforest in the Peruvian region of Madre de Dios. However, few studies have investigated Hg's distribution in terrestrial ecosystems in this region. We studied Hg's distribution and its predictors in soil and native plant species from artisanal mining sites. Total Hg concentrations were determined in soil samples collected at different depths (0–5 cm and 5–30 cm) and plant samples (roots, shoots, leaves) from 19 native plant species collected in different land cover categories: naked soil (L1), gravel piles (L2), natural regeneration (L3), reforestation (L4), and primary forest (L5) in the mining sites. Hg levels in air were also studied using passive air samplers. The highest Hg concentrations in soil (average 0.276 and 0.210 mg kg−1 dw.) were found in the intact primary forest (L5) at 0–5 cm depth and in the plant rooting zones at 5–30 cm depth, respectively.Moreover, the highest Hg levels in plants (average 0.64 mg kg−1 dw) were found in foliage of intact primary forest (L5). The results suggest that the forest in these sites receives Hg from the atmosphere through leaf deposition and that Hg accumulates in the soil surrounding the roots. The Hg levels found in the plant leaves of the primary forest are the highest ever recorded in this region, exceeding values found in forests impacted by Hg pollution worldwide and raising concerns about the extent of the ASGM impact in this ecosystem. Correlations between Hg concentrations in soil, bioaccumulation in plant roots, and soil physical-chemical characteristics were determined. Linear regression models showed that the soil organic matter content (SOM), pH, and electrical conductivity (EC) predict the Hg distribution and accumulation in soil and bioaccumulation in root plants.

Importance of conserving large and old trees to continuity of tree-related microhabitats.

Protecting structural features, such as tree-related microhabitats (TreMs), is a cost-effective tool crucial for biodiversity conservation applicable to large forested landscapes. Although the development of TreMs is influenced by tree diameter, species, and vitality, the relationships between tree age and TreM profile remain poorly understood. Using a tree-ring-based approach and a large data set of 8038 trees, we modeled the effects of tree age, diameter, and site characteristics on TreM richness and occurrence across some of the most intact primary temperate forests in Europe, including mixed beech and spruce forests. We observed an overall increase in TreM richness on old and large trees in both forest types. The occurrence of specific TreM groups was variably related to tree age and diameter, but some TreM groups (e.g., epiphytes) had a stronger positive relationship with tree species and elevation. Although many TreM groups were positively associated with tree age and diameter, only two TreM groups in spruce stands reacted exclusively to tree age (insect galleries and exposed sapwood) without responding to diameter. Thus, the retention of trees for conservation purposes based on tree diameter appears to be a generally feasible approach with a rather low risk of underrepresentation of TreMs. Because greater tree age and diameter positively affected TreM development, placing a greater emphasis on conserving large trees and allowing them to reach older ages, for example, through the establishment of conservation reserves, would better maintain the continuity of TreM resource and associated biodiversity. However, this approach may be difficult due to the widespread intensification of forest management and global climate change.

Effects of land use change on the functional diversity and composition of mixed species avian flocks in the high tropical Andes of southern Ecuador

One of the greatest threats to biodiversity is land use change. Habitat alteration can have strong impacts on functional diversity, i.e., the range of biological traits within a suite of organisms. Mixed species avian flocks are integral to maintaining both taxonomic and functional diversity in tropical forests as they provide participants with greater foraging efficiency, reduced predation risks, and increased resiliency of species and ecosystems to environmental change. Our aim for this study was to determine the effects of land use change on the taxonomic and functional structures of mixed species avian flocks in and around Cajas National Park, Azuay Province in the tropical Andes of southern Ecuador by comparing non-native vegetation in agricultural plots and forest regenerating from historical use as pastureland to the largest intact primary forest in the region. We found no changes in species richness and diversity or functional richness of flocks across habitats, but we did find significant differences in species composition. Surprisingly, we found higher functional diversity and uniqueness of flocks in regenerating forest with more diverse and structurally complex vegetation, but native and non-native forests were functionally similar. We did, however, find significant differences in the community weighted means of four of five functional traits in different habitat types. Overall, the taxonomic and functional structures of mixed species flocks in this region seem relatively unaffected by land use change, indicating flocking as a beneficial strategy for species with higher sensitivities to disturbance in areas with anthropogenic activities. It is critical to maintain functional diversity in ecosystems, as a greater variety of functional traits and functional redundancy implies an efficient and more resilient ecosystem in the face of environmental change. Mixed species flocks provide membership benefits that may mitigate impacts of disturbance via land use change and thus can be considered essential units for conserving avian biodiversity.

Above-ground biomass storage potential in primary rain forests managed for timber production in Costa Rica

Tropical forests play a fundamental role in mitigating climate change through storage of carbon in above- and below- ground biomass. Their mitigation potential is, however, affected by significant greenhouse gas emissions through tropical deforestation or forest degradation. Mitigating degradation caused by conventional logging is therefore an important challenge for silvicultural management, and various reduced impact logging techniques seek to reduce biomass loss and other logging impacts during forest logging activities.Little knowledge exists about the potential of sustainable management for maintaining and restoring the climate change mitigation capacity of tropical forests. Our research contributes to knowledge about this potential, as our aim is to evaluate the above-ground biomass (AGB) stock of tropical forests managed for sustainable timber production and compare it with that of intact primary forests. We also determine the environmental and spatial factors that influence AGB.We estimated the AGB of 141 permanent sampling plots in Costa Rican tropical forests (71 plots set up in areas managed for timber production forests and 70 plots set up in areas with intact primary forests) using data for the 2000–2015 period. We compared the AGB of timber production forests with that of primary forest using linear mixed models and examined the relationship between forest AGB and climate, soil fertility and spatial variables (PCNM eigenvalues) using variation partitioning (VARPART) and multiple linear regression in the mixed model framework.Mean AGB was higher in forest plots set up in areas managed for timber production than in plots set up in areas with intact primary forests. In VARPART, spatial variables had the strongest effect on AGB with a small but significant effect of soil fertility. Regression showed potassium levels in the soil to be positively related to AGB. There was no significant effect of climate, probably because of the short temperature and precipitation gradients.Sustainable forest management in these Costa Rican forests managed for timber production has enabled them to store as much carbon in biomass as primary forests, due to the low intensity logging and sustainability criteria stipulated by the country’s forestry legislation. As a result, sustainable forest management, in addition to providing a sustainable timber ecosystem service, is also a natural climate solution, maintaining the mitigation potential of Costa Rica’s tropical forests in the current climate context.

Agricultural land-use change alters the structure and diversity of Amazon riparian forests

Riparian forests play key roles in protecting biodiversity and water resources, making them priorities for conservation in human-dominated landscapes, but fragmentation associated with expanding tropical croplands threatens their ecological integrity. We compared the structure of tropical riparian forests within intact and cropland catchments in a region of intensive soybean production in the southeastern Brazilian Amazon. We studied forest plots (varying from 120 to 210 m long) that bisected riparian zone forests and headwater streams in ten catchments. Four plots were within large areas of intact primary forest and six were in bands of protected riparian forest along streams within croplands as required by the Brazilian Forest Code. We found that riparian forests in croplands harbored fewer species of trees and seedlings/saplings, and had higher proportions of opportunistic, pioneer tree species. We also found greater variation in tree species composition, and higher internal dissimilarity in croplands compared with forests. The observed patterns in tree species composition were driven mainly by differences between riparian forest-cropland edges and those bordering intact upland forests. Forests nearest to streams in cropland and forested catchments were more similar to one another. Results suggest that wider buffers are needed at the edges of croplands to maintain riparian forest structure. The minimum 30-m riparian buffers now required by the Brazilian Forest Code may thus be insufficient to prevent long-term shifts in riparian forest species composition and structure.

Temporal stability of cavity‐nesting bee and wasp communities in different types of reforestation in southeastern Amazonia

Global initiatives to recover degraded areas have intensified in recent years. However, the effectiveness of different reforestation practices in restoring habitat stability and essential resources for species over time is poorly known. We tested the degree of temporal stability of bee and wasp communities reestablishiment in different types of forest regeneration compared to intact primary forest in southern Amazonia. Using trap‐nest sampling, we collected, during 12 months, information about the nesting species in six different types of treatments: pastures, teak reforestation, fig and mixed native species, natural regeneration forest, and forest primary. We observed that in all reforested treatments, the abundance and richness of both bees and wasps were greater than in pasture sites. However, not all reforestation strategies had the same degree of effectiveness in maintaining the stability of bee and wasp communities over time than observed in primary forest communities. The high temporal variation in teak structure promoted high instability in bee and wasp communities over time. In contrast, reforestation using perennial species, such as fig or mixed species, resulted in a greater temporal stability of bee and wasp communities, although dissimilarity to primary forest remained high. Communities in natural regeneration were the most similar to primary forest, with high similarity of species composition and high temporal stability across seasons. Our findings suggest that reforestation strategies that promote increased complexity of vegetation structure, and better resemble “natural” forests in the provision of habitat resources throughout the year, will better restore and maintain communities through time.

Assessment of Terrestrial Small Mammals in an Agro-industrial Company Concession, Western Liberia

This study was conducted in a global context of biological assessment of potential oil palm plantation development in western Liberia. It has been recommended as a complementary study to design a biological baseline prior to the development of oil palm plantations. It is based on "Terrestrial small mammals” biological model. Thus, terrestrial small mammal richness and abundance were assessed in Sime Darby palm oil company Concession at Bong and Gbarpolu counties in western Liberia. Conventional live-trapped methods using mainly pitfalls and Sherman trapswere used to investigate terrestrial small mammals. The combination of these two methods allowed the capture of 76 specimens belonging to 11 species.The most frequent species was Crocidura jouvenetae(39.47 %) followed by Hylomyscus simus(14.47 %) and Hybomys planifrons(10.53 %). Small mammal communities wereglobally dominated by forest species (Crocidura eburnea, Crocidura jouvenetae, Crocidura muricauda, Crocidura obscurior, Dephomys defua, Hybomys planifrons, Hylomyscus simusand Mus setulosus), which indicates the lower level of forest degradation at this area. These species of rodent and shrew are threatened to disappear due to the conversion of their habitats to palm oil plantations. It is highly recommended that the company preserve intact primary forest relics within oil palm plantations in order to conserve representative sample local biodiversity.
 Int. J. Appl. Sci. Biotechnol. Vol 7(4): 434-439

The intermediate disturbance hypothesis explains arthropod beta-diversity responses to roads that cut through natural forests

Forests are sensitive ecosystems with a distinctive micro-climate to which forest arthropods have adapted. In intact primary forests, sunlight only fully reaches forest floors temporarily through tree fall, or more permanently at forest edges. Roads that cut through pristine forests are however permanent features that fragment forests and increase forest edge. In accordance with the intermediate disturbance hypothesis (IDH), these edges may allow generalist species to enter forests and replace some specialists, often leading to little change, or even higher numbers of arthropod species at edges. Here, we determined how roads and hiking trails affect epigaeic forest arthropods in the largest Afrotemperate forest complex in South Africa. Arthropods were collected using pitfall traps along transects set up perpendicular to different types of road, including wide arterial roads, narrower secondary roads and hiking trails. As expected, hiking trails affected arthropod assemblages to a much smaller extent than the roads. Edge effects, as measured by arthropod alpha diversity, were evident up to only 5 m for hiking trails yet as much as 20 m for secondary roads and >50 m into the adjoining forest for arterial roads. Our results support the intermediate disturbance hypothesis, as changes in beta-diversity, especially next to arterial roads, was driven by the replacement of species in conjunction with changes in species richness. The magnitude of edge effect was however different for the selected feeding guilds. We recommend that where possible roads and even many hiking trails are removed from many areas of the deep forests. These ancient Afrotemperate forests are fragmented by roads and to a lesser degree by hiking trails, which could have cascading effects on overall forest integrity and long-term impacts on these forests.

Conserving Himalayan birds in highly seasonal forested and agricultural landscapes.

The Himalayas are a global biodiversity hotspot threatened by widespread agriculture and pasture expansion. To determine the impact of these threats on biodiversity and to formulate appropriate conservation strategies, we surveyed birds along elevational gradients in primary forest and in human-dominated lands spanning a gradient of habitat alteration, including forest-agriculture mosaics, mixed agriculture mosaics, and pasture. We surveyed birds during the breeding season and in winter to account for pronounced seasonal migrations. Bird abundance and richness in forest-agriculture and mixed agriculture mosaics were equal to or greater than in primary forest and greater than in pasture at local and landscape scales during both seasons. Pasture had greater abundance and richness of birds in winter than primary forest, but richness was greater in primary forest at the landscape scale during the breeding season. All 4 land-use types held unique species, suggesting that all must be retained in the landscape to conserve the entire avifauna. Our results suggest forest-agriculture and mixed agriculture mosaics are particularly important for sustaining Himalayan bird communities during winter and primary forests are vital for sustaining Himalayan bird communities during the breeding season. Further conversion of forest-agriculture and mixed agriculture mosaics to pasture would likely result in significant biodiversity losses that would disproportionately affect breeding species. To ensure comprehensive conservation, strategies in the western Himalayas must balance the protection of intact primary forest with the minimization of pasture expansion.

Birds in the matrix: the role of agriculture in avian conservation in the Taita Hills, Kenya

AbstractAgricultural conversion of tropical forests is a major driver of biodiversity loss. Slowing rates of deforestation is a conservation priority, but it is also useful to consider how species diversity is retained across the agricultural matrix. Here, we assess how bird diversity varies in relation to land use in the Taita Hills, Kenya. We used point counts to survey birds along a land‐use gradient that included primary forest, secondary vegetation, agroforest, timber plantation and cropland. We found that the agricultural matrix supports an abundant and diverse bird community with high levels of species turnover, but that forest specialists are confined predominantly to primary forest, with the matrix dominated by forest visitors. Ordination analyses showed that representation of forest specialists decreases with distance from primary forest. With the exception of forest generalists, bird abundance and diversity are lowest in timber plantations. Contrary to expectation, we found feeding guilds at similar abundances in all land‐use types. We conclude that whilst the agricultural matrix, and agroforest in particular, makes a strong contribution to observed bird diversity at the landscape scale, intact primary forest is essential for maintaining this diversity, especially amongst species of conservation concern.

AN INVESTIGATION OF SOIL PHYSICO-CHEMICAL VARIABLES ACROSS DIFFERENT LOWLAND FOREST ECOSYSTEMS OF BRUNEI DARUSSALAM

Tropical forests undisputedly harbor the largest share of global plant diversity, but the mechanisms of maintenance for this diversity cannot be well understood without good data on environmental variables, primarily soil characteristics. This study investigates differences in soil physico-chemical properties in various tropical lowland forest types in Brunei Darussalam, in the Northwest Borneo plant diversity hotspot. Nine different vegetation types were investigated: intact primary mixed-dipterocarp forest, old disturbed secondary forest, young disturbed secondary forest (partly invaded by alien Acacias), heath (Kerangas) forest, peat swamp forest, swampy heath (Kerapah) forest, core mangrove, fringe mangrove and island mangrove forests. Nine 60 x 20 m plots were set up, and sampled for soils at topsoil (0-15 cm depth) and subsoil (15-30 cm depth) layers. Soil gravimetric water and organic matter content, texture, nutrient concentrations, pH, and salinity were determined. The peat swamp and core mangrove forests recorded highest soil nutrient concentrations. Peat swamp forest had the highest GWC, OM content, total N, and total Ca recorded, whereas the soil in core mangrove forest had higher total P, total Mg, total K, exchangeable Mg, exchangeable Ca, exchangeable K and salinity compared to the other habitat types. These results were also highlighted by the principal component analysis for the soil parameters measured. The most nutrient-poor soils were found in the Kerapah and heath forest sites. The difference between topsoil and subsoil for soil variables were generally not significantly different from each other. The present study has shown that soil physico-chemical properties differ significantly between the nine vegetation types studied, and this may have important implications upon differences seen in plant community compositions in these vegetation types.Keywords: Heath forest, Mangrove forest, Mixed Dipterocarp forest, Peat swamps, Edaphic

The importance of agricultural lands for Himalayan birds in winter

The impacts of land-use change on biodiversity in the Himalayas are poorly known, notwithstanding widespread deforestation and agricultural intensification in this highly biodiverse region. Although intact primary forests harbor many Himalayan birds during breeding, a large number of bird species use agricultural lands during winter. We assessed how Himalayan bird species richness, abundance, and composition during winter are affected by forest loss stemming from agriculture and grazing. Bird surveys along 12 elevational transects within primary forest, low-intensity agriculture, mixed subsistence agriculture, and intensively grazed pastures in winter revealed that bird species richness and abundance were greatest in low-intensity and mixed agriculture, intermediate in grazed pastures, and lowest in primary forest at both local and landscape scales; over twice as many species and individuals were recorded in low-intensity agriculture than in primary forest. Bird communities in primary forests were distinct from those in all other land-use classes, but only 4 species were unique to primary forests. Low-, medium-, and high-intensity agriculture harbored 32 unique species. Of the species observed in primary forest, 80% had equal or greater abundance in low-intensity agricultural lands, underscoring the value of these lands in retaining diverse community assemblages at high densities in winter. Among disturbed landscapes, bird species richness and abundance declined as land-use intensity increased, especially in high-intensity pastures. Our results suggest that agricultural landscapes are important for most Himalayan bird species in winter. But agricultural intensification-especially increased grazing-will likely result in biodiversity losses. Given that forest reserves alone may inadequately conserve Himalayan birds in winter, comprehensive conservation strategies in the region must go beyond protecting intact primary forests and ensure that low-intensity agricultural lands are not extensively converted to high-intensity pastures.

Changes of soil prokaryotic communities after clear-cutting in a karst forest: evidences for cutting-based disturbance promoting deterministic processes.

To understand the temporal responses of soil prokaryotic communities to clear-cutting disturbance, we examined the changes in soil bacterial and archaeal community composition, structure and diversity along a chronosequence of forest successional restoration using high-throughput 16S rRNA gene sequencing. Our results demonstrated that clear-cutting significantly altered soil bacterial community structure, while no significant shifts of soil archaeal communities were observed. The hypothesis that soil bacterial communities would become similar to those of surrounding intact primary forest with natural regeneration was supported by the shifts in the bacterial community composition and structure. Bacterial community diversity patterns induced by clear-cutting were consistent with the intermediate disturbance hypothesis. Dynamics of bacterial communities was mostly driven by soil properties, which collectively explained more than 70% of the variation in bacterial community composition. Community assembly data revealed that clear-cutting promoted the importance of the deterministic processes in shaping bacterial communities, coinciding with the resultant low resource environments. But assembly processes in the secondary forest returned a similar level compared to the intact primary forest. These findings suggest that bacterial community dynamics may be predictable during the natural recovery process.

The distribution and conservation of Gurney’s Pitta Pitta gurneyi in Myanmar

SummaryFollowing a recent assessment of the distribution and habitat use of Gurney’s Pitta in Myanmar (Burma), further extensive surveys were undertaken in 2010, 2011 and 2012. These have extended the species’ known altitudinal limit to between 250 m and 300 m asl and its latitudinal limit to above 12.5°N, around 80 km north of the northernmost historical record, although the species was recorded far less frequently at higher altitudes and latitudes. Birds were recorded in a range of forested habitats, from intact primary forest to secondary and bamboo forest, with no significant difference between major forest types in the likelihood of occurrence. Niche envelope modelling (MaxEnt) suggested a total range size in Myanmar of 3,379 km2, and did not identify any potentially suitable areas in adjacent parts of Thailand. The species’ preference for warmer, wetter areas on flat ground, conditions ideal for growing oil palm and rubber, suggest that its distribution is likely to contract in the near future. The entire range of Gurney’s Pitta in Myanmar falls within the part of the country most suitable for commercial oil palm production, although the projected yields within its range are low to moderate. Field surveys found evidence of rapid recent deforestation and high levels of hunting and trapping in many parts of the region. The species’ range in Myanmar does not overlap with any protected areas. The protection of southern Myanmar’s biodiversity will require substantial investment by foreign conservation interests, sympathetic land-use planning and the strengthening of environment legislation. Protection of extensive tracts of lowland forest within the range of Gurney’s Pitta, particularly the proposed Lenya National Park and the adjacent Ngawun and Htaung Pru Reserve Forests, is urgently needed. Conserving these areas will also protect populations of other globally threatened bird and mammal species.

Butterfly Community Composition Across a Successional Gradient in a Human‐disturbed Afro‐tropical Rain Forest

AbstractKnowledge of the recovery of insect communities after forest disturbance in tropical Africa is very limited. Here, fruit‐feeding butterflies in a tropical rain forest at Kibale National Park, Uganda, were used as a model system to uncover how, and how fast, insect communities recover after forest disturbance. We trapped butterflies monthly along a successional gradient for one year. Traps were placed in intact primary forest compartments, heavily logged forest compartments with and without arboricide treatment approximately 43 years ago, and in conifer‐clearcut compartments, ranging from 9 to 19 years of age. The species richness, total abundance, diversity, dominance, and similarity of the community composition of butterflies in the eight compartments were compared with uni‐ and multivariate statistics. A total of 16,728 individuals representing 88 species were trapped during the study. Butterfly species richness, abundance, and diversity did not show an increasing trend along the successional gradient but species richness and abundance peaked at intermediate stages. There was monthly variation in species richness, abundance, diversity and composition. Butterfly community structure differed significantly among the eight successional stages and only a marginal directional change along the successional gradient emerged. The greatest number of indicator species and intact forest interior specialists were found in one of the primary forests. Our results show that forest disturbance has a long‐term impact on the recovery of butterfly species composition, emphasizing the value of intact primary forests for butterfly conservation.

Land‐sharing versus land‐sparing logging: reconciling timber extraction with biodiversity conservation

Selective logging is a major driver of rainforest degradation across the tropics. Two competing logging strategies are proposed to meet timber demands with the least impact on biodiversity: land sharing, which combines timber extraction with biodiversity protection across the concession; and land sparing, in which higher intensity logging is combined with the protection of intact primary forest reserves. We evaluate these strategies by comparing the abundances and species richness of birds, dung beetles and ants in Borneo, using a protocol that allows us to control for both timber yield and net profit across strategies. Within each taxonomic group, more species had higher abundances with land-sparing than land-sharing logging, and this translated into significantly higher species richness within land-sparing concessions. Our results are similar when focusing only on species found in primary forest and restricted in range to Sundaland, and they are independent of the scale of sampling. For each taxonomic group, land-sparing logging was the most promising strategy for maximizing the biological value of logging operations.

Satellite-based primary forest degradation assessment in the Democratic Republic of the Congo, 2000–2010

Primary forest extent, loss and degradation within the Democratic Republic of the Congo (DRC) were quantified from 2000 to 2010 by combining directly mapped forest cover extent and loss data (CARPE) with indirectly mapped forest degradation data (intact forest landscapes, IFL). Landsat data were used to derive both map inputs, and data from the GLAS (Geoscience Laser Altimetry System) sensor were employed to validate the discrimination of primary intact and primary degraded forests. In the year 2000, primary humid tropical forests occupied 104 455 kha of the country, with 61% of these forests classified as intact. From 2000 to 2010, 1.02% of primary forest cover was lost due to clearing, and almost 2% of intact primary forests were degraded due to alteration and fragmentation. While primary forest clearing increased by a factor of two between 2000–2005 and 2005–2010, the degradation of intact forests slightly decreased. Fragmentation and selective logging were the leading causes of intact forest degradation, accounting for 91% of IFL area change. The 10 year forest degradation rate within designated logging permit areas was 3.8 times higher compared to other primary forest areas. Within protected areas the forest degradation rate was 3.7 times lower than in other primary forest areas. Forest degradation rates were high in the vicinity of major urban areas. Given the observed forest degradation rates, we infer that the degradation of intact forests could increase up to two-fold over the next decade.

Primary tree species diversity in secondary fallow forests of Laos

The area of primary forest is decreasing throughout the tropical world and being replaced by secondary forests. Many policy makers regard these secondary forests as being unworthy of protection since they are too degraded to have any commercial or conservation value. Because of this many are now being cleared for alternative land uses. But there are a variety of types of secondary forest differing in the extent to which they have been disturbed, the frequency at which this has taken place and, because of their position in the landscape, in their capacity to be recolonized from species from intact primary forests. This means that some secondary forests may not be as degraded as is supposed and many may have the capacity to recover if protected from further disturbances. This study reports on a comparison between remnant forest, and frequently and infrequently disturbed secondary forests in Lao PDR. The frequently disturbed forest had been cleared for shifting cultivation 3–5 times in the past 30years while the infrequently disturbed sites had been cleared only once. The study found comparatively small differences in the occurrence of primary forest species in these two types of secondary forest and that they still contained a large proportion of primary forest tree species despite the disturbance history. This apparent resilience may be due to the capacity of many species to resprout after disturbances and their ability to recolonize across the present agricultural matrix.

Contributions of secondary forest and nitrogen dynamics to terrestrial carbon uptake

Abstract. We use a terrestrial carbon-nitrogen cycle component of the Integrated Science Assessment Model (ISAM) to investigate the impacts of nitrogen dynamics on regrowing secondary forests over the 20th century. We further examine what the impacts of nitrogen deposition and land use change history are on terrestrial carbon uptake since preindustrial time. Our results suggest that global total net land use emissions for the 1990s associated with changes in cropland, pastureland, and wood harvest are 1.22 GtC/yr. Without considering the secondary forest regrowth, the estimated net global total land use emissions are 1.58 GtC/yr or about 0.36 GtC/yr higher than if secondary forest regrowth is considered. Results also show that without considering the nitrogen dynamics and deposition, the estimated global total secondary forest sink for the 1990s is 0.90 GtC/yr or about 0.54 GtC/yr higher than estimates that include the impacts of nitrogen dynamics and deposition. Nitrogen deposition alone is responsible for about 0.13 GtC/yr of the total secondary forest sink. While nitrogen is not a limiting nutrient in the intact primary forests in tropical regions, our study suggests that nitrogen becomes a limiting nutrient for regrowing secondary forests of the tropical regions, in particular Latin America and Tropical Africa. This is because land use change activities, especially wood harvest, removes large amounts of nitrogen from the system when slash is burnt or wood is removed for harvest. However, our model results show that carbon uptake is enhanced in the tropical secondary forests of the Indian region. We argue that this may be due to enhanced nitrogen mineralization and increased nitrogen availability following land use change in the Indian tropical forest ecosystems. Results also demonstrate that there is a significant amount of carbon accumulating in the Northern Hemisphere where most land use changes and forest regrowth has occurred in recent decades. This study indicates the significance of secondary forests to terrestrial carbon sinks, the importance of nitrogen dynamics to the magnitude of secondary forests carbon uptake, and therefore the need to include both primary and secondary forests and nitrogen dynamics in terrestrial ecosystem models.

Parasite prevalence in blue-eyed black lemurs Eulemur flavifrons in differently degraded forest fragments

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials ESR 12:215-225 (2010) - DOI: https://doi.org/10.3354/esr00304 Contribution to the Theme Section 'Responses of animals to habitat alteration' Parasite prevalence in blue-eyed black lemurs Eulemur flavifrons in differently degraded forest fragments Nora Schwitzer1,4, Dagmar Clough2, Horst Zahner1, Werner Kaumanns3, Peter Kappeler2, Christoph Schwitzer4,* 1Institut für Parasitologie, Justus-Liebig-Universität, Rudolf-Buchheim-Strasse 2, 35392 Giessen, Germany 2Abteilung Verhaltensökologie & Soziobiologie/Anthropologie, Deutsches Primatenzentrum, Kellnerweg 4, 37077 Göttingen, Germany 3Eschenweg 5, 37130 Gleichen, Germany 4Bristol Conservation and Science Foundation, Bristol Zoo Gardens, Clifton, Bristol BS8 3HA, UK *Corresponding author. Email: cschwitzer@bristolzoo.org.uk ABSTRACT: The parasite burden of an animal population has frequently been used as an indicator of the stress level to which the population is exposed. Primates inhabiting small forest fragments are more likely to experience human contact, reduced food availability and restricted ranging—any or all of which may contribute to a higher parasite prevalence—than populations inhabiting intact primary forest. Recent and ongoing human exploitation of otherwise intact forest may also affect disease burden and parasite transmission in primates. The parasites of blue-eyed black lemurs Eulemur flavifrons have not as yet been subject to scientific research. This paper describes the various parasites found in E. flavifrons and shows parasite prevalence in lemur groups living in differently degraded fragments of the Ankarafa Forest in Sahamalaza National Park, northwest Madagascar. We analysed 166 faecal samples of E. flavifrons inhabiting primary forest and 168 from groups inhabiting secondary forest. In addition, faecal samples and ectoparasites were collected from 18 immobilised lemurs. Forty-three (12.9%) samples contained parasite eggs (Lemuricola spp. and Callistoura spp.) or oocysts. Ten (55.6%) of the 18 samples from immobilised lemurs contained adult Lemuricola spp. Parasite prevalence was significantly higher in secondary than in primary forest, at 7.9 and 4.8% of all positive samples, respectively. Prevalence was high when compared to other studies on parasite load in wild lemurs, suggesting that in our survey area, E. flavifrons were generally under pressure, possibly due to the high degree of fragmentation and degradation of the remaining forest habitat. KEY WORDS: Eulemur flavifrons · Primary forest · Secondary forest · Lemuricola · Callistoura · Seasonality Full text in pdf format PreviousNextCite this article as: Schwitzer N, Clough D, Zahner H, Kaumanns W, Kappeler P, Schwitzer C (2010) Parasite prevalence in blue-eyed black lemurs Eulemur flavifrons in differently degraded forest fragments. Endang Species Res 12:215-225. https://doi.org/10.3354/esr00304Export citation Mail this link - Contents Mailing Lists - RSS Facebook - Tweet - linkedIn Cited by Published in ESR Vol. 12, No. 3. Online publication date: September 20, 2010 Print ISSN: 1863-5407; Online ISSN: 1613-4796 Copyright © 2010 Inter-Research.