The Contribution of Tropical Secondary Forest Fragments to the Conservation of Fruit-feeding Butterflies: Effects of Isolation and Age

Concomitant with the rapid loss of tropical mature forests, the relative abundance of secondary forests is increasing steadily and the latter are therefore of growing interest for conservation. We analysed species richness of fruit-feeding nymphalid butterflies in secondary forest fragments of different age and isolation and in mature forest at the eastern margin of the Lore Lindu National Park in Central Sulawesi, Indonesia. From April to August 2001 we collected 2322 individuals of fruit-feeding butterflies, belonging to 33 species. Butterfly species richness increased with succession, but was significantly higher in mature forests than in all types of secondary forest. Isolation of the forest fragments did not have a significant effect on butterfly species richness in the range of distances (up to 1700 m) studied. Rather it appeared to affect only a few species. Species richness of endemic species was higher than of non-endemic species. Although endemic species were most diverse in mature forests, many species captured were restricted to secondary forests. Our results show that mature forest is essential for the conservation of nymphalid butterflies and for the endemic species in this area. However, considering the relatively large number of species found in these rather small habitat islands, secondary forest fragments, especially older successional stages, can be taken into account in conservation efforts and thus contribute to the preservation of tropical biodiversity on a landscape scale.     

Incorporating zoning and socioeconomic costs in planning for bird conservation

New systematic conservation approaches have high potential in evaluation of different conservation scenarios and can be used as decision support tools for managers and planners with multiple goals. The present study focused on two major issues in conservation planning including socioeconomic costs and zoning procedure. The goal was to prioritize and identify representative areas for bird conservation, while minimizing the economic cost for the silvicultural sector and resolve conflicts with recreational activities. The study was conducted in forest areas of Golestan Province as part of Hyrcanian mixed forests, located along the southern coasts of the Caspian Sea and northern slopes of the Alborz Mountains, northern Iran. We used systematic conservation software Marxan with Zones to select candidate areas for conservation. Two types of conservation networks were defined, one with high and partial protection zones and the other with high protection zones only. We focused on four conservation scenarios varying in targets, costs, and multiple zones. The results showed that incorporation of socioeconomic costs significantly decreases the potential impacts on the silvicultural and recreational sectors without significant change in the area of protection zones. Furthermore, we found that design of multiple zone conservation areas facilitates evaluation of a wider range of conservation scenarios that can reduce potential socioeconomic impacts on other interests.     

One taxon does not fit all: Herb-layer diversity and stand structural complexity are weak predictors of biodiversity in Fagus sylvatica forests

Since adequate information on the distribution of biodiversity is hardly achievable, biodiversity indicators are necessary to support the management of ecosystems. These surrogates assume that either some habitat features, or the biodiversity patterns observed in a well-known taxon, can be used as a proxy of the diversity of one or more target taxa. Nevertheless, at least for certain taxa, the validity of this assumption has not yet been sufficiently demonstrated.We investigated the effectiveness of both a habitat- and a taxa-based surrogate in six European beech forests in the Apennines. Particularly, we tested: (1) whether the stand structural complexity and the herb-layer species richness were good predictors of the fine-scale patterns of species richness of five groups of forest-dwelling organisms (beetles, saproxylic and epigeous fungi, birds and epiphytic lichens); and (2) the cross-taxon congruence in species complementarity and composition between herb-layer plants and the target taxa.We used Generalized Linear Mixed Models (GLMMs), accumulation curves and Procrustes analysis to evaluate the effectiveness of these surrogates when species richness, complementarity and composition were considered, respectively.Our results provided a limited support to the hypothesis that the herb-layer plants and the stand structural complexity were good surrogates of the target taxa. Although the richness of the herb-layer plants received a stronger support from the data than structural complexity as a predictor for the general patterns of species richness, the overall magnitude of this effect was weak and distinct taxa responded differently. For instance, for increasing levels of herb-layer richness, the richness of lichens showed a marked increase, while the richness of saproxylic fungi decreased. We also found significantly similar complementarity patterns between the herb-layer plants and beetles, as well as a significant congruence in species composition between herb-layer plants and saproxylic fungi. Finally, when different stand structural attributes were considered singularly, only the total amount of deadwood received support from the data as a predictor of the overall species richness.At the fine scale of this study, herb-layer plants and stand structural complexity did not prove to be effective surrogates of multi-taxon biodiversity in well-preserved southern European beech forests. Rather than on weak surrogates, these results suggest that sound conservation decisions should be supported by the information provided by comprehensive multi-taxonomic assessments of forest biodiversity.     

Endemic vertebrates are the most effective surrogates for identifying conservation priorities among Brazilian ecoregions

Many studies have tested the performance of terrestrial vertebrates as surrogates for overall species diversity, because these are commonly used in priority‐setting conservation appraisals. Using a database of 3663 vertebrate species in 38 Brazilian ecoregions, we evaluated the effectiveness of various subsets for representing diversity of the entire vertebrate assemblage. Because ecoregions are established incorporating information on biotic assemblages, they are potentially more amenable to regional comparison than are national or state lists. We used 10 potential indicator groups (all species; all mammals, birds, reptiles, or amphibians; all endemic species; and endemic species within each class) to find priority sets of ecoregions that best represent the entire terrestrial vertebrate fauna. This is the first time such tests are employed to assess the effectiveness of indicator groups at the ecoregion level in Brazil. We show that patterns of species richness are highly correlated among mammals, birds, amphibians, and reptiles. Furthermore, we demonstrate that ecoregion sets selected according to endemic species richness captured more vertebrate species per unit area than sets based on overall vertebrate richness itself, or than those selected at random. Ecoregion sets based on endemic bird, endemic reptile, or endemic amphibian richness also performed well, capturing more species overall than random sets, or than those selected based on species richness of one or all vertebrate classes within ecoregions. Our results highlight the importance of evaluating biodiversity concordance and the use of indicator groups as well as aggregate species richness. We conclude that priority sets based on indicator groups provide a basis for a first assessment of priorities for conservation at an infracontinental scale. Areas with high endemism have long been highlighted for conservation of species. Our findings provide evidence that endemism is not only a worthwhile conservation goal, but also an effective surrogate for the conservation of all terrestrial vertebrates in Brazil.     

Assessing the mechanisms behind successful surrogates for biodiversity in conservation planning

Limited by the availability of data, conservation planners must use surrogates for biodiversity when selecting conservation areas. Although several methods have been proposed for selecting surrogates, no clear set of species attributes have been described that allow for the efficient a priori selection of surrogate groups. We used a database of 1449 species in two regions of the United States to (1) examine the consistency in the performance of simple taxonomic-based surrogates of biodiversity and (2) test five hypotheses proposed to explain surrogate performance. First, we compared the ability of sites selected to protect members of seven surrogate groups to protect non-surrogate species in the north-western United States and in the Middle-Atlantic region of the eastern United States. Then, in a separate analysis, we tested whether surrogate performance could be explained by (1) taxonomic diversity; (2) nested species distributions; (3) hotspots of biodiversity; (4) species range sizes; (5) environmental diversity. Our first analysis revealed little consistency in the performance of surrogates in the two different study regions. For example, butterflies provided protection for 76% of all other species in the north-western United States but only 56% of all other species in the eastern United States. Our second analysis revealed only weak associations between species characteristics and surrogate performance. Furthermore, these associations proved inadequate for selecting successful surrogates across study regions. Overall, our results suggest that in lieu of searching for optimal surrogate groups, research efforts will be better spent by developing alternative methods for assessing conservation value in areas where data on species distributions are limited.     

Effectiveness of Biodiversity Surrogates for Conservation Planning: Different Measures of Effectiveness Generate a Kaleidoscope of Variation

Conservation planners represent many aspects of biodiversity by using surrogates with spatial distributions readily observed or quantified, but tests of their effectiveness have produced varied and conflicting results. We identified four factors likely to have a strong influence on the apparent effectiveness of surrogates: (1) the choice of surrogate; (2) differences among study regions, which might be large and unquantified (3) the test method, that is, how effectiveness is quantified, and (4) the test features that the surrogates are intended to represent. Analysis of an unusually rich dataset enabled us, for the first time, to disentangle these factors and to compare their individual and interacting influences. Using two data-rich regions, we estimated effectiveness using five alternative methods: two forms of incidental representation, two forms of species accumulation index and irreplaceability correlation, to assess the performance of ‘forest ecosystems’ and ‘environmental units’ as surrogates for six groups of threatened species—the test features—mammals, birds, reptiles, frogs, plants and all of these combined. Four methods tested the effectiveness of the surrogates by selecting areas for conservation of the surrogates then estimating how effective those areas were at representing test features. One method measured the spatial match between conservation priorities for surrogates and test features. For methods that selected conservation areas, we measured effectiveness using two analytical approaches: (1) when representation targets for the surrogates were achieved (incidental representation), or (2) progressively as areas were selected (species accumulation index). We estimated the spatial correlation of conservation priorities using an index known as summed irreplaceability. In general, the effectiveness of surrogates for our taxa (mostly threatened species) was low, although environmental units tended to be more effective than forest ecosystems. The surrogates were most effective for plants and mammals and least effective for frogs and reptiles. The five testing methods differed in their rankings of effectiveness of the two surrogates in relation to different groups of test features. There were differences between study areas in terms of the effectiveness of surrogates for different test feature groups. Overall, the effectiveness of the surrogates was sensitive to all four factors. This indicates the need for caution in generalizing surrogacy tests.     

The white-backed woodpecker: umbrella species for forest conservation planning?

In northern Europe, a long history of land use has led to profound changes within forest ecosystems. The white-backed woodpecker (Dendrocopos leucotos) is one of several specialised forest species whose populations have declined. Conservation management directed at this species’ habitat has made it a de facto umbrella species for conservation of the biodiversity associated with forests rich in deciduous trees and dead wood. We assessed empirically the value of the white-backed woodpecker as an indicator and umbrella species in central Sweden. Occurrence of the woodpecker in breeding bird atlas squares (5 × 5 km²) indicated high species richness of forest birds, particularly species of special conservation concern, which included on average 13% more species in squares with than without the woodpecker. The number of red-listed cryptogam species expected to benefit from conservation actions directed at white-backed woodpecker habitats was higher in squares where the woodpecker bred compared to where is was absent. However, no such pattern was found for red-listed beetles, a group with very few records in the studied squares. White-backed woodpecker occurrence was positively associated with the current area of deciduous and mixed forest of high conservation value. Considering its indicator value, its specialised habitat requirements and its potential as a communication tool, using the white-backed woodpecker as an umbrella species may provide a coarse filter for the conservation of several other deciduous forest species. However, focusing solely on white-backed woodpecker habitat may not provide for the conservation of all such species, which stresses the need for a suite of complementary planning approaches.     

The adequacy of Victoria's protected areas for conserving its forest‐dependent fauna

Networks of protected areas are a key component of efforts to conserve biodiversity. However, there are concerns about an uncritical focus on the percentage area of reserves without an assessment of how well formal reserves are actually protecting biodiversity. In response, we completed a spatial analysis of the formal reserve system in the Australian state of Victoria. We quantified how well the reserve system captured a crude surrogate for vegetation communities (viz: Ecological Vegetation Classes) as well as distribution models for an array of threatened forest‐dependent species. We found evidence of a high degree of overlap between areas subject to intensive forestry (clearcutting) operations and the modelled distribution of a suite of forest‐dependent species. A key outcome of our study was that areas around sites subject to past logging as well as new areas proposed for logging under the Timber Release Plan in Victoria had significantly higher values for threatened forest‐dependent species (as determined by habitat distribution models) than areas that had not been logged. We found significant differences in the spatial characteristics of the dedicated reserve systems and informal protected area networks, with the latter featuring much of its area close to a tenure boundary where logging occurs. Our empirical analyses demonstrating the impacts of ongoing logging operations on areas with high environmental suitability for threatened species have important implications. In particular, the current reserve system is inadequate for a suite of forest‐dependent taxa, including critically endangered Leadbeater's Possum (Gymnobelideus leadbeateri) and the vulnerable Greater Glider (Petauroides volans). This suggests a high degree of conflict between areas of high value for conservation and areas targeted for wood production.     

Fungal disease incidence along tree diversity gradients depends on latitude in European forests

European forests host a diversity of tree species that are increasingly threatened by fungal pathogens, which may have cascading consequences for forest ecosystems and their functioning. Previous experimental studies suggest that foliar and root pathogen abundance and disease severity decrease with increasing tree species diversity, but evidences from natural forests are rare. Here, we tested whether foliar fungal disease incidence was negatively affected by tree species diversity in different forest types across Europe. We measured the foliar fungal disease incidence on 16 different tree species in 209 plots in six European countries, representing a forest‐type gradient from the Mediterranean to boreal forests. Forest plots of single species (monoculture plots) and those with different combinations of two to five tree species (mixed species plots) were compared. Specifically, we analyzed the influence of tree species richness, functional type (conifer vs. broadleaved) and phylogenetic diversity on overall fungal disease incidence. The effect of tree species richness on disease incidence varied with latitude and functional type. Disease incidence tended to increase with tree diversity, in particular in northern latitudes. Disease incidence decreased with tree species richness in conifers, but not in broadleaved trees. However, for specific damage symptoms, no tree species richness effects were observed. Although the patterns were weak, susceptibility of forests to disease appears to depend on the forest site and tree type.     

Metabarcoding技术在真菌多样性研究中的应用

由于受到气候变化、土地利用变化及环境污染等诸多因素的干扰, 真菌多样性受到不容忽视的威胁, 亟需得到保护。构建物种数据库是实现真菌多样性研究和保护的重要前提。近年来兴起的DNA条形码及metabarcoding技术能够在很大程度上弥补传统鉴定方法的缺陷, 可对真菌物种进行大规模、准确、快速、高效地鉴定。本文梳理了metabarcoding技术在真菌物种多样性评估、真菌多样性影响机制和真菌古生态重建等研究中的应用, 同时强调了metabarcoding技术用于真菌多样性研究尚处于初期阶段, 在构建有效参照数据库、优化实验流程以及升级生物信息学工具等方面仍需要进一步的完善。建议加强真菌分类学家、生态学家以及计算机工具研发工程师之间的合作, 共同解决metabarcoding技术在真菌多样性研究及应用中面临的问题, 为宏观尺度上真菌多样性保护提供更加科学的依据。     

Scale dependency of two endangered charismatic species as biodiversity surrogates

Charismatic megafauna have been used as icons and financial drivers of conservation efforts worldwide given that they are useful surrogates for biodiversity in general. However, tests of this premise have been constrained by data limitations, especially at large scales. Here we overcome this problem by combining large-scale citizen-sourced data with intensive expert observations of two endangered charismatic species, Blakiston’s fish owl (forest specialist) and the red-crowned crane (wetland specialist). We constructed large-scale maps of species richness for 52 forest and 23 grassland/wetland bird species using hierarchical community modeling and citizen-sourced data at 1, 2, 5, and 10-km grid resolutions. We compared the species richness of forest and grassland/wetland birds between the breeding and non-breeding sites of the two charismatic birds at each of the four spatial resolutions, and then assessed the scale dependency of the biodiversity surrogates. Regardless of the habitat amounts, owl and crane breeding sites had higher forest and grassland/wetland bird species richness, respectively. However, this surrogacy was more effective at finer scales (1–2-km resolutions), which corresponds to the charismatic species’ home range sizes (up to 9.4 ± 2.0 km² for fish owls, and 3–4 km² for cranes). Species richness showed the highest spatial variations at 1–2-km resolutions. We suggest that the agreement of functional scales between surrogate species and broader biodiversity is essential for successful surrogacy, and that habitat conservation and restoration targeting multiple charismatic species with different specialties can complement to biodiversity conservation.     

Recommendations for Assessing the Effectiveness of Surrogate Species Approaches

Surrogate species approaches, including flagship, focal, keystone, indicator, and umbrella, are considered an effective means of conservation planning. For conservation biologists to apply surrogates with confidence, they must have some idea of the effectiveness of surrogates for the circumstances in which they will be applied. We reviewed tests of the effectiveness of surrogate species planning to see if research supports the development of generalized rules for (1) determining when and where surrogate species are an effective conservation tool and (2) how surrogate species should be selected such that the resulting conservation plan will effectively protect biodiversity or achieve other conservation goals. The context and methods of published studies were so diverse that we could not draw general conclusions about the spatial or temporal scales, or ecosystems or taxonomic groups for which surrogate species approaches will succeed. The science of surrogate species can progress by (1) establishing methods to compare diverse measures of effectiveness; (2) taking advantage of data-rich regions to examine the potential effectiveness of surrogate approaches; (3) incorporating spatial scale as an explanatory variable; (4) evaluating surrogate species approaches at broader temporal scales; (5) seeking patterns that will lead to hypothesis driven research; and (6) monitoring surrogate species and their target species.     

Prospects for tropical forest biodiversity in a human-modified world

The future of tropical forest biodiversity depends more than ever on the effective management of human-modified landscapes, presenting a daunting challenge to conservation practitioners and land use managers. We provide a critical synthesis of the scientific insights that guide our understanding of patterns and processes underpinning forest biodiversity in the human-modified tropics, and present a conceptual framework that integrates a broad range of social and ecological factors that define and contextualize the possible future of tropical forest species. A growing body of research demonstrates that spatial and temporal patterns of biodiversity are the dynamic product of interacting historical and contemporary human and ecological processes. These processes vary radically in their relative importance within and among regions, and have effects that may take years to become fully manifest. Interpreting biodiversity research findings is frequently made difficult by constrained study designs, low congruence in species responses to disturbance, shifting baselines and an over-dependence on comparative inferences from a small number of well studied localities. Spatial and temporal heterogeneity in the potential prospects for biodiversity conservation can be explained by regional differences in biotic vulnerability and anthropogenic legacies, an ever-tighter coupling of human-ecological systems and the influence of global environmental change. These differences provide both challenges and opportunities for biodiversity conservation. Building upon our synthesis we outline a simple adaptive-landscape planning framework that can help guide a new research agenda to enhance biodiversity conservation prospects in the human-modified tropics.     

The importance of littoral forest remnants for indigenous bird conservation in southeastern Madagascar

The littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 littoral forest remnants. Of these species, 40 are endemic to Madagascar and a further 21 are endemic to the Indian Ocean sub-region, consisting of Madagascar, the Comoros and the Mascarenes. The matrix habitats (Melaleuca forests, marécage swamp forest, Eucalyptus plantations and Erica grassland) that immediately surround the littoral forests were depauperate of bird species and contained few species that were found within the littoral forests. The geographic location of littoral forest remnants had an important role in determining what bird species occurred within them, with the northern remnants having similar bird communities to nearby humid forest whilst the most southern remnant had a bird community that resembled those of nearby spiny forest habitats. Eleven bird species that have been previously described as being habitat-restricted endemics to either spiny forests or humid forests, were found in littoral forest remnants. These results suggest that these littoral forests may play an important transitional role between the two other major natural habitats (spiny forest and humid forest) of southeastern Madagascar. On this basis we advocate that the littoral forest remnants of southeastern Madagascar should be afforded continuing conservation priority.     

Efficiency of protected areas in Amazon and Atlantic Forest conservation: A spatio-temporal view

The Amazon and Atlantic Forest are considered the world's most biodiverse biomes. Human and climate change impacts are the principal drivers of species loss in both biomes, more severely in the Atlantic Forest. In response to species loss, the main conservation action is the creation of protected areas (PAs). Current knowledge and research on the PA network's conservation efficiency is scarce, and existing studies have mainly considered a past temporal view. In this study, we tested the efficiency of the current PA network to maintain climatically stable areas (CSAs) across the Amazon and Atlantic Forest. To this, we used an ecological niche modeling approach to biome and paleoclimatic simulations. We propose three categories of conservation priority areas for both biomes, considering CSAs, PAs and intact forest remnants. The biomes vary in their respective PA networks' protection efficiency. Regarding protect CSAs, the Amazon PA network is four times more efficient than the Atlantic Forest PA network. New conservation efforts in these two forest biomes require different approaches. We discussed the conservation actions that should be taken in each biome to increase the efficiency of the PA network, considering both the creation and expansion of PAs as well as restoration programs.     

露水河林业局森林多目标经营规划设计

改变单一经营目标的传统森林经营方式,进行森林多目标经营,综合发挥森林的生态、社会与经济功能是我国林业发展的一个新阶段。如何从一个生产单位的角度出发,统筹森林利用和保护相关的社会、经济及环境等各方面,进行多目标规划和决策,是林业研究和实践中的重要命题。以长白山区露水河林业局为例,探讨了森林多目标经营的必要性,设计了森林多目标经营的规划设计体系,从群落生境分析、发展类型设计、林分作业设计以及生命周期经营计划设计等方面对露水河林业局森林多目标经营进行了规划设计,以期为我国开展森林多目标经营提供借鉴和手段支撑。     

Avian Composition Co‐varies with Floristic Composition and Soil Nutrient Concentration in Amazonian Upland Forests

Spatial heterogeneity in the plant species composition of tropical forests is expected to influence animal species abundance and composition because vegetation constitutes the primary habitat feature for forest animals. Floristic variation is tied to variation in soils, so edaphic properties should ultimately influence animal species composition as well. The study of covariation in floristic and faunistic turnover has been hindered by the difficulty of completing coordinated surveys in hyperdiverse tropical communities, but this can be overcome with the use of a few plant taxa that function as surrogates for general floristic turnover. We used avian and plant transect surveys and soil sampling in a western Amazonian upland (terra firme) forest landscape to test whether spatial variation in bird community composition is associated with floristic turnover and corresponding edaphic gradients. Partial Mantel tests and Non‐metric Multidimensional Scaling showed floristic distinctiveness between two forest types closely associated with differences in soil cation concentrations, and differences in both floristic composition and cation concentrations were further linked to compositional differences in avian species, independent of geographic distances among sites. Ten percent of bird species included in Indicator Species Analyses showed significant associations with one of the two forest types. The upland forest types that we sampled, each corresponding to a different geological formation, are intermediate relative to edaphically extreme environments in the region. Models of avian diversification should take into account this environmental heterogeneity, as should conservation planning approaches that aim to represent faunal diversity. Abstract in Spanish is available in the online version of this article.     

A test for assessment of saproxylic beetle biodiversity using subsets of “monitoring species”

In European forests, large scale biodiversity monitoring networks need to be implemented – networks which include components such as taxonomical groups that are at risk and that depend directly on forest stand structure. In this context, monitoring the species-rich group of saproxylic beetles is challenging. In the absence of sufficient resources to comprehensively survey a particular group, surrogates of species richness can be meaningful tools in biodiversity evaluations. In search of restricted subsets of species to use as surrogates of saproxylic beetle richness, we led a case study in Western Europe.Beetle data were compiled from 67 biodiversity surveys and ecological studies carried out from 1999 to 2010 with standardised trapping methods in France and Belgium. This large-scale dataset contains 642 forest plots, 1521 traps and 856 species. Twenty-two simplified species subsets were identified as potential surrogates, as well as the number of genera, a higher taxonomic level, taking into account, for each surrogate, the effort required for species identification, the practical monitoring experience necessary, the species conservation potential or the frequency of species occurrence. The performance of each surrogate was analyzed based on the following parameters: overall surrogacy (correlation between subset richness and total species richness), surrogacy vs. identification cost balance, surrogacy variation over a wide range of ecological conditions (forest type, altitude, latitude and bio-geographical area) and consistency with spatial scale. Ecological representativeness and ability to monitor rare species were supplementary criteria used to assess surrogate performance.The subsets consisting of the identifiable (or only easy-to-identify species) could easily be applied in practice and appear to be the best performing subsets, from a global point of view.The number of genera showed good prediction at the trap level and its surrogacy did not vary across wide environmental gradients. However, the subset of easy-to-identify species and the genus number were highly sensitive to spatial scale, which limits their use in large-scale studies. The number of rare species or the species richness of single beetle families (even the best single-family subset, the Cerambycidae) was very weak surrogates for total species richness. Conversely, the German list of monitoring species had high surrogacy, low identification costs and was not strongly influenced by the main geographical parameters, even with our French and Belgian data.In European-wide monitoring networks, such internationally validated subsets could be very useful with regard to the timing and cost-efficiency of field inventories.     

Forest disturbance and recovery in Peruvian Amazonia

Amazonian forests function as biomass and biodiversity reservoirs, contributing to climate change mitigation. While they continuously experience disturbance, the effect that disturbances have on biomass and biodiversity over time has not yet been assessed at a large scale. Here, we evaluate the degree of recent forest disturbance in Peruvian Amazonia and the effects that disturbance, environmental conditions and human use have on biomass and biodiversity in disturbed forests. We integrate tree-level data on aboveground biomass (AGB) and species richness from 1840 forest plots from Peru's National Forest Inventory with remotely sensed monitoring of forest change dynamics, based on disturbances detected from Landsat-derived Normalized Difference Moisture Index time series. Our results show a clear negative effect of disturbance intensity tree species richness. This effect was also observed on AGB and species richness recovery values towards undisturbed levels, as well as on the recovery of species composition towards undisturbed levels. Time since disturbance had a larger effect on AGB than on species richness. While time since disturbance has a positive effect on AGB, unexpectedly we found a small negative effect of time since disturbance on species richness. We estimate that roughly 15% of Peruvian Amazonian forests have experienced disturbance at least once since 1984, and that, following disturbance, have been increasing in AGB at a rate of 4.7 Mg ha⁻¹ year⁻¹ during the first 20 years. Furthermore, the positive effect of surrounding forest cover was evident for both AGB and its recovery towards undisturbed levels, as well as for species richness. There was a negative effect of forest accessibility on the recovery of species composition towards undisturbed levels. Moving forward, we recommend that forest-based climate change mitigation endeavours consider forest disturbance through the integration of forest inventory data with remote sensing methods.     

Tropical dry forests in New Caledonia

Tropical dry forest is the most endangered major vegetation type in the New Caledonia biodiversity hotspot. Vegetation surveys following a transect method used by Gentry were undertaken in two tropical dry forest sites, Ouen-Toro and Pindai, in order to compare species richness, floristic composition, and structure. Pindai contained significantly higher species richness than Ouen-Toro, although there was little difference in forest structure. Tropical dry forest sites in New Caledonia were compared to seven other biodiversity hotspots with tropical dry forest where Gentry's transect method was employed. New Caledonia and other tropical dry forests on islands contain significantly lower species richness than mainland tropical dry forests in biodiversity hotspots. However, New Caledonia contained the highest number of threatened species based on IUCN global conservation categories. Tropical dry forest in New Caledonia appears to be the world's most endangered tropical dry forest based on the extent of forest, number of reserves, and threatened species. Management of tropical dry forests on private and community lands is absolutely imperative to the long-term persistence of this ecosystem.