Genetic variation and structure of endemic and endangered wild celery (Kelussia odoratissima Mozaff.) quantified using novel microsatellite markers developed by next-generation sequencing

Kelussia odoratissima Mozaff. (Apiaceae) is a native plant that has been traditionally consumed in Iran's food and pharmaceutical industries. Overharvesting of the taxon, especially at the beginning of the growing season, due to its considerable medicinal and economic value, is believed to be the main reason for the extirpating of this plant. The consequences of the severe anthropogenic impacts on the genetic diversity of populations are poorly known. In order to investigate the level of genetic variation and patterns of the genetic structure of K. odoratissima, we developed novel microsatellite markers using the 454 Roche next-generation sequencing (NGS) platform for the first time. Out of 1,165 microsatellite markers bioinformatically confirmed, twenty-five were tested, of which 23 were used to screen genetic variation across 12 natural populations. Our results showed that the average number of alleles per locus and the polymorphic information content (PIC) were 10.87 (range 7 to 27), and 0.81 (range 0.67 to 0.94), respectively. The mean observed and expected heterozygosities (± SD) across all populations were 0.80 ± 0.31 and 0.72 ± 0.14, respectively. The average pairwise FST among the populations was 0.37 (range 0.04 to 0.81). Bayesian and distance-based clustering, and principal coordinate analyses revealed at least four major genetic clusters. Although high level of structure can be explained by landscape topography and geographic distance, presence of admixed populations can be associated to seed or pollen dispersal. Contrary to expectations, the high level of genetic variation and lack of inbreeding suggest that overexploitation has not yet significantly purged the allelic variability within the natural populations in protected areas.

Multi-scale effects of habitat loss and the role of trait evolution

Habitat loss (HL) is a major cause of species extinctions. Although the effects of HL beyond the directly impacted area have been previously observed, they have not been modelled explicitly, especially in an eco-evolutionary context. To start filling this gap, we study a two-patch deterministic consumer-resource model, with one of the patches experiencing loss of resources as a special case of HL. Our model allows foraging and mating within a patch as well as between patches. We then introduce heritable variation in consumer traits related to resource utilization and patch use to investigate eco-evolutionary dynamics and compare results with constant and no trait variation scenarios. Our results show that HL in one patch can indeed reduce consumer densities in the neighbouring patch but can also increase consumer densities in the neighbouring patch when the resources are overexploited. Yet at the landscape scale, the effect of HL on consumer densities is consistently negative. Patch isolation increases consumer density in the patch experiencing HL but has generally negative effects on the neighbouring patch, with context-dependent results at the landscape scale. With high cross-patch dependence and coupled foraging and mating preferences, local HL can sometimes even lead to landscape-level consumer extinction. Eco-evolutionary dynamics can rescue consumers from such extinction in some cases if their death rates are sufficiently small. More generally, trait evolution had positive or negative effects on equilibrium consumer densities after HL, depending on the evolving trait and the spatial scale considered. In summary, our findings show that HL at a local scale can affect the neighbouring patch and the landscape as a whole, where heritable trait variation can, in some cases, alleviate the impact of HL. We thus suggest joint consideration of multiple spatial scales and trait variation when assessing and predicting the impacts of HL.

Habitat Selection and Home Range of Reeves' Turtle (Mauremys reevesii) in Qichun County, Hubei Province, China

Habitat selection and range are crucial factors in understanding the life history of species. We tracked 23 adult wild Reeves' turtles (Mauremys reevesii) from August 2021 to August 2022 in Qichun County, Hubei Province, China, to study their habitat selection, home range, and the characteristics of chosen habitats. Significant differences were observed in aquatic habitats, regarding shelter cover (Z = -6.032, p < 0.001), shelter height (Z = -6.783, p < 0.001), depth of water (Z = -2.009, p = 0.045), and distance from the edge (Z = -4.288, p < 0.001), between selected and random habitats. In terrestrial habitats, significant differences were observed in canopy cover (Z = -2.100, p = 0.036), herbage cover (Z = -2.347, p = 0.019), distance from the field edge (Z = -2.724, p = 0.006), dead grass cover (Z = -2.921, p = 0.003), and dead grass thickness (t = 3.735, df = 17, p = 0.002) between the selected and random habitats. The mean home range area observed for this turtle population was 14.34 ± 4.29 ha, the mean core home range was 2.91 ± 2.28 ha, and the mean line home range was 670.23 ± 119.62 m. This study provides valuable information on this endangered species, providing a foundation for the development of conservation plans.

Major drivers of biodiversity loss and their impacts on helminth parasite populations and communities

The world's biodiversity is in peril. The major threats to biodiversity globally are habitat change, overexploitation, climate change, invasive species and pollution. Not only do these stressors impact free-living organisms, but they affect parasitic ones as well. Herein, this perspective examines the potential consequences of these anthropogenic perturbations on helminth populations and communities, with emphasis on significant developments over the past decade. Furthermore, several case studies are examined in more detail for each of these threats to biodiversity. While effects are widespread and diverse, for the most part all these environmental stressors have negative effects on parasite populations and communities. Those parasites with complex life cycles that are trophically transmitted are often more at risk, although larval parasites with a wide host spectrum, and directly transmitted ectoparasites, appear less threatened and may even benefit. However, differential effects on hosts and parasites, on parasite life cycle stages and on host-parasite interactions made specific predictions difficult and context-dependent. Experimental laboratory and mesocosm studies on specific parasites that test effects on the different life cycle stages, hosts and host-parasite interactions, permitting the determination of net effects of an environmental stressor, yield insightful and sometimes counterintuitive results, although they remain a simplification of real-world complexity. Recent advances in the use of parasites as bioindicators of effects also are discussed.

Parasites as conservation tools

Parasite success typically depends on a close relationship with one or more hosts; therefore, attributes of parasitic infection have the potential to provide indirect details of host natural history and are biologically relevant to animal conservation. Characterization of parasite infections has been useful in delineating host populations and has served as a proxy for assessment of environmental quality. In other cases, the utility of parasites is just being explored, for example, as indicators of host connectivity. Innovative studies of parasite biology can provide information to manage major conservation threats by using parasite assemblage, prevalence, or genetic data to provide insights into the host. Overexploitation, habitat loss and fragmentation, invasive species, and climate change are major threats to animal conservation, and all of these can be informed by parasites.

Ecological theory of mutualism: Robust patterns of stability and thresholds in two-species population models

Mutualisms are ubiquitous in nature, provide important ecosystem services, and involve many species of interest for conservation. Theoretical progress on the population dynamics of mutualistic interactions, however, comparatively lagged behind that of trophic and competitive interactions, leading to the impression that ecologists still lack a generalized framework to investigate the population dynamics of mutualisms. Yet, over the last 90 years, abundant theoretical work has accumulated, ranging from abstract to detailed. Here, we review and synthesize historical models of two-species mutualisms. We find that population dynamics of mutualisms are qualitatively robust across derivations, including levels of detail, types of benefit, and inspiring systems. Specifically, mutualisms tend to exhibit stable coexistence at high density and destabilizing thresholds at low density. These dynamics emerge when benefits of mutualism saturate, whether due to intrinsic or extrinsic density dependence in intraspecific processes, interspecific processes, or both. We distinguish between thresholds resulting from Allee effects, low partner density, and high partner density, and their mathematical and conceptual causes. Our synthesis suggests that there exists a robust population dynamic theory of mutualism that can make general predictions.

Illegal fisheries, environmental crime, and the conservation of marine resources

The illegal harvest of marine species within exclusive economic zones can have a strong impact on the function of local ecosystems and livelihoods of coastal communities. The complexity of these problems is often overlooked in the development of solutions, leading to ineffective and sometimes harmful social and environmental outcomes. One-dimensional, oversimplified perspectives can lead to conservation prescriptions that exacerbate social stressors. This is particularly critical in the case of international illegal trade of endangered, high-value species, which generate a value chain in which artisanal fishers are the first operational and often the weakest link of an intricate web. We examined 2 illegal fisheries, totoaba (Totoaba macdonaldi) and sea cucumber (Isostichopus badionotus and Holothuria floridana), in Mexico. Although these are 2 separate and independent fisheries, important ecological (resource condition, fishery impacts at the ecosystem level) and social (governance, markets) similarities improve understanding of their complexity. Our findings are relevant globally and show the need for interdisciplinary decision-making groups, community engagement, and the development of demand reduction measures.

Dactylorhiza hatagirea (D. Don) Soo: A Critically Endangered Perennial Orchid from the North-West Himalayas

Dactylorhiza hatagirea (Orchidaceae) is a perennial herb inhabiting sub-alpine to alpine regions, ranging at elevations between 2500 and 5000 m.a.s.l. With palmately lobed rhizome and lanceolate leaves having a sheathing leaf base, it bears pink flowers with purple-colored notches and a curved spur. It finds wide use in ayurveda, siddha, unani, and folk medicine in curing disorders of the circulatory, respiratory, nervous, digestive, skeletal, and reproductive systems, besides boosting the immune system to fight infectious diseases. Secondary metabolites such as dactylorhins A–E, dactyloses A–B, and others exhibit a wide spectrum of pharmacological activities (antioxidant, antimicrobial, antiseptic, anticancer, and immune enhancing activities). Its use as a dietary supplement was found to be beneficial in increasing testosterone levels, resulting in improved sexual desire and arousal. Incessant overexploitation of this medicinally important herb has resulted in the dwindling of its populations in the wild, which has resulted in its classification as a critically endangered plant species. Efforts involving mass reproduction through in vitro (through tissue culture) and in vivo (by vegetative propagation) means are currently being made to maintain the germplasm of this critically endangered orchid. Holding immense significance in clinical research and drug discovery, work on the genomic front (transcriptomics) has recently been carried out to discover the wealth of unexplored genetic information for this perennial herb. The present study is aimed at reviewing different aspects of the orchid to present collective (summarized) information on this medicinally important herb in the present, particularly its botany, ethnobotanical uses, phytochemistry, and pharmacognosy, along with the strategies that need to be adopted to prevent its overexploitation in natural habitats.

Combined effects of land use and hunting on distributions of tropical mammals

Land use and hunting are 2 major pressures on biodiversity in the tropics. Yet, their combined impacts have not been systematically quantified at a large scale. We estimated the effects of both pressures on the distributions of 1884 tropical mammal species by integrating species' range maps, detailed land-use maps (1992 and 2015), species-specific habitat preference data, and a hunting pressure model. We further identified areas where the combined impacts were greatest (hotspots) and least (coolspots) to determine priority areas for mitigation or prevention of the pressures. Land use was the main driver of reduced distribution of all mammal species considered. Yet, hunting pressure caused additional reductions in large-bodied species' distributions. Together, land use and hunting reduced distributions of species by 41% (SD 30) on average (year 2015). Overlap between impacts was only 2% on average. Land use contributed more to the loss of distribution (39% on average) than hunting (4% on average). However, hunting reduced the distribution of large mammals by 29% on average; hence, large mammals lost a disproportional amount of area due to the combination of both pressures. Gran Chaco, the Atlantic Forest, and Thailand had high levels of impact across the species (hotspots of area loss). In contrast, the Amazon and Congo Basins, the Guianas, and Borneo had relatively low levels of impact (coolspots of area loss). Overall, hunting pressure and human land use increased from 1992 to 2015 and corresponding losses in distribution increased from 38% to 41% on average across the species. To effectively protect tropical mammals, conservation policies should address both pressures simultaneously because their effects are highly complementary. Our spatially detailed and species-specific results may support future national and global conservation agendas, including the design of post-2020 protected area targets and strategies.

Global change in the functional diversity of marine fisheries exploitation over the past 65 years

Overexploitation is recognized as one of the main threats to global biodiversity. Here, we report a widespread change in the functional diversity of fisheries catches from the large marine ecosystems (LMEs) of the world over the past 65 years (1950 to 2014). The spatial and temporal trends of functional diversity exploited from the LMEs were calculated using global reconstructed marine fisheries catch data provided by the Sea Around Us initiative (including subsistence, artisanal, recreational, industrial fisheries, and discards) and functional trait data available in FishBase. Our analyses uncovered a substantial increase in the functional richness of both ray-finned fishes (80% of LMEs) and cartilaginous species (sharks and rays) (75% of LMESs), in line with an increase in the taxonomic richness, extracted from these ecosystems. The functional evenness and functional divergence of these catches have also altered substantially over the time span of this study, with considerable geographic variation in the patterns detected. These trends show that global fisheries are increasingly targeting species that play diverse roles within the marine ecosystem and underline the importance of incorporating functional diversity in ecosystem management.

Human exploitation shapes productivity-biomass relationships on coral reefs

Coral reef fisheries support the livelihoods of millions of people in tropical countries, despite large-scale depletion of fish biomass. While human adaptability can help to explain the resistance of fisheries to biomass depletion, compensatory ecological mechanisms may also be involved. If this is the case, high productivity should coexist with low biomass under relatively high exploitation. Here we integrate large spatial scale empirical data analysis and a theory-driven modelling approach to unveil the effects of human exploitation on reef fish productivity-biomass relationships. We show that differences in how productivity and biomass respond to overexploitation can decouple their relationship. As size-selective exploitation depletes fish biomass, it triggers increased production per unit biomass, averting immediate productivity collapse in both the modelling and the empirical systems. This 'buffering productivity' exposes the danger of assuming resource production-biomass equivalence, but may help to explain why some biomass-depleted fish assemblages still provide ecosystem goods under continued global fishing exploitation.

The complete plastome genome and its inference on the phylogenetic position of Bletilla formosana (Orchidaceae)

Bletilla formosana is a traditional Chinese medicinal herb and recently threatened by overexploitation owing to the increasing demand. In present study, we sequenced and assembled the complete chloroplast (cp) genomes of this species. The plastome genome is a typical quadripartite circle molecule with the total lenth of 158,968 bp and overall GC content of 37.3%. We predicted 104 genes in the cp genome, including 80 protein coding gens, 20 tRNA and 4 rRNA. Phylogenetic analysis shows that B. formosana is sister to B. striata.

Historical photographs of captures of recreational fishers indicate overexploitation of nearshore resources at an oceanic island

In this study, we used a historical collection of photographs taken by recreational fishers from 1940 to 2014, at the island of Gran Canaria, to show both a significant decrease in the mean total length of Epinephelus marginatus and a concurrent change in the composition of captures. Before 1980, the mean total length of fish caught and photographed was c. 100 cm, while after 2009 this was typically < 40 cm. Before 1980, the predominant captured species was E. marginatus (an apex predator), but currently the majority of catches are of omnivorous species, in particular the parrotfish, Sparisoma cretense and seabreams Diplodus spp. Overall, integration of these results indicates a qualitative and quantitative variation in captures of recreational fishers, probably as a sign of change in ecological balances and the overfished status of many target species.

How Does the Evolution of Universal Ecological Traits Affect Population Size? Lessons from Simple Models

This article argues that adaptive evolutionary change in a consumer species should frequently decrease (and maladaptive change should increase) population size, producing adaptive decline. This conclusion is based on analysis of multiple consumer-resource models that examine evolutionary change in consumer traits affecting the universal ecological parameters of attack rate, conversion efficiency, and mortality. Two scenarios are investigated. In one, evolutionary equilibrium is initially maintained by opposing effects on the attack rate and other growth rate parameters; the environment or trait is perturbed, and the trait then evolves to a new (or back to a previous) equilibrium. Here evolution exhibits adaptive decline in up to one-half of all cases. The other scenario assumes a genetic perturbation having purely fitness-increasing effects. Here adaptive decline in the consumer requires that the resource be self-reproducing and overexploited and requires a sufficient increase in the attack rate. However, if the resource exhibits adaptive defense via behavior or evolution, adaptive decline may characterize consumer traits affecting all parameters. Favorable environmental change producing parameter shifts similar to those produced by adaptive evolution has similar counterintuitive effects on consumer population size. Many different food web models have already been shown to exhibit such counterintuitive changes in some species.

An overlooked plant-parakeet mutualism counteracts human overharvesting on an endangered tree

The exponential growth of the human population often causes the overexploitation of resources and disruption of ecological interactions. Here, we propose that the antagonist effect of humans on exploited species might be alleviated with the advent of a second predator species. We focused on the complex interactions between an endangered conifer (Araucaria araucana) and two seed exploiters: the Austral parakeet (Enicognathus ferrugineus) and human seed collectors. We tested the importance of partial seed consumption by parakeets as an escape from human seed harvesting. Although parakeets frequently ate whole seeds, a substantial proportion of the seeds found under trees were only partially eaten and avoided by human seed collectors. These seeds germinated at a similar proportion but faster than intact seeds under laboratory conditions. Our results revealed an overlooked mutualism between parakeets and an endangered tree. Incomplete seed eating by parakeets, plus selection against these eaten seeds by humans, may enhance regeneration possibilities for this conifer species subject to human seed collection, turning the scale of the antagonism-mutualism continuum to the mutualistic side. In this context, parakeets might be providing an important service in those forests subject to human harvesting by allowing a fraction of seeds to escape human predation.

Isotopes to assess sustainability of overexploited groundwater in the Souss-Massa system (Morocco)

Groundwater depletion and changes in isotopic and chemical contents constitute the main indicators of overexploitation, recharge, and flow paths in the Souss-Massa aquifer. These indicators highlight processes concerning sustainability of water resources in the aquifer (e.g. surface/groundwater interaction, recharge processes, and marine intrusion). The spatial variation of stable and radioactive isotopic contents indicates a mixing of modern and old water within the system. Recent recharge was observed mainly along the Souss River (the major surface-water drainage in the study area) and in the irrigated areas. Mapping of chemical and isotopic variation shows that the area is affected by abstraction, irrigation water return, and the evolution of modern recharge in time and space. The processes, distribution, and timing of groundwater flow are influenced by short- and long-term effects; long-term recharge is dependent on climatic conditions. This study can be used to make informed decisions about water-resource allocation and alternative management practices.

Measuring the impact of the pet trade on Indonesian birds

The trade in wild animals involves one-third of the world's bird species and thousands of other vertebrate species. Although a few species are imperiled as a result of the wildlife trade, the lack of field studies makes it difficult to gauge how serious a threat it is to biodiversity. We used data on changes in bird abundances across space and time and information from trapper interviews to evaluate the effects of trapping wild birds for the pet trade in Sumatra, Indonesia. To analyze changes in bird abundance over time, we used data gathered over 14 years of repeated bird surveys in a 900-ha forest in southern Sumatra. In northern Sumatra, we surveyed birds along a gradient of trapping accessibility, from the edge of roads to 5 km into the forest interior. We interviewed 49 bird trappers in northern Sumatra to learn which species they targeted and how far they went into the forest to trap. We used prices from Sumatran bird markets as a proxy for demand and, therefore, trapping pressure. Market price was a significant predictor of species declines over time in southern Sumatra (e.g., given a market price increase of approximately $50, the log change in abundance per year decreased by 0.06 on average). This result indicates a link between the market-based pet trade and community-wide species declines. In northern Sumatra, price and change in abundance were not related to remoteness (distance from the nearest road). However, based on our field surveys, high-value species were rare or absent across this region. The median maximum distance trappers went into the forest each day was 5.0 km. This suggests that trapping has depleted bird populations across our remoteness gradient. We found that less than half of Sumatra's remaining forests are >5 km from a major road. Our results suggest that trapping for the pet trade threatens birds in Sumatra. Given the popularity of pet birds across Southeast Asia, additional studies are urgently needed to determine the extent and magnitude of the threat posed by the pet trade.

Impacts of hunting on tropical forests in Southeast Asia

Although deforestation and forest degradation have long been considered the most significant threats to tropical biodiversity, across Southeast Asia (Northeast India, Indochina, Sundaland, Philippines) substantial areas of natural habitat have few wild animals (>1 kg), bar a few hunting-tolerant species. To document hunting impacts on vertebrate populations regionally, we conducted an extensive literature review, including papers in local journals and reports of governmental and nongovernmental agencies. Evidence from multiple sites indicated animal populations declined precipitously across the region since approximately 1980, and many species are now extirpated from substantial portions of their former ranges. Hunting is by far the greatest immediate threat to the survival of most of the region's endangered vertebrates. Causes of recent overhunting include improved access to forests and markets, improved hunting technology, and escalating demand for wild meat, wildlife-derived medicinal products, and wild animals as pets. Although hunters often take common species, such as pigs or rats, for their own consumption, they take rarer species opportunistically and sell surplus meat and commercially valuable products. There is also widespread targeted hunting of high-value species. Consequently, as currently practiced, hunting cannot be considered sustainable anywhere in the region, and in most places enforcement of protected-area and protected-species legislation is weak. The international community's focus on cross-border trade fails to address overexploitation of wildlife because hunting and the sale of wild meat is largely a local issue and most of the harvest is consumed in villages, rural towns, and nearby cities. In addition to improved enforcement, efforts to engage hunters and manage wildlife populations through sustainable hunting practices are urgently needed. Unless there is a step change in efforts to reduce wildlife exploitation to sustainable levels, the region will likely lose most of its iconic species, and many others besides, within the next few years.

'Neo-Europe' and its ecological consequences: the example of systematic degradation in Australia's inland fisheries

The antiquity of human impact on ecosystems is increasingly understood, though the arrival of settlers to new lands remains a defining period. Colonization of the 'neo-Europes', a reference from the discipline of history, precipitated changes in aquatic ecosystems through modification of waterways and introductions of non-native species. We considered historical fisheries and fish market records from South Australia (1900-1946) against contemporary production statistics (1987-2011). Native inland species historically contributed large quantities to the market but have deteriorated such that fishing is now limited, and conservation regulations exist. This pattern mirrors the demand-driven transition from freshwater to marine fisheries in Europe; hence, we propose that this pattern was predicated on societal expectations and that European settlement and introduction of non-native fishes led to systematic overexploitation and degradation of native inland fisheries species in Australia, representing a further consequence of neo-European colonization to ecology. Accurate interpretation of ecological change can ensure more appropriate management intervention. Concepts, such as neo-Europe, from alternative disciplines can inform the recognition and evaluation of patterns at regional and global scales.

Microsatellite loci confirm a lack of population connectivity among globally distributed populations of the tope shark Galeorhinus galeus (Triakidae)

This study used 11 polymorphic nuclear microsatellite loci to determine the population connectivity of five geographically isolated populations of tope shark Galeorhinus galeus (Africa, Australia, North America, South America and western Europe). Genetic analyses revealed significant structure among all populations indicating a lack of population connectivity. These findings indicate that globally distributed populations of G. galeus are isolated and should be managed as distinct, independent stocks.

Demographic evidence of illegal harvesting of an endangered asian turtle

Harvesting pressure on Asian freshwater turtles is severe, and dramatic population declines of these turtles are being driven by unsustainable collection for food markets, pet trade, and traditional Chinese medicine. Populations of big-headed turtle (Platysternon megacephalum) have declined substantially across its distribution, particularly in China, because of overcollection. To understand the effects of chronic harvesting pressure on big-headed turtle populations, we examined the effects of illegal harvesting on the demography of populations in Hong Kong, where some populations still exist. We used mark-recapture methods to compare demographic characteristics between sites with harvesting histories and one site in a fully protected area. Sites with a history of illegal turtle harvesting were characterized by the absence of large adults and skewed ratios of juveniles to adults, which may have negative implications for the long-term viability of populations. These sites also had lower densities of adults and smaller adult body sizes than the protected site. Given that populations throughout most of the species' range are heavily harvested and individuals are increasingly difficult to find in mainland China, the illegal collection of turtles from populations in Hong Kong may increase over time. Long-term monitoring of populations is essential to track effects of illegal collection, and increased patrolling is needed to help control illegal harvesting of populations, particularly in national parks. Because few, if any, other completely protected populations remain in the region, our data on an unharvested population of big-headed turtles serve as an important reference for assessing the negative consequences of harvesting on populations of stream turtles. Evidencia Demográfica de la Captura Ilegal de una Tortuga Asiática en Peligro.

Anthropogenic effects on forest ecosystems at various spatio-temporal scales

The focus in this review of long-term effects on forest ecosystems is on human impact. As a classification of this differentiated and complex matter, three domains of long-term effects with different scales in space and time are distinguished: Exploitation and conversion history of forests in areas of extended human settlement, Long-range air pollution and acid deposition in industrialized regions, Current global loss of forests and soil degradation. There is an evident link between the first and the third point in the list. Cultivation of primary forestland--with its tremendous effects on land cover--took place in Europe many centuries ago and continued for centuries. Deforestation today is a phenomenon predominantly observed in the developing countries, yet it threatens biotic and soil resources on a global scale. Acidification of forest soils caused by long-range air pollution from anthropogenic emission sources is a regional to continental problem in industrialized parts of the world. As a result of emission reduction legislation, atmospheric acid deposition is currently on the retreat in the richer industrialized regions (e.g., Europe, U.S., Japan); however, because many other regions of the world are at present rapidly developing their polluting industries (e.g., China and India), "acid rain" will most probably remain a serious ecological problem on regional scales. It is believed to have caused considerable destabilization of forest ecosystems, adding to the strong structural and biogeochemical impacts resulting from exploitation history. Deforestation and soil degradation cause the most pressing ecological problems for the time being, at least on the global scale. In many of those regions where loss of forests and soils is now high, it may be extremely difficult or impossible to restore forest ecosystems and soil productivity. Moreover, the driving forces, which are predominantly of a demographic and socioeconomic nature, do not yet seem to be lessening in strength. It can only be hoped that a wise policy of international cooperation and shared aims can cope with this problem in the future.