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China’s Hengduan Mountain region has been considered one of the most diverse regions in the northern hemisphere. Its stunning topography with many deep valleys and impassable mountain barriers has promoted an astonishing diversification in many groups of organisms including plants, birds, mammals, and amphibians. However, the insect biodiversity in this region is still poorly known. Here, the first checklist of ant species from the Southern Hengduan Mountain region is presented, generated by sampling ant diversity using a wide array of collection methods, including Winkler leaf litter extraction, vegetation beating, and hand collection. 130 species/morphospecies from nine subfamilies and 49 genera were identified. Among them, 17 species from 13 genera represent new records for Yunnan province, and eight species are newly recorded for China. Moreover, we believe 41 novel morphospecies (31% of the total collected taxa) will prove to be new to science. These results highlight the rich ant fauna of this region and strongly support its status as a biodiversity hotspot. The current ant species checklist for the whole of Yunnan Province was updated by recording 550 named species from 99 genera. Taken together, our results suggest that the Yunnan ant fauna still remains under-sampled, and future sampling will likely yield many more species, among them many undescribed ones.

This study updates and summarizes information on the taxonomy and status of the Arabian Lepisiota fauna. We describe and illustrate the new species Lepisiota elbazi sp. nov. from the Dhofar Governorate, Oman based on the worker caste. The new species is closest to the Arabian species, L. arabica Collingwood, 1985 from the southwestern mountains of the Kingdom of Saudi Arabia (KSA) and can be separated by having fewer body hairs (two pairs on the posterior margin of the head, two or three pairs on the promesonotum and, one or two pairs on the first gastral tergite), the longer head, scapes, and propodeal spines, and the shorter mesosoma. We present the first illustrated key to the worker caste of the Arabian species of Lepisiota using stacked digital color images to facilitate species determination. The new species is probably endemic to the Dhofar Governorate and seems rare. An up-to-date synoptic checklist of 21 species representing the Arabian Lepisiota Santschi, 1926 is emended based upon the most recent literature in ant systematics. Five species are excluded from the Arabian Lepisiota fauna, L. arenaria (Arnold, 1920), L. erythraea (Forel, 1910), L. incisa (Forel, 1913), L. sericea (Forel, 1892a), and L. simplex (Forel, 1892) for issues related to previous species misidentification. Lepisiota carbonaria (Emery, 1892) is proposed as a senior synonym of L. depilis (Emery, 1897) syn. nov. The faunal composition of Lepisiota species recorded from the Arabian Peninsula can be divided/delineated into two main groups according to their zoogeographical relationships; (1) Afrotropical (11 species-~52.38%); (2) Palearctic (10 species-~47.62%) elements whereas eight species (~38%) are Arabian endemics.

The genus Crematogaster is one of the most species-rich and widespread groups of ants. Despite their often-high local abundance and important ecological interactions, the taxonomy of the genus is fragmentary and in great need of modern revisionary studies. As a first step towards a revision for the Arabian fauna of Crematogaster, a review of all known species with synoptic species accounts is provided. Seventeen species are recognized and illustrated from the Arabian Peninsula, of which two new species are described: C. jacindae Sharaf & Hita Garcia, sp. nov. from the Dhofar Governorate, Oman, and C. gryllsi Sharaf & Hita Garcia, sp. nov. from the Kingdom of Saudi Arabia (KSA) based on the worker caste. Crematogaster jacindae sp. nov. is easily separated from the remainder of the Arabian Crematogaster fauna due to its complete lack of propodeal spines, slit-shaped propodeal spiracles, and its distinct bicoloration, whereas C. gryllsi sp. nov. is readily distinguished by its unlobed postpetiolar dorsum. Furthermore, new country records are presented: C. acaciae Forel for the KSA and Yemen, and C. delagoensis Forel and C. jehovae Forel for the KSA C. antaris for Qatar, whereas C. luctans Forel is excluded from the Arabian fauna. In addition, on the basis of morphological examination of original type material, C. affabilis Forel is proposed as junior synonym of C. chiarinii Mayr, and C. striaticeps is elevated to species rank stat. nov. Furthermore, a new identification key for the Arabian species is provided, as well as distribution maps for all species.

Abstract Background While thousands of ant species are arboreal, very few are able to chew and tunnel through living wood. Ants of the genus Melissotarsus (subfamily Myrmicinae) inhabit tunnel systems excavated under the bark of living trees, where they keep large numbers of symbiotic armoured scale insects (family Diaspididae). Construction of these tunnels by chewing through healthy wood requires tremendous power, but the adaptations that give Melissotarsus these abilities are unclear. Here, we investigate the morphology of the musculoskeletal system of Melissotarsus using histology, scanning electron microscopy, X-ray spectrometry, X-ray microcomputed tomography (micro-CT), and 3D modelling. Results Both the head and legs of Melissotarsus workers contain novel skeletomuscular adaptations to increase their ability to tunnel through living wood. The head is greatly enlarged dorsoventrally, with large mandibular closer muscles occupying most of the dorsal half of the head cavity, while ventrally-located opener muscles are also exceptionally large. This differs from the strong closing: opening asymmetry typical of most mandibulated animals, where closing the mandibles requires more force than opening. Furthermore, the mandibles are short and cone-shaped with a wide articulatory base that concentrates the force generated by the muscles towards the tips. The increased distance between the axis of mandibular rotation and the points of muscle insertion provides a mechanical advantage that amplifies the force from the closer and opener muscles. We suggest that the uncommonly strong opening action is required to move away crushed plant tissues during tunnelling and allow a steady forward motion. X-ray spectrometry showed that the tip of the mandibles is reinforced with zinc. Workers in this genus have aberrant legs, including mid- and hindlegs with hypertrophied coxae and stout basitarsi equipped with peg-like setae, and midleg femura pointed upward and close to the body. This unusual design famously prevents them from standing and walking on a normal two-dimensional surface. We reinterpret these unique traits as modifications to brace the body during tunnelling rather than locomotion per se. Conclusions Melissotarsus represents an extraordinary case study of how the adaptation to – and indeed engineering of – a novel ecological niche can lead to the evolutionary redesign of core biomechanical systems.

The genus Proceratium Roger, 1863 contains cryptic, subterranean ants that are seldom sampled and rare in natural history collections. Furthermore, most Proceratium specimens are extremely hairy and, due to their enlarged and curved gaster, often mounted suboptimally. As a consequence, the poorly observable physical characteristics of the material and its scarcity result in a rather challenging alpha taxonomy of this group. In this study, the taxonomy of the Chinese Proceratium fauna is reviewed and updated by combining examinations of traditional light microscopy with x-ray microtomography (micro-CT). Based on micro-CT scans of seven out of eight species, virtual 3D surface models were generated that permit in-depth comparative analyses of specimen morphology in order to overcome the difficulties to examine physical material of Proceratium. Eight Chinese species are recognized, of which three are newly described: Proceratium bruelheidei Staab, Xu & Hita Garcia, sp. n. and P. kepingmai sp. n. belong to the P. itoi clade and have been collected in the subtropical forests of southeast China, whereas P. shohei sp. n. belongs to the P. stictum clade and it is only known from a tropical forest of Yunnan Province. Proceratium nujiangense Xu, 2006 syn. n. is proposed as a junior synonym of P. zhaoi Xu, 2000. These taxonomic acts raise the number of known Chinese Proceratium species to eight. In order to integrate the new species into the existing taxonomic system and to facilitate identifications, an illustrated key to the worker caste of all Chinese species is provided, supplemented by species accounts with high-resolution montage images and still images of volume renderings of 3D models based on micro-CT. Moreover, cybertype datasets are provided for the new species, as well as digital datasets for the remaining species that include the raw micro-CT scan data, 3D surface models, 3D rotation videos, and all light photography and micro-CT still images. These datasets are available online (Dryad, Staab et al. 2018, http://dx.doi.org/10.5061/dryad.h6j0g4p).

New technologies for imaging and analysis of morphological characters offer opportunities to enhance revisionary taxonomy and better integrate it with the rest of biology. In this study, we revise the Afrotropical fauna of the ant genus Zasphinctus Wheeler, and use high-resolution X-ray microtomography (micro-CT) to analyse a number of morphological characters of taxonomic and biological interest. We recognise and describe three new species: Z. obamai sp. n., Z. sarowiwai sp. n., and Z. wilsoni sp. n. The species delimitations are based on the morphological examination of all physical specimens in combination with 3D scans and volume reconstructions. Based on this approach, we present a new taxonomic discrimination system for the regional fauna that consists of a combination of easily observable morphological characters visible at magnifications of around 80–100 ×, less observable characters that require higher magnifications, as well as characters made visible through virtual dissections that would otherwise require destructive treatment. Zasphinctus are rarely collected ants and the material available to us is comparatively scarce. Consequently, we explore the use of micro-CT as a non-invasive tool for the virtual examination, manipulation, and dissection of such rare material. Furthermore, we delineate the treated species by providing a diagnostic character matrix illustrated by numerous images and supplement that with additional evidence in the form of stacked montage images, 3D PDFs and 3D rotation videos of scans of major body parts and full body (in total we provide 16 stacked montage photographs, 116 images of 3D reconstructions, 15 3D rotation videos, and 13 3D PDFs). In addition to the comparative morphology analyses used for species delimitations, we also apply micro-CT data to examine certain traits, such as mouthparts, cuticle thickness, and thoracic and abdominal muscles in order to assess their taxonomic usefulness or gain insights into the natural history of the genus. The complete datasets comprising the raw micro-CT data, 3D PDFs, 3D rotation videos, still images of 3D models, and coloured montage photos have been made available online as cybertypes (Dryad, http://dx.doi.org/10.5061/dryad.4s3v1).

In this study, we review the Arabian species of the ant genus Nesomyrmex Wheeler. We provide species reviews for the two previously known species, N. angulatus (Mayr, 1862) and N. humerosus (Emery, 1896) and describe a new species N. zaheri sp. n. from Yemen based on the worker caste. An illustrated key to the Arabian species of the genus and montage photos of all three species are provided.

Ants of the Tetramorium solidum group occur in Africa, with the vast majority of species endemic to the arid regions of southern Africa. The first revision of the genus was published more than 30 years ago and ant surveys have since considerably expanded the number of specimens available for study. The revision of this group reveals five new species, expanding the total number to 19. Almost all the species in this group occur in the southern parts of the Afrotropical region, with the exception of T. setuliferum Emery, 1895 and T. rothschildi (Forel, 1907). These two species have broad distributions within African grasslands and savannas, with T. setuliferum occurring in southern Africa and T. rothschildi in East Africa and the Sahel. Five new species are described in this revision: T. aisha sp. nov., T. brigitteae sp. nov., T. duncani sp. nov., T. lerouxi sp. nov. and T. margueriteae sp. nov. An illustrated key is presented and descriptions of new species are provided, supported by montage images and distribution maps.

We revise the taxonomy of the myrmicine ants of the Monomorium monomorium species-group for the Arabian Peninsula. Six species are recognized: Monomorium aeyade Collingwood & Agosti, 1996, M. clavicorne André, 1881, M. exiguum Forel, 1894, M. holothir Bolton, 1987, M. mohammedi sp. n., and M. sarawatense Sharaf & Aldawood, 2013. On the basis of the worker caste, we describe Monomorium mohammedi sp. n. from the southwestern region of the Kingdom of Saudi Arabia (KSA). We designate a neotype for Monomorium aeyade Collingwood & Agosti and redescribe and illustrate the worker caste. Furthermore, we provide a worker-based species identification key, distribution maps for the treated species, and ecological and biological notes, if available. Monomorium holothir is recorded for the first time from the KSA. Also, we propose M. clavicorne var. punica Santschi, 1915a as a junior synonym of M. clavicorne, as well as M. dryhimi Aldawood & Sharaf, 2011 and M. montanum Collingwood & Agosti, 1996 to be treated as junior synonyms of Monomorium exiguum.

In this study we provide an update to the taxonomy of the ant genus Tetramorium Mayr in Madagascar. We report the first record of the T. setigerum species group in Madagascar and describe the only Malagasy representative as T. cavernicola sp. n., which is known only from a cave in Ankarana. In addition, we provide an overview of the 19 proposed Malagasy species groups, and discuss their zoogeography and relationships to other groups and larger lineages within the hyper-diverse genus Tetramorium. At present, we recognise a highly unique Malagasy Tetramorium fauna with 113 species endemic to the island of Madagascar out of a total of 125 translating into an endemism rate of 93%. We hypothesise that this fauna is based on one or a few colonisation events from the Afrotropical region, with subsequent adaptive radiation in Madagascar. Furthermore, we present an updated and illustrated identification key to the Tetramorium species groups in the Malagasy region.

In this study we present a taxonomic update for the Aenictus ceylonicus group. A recent survey of the leaf litter ant fauna of Xingshuangbanna (Yunnan, China) yielded material of a hitherto unknown member of the group, which we describe here as Aenictus yangi sp. n. The new species is clearly distinguishable from the other species of the A. ceylonicus group based on differences in mandibular dentition, the development of the metanotal groove, the shape of the propodeum and subpetiolar process, as well as surface sculpture on the mesosoma and waist segments. In order to integrate A. yangi sp. n. into the taxonomic system created by Jaitrong and Yamane (2013) we provide an update to the identification key provided in the latter revision, as well as a diagnostic discussion and high-quality illustrations of important species and morphological characters.

As with many other regions of the world, significant collecting, curation, and taxonomic efforts will be needed to complete the inventory of China’s ant fauna. This is especially true for the highly diverse tropical regions in the south of the country, where moist tropical forests harbor high species richness typical of the Southeast Asian region. We inventoried ants in the Xingshuangbanna prefecture, Yunnan, in June 2013, using a variety of methods including Winkler extraction and hand collection to sample ant diversity. We identified 213 species/morphospecies of ants from 10 subfamilies and 61 genera. After identification of 148 valid species of the 213 total species collected, 40 species represent new records for Yunnan province and 17 species are newly recorded for China. This increases the total number of named ant species in Yunnan and China to 447 and 951 respectively. The most common species collected were Brachyponera luteipes and Vollenhovia emeryi. Only one confirmed exotic species Strumigenys membranifera, was collected, although several others were potentially introduced by humans. These results highlight the high biodiversity value of the region, but also underscore how much work remains to fully document the native myrmecofauna.

The Fiji archipelago harbours a surprisingly diverse and endemic ant fauna, despite its isolated and remote location in the South Pacific. The ant genus Proceratium is present on Fiji with three endemic species, of which P. oceanicum De Andrade, 2003 and P. relictum Mann, 1921 were previously known. In this study we describe the third species: P. vinaka sp. n. All three species are members of the widespread and species-rich P. silaceum clade. In order to integrate the new species into the current taxonomic system, we present an illustrated identification key to the worker caste of the three Fijian species. In addition, we provide a detailed description of P. vinaka, as well as species accounts for the other two species, which include diagnoses, taxonomic discussions, specimen photographs, and a distribution map.

With 600 described species, the ant genus Tetramorium represents one of the most species-rich ant radiations. However, much work remains to fully document the hyperdiversity of this remarkable group. Tetramorium, while globally distributed, is thought to have originated in the Afrotropics and is particularly diverse in the Old World. Here, we focus attention on the Tetramorium fauna of India, a region of high biodiversity value and interest for conservation. We overview Tetramorium diversity in India by providing a species list, accounts of all species groups present, an illustrated identification key to Indian Tetramorium species groups and notes on the Indian Tetramorium fauna. Further, we describe two new species, Tetramorium krishnani sp. n. and Tetramorium jarawa sp. n. from the Andaman Islands archipelago and embed them into currently recognized Tetramorium tonganum and Tetramorium inglebyi species groups. We also provide illustrated species level keys for these groups. Along with detailed species descriptions and high-resolution montage images of types, we provide 3D cybertypes of the new species derived from X-ray micro-computed tomography.

This study reviews the taxonomy of the ant genus Nesomyrmex Wheeler, 1910 in the Afrotropical region. Previous revisionary studies are discussed and four species groups are proposed on the basis of external morphology. The N. angulatus group contains seven species that are widely distributed throughout the whole Afrotropical region, with one species also occurring in the Palaearctic and Malagasy regions. The N. cataulacoides group is monotypic, with one morphologically bizarre species found in Equatorial rain forests. The N. humerosus group is also monotypic and occurs in East Africa. The last and by far most species-rich group is the N. simoni group that contains 17 species, all of which are endemic to South Africa. The four groups are defined for the first time for the region, and an illustrated identification key is provided. Furthermore, the N. angulatus group is more thoroughly reviewed. One new species from Mozambique is described, N. inhaca sp. nov., and species accounts for the other six are provided. Also, an illustrated identification key to the species of the N. angulatus group is presented.

We explore the potential of x-ray micro computed tomography (μCT) for the field of ant taxonomy by using it to enhance the descriptions of two remarkable new species of the ant genus Terataner: T. balrog sp. n. and T. nymeria sp. n.. We provide an illustrated worker-based species identification key for all species found on Madagascar, as well as detailed taxonomic descriptions, which include diagnoses, discussions, measurements, natural history data, high-quality montage images and distribution maps for both new species. In addition to conventional morphological examination, we have used virtual reconstructions based on volumetric μCT scanning data for the species descriptions. We also include 3D PDFs, still images of virtual reconstructions, and 3D rotation videos for both holotype workers and one paratype queen. The complete μCT datasets have been made available online (Dryad, https://datadryad.org) and represent the first cybertypes in ants (and insects). We discuss the potential of μCT scanning and critically assess the usefulness of cybertypes for ant taxonomy.

The taxonomy of the genus Proceratium Roger is updated for the Afrotropical region. We give an overview of the genus in the region, provide an illustrated identification key to the three clades (P. arnoldi, P. stictum and P. toschii clades) and revise the P. arnoldi clade. Four new species from the P. arnoldi clade are described as new: P. sokoke sp. n. from Kenya, P. carri sp. n. from Mozambique, and P. nilo sp. n. and P. sali sp. n. from Tanzania. In order to integrate the new species into the existing taxonomic system we present an illustrated identification key to distinguish the seven Afrotropical species of the P. arnoldi clade. In addition, we provide accounts for all members of the P. arnoldi clade including detailed descriptions, diagnoses, taxonomic discussions, distribution data and high quality montage images.

The taxonomy of the Tetramorium naganum, T. plesiarum, T. schaufussii, and T. severini species groups are revised for the Malagasy region. A total of 31 species are treated, of which 22 are newly described and nine redescribed. This increases the richness of the hyper-diverse genus Tetramorium in the Malagasy region to 106 species, which makes it the most species-rich genus in the region. Twenty-nine of the treated species are endemic to Madagascar, one is endemic to the Comoros, and one species is found predominantly in Madagascar but also on the island of Reunion. The T. naganum species group contains five species, which are mainly distributed in the rainforests and montane rainforests of eastern and northern Madagascar: T. alperti sp. n., T. dalek sp. n., T. enkidu sp. n., T. gilgamesh sp. n., and T. naganum Bolton, 1979. The T.plesiarum species group holds five species: T. bressleri sp. n., T. hobbit sp. n., T. gollum sp. n., T. mars sp.n., and T. plesiarum Bolton, 1979. All five are arid-adapted species occurring in the southwest and west of Madagascar. The second-most species-rich group in the region is the T. schaufussii species group with 20 species, most of which inhabit rainforests or montane rainforests of eastern and northern Madagascar. This group includes two species complexes each containing ten species: the T. cognatum complex with the species T. aspis sp. n., T. camelliae sp. n., T. cognatum Bolton, 1979, T. freya sp. n., T. gladius sp. n., T.karthala sp. n., T. myrmidon sp. n., T. proximum Bolton, 1979, T. rumo sp. n., and T. tenuinode sp. n.; and the T. schaufussii complex with the species T. merina sp. n., T. monticola sp. n., T. nassonowii Forel, 1892 stat. n., T. obiwan sp. n., T. pseudogladius sp. n., T. rala sp. n., T. schaufussii Forel, 1891, T. sikorae Forel, 1892 (=T. latior (Santschi, 1926)), T. scutum sp. n., T. xanthogaster Santschi, 1911. The last group treated in this study is the T. severini species group, which contains only the species T. severini (Emery, 1895). This very conspicuous species is widely distributed in the rainforests and montane rainforests of eastern and northern Madagascar. All four groups are fully revised with group diagnoses, illustrated species-level identification keys, and detailed descriptions for all species that include multifocused montage images and distribution maps.

In this study we synonymise the genus Decamorium Forel under Tetramorium Mayr, revise the new T. decem species group by providing a diagnosis of the group, an illustrated identification key to species level, and worker-based species descriptions for all five species, which include diagnoses, discussions, images, and distribution maps. The following species are revised in this study: T. decem Forel, comb. r., T. raptor sp. n., T. uelense Santschi, comb. r., T. ultor Forel, comb. r., stat. r. & stat. n., and T. venator sp. n. In addition, we also designate lectotypes for T. decem, T. uelense, and T. ultor.

The alpha taxonomy of the ant genus Probolomyrmex in Madagascar is revised on the basis of the worker caste. Two new species are described: P. curculiformis sp. n. and P. zahamena sp. n. and the previously known P. tani is re-described. All three species are members of the P. greavesi species group. The species descriptions include diagnoses, taxonomic discussions, high quality montage images, and distribution maps. In addition, we provide an illustrated species level identification key.

In this study we revise the taxonomy of the Tetramorium tortuosum species group members encountered in the Afrotropical region, which we have placed in its own subgroup: the T. capillosum species complex. We re-describe the two previously known species T. capillosum Bolton and T. tabarum Bolton, and describe the new species T. hecate sp. n. The geographic distribution of the three species appears to be restricted to the equatorial rainforests of Central Africa. We provide a diagnosis of the T. capillosum species complex, an illustrated identification key to species level, and worker-based species descriptions, which include diagnoses, discussions, high-quality montage images, and distribution maps. Furthermore, we discuss biogeography and composition of the globally distributed T. tortuosum group.

This study presents a taxonomic update of the Tetramorium weitzeckeri species group. Tetramorium mpala sp. nov. is described from Laikipia, Kenya, and placed in the T. weitzeckeri species complex. In addition, we also provide an illustrated identification key to the three species complexes of the T. weitzeckeri species group, and an updated illustrated identification key to species of this species complex.

Martialinae are pale, eyeless and probably hypogaeic predatory ants. Morphological character sets suggest a close relationship to the ant subfamily Leptanillinae. Recent analyses based on molecular sequence data suggest that Martialinae are the sister group to all extant ants. However, by comparing molecular studies and different reconstruction methods, the position of Martialinae remains ambiguous. While this sister group relationship was well supported by Bayesian partitioned analyses, Maximum Likelihood approaches could not unequivocally resolve the position of Martialinae. By re-analysing a previous published molecular data set, we show that the Maximum Likelihood approach is highly appropriate to resolve deep ant relationships, especially between Leptanillinae, Martialinae and the remaining ant subfamilies. Based on improved alignments, alignment masking, and tree reconstructions with a sufficient number of bootstrap replicates, our results strongly reject a placement of Martialinae at the first split within the ant tree of life. Instead, we suggest that Leptanillinae are a sister group to all other extant ant subfamilies, whereas Martialinae branch off as a second lineage. This assumption is backed by approximately unbiased (AU) tests, additional Bayesian analyses and split networks. Our results demonstrate clear effects of improved alignment approaches, alignment masking and data partitioning. We hope that our study illustrates the importance of thorough, comprehensible phylogenetic analyses using the example of ant relationships.

Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes show that the functionality of tropical forests can be maintained in moderately disturbed forest fragments. Conservation concepts for tropical forests should thus include not only remaining pristine forests but also functionally viable forest remnants.