Gilbert Adum | Kwame Nkrumah University of Science and Technology (original) (raw)

Papers by Gilbert Adum

Logging intensity and the area size continue to increase rapidly each year. As a result, there ar... more Logging intensity and the area size continue to increase rapidly each year. As a result, there are indications that by the year 2050 nearly all tropical forests will be logged. However, to date there is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating impacts of logging on faunal communities. To assess post-logging effects on amphibian assemblages, we conducted a large-scale replicated field study in three Ghanaian selectively logged moist semi-deciduous forests at varying times after timber extraction. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. We also investigated and herein we provide novel data on the ecology of one of the world's rarest frogs, the Giant West African Squeaker Frog, Arthroleptis krokosua.

Ecology and Evolution, Dec 1, 2014

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Reported are the results of an amphibian survey in the district of Daloa and surroundings, in cen... more Reported are the results of an amphibian survey in the district of Daloa and surroundings, in central-western Ivory Coast. Spanning a three year period, we investigated two general areas, each during the rainy and dry seasons. During 62 days of field work 30 anuran species were recorded. The urban environment mainly contained widespread anuran species with preferences for savannah-dominated landscapes and farmbush habitats. The recorded total anuran species richness in the urban area exceeded the diversity in the savannah islands/forest mosaic bordering the Daloa district. This indicates many savannah species may do well in urban situations. However, this higher species richness was only due to one site that possessed particularly diverse amphibian breeding sites, thus illustrating the necessity of maintaining suitable habitats for a wide-range of species. One of the most surprising findings was Kassina schioetzi, a species usually difficult to find in its natural habitat. In Daloa it seems to have successfully adapted to the urban conditions. Although the anuran richness in the Daloa area was relatively low compared to other Ivorian humid savannah areas, it supported an important part of the countries amphibian diversity. Nevertheless the forest habitats, and specifically the forest islands bordering the Daloa district, should be considered sensitive conservation areas.

Ecological Solutions and Evidence, 2021

The version in the Kent Academic Repository may differ from the final published version. Users ar... more The version in the Kent Academic Repository may differ from the final published version. Users are advised to check http://kar.kent.ac.uk for the status of the paper. Users should always cite the published version of record.

Ecology and evolution, 2017

The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems... more The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international effort...

T he Giant West African squeaker frog (Arthroleptis krokosua) is evolutionarily distinct from any... more T he Giant West African squeaker frog (Arthroleptis krokosua) is evolutionarily distinct from any West African amphibian. It differs from all known members of its genus Arthroleptis by its large size, coloration and other morphological characters, such as a very broad head. This unusual frog, may be one of West Africa's rarest and most endangered amphibians. To date, only 16 individuals of the Giant squeaker frog have been observed in spite of four successive years of intense surveys. Unfortunately, the fate of these surviving individuals hangs in the balance due to prevailing threats from mining, logging, farming and the non-native and invasive Devil weed (Chromolaena odorata) at their only remaining home on earth, Sui River Forest Reserve. In the light of the persistent threats, to save the Giant squeaker frog from imminent extinction, we have proposed herein drastic and focused measures including the upgrading of its conservation status from Endangered to Critically Endangered.

Temperature and moisture regimes are the two key variables that determine the distribution, growt... more Temperature and moisture regimes are the two key variables that determine the distribution, growth, productivity, and reproduction of plants and animals on which humans depend for their nutritional and medicinal needs (Alcamo et al. 1998; MEA, 2005; van Vuuren and Pereira, 2006; Hof et al. 2011) (Fig. 1-3). Climate change increasingly alters temperature and moisture regimes to the threat of plants and animals that support humans. Thus, increasingly threatening the very existence of humans (Hof et al., 2010; Hof et al., 2011a and Hof et al., 2011b). Current projections do not point to this trend changing in subsequent centuries, based on UNFCCC's report that the average temperature of the earth's surface has risen by 0.74°C since the late 1800s, and is expected to increase by another 1.8°C to 4°C by the year 2100 (UNFCCC, 2011) (Fig. 1). Rising temperature is emerging as the one single variable that spells the most uncertainty for human survival on earth ever since anthropoge...

Ecology and evolution, 2014

Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habit... more Biodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of…

PLoS ONE, 2013

A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium de... more A putative driver of global amphibian decline is the panzootic chytrid fungus Batrachochytrium dendrobatidis (Bd). While Bd has been documented across continental Africa, its distribution in West Africa remains ambiguous. We tested 793 West African amphibians (one caecilian and 61 anuran species) for the presence of Bd. The samples originated from seven West African countries-Bénin, Burkina Faso, Cô te d'Ivoire, Ghana, Guinea, Liberia, Sierra Leone-and were collected from a variety of habitats, ranging from lowland rainforests to montane forests, montane grasslands to humid and dry lowland savannahs. The species investigated comprised various life-history strategies, but we focused particularly on aquatic and riparian species. We used diagnostic PCR to screen 656 specimen swabs and histology to analyse 137 specimen toe tips. All samples tested negative for Bd, including a widespread habitat generalist Hoplobatrachus occipitalis which is intensively traded on the West African food market and thus could be a potential dispersal agent for Bd. Continental fine-grained (30 arc seconds) environmental niche models suggest that Bd should have a broad distribution across West Africa that includes most of the regions and habitats that we surveyed. The surprising apparent absence of Bd in West Africa indicates that the Dahomey Gap may have acted as a natural barrier. Herein we highlight the importance of this Bd-free region of the African continentespecially for the long-term conservation of several threatened species depending on fast flowing forest streams (Conraua alleni (''Vulnerable'') and Petropedetes natator (''Near Threatened'')) as well as the ''Critically Endangered'' viviparous toad endemic to the montane grasslands of Mount Nimba (Nimbaphrynoides occidentalis).

Biotropica, 2012

Making generalizations about the impact of commercial selective logging on biodiversity has so fa... more Making generalizations about the impact of commercial selective logging on biodiversity has so far remained elusive. Species responses to logging depend on a number of factors, many of which have not been studied in detail. These factors may include the natural forest conditions (forest types) under which logging impacts are investigated; but this question has so far remained unexamined. In a largescale replicate study we aimed at clarifying the relationship between logging and forest types on leaf litter frogs. We contrast three distinct and naturally occurring forest types, including wet evergreen, moist evergreen and semi-deciduous forests. Selectively logged sites were compared with primary forest sites for each forest type. We found that the response of frog communities to logging varies in different forest types. In the wet evergreen forest, richness was higher in logged forest than primary forest, while diversity measures were not different between logged and primary forest habitats. In the moist evergreen, richness and diversity were higher in selectively logged areas compared with primary forest habitats. In the semi-deciduous, logged forests were characterized by drastic loss of forest specialists, reduced richness, and diversity. These results indicate that the net effect of logging varies with respect to forest type. Forest types that are characterized by adverse climatic conditions (i.e., low rainfall and protracted dry seasons) are more likely to produce negative effects on leaf litter anuran communities. For comparisons of the impact of logging on species to be effective, future research must endeavor to include details of forest type.

Conservation Biology, 2013

There is a lack of quantitative information on the effectiveness of selective-logging practices i... more There is a lack of quantitative information on the effectiveness of selective-logging practices in ameliorating effects of logging on faunal communities. We conducted a large-scale replicated field study in 3 selectively logged moist semideciduous forests in West Africa at varying times after timber extraction to assess post logging effects on amphibian assemblages. Specifically, we assessed whether the diversity, abundance, and assemblage composition of amphibians changed over time for forest-dependent species and those tolerant of forest disturbance. In 2009, we sampled amphibians in 3 forests (total of 48 study plots, each 2 ha) in southwestern Ghana. In each forest, we established plots in undisturbed forest, recently logged forest, and forest logged 10 and 20 years previously. Logging intensity was constant across sites with 3 trees/ha removed. Recently logged forests supported substantially more species than unlogged forests. This was due to an influx of disturbance-tolerant species after logging. Simultaneously Simpson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s index decreased, with increased in dominance of a few species. As time since logging increased richness of disturbance-tolerant species decreased until 10 years after logging when their composition was indistinguishable from unlogged forests. Simpson&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s index increased with time since logging and was indistinguishable from unlogged forest 20 years after logging. Forest specialists decreased after logging and recovered slowly. However, after 20 years amphibian assemblages had returned to a state indistinguishable from that of undisturbed forest in both abundance and composition. These results demonstrate that even with low-intensity logging (≤3 trees/ha) a minimum 20-year rotation of logging is required for effective conservation of amphibian assemblages in moist semideciduous forests. Furthermore, remnant patches of intact forests retained in the landscape and the presence of permanent brooks may aid in the effective recovery of amphibian assemblages.

Journal for Nature Conservation

A Thesis submitted to the Department of Wildlife and Range Management, Kwame Nkrumah University o... more A Thesis submitted to the Department of Wildlife and Range Management, Kwame Nkrumah University of Science and Technology in partial fulfillment of the requirements for the degree of Master of Philosophy, 2014

This dataset contains site-level summaries of more than 1.6 million samples from 78 countries rep... more This dataset contains site-level summaries of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The underlying database is being assembled as part of the [PREDICTS project](http://www.predicts.org.uk) - Projecting Responses of Ecological Diversity In Changing Terrestrial Systems. A complete description of the data is given in [http://dx.doi.org/10.1002/ece3.1303](http://dx.doi.org/10.1002/ece3.1303).

A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and ... more A dataset of 3,250,404 measurements, collated from 26,114 sampling locations in 94 countries and representing 47,044 species. The data were collated from 480 existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database was assembled as part of the PREDICTS project - Projecting Responses of Ecological Diversity In Changing Terrestrial Systems; [www.predicts.org.uk](http://www.predicts.org.uk).\r\n\r\nThe taxonomic identifications provided in the original data sets are those determined at the time of the original research, and so will not reflect subsequent taxonomic changes.\r\n\r\nThis dataset is described in [10.1002/ece3.2579](http://dx.doi.org/10.1002/ece3.2579). A description of the way that this dataset was assembled is given in [10.1002/ece3.1303](http://dx.doi.org/10.1002/ece3.1303).\r\n\r\n* `columns.csv`: Description of data extract columns\r\n* `database...

Ecological Solutions and Evidence, 2020

To be effective, the next generation of conservation practitioners and managers need to be critic... more To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence-based decisions and of the value of evidence synthesis. If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an effective contribution to conservation practice. To help overcome this problem we have created open access online teaching materials in multiple languages that are stored in Applied Ecological Resources. So far, 117 educators from 23 countries have acknowledged the importance of this and are already teaching or about to teach skills in appraising or using evidence in conservation decision-making. This includes 145 undergraduate, postgraduate or professional development courses. We call for wider teaching of the tools and skills that facilitate evidence-based conservation and also suggest that providing online teaching materials in multiple lang...

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems... more The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international effort...