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Marshall CAM, Dabo J, Mensah M, Ekpe P, Hawthorne WD. Implications for conservation assessment from flux in the botanical record over 20 years in southwest Ghana. Ecol Evol 2023; 13:e9775. [PMID: 36713481 PMCID: PMC9873867 DOI: 10.1002/ece3.9775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/05/2023] [Accepted: 01/11/2023] [Indexed: 01/26/2023] Open
Abstract
At best, conservation decisions can only be made using the data available at the time. For plants and especially in the tropics, natural history collections remain the best available baseline information upon which to base conservation assessments, in spite of well-documented limitations in their taxonomic, geographic, and temporal coverage. We explore the extent to which changes to the plant biological record over 20 years have changed our conception of the conservation importance of 931 plant taxa, and 114 vegetation samples, recorded in forest reserves of the southwest Ghana biodiversity hotspot. 36% of species-level assessments changed as a result of new distribution data. 12% of species accepted in 2016 had no assessment in 1996: of those, 20% are new species publications, 60% are new records for SW Ghana, and 20% are taxonomic resolutions. Apparent species ranges have increased over time as new records are made, but new species publications are overwhelmingly of globally rare species, keeping the balance of perceived rarity in the flora constant over 20 years. Thus, in spite of considerable flux at the species record level, range size rarity scores calculated for 114 vegetation samples of the reserves in 1996 and 2016 are highly correlated with each other: r(112) = 0.84, p < .0005, and showed no difference in mean score over 20 years: paired t(113) = -0.482, p = .631. This consistency in results at the area level allows for worthwhile conservation priority setting over time, and we argue is the better course of action than taking no action at all.
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Affiliation(s)
| | | | | | - Patrick Ekpe
- Ghana Herbarium, Department of Plant & Environmental BiologyUniversity of GhanaLegonGhana
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Marshall CAM, Dabo J, Mensah M, Ekpe P, Kpadehyea JT, Haba OO, Bilivogui D, Hawthorne WD. Predictors of plant endemism in two west African forest hotspots. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.980660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Centres of endemism have been much studied by biogeographers, ecologists, and evolutionary theorists, and are considered conservation priorities. It is therefore important to understand the ecological traits of restricted range taxa, and the landscape-scale drivers of high endemism. Here, we investigate correlates of floristic endemism within two of west Africa’s forest biodiversity hotspots at local scale. We assembled distribution data for 1,042 vascular plant taxa from 114 sample locations within forest reserves of south west Ghana, and for 1,735 vascular plant taxa from 454 sample locations within the Nimba Mountains (Liberia and Guinea). A quantitative index of global endemism called the Genetic Heat Index was modelled linearly. We tested the significance of modern climate, altitude and disturbance as factors predicting endemism rates in these two forest reserves. Annual rainfall was significantly and positively related to endemism rates in both south west Ghana and the Nimba Mountains. Altitude was a significant predictor of endemism rates in the Nimba Mountains, with a quadratic relationship highlighting particularly high endemism over 1,000 m. Local topography rather than altitude was a significant predictor or endemism in SW Ghana, where altitude varies less. Areas of high rainfall and high altitude are geographically restricted across the western African forests, acting as edaphic islands driving spatial isolation. Disturbed vegetation samples had lower endemism rates than undisturbed samples in both Nimba and SW Ghana, and overall pioneer species had wider areas of occupancy than shade-bearing species. Endemism rates increased slightly with each year following clearance. Disturbance thus creates and maintains vegetation types which support a lower proportion of globally rare species in the two biodiversity hotspots surveyed. From the point of view of the conservation of globally rare plants, it is important to keep additional disturbance in the south west Ghana hotspot, particularly Ankasa, to a minimum, as is the current practice, and in the Nimba mountains to establish community forests which may be left relatively undisturbed amid farming and mining activities.
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Ofosu‐Bamfo B, Addo‐Fordjour P, Belford EJ. Edge disturbance shapes liana diversity and abundance but not liana‐tree interaction network patterns in moist semi‐deciduous forests, Ghana. Ecol Evol 2022; 12:e8585. [PMID: 35371433 PMCID: PMC8859495 DOI: 10.1002/ece3.8585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 01/05/2022] [Accepted: 01/11/2022] [Indexed: 11/10/2022] Open
Abstract
Edge disturbance can drive liana community changes and alter liana‐tree interaction networks, with ramifications for forest functioning. Understanding edge effects on liana community structure and liana‐tree interactions is therefore essential for forest management and conservation. We evaluated the response patterns of liana community structure and liana‐tree interaction structure to forest edge in two moist semi‐deciduous forests in Ghana (Asenanyo and Suhuma Forest Reserves: AFR and SFR, respectively). Liana community structure and liana‐tree interactions were assessed in 24 50 × 50 m randomly located plots in three forest sites (edge, interior and deep‐interior) established at 0–50 m, 200 m and 400 m from edge. Edge effects positively and negatively influenced liana diversity in forest edges of AFR and SFR, respectively. There was a positive influence of edge disturbance on liana abundance in both forests. We observed anti‐nested structure in all the liana‐tree networks in AFR, while no nestedness was observed in the networks in SFR. The networks in both forests were less connected, and thus more modular and specialised than their null models. Many liana and tree species were specialised, with specialisation tending to be symmetrical. The plant species played different roles in relation to modularity. Most of the species acted as peripherals (specialists), with only a few species having structural importance to the networks. The latter species group consisted of connectors (generalists) and hubs (highly connected generalists). Some of the species showed consistency in their roles across the sites, while the roles of other species changed. Generally, liana species co‐occurred randomly on tree species in all the forest sites, except edge site in AFR where lianas showed positive co‐occurrence. Our findings deepen our understanding of the response of liana communities and liana‐tree interactions to forest edge disturbance, which are useful for managing forest edge.
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Affiliation(s)
- Bismark Ofosu‐Bamfo
- Department of Basic and Applied Biology School of Sciences University of Energy and Natural Resources Sunyani Ghana
| | - Patrick Addo‐Fordjour
- Department of Theoretical and Applied Biology Faculty of Biosciences College of Science Kwame Nkrumah University of Science and Technology Kumasi Ghana
| | - Ebenezer J.D. Belford
- Department of Theoretical and Applied Biology Faculty of Biosciences College of Science Kwame Nkrumah University of Science and Technology Kumasi Ghana
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Gyamfi E, Derkyi MAA, Brobbey LK. Insights, motives, and means of overcoming forest offenses in Ghana's forestry sector: The case of the Bibiani Forest District. SCIENTIFIC AFRICAN 2021. [DOI: 10.1016/j.sciaf.2021.e00962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Acheampong EB, Manu G, Asante WA, Kyere B. The role of urban tropical botanic gardens in biodiversity conservation: An example from the KNUST botanic garden in Kumasi, Ghana. Biotropica 2021. [DOI: 10.1111/btp.12950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eric Boateng Acheampong
- Department of Land, Environment, Agriculture, and Forestry University of Padova Legnaro Italy
| | - Gordon Manu
- Institute of International Forestry and Forest Products Technical University of Dresden Dresden Germany
- Department of Silviculture and Forest Management Kwame Nkrumah University of Science and Technology (KNUST) Kumasi Ghana
| | - Winston Adams Asante
- Department of Silviculture and Forest Management Kwame Nkrumah University of Science and Technology (KNUST) Kumasi Ghana
| | - Boateng Kyere
- Department of Silviculture and Forest Management Kwame Nkrumah University of Science and Technology (KNUST) Kumasi Ghana
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6
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Successional dynamics shape tree diversity in evergreen forests of Côte d’Ivoire, West Africa. JOURNAL OF TROPICAL ECOLOGY 2020. [DOI: 10.1017/s0266467420000152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractDisturbances and successional dynamics shape the composition of tree communities, but data remain scarce for tropical forests of West Africa. We assessed the imprint of past disturbances on the composition of evergreen forests in an Ivorian National Park. We hypothesized that (i) Pioneer indices (PI) based on the relative proportion of pioneer and non-pioneer trees relate to changing floristic composition due to successional dynamics, (ii) local community richness peaks at an intermediate value of PI under the Intermediate Disturbance Hypothesis (IDH) and (iii) early successional communities have higher beta diversity due to erratic founder effects. We performed a Correspondence Analysis of tree composition of 38 plots and examined how the main components of floristic variation related to environmental factors and PI. In addition, we tested the relationship between PI, local richness and beta diversity. The variation of PI better explained the main components of floristic variation than abiotic environmental variation, supporting a primary role of successional dynamics in shaping tree communities. We found a peak of richness at intermediate values of PI, supporting the IDH, with a mixture and earlier and later-successional species and more even abundances. The communities were very diverse and included many endemics and rare species. The results underline that the composition of early successional forests greatly varies depending on chance colonization events, while more similar old-growth communities are eventually observed after several decades. The findings should guide management practices for forest restoration, and for conservation of endangered species depending on their successional status.
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Afromontane Forest Diversity and the Role of Grassland-Forest Transition in Tree Species Distribution. DIVERSITY 2020. [DOI: 10.3390/d12010030] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Local factors can play an important role in defining tree species distributions in species rich tropical forests. To what extent the same applies to relatively small, species poor West African montane forests is unknown. Here, forests survive in a grassland matrix and fire has played a key role in their spatial and temporal dynamics since the Miocene. To what extent these dynamics influence local species distributions, as compared with other environmental variables such as altitude and moisture remain unknown. Here, we use data from the 20.28 ha montane forest plot in Ngel Nyaki Forest Reserve, South-East Nigeria to explore these questions. The plot features a gradient from grassland to core forest, with significant edges. Within the plot, we determined tree stand structure and species diversity and identified all trees ≥1 cm in diameter. We recorded species guild (pioneer vs. shade tolerant), seed size, and dispersal mode. We analyzed and identified to what extent species showed a preference for forest edges/grasslands or core forest. Similarly, we looked for associations with elevation, distance to streams and forest versus grassland. We recorded 41,031 individuals belonging to 105 morphospecies in 87 genera and 47 families. Around 40% of all tree species, and 50% of the abundant species, showed a clear preference for either the edge/grassland habitat or the forest core. However, we found no obvious association between species guild, seed size or dispersal mode, and distance to edge, so what leads to this sorting remains unclear. Few species distributions were influenced by distance to streams or altitude.
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Amissah L, Mohren GMJ, Kyereh B, Agyeman VK, Poorter L. Rainfall seasonality and drought performance shape the distribution of tropical tree species in Ghana. Ecol Evol 2018; 8:8582-8597. [PMID: 30250725 PMCID: PMC6144999 DOI: 10.1002/ece3.4384] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 06/04/2018] [Accepted: 06/17/2018] [Indexed: 11/07/2022] Open
Abstract
Tree species distribution in lowland tropical forests is strongly associated with rainfall amount and distribution. Not only plant water availability, but also irradiance, soil fertility, and pest pressure covary along rainfall gradients. To assess the role of water availability in shaping species distribution, we carried out a reciprocal transplanting experiment in gaps in a dry and a wet forest site in Ghana, using 2,670 seedlings of 23 tree species belonging to three contrasting rainfall distributions groups (dry species, ubiquitous species, and wet species). We evaluated seasonal patterns in climatic conditions, seedling physiology and performance (survival and growth) over a 2-year period and related seedling performance to species distribution along Ghana's rainfall gradient. The dry forest site had, compared to the wet forest, higher irradiance, and soil nutrient availability and experienced stronger atmospheric drought (2.0 vs. 0.6 kPa vapor pressure deficit) and reduced soil water potential (-5.0 vs. -0.6 MPa soil water potential) during the dry season. In both forests, dry species showed significantly higher stomatal conductance and lower leaf water potential, than wet species, and in the dry forest, dry species also realized higher drought survival and growth rate than wet species. Dry species are therefore more drought tolerant, and unlike the wet forest species, they achieve a home advantage. Species drought performance in the dry forest relative to the wet forest significantly predicted species position on the rainfall gradient in Ghana, indicating that the ability to grow and survive better in dry forests and during dry seasons may allow species to occur in low rainfall areas. Drought is therefore an important environmental filter that influences forest composition and dynamics. Currently, many tropical forests experience increase in frequency and intensity of droughts, and our results suggest that this may lead to reduction in tree productivity and shifts in species distribution.
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Affiliation(s)
- Lucy Amissah
- Council for Scientific and Industrial Research‐Forestry Research Institute of GhanaKumasiGhana
- Forest Ecology and Forest Management GroupWageningen University & ResearchWageningenThe Netherlands
| | - Godefridus M. J. Mohren
- Forest Ecology and Forest Management GroupWageningen University & ResearchWageningenThe Netherlands
| | - Boateng Kyereh
- College of Agriculture and Natural ResourcesKwame Nkrumah University of Science and TechnologyKumasiGhana
| | - Victor K. Agyeman
- Council for Scientific and Industrial Research‐Forestry Research Institute of GhanaKumasiGhana
| | - Lourens Poorter
- Forest Ecology and Forest Management GroupWageningen University & ResearchWageningenThe Netherlands
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Guitet S, Sabatier D, Brunaux O, Couteron P, Denis T, Freycon V, Gonzalez S, Hérault B, Jaouen G, Molino JF, Pélissier R, Richard-Hansen C, Vincent G. Disturbance Regimes Drive The Diversity of Regional Floristic Pools Across Guianan Rainforest Landscapes. Sci Rep 2018; 8:3872. [PMID: 29497098 PMCID: PMC5832822 DOI: 10.1038/s41598-018-22209-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 02/19/2018] [Indexed: 11/09/2022] Open
Abstract
Disturbances control rainforest dynamics, and, according to the intermediate disturbance hypothesis (IDH), disturbance regime is a key driver of local diversity. Variations in disturbance regimes and their consequences on regional diversity at broad spatiotemporal scales are still poorly understood. Using multidisciplinary large-scale inventories and LiDAR acquisitions, we developed a robust indicator of disturbance regimes based on the frequency of a few early successional and widely distributed pioneer species. We demonstrate at the landscape scale that tree-species diversity and disturbance regimes vary with climate and relief. Significant relationships between the disturbance indicator, tree-species diversity and soil phosphorus content agree with the hypothesis that rainforest diversity is controlled both by disturbance regimes and long-term ecosystem stability. These effects explain the broad-scale patterns of floristic diversity observed between landscapes. In fact, species-rich forests in highlands, which have benefited from long-term stability combined with a moderate and regular regime of local disturbances, contrast with less diversified forests on recently shaped lowlands, which have undergone more recent changes and irregular dynamics. These results suggest that taking the current disturbance regime into account and including geomorphological stratifications in climate-vegetation models may be an effective way to improve the prediction of changes in species diversity under climate change.
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Affiliation(s)
- Stéphane Guitet
- AMAP, IRD, Cirad, CNRS, INRA, Université de Montpellier, Montpellier, France.
- ONF Guyane, Département Recherche et Développement, Réserve de Montabo, 97307, Cayenne, French Guiana.
| | - Daniel Sabatier
- AMAP, IRD, Cirad, CNRS, INRA, Université de Montpellier, Montpellier, France
| | - Olivier Brunaux
- ONF Guyane, Département Recherche et Développement, Réserve de Montabo, 97307, Cayenne, French Guiana
| | - Pierre Couteron
- AMAP, IRD, Cirad, CNRS, INRA, Université de Montpellier, Montpellier, France
| | - Thomas Denis
- ONCFS, Direction de la Recherche et de l'Expertise, Campus agronomique, 97379, Kourou, French Guiana
| | - Vincent Freycon
- CIRAD, Forêts et Sociétés, Campus de Baillarguet, 34398, Montpellier, France
| | - Sophie Gonzalez
- IRD, Amap, Herbier de Cayenne, 97307, Cayenne, French Guiana
| | | | | | | | - Raphaël Pélissier
- AMAP, IRD, Cirad, CNRS, INRA, Université de Montpellier, Montpellier, France
| | - Cécile Richard-Hansen
- ONCFS, Direction de la Recherche et de l'Expertise, Campus agronomique, 97379, Kourou, French Guiana
| | - Grégoire Vincent
- AMAP, IRD, Cirad, CNRS, INRA, Université de Montpellier, Montpellier, France
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Marshall CAM, Wieringa JJ, Hawthorne WD. Bioquality Hotspots in the Tropical African Flora. Curr Biol 2016; 26:3214-3219. [PMID: 27839969 DOI: 10.1016/j.cub.2016.09.045] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 09/17/2016] [Accepted: 09/23/2016] [Indexed: 11/26/2022]
Abstract
Identifying areas of high biodiversity is an established way to prioritize areas for conservation [1-3], but global approaches have been criticized for failing to render global biodiversity value at a scale suitable for local management [4-6]. We assembled 3.1 million species distribution records for 40,401 vascular plant species of tropical Africa from sources including plot data, herbarium databases, checklists, and the Global Biodiversity Information Facility (GBIF) and cleaned the records for geographic accuracy and taxonomic consistency. We summarized the global ranges of tropical African plant species into four weighted categories of global rarity called Stars. We applied the Star weights to summaries of species distribution data at fine resolutions to map the bioquality (range-restricted global endemism) of areas [7]. We generated confidence intervals around bioquality scores to account for the remaining uncertainty in the species inventory. We confirm the broad significance of the Horn of Africa, Guinean forests, coastal forests of East Africa, and Afromontane regions for plant biodiversity but also reveal the variation in bioquality within these broad regions and others, particularly at local scales. Our framework offers practitioners a quantitative, scalable, and replicable approach for measuring the irreplaceability of particular local areas for global biodiversity conservation and comparing those areas within their global and regional context.
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Affiliation(s)
- Cicely A M Marshall
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
| | - Jan J Wieringa
- Naturalis Biodiversity Center, National Herbarium of the Netherlands, Darwinweg 2, 2333 CR Leiden, the Netherlands
| | - William D Hawthorne
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK
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11
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Gogarten JF, Jacob AL, Ghai RR, Rothman JM, Twinomugisha D, Wasserman MD, Chapman CA. Group Size Dynamics over 15+ Years in an African Forest Primate Community. Biotropica 2014. [DOI: 10.1111/btp.12177] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jan F. Gogarten
- Department of Biology; McGill University; 1205 Docteur Penfield Montreal QC Canada H3A 1B1
- Department of Primatology; Max Planck Institute for Evolutionary Anthropology; Deutscher Platz 6 Leipzig 04103 Germany
- Research Group Epidemiology of Highly Pathogenic Microorganisms; Robert Koch Institut; Nordufer 20 13353 Berlin Germany
| | - Aerin L. Jacob
- Department of Biology; McGill University; 1205 Docteur Penfield Montreal QC Canada H3A 1B1
- Department of Geography; University of Victoria; PO Box 3060 STN CSC Victoria BC Canada V8W 3R4
| | - Ria R. Ghai
- Department of Biology; McGill University; 1205 Docteur Penfield Montreal QC Canada H3A 1B1
| | - Jessica M. Rothman
- Department of Anthropology; Hunter College of the City University of New York, and New York Consortium in Evolutionary Primatology; 695 Park Avenue New York NY 10065 U.S.A
| | | | - Michael D. Wasserman
- School of Environmental Science & Policy; St. Edward's University; 3001 South Congress Ave. Austin TX 78704-6489 U.S.A
| | - Colin A. Chapman
- Makerere University Biological Field Station; PO Box 967 Fort Portal Uganda
- McGill School of Environment and Department of Anthropology; McGill University; Montreal QC Canada H3A 2T7
- The Wildlife Conservation Society; 2300 Southern Blvd Bronx NY 10640 U.S.A
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12
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Rainfall and temperature affect tree species distribution in Ghana. JOURNAL OF TROPICAL ECOLOGY 2014. [DOI: 10.1017/s026646741400025x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract:We evaluated the relative importance of annual rainfall, temperature and their seasonality to tree species distribution in Ghana. We used species presence/absence data from 2505 1-ha plots systematically distributed over Ghana's forests. Logistic regression was used to determine species responses to four climatic variables generated from the Worldclim database. The distribution of 95% of 20 species was significantly associated with annual rainfall, 60% with rainfall seasonality, 45% with isothermality and 40% with temperature seasonality. Annual rainfall explained on average most of the variation (17%, range = 0.5–52%) in species distribution, followed by rainfall seasonality 5% (range = 0.5–27%), isothermality 4% (range = 0.8–24%) and temperature seasonality 1% (range = 0.4–4.5%). Our results suggest that, out of the climatic variables investigated, rainfall is the main factor determining tree species distribution in Ghana; temperature also influences the distribution of a number of species, although it explains much less of the variation. The reduction in annual rainfall that prevailing climate-change scenarios predict for the region will result in a shift in the distribution of most species, whereas the predicted increase in temperature variation is likely to have little effect.
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Poorter L, McNeil A, Hurtado VH, Prins HHT, Putz FE. Bark traits and life-history strategies of tropical dry- and moist forest trees. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12158] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lourens Poorter
- Forest Ecology and Forest Management Group; Wageningen University; P.O. Box 47 6700 AA Wageningen The Netherlands
- Instituto Boliviano de Investigación Forestal (IBIF); P.O. Box 6204 Santa Cruz Bolivia
- Resource Ecology Group; Wageningen University; P.O. Box 47 6700 AA Wageningen the Netherlands
| | - Adam McNeil
- Instituto Boliviano de Investigación Forestal (IBIF); P.O. Box 6204 Santa Cruz Bolivia
- School of Natural Sciences & Mathematics; Ferrum College; 212 Garber Hall Ferrum VA 24088 USA
| | - Victor-Hugo Hurtado
- Instituto Boliviano de Investigación Forestal (IBIF); P.O. Box 6204 Santa Cruz Bolivia
| | - Herbert H. T. Prins
- Resource Ecology Group; Wageningen University; P.O. Box 47 6700 AA Wageningen the Netherlands
- School of Biological and Conservation Sciences; University of KwaZulu-Natal; ZA-3209 Scottsville South Africa
| | - Francis E. Putz
- Department of Biology; University of Florida; P.O. Box 118526 Gainesville FL 32611 USA
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Factors Influencing Liana Species Richness and Structure following Anthropogenic Disturbance in a Tropical Forest, Ghana. ACTA ACUST UNITED AC 2013. [DOI: 10.1155/2013/920370] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study was conducted to determine the factors that influenced liana species richness and structure in forests of different disturbance intensities (high, moderate, and low disturbance forests) in the Southern Scarp Forest Reserve, Ghana. Within each forest, lianas (dbh cm) were enumerated in six m2 plots located along transects. Soil physicochemical properties and forest structure were determined within the plots. Liana species richness and abundance were significantly lower in the high disturbance forest () whereas basal area was significantly higher in the low disturbance forest (). Tree abundance and dbh significantly predicted liana species richness and structure in the study (). On the basis of the importance value index, three main liana communities, each corresponding with a forest type, were identified. Stepwise multiple regression analysis revealed that exchangeable magnesium and calcium, and total exchangeable bases were the main soil variables that affected liana species richness. Liana structure was influenced by the above-mentioned soil variables as well as exchangeable potassium and sodium, and pH. The present study has demonstrated that changes in liana species richness and structure following human disturbance may be due to variations in soil properties and forest structure.
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Robiglio V, Sinclair F. Maintaining the conservation value of shifting cultivation landscapes requires spatially explicit interventions. ENVIRONMENTAL MANAGEMENT 2011; 48:289-306. [PMID: 21336849 DOI: 10.1007/s00267-010-9611-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 12/28/2010] [Indexed: 05/30/2023]
Abstract
Fallow vegetation within landscapes dominated by shifting cultivation represents a woody species pool of critical importance with considerable potential for biodiversity conservation. Here, through the analysis of factors that influence the early stages of fallow vegetation regrowth in two contrasting forest margin landscapes in Southern Cameroon, we assessed the impact of current trends of land use intensification and expansion of the cultivated areas, upon the conservation potential of shifting cultivation landscapes. We combined the analysis of plot and landscape scale factors and identified a complex set of variables that influence fallow regrowth processes in particular the characteristics of the agricultural matrix and the distance from forest. Overall we observed a decline in the fallow species pool, with composition becoming increasingly dominated by species adapted to recurrent disturbance. It is clear that without intervention and if present intensification trends continue, the potential of fallow vegetation to contribute to biodiversity conservation declines because of a reduced capacity, (1) to recover forest vegetation with anything like its original species composition, (2) to connect less disturbed forest patches for forest dependent organisms. Strategies to combat biodiversity loss, including promotion of agroforestry practices and the increase of old secondary forest cover, will need not only to operate at a landscape scale but also to be spatially explicit, reflecting the spatial pattern of species reservoirs and dispersal strategies and human usage across landscapes.
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Affiliation(s)
- Valentina Robiglio
- International Institute for Tropical Agriculture, Nkolbisson Yaounde, BP 2008, Cameroon.
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