Habitats naturels des écosystèmes du Cameroun

Dans le cadre de la Stratégie et le Plan d’Action National sur la Biodiversité, afin d’améliorer la compréhension et la documentation des écosystèmes, l’objectif de cette étude est l’identification et la cartographie les habitats naturels du Cameroun. Les matériels utilisés ont été les référentiels constitués de la classification standard des habitats de l’Union Internationale pour la Conservation de la Nature (UICN) pour la nomenclature, et les cartes phytogéographique, du relief et de l’hydrographie pour les habitats terrestres et aquatiques pour les cartes thématiques respectivement. Les méthodes ont été d’adapter la classification de l’UICN à celle des phytochories pour la nomenclature ; et la fabrique des délimitations sur des fonds de cartes existantes pour la cartographie. Les résultats obtenus sont la reconnaissance de différents types d’habitats naturels du Cameroun : trois cartes qui présentent les délimitations des habitats naturels terrestres par écosystème, et aquatiques par bassin hydrographique ; et que la répartition des habitats terrestres est corrélée avec la nature des sols. Ces données complètent les connaissances sur les écosystèmes et sont un outil pour l’application de l’approche par écosystème. C’est une contribution à la cartographie des milieux naturels du Cameroun en rapport avec la gestion durable de la biodiversité.Mots clés. Cameroun, habitat naturel, écosystème, phytochorie, hydrographie, cartographie. English Title: Natural habitats of the ecosystems of CameroonWithin the framework of the National Biodiversity Strategy and Action Plan, to improve the understanding and documentation of the ecosystems, the objectives of this study are the identification and the mapping of natural habitats of Cameroon. The materials used have been the referentials made up of the classification standard scheme of the habitats of the International Union for the Conservation of Nature (IUCN) for nomenclature, and the phytogeographic, relief and hydrography maps for terrestrial and aquatic habitats respectively. The methods have been to adapt the IUCN classification to that of phytochoria for nomenclature; and fabricate boundaries on existing maps for cartography. The results obtain are the recognition of different natural habitat types in Cameroon: three maps showing the boundaries of terrestrial natural habitats by ecosystem, and aquatic by watershed; and that the distribution of terrestrial habitats is correlated with the nature of the soil. These data improve the knowledge on ecosystems, and are an instrument for the implementation of the ecosystem approach. It’s a contribution to the mapping of natural environments of Cameroon in relation with the sustainable management of the biodiversity.Keywords: Cameroon, natural habitat, ecosystem, phytochoria, hydrography, mapping

Download Full-text

Determining Plant Diversity within Interconnected Natural Habitat Remnants (Ecological Network) in an Agricultural Landscape: A Matter of Sampling Design?

Diversity ◽

10.3390/d14010012 ◽

2021 ◽

Vol 14 (1) ◽

pp. 12

Author(s):

Francesco Liccari ◽

Maurizia Sigura ◽

Enrico Tordoni ◽

Francesco Boscutti ◽

Giovanni Bacaro

Keyword(s):

Plant Communities ◽

Plant Diversity ◽

Sampling Design ◽

Agricultural Landscape ◽

Natural Habitat ◽

Vascular Plant ◽

Habitat Types ◽

Natural Habitats ◽

Pilot Studies ◽

Integrated Method

In intensively used and human-modified landscapes, biodiversity is often confined to remnants of natural habitats. Thus, identifying ecological networks (ENs) necessary to connect these patches and maintain high levels of biodiversity, not only for conservation but also for the effective management of the landscape, is required. However, ENs are often defined without a clear a-priori evaluation of their biodiversity and are seldom even monitored after their establishment. The objective of this study was to determine the adequate number of replicates to effectively characterize biodiversity content of natural habitats within the nodes of an EN in north-eastern Italy, based on vascular plant diversity. Plant communities within habitat types of the EN’s nodes were sampled through a hierarchical sampling design, evaluating both species richness and compositional dissimilarity. We developed an integrated method, consisting of multivariate measures of precision (MultSE), rarefaction curves and diversity partitioning approaches, which was applied to estimate the minimum number of replicates needed to characterize plant communities within the EN, evaluating also how the proposed optimization in sampling size affected the estimations of the characteristics of habitat types and nodes of the EN. We observed that reducing the total sampled replicates by 85.5% resulted to sufficiently characterize plant diversity of the whole EN, and by 72.5% to exhaustively distinguish plant communities among habitat types. This integrated method helped to fill the gap regarding the data collection to monitor biodiversity content within existing ENs, considering temporal and economic resources. We therefore suggest the use of this quantitative approach, based on probabilistic sampling, to conduct pilot studies in the context of ENs design and monitoring, and in general for habitat monitoring.

Download Full-text

Naturalization of European plants on other continents: The role of donor habitats

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1705487114 ◽

2017 ◽

Vol 114 (52) ◽

pp. 13756-13761 ◽

Cited By ~ 27

Author(s):

Veronika Kalusová ◽

Milan Chytrý ◽

Mark van Kleunen ◽

Ladislav Mucina ◽

Wayne Dawson ◽

...

Keyword(s):

Plant Species ◽

Natural Habitat ◽

Vascular Plant ◽

Arable Land ◽

Plant Invasions ◽

Habitat Types ◽

Natural Habitats ◽

Species Association ◽

Alien Flora

The success of European plant species as aliens worldwide is thought to reflect their association with human-disturbed environments. However, an explicit test including all human-made, seminatural and natural habitat types of Europe, and their contributions as donor habitats of naturalized species to the rest of the globe, has been missing. Here we combine two databases, the European Vegetation Checklist and the Global Naturalized Alien Flora, to assess how human influence in European habitats affects the probability of naturalization of their plant species on other continents. A total of 9,875 native European vascular plant species were assigned to 39 European habitat types; of these, 2,550 species have become naturalized somewhere in the world. Species that occur in both human-made habitats and seminatural or natural habitats in Europe have the highest probability of naturalization (64.7% and 64.5% of them have naturalized). Species associated only with human-made or seminatural habitats still have a significantly higher probability of becoming naturalized (41.7% and 28.6%, respectively) than species confined to natural habitats (19.4%). Species associated with arable land and human settlements were recorded as naturalized in the largest number of regions worldwide. Our findings highlight that plant species’ association with native-range habitats disturbed by human activities, combined with broad habitat range, play an important role in shaping global patterns of plant invasions.

Download Full-text

Foraging analysis of Endangered Greater Adsjutant Stork Leptotilus dubios Gemlin in certain habitat of Assam, India

10.1101/2020.05.31.125328 ◽

2020 ◽

Author(s):

Purnima Devi Barman ◽

D. K. Sharma

Keyword(s):

Migratory Birds ◽

Action Plan ◽

Natural Habitat ◽

The Body ◽

Conservation Action ◽

Natural Habitats ◽

Nesting Sites ◽

Baseline Information ◽

Fish Group ◽

Beak Length

AbstractThe endangered Greater Adjutant Stok Leptotilus dubius Gemlin confined only in some pockets in Assam and Bihar in India and in certain areas of Laos and Cambodia has poorly understood in its foraging activities in its natural habitats. Attempt has been made to address the forage pattern in its natural habitat wetlands in the Kamup district and in a city garbage dump in Guwahati in Assam, India. The various forage methods like walking, visual tactile etc and their relation with the body metrices like beak length, tibia tarsus length and its mass were assessed in terms of foraging habits. Forage actvities were evaluated during the breeding (May to September) and non breeding (October to April) time of the study period of 2012-2017 at different water level of the wetland(s). The foraging range of this stork assessed at an confinement of aerial distance of 15 km from the nesting sites appears as resident non migratory birds by habits. Types of diet composition obtained from the regurgitated food at the ground of the nesting sites were mostly the fish group channa and cyprinids. Profitability index was determined at the captive stork showed in favour of these two groups within the size group of 5 to 15 cm. Larger food item showed lesser profitability index. PCA analysis showed negative foraging correlation with the Prey size greater than 8cm and 15 cm, while the captivity study was conducted Thus the present findings on the foraging assessment of Greater Adjutant might be the baseline information for conservation action plan.

Download Full-text

The significance of the Danube ecological corridor in the proceedings of implementing ecological networks in Serbia

Glasnik srpskog geografskog drustva ◽

10.2298/gsgd1502109f ◽

2015 ◽

Vol 95 (2) ◽

pp. 109-124

Author(s):

Dejan Filipovic ◽

Ljubica Petrovic

Keyword(s):

Protected Areas ◽

Sustainable Management ◽

Ecological Networks ◽

Natural Environments ◽

Ecological Interactions ◽

Ecological Network ◽

Natural Habitats ◽

Natural Processes ◽

Ecological Corridor ◽

International Importance

With the modern processes for exploiting land people have altered the original appearance of areas and created cultural environments. The remaining natural environments, whether protected or not, take up a relatively small portion of space and represent isolated islands which in itself can not be sufficient for the preservation of biodiversity or for the fulfillment of national, regional or international goals and commitments related to their preservation. In order to secure the preservation of biodiversity, the strengthening of integrity and the natural processes, such as animal migrations, succession of vegetation and evolution processes, the communication between natural habitats is imperative. Ecological corridors, as integral elements of ecological networks, ensure the preservation of vital ecological interactions by providing a connection between different habitats or areas. Depending on a range of factors, from the fulfillment of demands of different species to the connecting of regions, corridors of local, sub-regional, regional and international importance are identified. The Danube ecological corridor is one of the most significant corridors of international importance which encompasses a large number of habitats which are part of the natural watercourse of the corridor. There are numerous protected areas in the Danube coastal area on Serbia's territory which present themselves as central areas for forming the ecological network, such as: Gornje Podunavlje, Karadjordjevo, Fruska Gora, Titelski Breg hill, Kovalski rit marsh, Dunavski loess bluffs, the Sava mouth, Labudovo okno, Deliblato sands, Djerdap and Mala Vrbica. The diverse and mosaic vegetation of the floodplain, as well as the consistency of the protected areas within the Danube corridor have a direct influence on the quality and functionality of this corridor. The goal of this paper is to show the significance of the Danube ecological corridor in the process of implementing ecological networks, the potential of the area in question for forming corridors, but also to present the limitations which may decrease the functionality of the corridors as well as the guidelines for a sustainable management of the corridor on Serbia's territory.

Download Full-text

Effect of Iron Limitation on the Ultrastructure of Agmenellum Quadruplicatum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098551 ◽

1981 ◽

Vol 39 ◽

pp. 410-411

Author(s):

L. P. Hardie ◽

D. L. Balkwill ◽

S. E. Stevens

Keyword(s):

Growth Medium ◽

Green Alga ◽

Natural Habitat ◽

Iron Limitation ◽

Natural Environments ◽

Blue Green Alga ◽

Marine Cyanobacterium ◽

Natural Systems ◽

Thin Sectioning ◽

Agmenellum Quadruplicatum

Agmenellum quadruplicatum is a unicellular, non-nitrogen-fixing, marine cyanobacterium (blue-green alga). The ultrastructure of this organism, when grown in the laboratory with all necessary nutrients, has been characterized thoroughly. In contrast, little is known of its ultrastructure in the specific nutrient-limiting conditions typical of its natural habitat. Iron is one of the nutrients likely to limit this organism in such natural environments. It is also of great importance metabolically, being required for both photosynthesis and assimilation of nitrate. The purpose of this study was to assess the effects (if any) of iron limitation on the ultrastructure of A. quadruplicatum. It was part of a broader endeavor to elucidate the ultrastructure of cyanobacteria in natural systemsActively growing cells were placed in a growth medium containing 1% of its usual iron. The cultures were then sampled periodically for 10 days and prepared for thin sectioning TEM to assess the effects of iron limitation.

Download Full-text

Family graveyards form underappreciated local plant diversity hotspots in China's agricultural landscapes

Scientific Reports ◽

10.1038/s41598-020-80362-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Cheng Gong ◽

Liangtao Li ◽

Jan C. Axmarcher ◽

Zhenrong Yu ◽

Yunhui Liu

Keyword(s):

Species Richness ◽

Plant Species ◽

Natural Habitat ◽

Plant Species Richness ◽

Agricultural Landscapes ◽

Natural Habitats ◽

Landscape Features ◽

Habitat Islands ◽

Local Plant ◽

Ecological Functioning

AbstractIn the intensively farmed, homogenous agricultural landscape of the North China Plain, family graveyards form distinct cultural landscape features. In addition to their cultural value, these graveyards represent semi-natural habitat islands whose potential roles in biodiversity conservation and ecological functioning has remained poorly understood. In this study, we investigated plant species richness on 199 family graveyards of different ages and sizes. In accordance with biogeography theory, both overall and insect-pollinated plant species richness increased with area and age of graveyards. Even small graveyards show a strong potential for conserving local plant richness, and a mosaic of both large and small family graveyards could play an important role in the conservation of farmland biodiversity and related ecosystem functions. The launch of agri-environmental measures that conserve and create semi-natural habitats, in turn benefitting agricultural biodiversity and ecological functioning, has proven difficult in China due to the shortage of dispensable arable land. Given the great value of family graveyards as semi-natural habitats reflected in our study, we propose to focus preliminary efforts on conserving these landscape features as existing, widespread and culturally important semi-natural habitat islands. This would represent an effective, complementary policy to a subsequent re-establishment of other semi-natural habitats for the conservation of biodiversity and ecological functioning in agricultural landscapes.

Download Full-text

Remarkable Population Resilience in a North African Endemic Damselfly in the Face of Rapid Agricultural Transformation

Insects ◽

10.3390/insects12040353 ◽

2021 ◽

Vol 12 (4) ◽

pp. 353

Author(s):

Rassim Khelifa ◽

Hayat Mahdjoub ◽

Affef Baaloudj ◽

Robert A. Cannings ◽

Michael J. Samways

Keyword(s):

Land Cover ◽

Agricultural Land ◽

Large Population ◽

Agricultural Practices ◽

Agricultural Expansion ◽

North African ◽

Natural Habitats ◽

Agricultural Transformation ◽

The Face ◽

Terrestrial Habitats

Agriculture can be pervasive in its effect on wild nature, affecting various types of natural habitats, including lotic ecosystems. Here, we assess the extent of agricultural expansion on lotic systems in Northern Africa (Algeria, Tunisia, and Morocco) and document its overlap with the distribution of an endemic damselfly, Platycnemis subdilatata Selys, using species distribution modeling. We found that agricultural land cover increased by 321% in the region between 1992 and 2005, and, in particular, the main watercourses experienced an increase in agricultural land cover from 21.4% in 1992 to 78.1% in 2005, together with an increase in the intensity of 226% in agricultural practices. We used capture–mark–recapture (CMR) surveys in terrestrial habitats surrounding a stream bordered by grassland and cropland in northeastern Algeria to determine demographic parameters and population size, as well as cropland occupancy. CMR modeling showed that the recapture and survival probabilities had an average of 0.14 (95%CI: 0.14–0.17) and 0.86 (0.85–0.87), respectively. We estimated a relatively large population of P. subdilatata (~1750 individuals) in terrestrial habitats. The occupancy of terrestrial habitats by adults was spatially structured by age. Our data suggest that P. subdilatata has survived agricultural expansion and intensification better than other local odonate species, mainly because it can occupy transformed landscapes, such as croplands and grasslands.

Download Full-text

Recent Invasion of the Endemic Banggai Cardinalfish, Pterapogon kauderni at The Strait of Bali: Assessment of the Habitat Type and Population Structure

ILMU KELAUTAN Indonesian Journal of Marine Sciences ◽

10.14710/ik.ijms.24.1.15-22 ◽

2019 ◽

Vol 24 (1) ◽

pp. 15 ◽

Cited By ~ 1

Author(s):

I Nyoman Giri Putra ◽

I Dewa Nyoman Nurweda Putra

Keyword(s):

Natural Habitat ◽

Habitat Type ◽

Marine Organisms ◽

Aquarium Trade ◽

Small Populations ◽

Depth Range ◽

Habitat Types ◽

Weight Relationship ◽

Narrow Bay ◽

Sexually Mature

The demands of marine organisms for the aquarium trade are remain high and seems continue to increase. Consequently, many of marine organisms has been spread out from its natural habitat as in the case of endemic Banggai cardinalfish, (Pterapogon kauderni). That has invaded “new” habitat since it being trade in 1995. In recent years, a small populations of P. kauderni is known to be exist in a narrow bay near the Gilimanuk harbor, Bali. An underwater visual fish census survey was conducted on June 2018 to estimate the habitat types and densities of P. kauderni. Additionally, 23 specimens of P. kauderni were collected randomly in order to assess biological parameters such as the length-weight relationship. We successfully recorded 30 groups of P. kauderni that inhabit a shallow areas with a depth range between 0.5m to 2m. Of these, more than 90% of the groups were found to be associated with sea urchin (Diadema sp.) while the rest were found to live together with branching coral (Acropora sp.) and branching sponge (Ptylocaulis sp.). Total number of fish observed during the survey were 381 individuals. The fish density is 0.76 individu.m-2. Length-weight relationship showed that P. kauderni exhibit is negative allometry (b<3) which mean that the increase in length is faster than the weight gain. Interestingly, from the 23 specimens collected, none of these were sexually mature (SL<41 mm) which may indicated that the population of P. kauderni in Bali are under serious threats of exploitation.

Download Full-text

Aspects of the Water, Electrolyte and Carbohydrate Physiology of the Silvereye, Zosterops Lateralis (Aves).

Australian Journal of Zoology ◽

10.1071/zo9830695 ◽

1983 ◽

Vol 31 (5) ◽

pp. 695 ◽

Cited By ~ 11

Author(s):

IJ Rooke ◽

SD Bradshaw ◽

RA Langworthy

Keyword(s):

Natural Habitat ◽

Tritiated Water ◽

Free Water ◽

Laboratory Studies ◽

Turnover Rates ◽

Natural Habitats ◽

Water Influx ◽

Zosterops Lateralis ◽

Total Body ◽

Free Ranging

Total body water content (TBW) and TBW turnover were measured by means of tritiated water (HTO) in free-ranging populations of silvereyes, Zosterops lateralis, near Margaret River, W.A. Birds were studied in their natural habitats during spring and summer, and compared with a vineyard population in summer. In the natural habitat TBW content was found to be 77.6% in spring, which was not significantly different from that measured in summer (78.3%). Birds in vineyards in summer, however, were dehydrated, with a TBW content of 69.4%. Calculated rates of water influx for spring, summer and summer vineyards birds were 1.44,2.20 and 0.65 ml g.day-' respectively. These water turnover rates are much higher than those of any other bird yet studied. Dehydration was marked in the vineyard birds, with a significantly lower TBW content and an average net water loss of 0.63 ml day-'. Laboratory studies showed that silvereyes have a low tolerance to sodium loading. Their tolerance is, however, quite adequate for them to drink the most concentrated free water available to them in the field. Ingestion of concentrated sugar solutions of up to 25% did not provoke an osmotic diuresis and thus cannot account for the dehydration and negative water balance of vineyard birds.

Download Full-text

Rapid Assessment and Ground Truthing of Habitat Composition and Analysis of Semi-Natural Habitat Diversity of Proposed Greenway Developments

Landscape Online ◽

10.3097/lo.201977 ◽

2019 ◽

Vol 77 ◽

pp. 1-18

Author(s):

Julien Carlier ◽

James Moran

Keyword(s):

Remote Sensing ◽

Land Use ◽

Green Infrastructure ◽

Natural Habitat ◽

Rapid Assessment ◽

Habitat Diversity ◽

Matrix Composition ◽

Natural Habitats ◽

Land Use Intensification ◽

Ground Truthing

Across Europe, Greenways upcycle disused railway infrastructure into non-motorised public infrastructure, often with limited consideration to potential ecological synergies. Pre-development, disused transport corridors become relatively undisturbed and potentially host diverse semi-natural habitats. The study objectives were 1) to produce a highly detailed and accurate dataset using remote sensing with rapid assessment techniques for ground truthing and 2) subsequently examine habitat diversity existing along a proposed Greenway. A 7000 ha study corridor was based on a disused railway proposed as a transfrontier Greenway connecting the Republic of Ireland and the United Kingdom. The study applied a rapid-assessment virtual validation techniquealongside remote sensing and accuracy assessment. Inter-relationship between seminatural habitat diversity and land-use intensification was examined. Remote sensing accuracies of 89% and 99% for a real and linear habitat classification were obtained. Degrees of land-use intensification were observed throughout the corridor, highlighting the importance of maintaining and enhancing remaining semi-natural habitat that exists along the proposed Greenway route. Through understanding the landscape matrix composition and semi-natural habitat diversity, European Greenwayscan achieve multi-functionality for ecosystem conservation, forming integral components of Green Infrastructure.

Download Full-text