Floral diversity of the littoral vegetation of Southeastern Nigeria

Published Date
Received: 01 August 2016   Accepted: 19 October 2016  Published: 31 December 2016

Vol.8(12), pp. 320-333 , December 2016
DOI: 10.5897/IJBC2016.1027  
ISSN: 2141-243X 

Author

Olowokudejo, J. D.

 

Oyebanji, O. O

Abstract

An investigation of the floral diversity of the littoral vegetation of Akwa-Ibom State coastline of South eastern Nigeria was carried out using quadrat and transects techniques. The results revealed three (3) vegetation types viz: coastal/shoreline, mangrove and secondary forest vegetation. Although, the most encountered ecosystem was the mangrove yet, coastal vegetation had the highest flora diversity of 100 (47%) as compared to mangrove and secondary forest with 87 (41%) and 27 (12%) species, respectively. A total of 147 taxa belonging to 134 genera and 58 families were recorded from the study area. The dominant family was Fabaceae with 17 species (29.3%), while the dominant genus was Ipomoea with 5 species (3.73%). Of these taxa, 59 occurred in more than one vegetation type while 11 were present in all the three (3) vegetation types. Phanerophytes are the dominant life form covering 36% (53 species) of the encountered species. Similarly, diversity index revealed the highest diversity of species in the coastal ecosystem with Shannon-wiener’s, Simpson’s and Margalef values of 0.99, 4.61 and 21.67, respectively. Correlation matrix and Jaccard similarity coefficient value (0.35) was high between the coastal and mangrove pairs; however, it depicts a minimal significant difference in the species composition within the three ecosystems at 0.05% probability level. Also, PCA scatter plot established less variation between the coastal and mangrove vegetation. Also, 16 economic plants were encountered during the study with uses ranging from edible fruits, spices, vegetables, root crop, and medicine, to palm wine. Factors affecting species distribution are introduction of alien species (Nypa fruticans), canalization, dredging, over exploitation of mangrove and pollution. Conservation status of these taxa according to IUCN 2014-2 showed that no endangered species was encountered during the study. However, conservation of this littoral vegetation is highly imperative in other to stabilize the ecosystem dynamics, protect the biodiversity, prevent or reduce potential effects of ecological disasters such as flooding and erosion.

References

Bowman DMJS, Wightman GM (1985). Small scale vegetation pattern associated with a deeply incised gully, Gunn Point, northern Australia. Proceed. R. Soc. Queensland 96:63-73.
Cintrón G, Lugo AE, Pool DJ, Morris G (1978). Mangroves of arid environments in Puerto Rico and adjacent islands. Biotropica 10:110-121. Crossref
Ellison JC (1991).The Pacific palaeogeography of Rhizophora mangle L. (Rhizophoraceae). Bot.J. Linnean Soc. 105:271-284. Crossref
Feller, IC, Whigham DF, McKee KL, Lovelock CE (2003). Nitrogen limitation of growth and nutrient dynamics in a mangrove forest, Indian River Lagoon, Florida. Oecologia 134:405-414. Crossref
Feller IC, Whigham DF, McKee KM, O'Neill JP (2002). Nitrogen vs. phosphorus limitation across an ecotonal gradient in a mangrove forest. Biogeochem. 62:145-175. Crossref
Flyod B. (1969) Eastern Nigeria: A geographical review. London, Macmillan. pp. 173. Crossref
Fromard F, Puig H, Mougin E, Marty G, Betoulle LL, Cadamuro C (1998). Structure, aboveground biomass and dynamics of mangrove ecosystems: new data from French Guiana. Oecologia 115:39-53. Crossref
Hughes L (2000). Biological consequences of global warming: is the signal already apparent? Trends Ecol. Evol. 15: 56-61. Crossref
IUCN (2014). IUCN Red List of Threatened Species. Retrieved from: www.iucnredlist.org.
Jessica Dianna (2004). Are invasive species a major cause of extinctions? Trends Ecol. Evol. 19(9):470-474. Crossref
Keddy PA (2010). Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. Crossref
Kershaw KA (1973). Quantitative and Dynamic Plant Ecology ELBS and Edward Arnold Ltd., London. pp. 1-5.
Kikkawa J, Webb LJ, Dale MB, Monteith GB, Tracey JG, Williams WT (1981). Gradients and boundaries in monsoon forests in Australia. Proc. Ecol. Soc. 11:39-52.
Koch MS (1997). Rhizophora mangle L. seedling development into the sapling stage across resource and stress gradients in subtropical Florida. Biotropica 29:427-439. Crossref
Layman CA, Arriington DA, Langerahans RB, Reed Silliman B (2004). Degree of fragmentation affects fish assemblage structure in Andros Island (Bahamas) estuaries. Caribbean J. Sci. 40:232-244.
McKee KL (1993). Soil physicochemical patterns and mangrove species distribution reciprocal effects. J. Ecol. 81:477-487. Crossref
Mumby PJ, Edwards AJ, Arias-Gonzalez JE, Lindeman KC, Blackwell, PG, Gall A, Gorczynska MI, Harborne AR, Pescod CL, Wabnitz C. CC, Llewellyn G (2004). Mangroves enhance the biomass of coral reef fish communities in the Caribbean. Nat. 427(6974):533-536. Crossref
Parmesan C (1996). Climate and species' range. Nature 382: 765-766. Crossref
Radford AE, Dickison WC, Massey JR, Bell CR (1974). Vascular Plant Systematics. Harper and Row, New York. pp. 891.
Raunkiaer C (1934). The life-forms of plants and their bearings on geography, pp. 2-104.
Rützler K, Feller C (1996). Caribbean mangrove swamps. Sci. Am. 274:94-99. Crossref
Udo RK (1970). Geographical Region of Nigeria. London, Heinemann. P 212.
Webb LJ, Tracey JG (1981). Australian rain- forest: Patterns and change. Ecological biogeography of Australia (ed. by A. Keast), Dr W. Junk, The Hague. pp. 605-694. Crossref

For further details log on website :
http://www.academicjournals.org/journal/IJBC/article-abstract/11BA91961987

Giant cell blob can learn and teach, study shows

Published Date
Date: December 21, 2016
Source: CNRS

Summary: It isn't an animal, a plant, or a fungus. The slime mold (Physarum polycephalum) is a strange, creeping, bloblike organism made up of one giant cell. Though it has no brain, it can learn from experience, as biologists have demonstrated. Now the same team of scientists has gone a step further, proving that a slime mold can transmit what it has learned to a fellow slime mold when the two combine.

Share:

FULL STORY

---

P. polycephalum, a single-celled organism otherwise known as a slime mold, grown on agar in the laboratory.

Credit: Audrey Dussutour (CNRS)

It isn't an animal, a plant, or a fungus. The slime mold (Physarum polycephalum) is a strange, creeping, bloblike organism made up of one giant cell. Though it has no brain, it can learn from experience, as biologists at the Research Centre on Animal Cognition (CNRS, Université Toulouse III -- Paul Sabatier) previously demonstrated. Now the same team of scientists has gone a step further, proving that a slime mold can transmit what it has learned to a fellow slime mold when the two combine. These new findings are published in the December 21, 2016, issue of the Proceedings of the Royal Society B.

Imagine you could temporarily fuse with someone, acquire that person's knowledge, and then split off to become your separate self again. With slime molds, that really happens! The slime mold -- Physarum polycephalum for scientists -- is a unicellular organism whose natural habitat is forest litter. But it can also be cultured in a laboratory petri dish. Audrey Dussutour and David Vogel had already trained slime molds to move past repellent but harmless substances (e.g. coffee, quinine, or salt) to reach their food. They now reveal that a slime mold that has learned to ignore salt can transmit this acquired behavior to another simply by fusing with it.

To achieve this, the researchers taught more than 2,000 slime molds that salt posed no threat. In order to reach their food, these slime molds had to cross a bridge covered with salt. This experience made them habituated slime molds. Meanwhile, another 2,000 slime molds had to cross a bridge bare of any substance. They made up the group of naive slime molds. After this training period, the scientists grouped slime molds into habituated, naive, and mixed pairs. Paired slime molds fused together where they came into contact. The new, fused slime molds then had to cross salt-covered bridges. To the researchers' surprise, the mixed slime molds moved just as fast as habituated pairs, and much faster than naive ones, suggesting that knowledge of the harmless nature of salt had been shared. This held true for slime molds formed from 3 or 4 individuals. No matter how many fused, only 1 habituated slime mold was needed to transfer the information.

To check that transfer had indeed taken place, the scientists separated the slime molds 1 hour and 3 hours after fusion and repeated the bridge experiment. Only naive slime molds that had been fused with habituated slime molds for 3 hours ignored the salt; all others were repulsed by it. This was proof of learning. When viewing the slime molds through a microscope, the scientists noticed that, after 3 hours, a vein formed at the point of fusion. This vein is undoubtedly the channel through which information is shared. The next challenges facing the researchers are to elucidate the form this information takes, and to test whether more than one behavior can be transmitted simultaneously. If Slime Mold A learns how to ignore quinine and Slime Mold B to ignore salt, the biologists wonder whether both behaviors can be transmitted and retained through fusion.

---

Story Source:

Materials provided by CNRS. Note: Content may be edited for style and length.

---

Journal Reference:

1. David Vogel, Audrey Dussutour. Direct transfer of learned behaviour via cell fusion in non-neural organisms. Proceedings of the Royal Society B: Biological Sciences, 2016; 283 (1845): 20162382 DOI: 10.1098/rspb.2016.2382

---

Cite This Page:

• MLA
• APA
• Chicago

CNRS. "Giant cell blob can learn and teach, study shows." ScienceDaily. ScienceDaily, 21 December 2016. <www.sciencedaily.com/releases/2016/12/161221090246.htm>.

For further details log on website :
https://www.sciencedaily.com/releases/2016/12/161221090246.htm