1204
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Santoro R, Jucker T, Prisco I, Carboni M, Battisti C, Acosta ATR. Effects of trampling limitation on coastal dune plant communities. ENVIRONMENTAL MANAGEMENT 2012; 49:534-42. [PMID: 22302225 DOI: 10.1007/s00267-012-9809-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 01/05/2012] [Indexed: 05/05/2023]
Abstract
Sandy coastlines are sensitive ecosystems where human activities can have considerable negative impacts. In particular, trampling by beach visitors is a disturbance that affects dune vegetation both at the species and community level. In this study we assess the effects of the limitation of human trampling on dune vegetation in a coastal protected area of Central Italy. We compare plant species diversity in two recently fenced sectors with that of an unfenced area (and therefore subject to human trampling) using rarefaction curves and a diversity/dominance approach during a two year study period. Our results indicate that limiting human trampling seems to be a key factor in driving changes in the plant diversity of dune systems. In 2007 the regression lines of species abundance as a function of rank showed steep slopes and high Y-intercept values in all sectors, indicating a comparable level of stress and dominance across the entire study site. On the contrary, in 2009 the regression lines of the two fenced sectors clearly diverge from that of the open sector, showing less steep slopes. This change in the slopes of the tendency lines, evidenced by the diversity/dominance diagrams and related to an increase in species diversity, suggests the recovery of plant communities in the two fences between 2007 and 2009. In general, plant communities subject to trampling tended to be poorer in species and less structured, since only dominant and tolerant plant species persisted. Furthermore, limiting trampling appears to have produced positive changes in the dune vegetation assemblage after a period of only two years. These results are encouraging for the management of coastal dune systems. They highlight how a simple and cost-effective management strategy, based on passive recovery conservation measures (i.e., fence building), can be a quick (1–2 years) and effective method for improving and safeguarding the diversity of dune plant communities.
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Affiliation(s)
- Riccardo Santoro
- Dipartimento di Biologia Ambientale, Università degli Studi di Roma Tre, Viale Marconi 446, 00146 Roma, Italy
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1205
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Guerry AD, Ruckelshaus MH, Arkema KK, Bernhardt JR, Guannel G, Kim CK, Marsik M, Papenfus M, Toft JE, Verutes G, Wood SA, Beck M, Chan F, Chan KM, Gelfenbaum G, Gold BD, Halpern BS, Labiosa WB, Lester SE, Levin PS, McField M, Pinsky ML, Plummer M, Polasky S, Ruggiero P, Sutherland DA, Tallis H, Day A, Spencer J. Modeling benefits from nature: using ecosystem services to inform coastal and marine spatial planning. INTERNATIONAL JOURNAL OF BIODIVERSITY SCIENCE, ECOSYSTEM SERVICES & MANAGEMENT 2012. [DOI: 10.1080/21513732.2011.647835] [Citation(s) in RCA: 121] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
Affiliation(s)
- Anne D. Guerry
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Mary H. Ruckelshaus
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Katie K. Arkema
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Joey R. Bernhardt
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Gregory Guannel
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Choong-Ki Kim
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Matthew Marsik
- b NOAA Northwest Fisheries Science Center , Seattle , WA , USA
| | - Michael Papenfus
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Jodie E. Toft
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Gregory Verutes
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Spencer A. Wood
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Michael Beck
- c Global Marine Team, The Nature Conservancy , Santa Cruz , CA , USA
| | - Francis Chan
- d Oregon State University , Corvallis , OR , USA
| | - Kai M.A. Chan
- e IRES, University of British Columbia , Vancouver , BC , Canada
| | | | - Barry D. Gold
- g Marine Conservation Initiative, Gordon and Betty Moore Foundation , Palo Alto , CA , USA
| | - Benjamin S. Halpern
- h National Center for Ecological Analysis and Synthesis , Santa Barbara , CA , USA
| | | | - Sarah E. Lester
- j Marine Science Institute and Bren School of Environmental Science and Management, University of California , Santa Barbara , CA , USA
| | - Phil S. Levin
- b NOAA Northwest Fisheries Science Center , Seattle , WA , USA
| | | | - Malin L. Pinsky
- l Hopkins Marine Station, Department of Biology , Stanford University , Pacific Grove , CA , USA
| | - Mark Plummer
- b NOAA Northwest Fisheries Science Center , Seattle , WA , USA
| | - Stephen Polasky
- m Department of Applied Economics , University of Minnesota , St Paul , MN , USA
| | | | | | - Heather Tallis
- a Natural Capital Project, Woods Institute for the Environment, Stanford University , Stanford , CA , USA
| | - Andrew Day
- m Department of Applied Economics , University of Minnesota , St Paul , MN , USA
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1206
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Thomsen MS, Wernberg T, Engelen AH, Tuya F, Vanderklift MA, Holmer M, McGlathery KJ, Arenas F, Kotta J, Silliman BR. A meta-analysis of seaweed impacts on seagrasses: generalities and knowledge gaps. PLoS One 2012; 7:e28595. [PMID: 22253693 PMCID: PMC3254607 DOI: 10.1371/journal.pone.0028595] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 11/11/2011] [Indexed: 11/19/2022] Open
Abstract
Seagrasses are important habitat-formers and ecosystem engineers that are under threat from bloom-forming seaweeds. These seaweeds have been suggested to outcompete the seagrasses, particularly when facilitated by eutrophication, causing regime shifts where green meadows and clear waters are replaced with unstable sediments, turbid waters, hypoxia, and poor habitat conditions for fishes and invertebrates. Understanding the situations under which seaweeds impact seagrasses on local patch scales can help proactive management and prevent losses at greater scales. Here, we provide a quantitative review of available published manipulative experiments (all conducted at the patch-scale), to test which attributes of seaweeds and seagrasses (e.g., their abundances, sizes, morphology, taxonomy, attachment type, or origin) influence impacts. Weighted and unweighted meta-analyses (Hedges d metric) of 59 experiments showed generally high variability in attribute-impact relationships. Our main significant findings were that (a) abundant seaweeds had stronger negative impacts on seagrasses than sparse seaweeds, (b) unattached and epiphytic seaweeds had stronger impacts than 'rooted' seaweeds, and (c) small seagrass species were more susceptible than larger species. Findings (a) and (c) were rather intuitive. It was more surprising that 'rooted' seaweeds had comparatively small impacts, particularly given that this category included the infamous invasive Caulerpa species. This result may reflect that seaweed biomass and/or shading and metabolic by-products like anoxia and sulphides could be lower for rooted seaweeds. In conclusion, our results represent simple and robust first-order generalities about seaweed impacts on seagrasses. This review also documented a limited number of primary studies. We therefore identified major knowledge gaps that need to be addressed before general predictive models on seaweed-seagrass interactions can be build, in order to effectively protect seagrass habitats from detrimental competition from seaweeds.
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Affiliation(s)
- Mads S Thomsen
- Oceans Institute and School of Plant Biology, University of Western Australia, Crawley, Western Australia, Australia.
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1208
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Nfotabong-Atheull A, Din N, Essomè Koum LG, Satyanarayana B, Koedam N, Dahdouh-Guebas F. Assessing forest products usage and local residents' perception of environmental changes in peri-urban and rural mangroves of Cameroon, Central Africa. JOURNAL OF ETHNOBIOLOGY AND ETHNOMEDICINE 2011; 7:41. [PMID: 22146073 PMCID: PMC3261808 DOI: 10.1186/1746-4269-7-41] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Accepted: 12/06/2011] [Indexed: 05/25/2023]
Abstract
BACKGROUND Deforestation is one of the most ubiquitous forms of land degradation worldwide. Although remote sensing and aerial photographs can supply valuable information on land/use cover changes, they may not regularly be available for some tropical coasts (e.g., Cameroon estuary) where cloud cover is frequent. With respect to mangroves, researchers are now employing local knowledge as an alternative means of understanding forest disturbances. This paper was primarily aimed at assessing the mangrove forest products usage, along with the local people's perceptions on environmental changes, between Littoral (Cameroon estuary) and Southern (mouth of the Nyong River and Mpalla village) regions of Cameroon. METHODS The data from both locations were obtained through conducting household interviews and field observations. RESULTS In the Cameroon estuary (Littoral region), 69.23% of respondents (mostly elders) could distinguish two to four mangrove plants, whereas the informants (65.45%) in the mouth of the Nyong River and Mpalla village (mostly young people interviewed from the Southern region) are familiar with only one or two commonly found mangroves. Also, more respondents from the Cameroon estuary are depending on mangroves for fuelwood (Rhizophora spp.) and housing (Rhizophora spp., Avicennia germinans (L.) Stearn and Nypa fruticans (Thumb.) Wurmb.) purposes, in contrast to Nyong River mouth and Mpalla village. Although local people perceived wood extraction as a greater disruptive factor, there are several causes for mangrove depletion in the Cameroon estuary. Among others, over-harvesting, clear-felled corridors, sand extraction and housing were found important. Furthermore, a decline in mangrove fauna composition (in terms of fishery products) was recorded in the Littoral as well as Southern regions. However, the causes of such perceived negative changes were not similar in both cases. CONCLUSIONS Findings of this study highlight the need to improve sustainable management of the mangrove ecosystems through afforestation (in large impacted areas), selective removal of senescent tree stems and branches (in little damage stands), regulating sand extraction and housing activities, and creating awareness and law enforcement.
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Affiliation(s)
- Adolphe Nfotabong-Atheull
- Laboratory of Systems Ecology and Resource Management, Département de Biologie des Organismes, Faculté des Sciences, Université Libre de Bruxelles-ULB, Avenue Franklin D. Roosevelt 50, CPI 169, B-1050 Brussels, Belgium
- The University of Douala, Faculty of Science, Department of Botany, P.O. Box 8948 Douala, Cameroon
- University of Yaoundé I, Faculty of Science, Department of Plant Biology, P.O. Box 812 Yaoundé, Cameroon
| | - Ndongo Din
- The University of Douala, Faculty of Science, Department of Botany, P.O. Box 8948 Douala, Cameroon
| | - Léopold G Essomè Koum
- The University of Douala, Faculty of Science, Department of Botany, P.O. Box 8948 Douala, Cameroon
| | - Behara Satyanarayana
- Laboratory of Systems Ecology and Resource Management, Département de Biologie des Organismes, Faculté des Sciences, Université Libre de Bruxelles-ULB, Avenue Franklin D. Roosevelt 50, CPI 169, B-1050 Brussels, Belgium
- Laboratory of Plant Biology and Nature Management, Mangrove Management Group, Vrije Universiteit Brussel-VUB, Pleinlaan 2, B-1050 Brussels, Belgium
- Institute of Oceanography, Universiti Malaysia Terengganu - UMT, 21030 Kuala Terengganu, Malaysia
| | - Nico Koedam
- Laboratory of Plant Biology and Nature Management, Mangrove Management Group, Vrije Universiteit Brussel-VUB, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Farid Dahdouh-Guebas
- Laboratory of Systems Ecology and Resource Management, Département de Biologie des Organismes, Faculté des Sciences, Université Libre de Bruxelles-ULB, Avenue Franklin D. Roosevelt 50, CPI 169, B-1050 Brussels, Belgium
- Laboratory of Plant Biology and Nature Management, Mangrove Management Group, Vrije Universiteit Brussel-VUB, Pleinlaan 2, B-1050 Brussels, Belgium
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