Estimating the species number and cover of a mangrove-root community: a comparison of methods

Abstract

Methods and designs have been validated for sampling coral reefs and reef-associated communities, but the accuracy and equivalence of results obtained from studies of mangrove-root communities can not be assured. Thus, it is convenient to establish the accuracy and reliability of sampling methods on a practical basis. Line interception, point interception, and quadrat sampling were used to estimate several basic features of the community associated with mangrove roots. Species-number estimates, cover estimates, sampling efforts, and some statistical properties of the three methods were compared. A sampling design should be chosen if it yields estimates with the greatest accuracy at the lowest cost. Results showed that sampling of mangrove roots could start by using 4 × 4-cm quadrats with a mean sample size of 50 for detecting the number of species, and for establishing species cover it appears that the point-interception method with a sample size of 50 would be appropriate. The effort involved in such a sequence would be approximately 10 h for 20 roots. This combined strategy is clearly laborious and time-consuming in comparison with the use of just a 200-point interception, which would require only 3.25 h for the same number of roots. Although it would cost more than the above methods, a fast and accurate technique based upon existing computer hardware to estimate cover from photographic or video material would result in a census of the whole community. This might prove to be a reliable way to approach the problem.

Scale‐Dependent Spatial and Temporal Variability in Biogeography of Mangrove Root Epibiont Communities

“…Epibiont communities have been described from mangroves in Florida (Mook 1976, Bingham 1992, Puerto Rico (Burkholder andAlmodovar 1973, Rodriguez andStoner 1990), Bermuda (Thomas 1993), the French West Indies (Sheridan 1991(Sheridan , 1992, Belize (Riitzler and Feller 1987, Ellison and Farnsworth 1990, de Weerdt et al 1991, Costa Rica (Perry 1988), Panama (Jackson et al 1989, Garrity andLevings 1992), Venezuela (Sutherland 1980, Alvarez I. 1989, Orihuela et al 1991, Dfaz et al 1992, Brazil (Eston et al 1991), South Africa (Steinke and Naidoo 1990), and Malaysia (Cheh 1982a, b). Typical of most speciose assemblages (Preston 1962, Brown 1984, the majority of epibionts in the Caribbean subtidal root communities are "sparse" (sensu Rabinowitz et al 1986); they occur at many sites, but on few roots and at low percentage cover.…”

Inventory of ascidians (Tunicata, Ascidiacea) from the National Park La Restinga, Isla Margarita, Venezuela

“…In general, the ascidians attach to the mangrove prop roots of Rhizophora mangle, usually in large biomass, and represent an important portion of the fouling community (Sutherland 1980, Álvarez 1989, Díaz et al 1992, Farnsworth & Ellison 1996, Goodbody 2000.…”

“…The survey reported here was done in the National Park La Restinga where diverse and abundant assemblages of tunicates grow on the mangrove roots (Cervigon & Gomez 1986, Orihuela et al 1991, Díaz et al 1992. La Restinga has been preserved as a national park since 1974 because of its highly diverse habitat contrasting with the arid vegetation of the terrestrial environment surrounding it (Presidential Ordinance nº 1591).…”

Marine biodiversity in Venezuela: Status and perspectives

“…Mangrove forests have horizontal zonations from the sea to inland, Rhizophora mangle being the most seaward species followed by Avicennia germinans, Laguncularia racemosa, and Conocarpus erectus which prospers on firm sandy soil away from the tides (Pannier & Pannier 1989). Vertically, the mangrove community is also very complex; the sediments underneath the trees are muddy with several infaunal bivalve species and the roots are covered mainly with sponges with a highly diverse associated fauna and hydrocorals (Sutherland 1980, Morao 1983, Ordosgoitti 1985, Díaz et al 1992. Coastal lagoons cover an area of approximately 26,900 ha, distributed between 25 lagoons present from the Goajira Peninsula in the west to Sucre State and Nueva Esparta State (Margarita, Coche, and Cubagua islands) in the east, each of them characterized by a particular ecosystem (Penchaszadeh et al 2000).…”