Basin Mangrove Research Articles

Distribution and Sampling of Aedes taeniorhynchus (Diptera: Culicidae) Eggs in a Florida Mangrove Forest

The distribution of Aedes taeniorhynchus (Wiedemann) eggs in a Florida mangrove basin forest was quantified and used to design a sampling plan. Eggs were found in detritus-rich soil with the highest densities in a band at elevations 0.1-0.2 m above the water line. Dispersion indices (k and Taylor's b) indicated that the eggs were aggregated; 14 of 16 populations tested fit the negative binomial distribution. A fixed-size sampling plan using systematic sampling was designed from these data.

Recent Accretion in Mangrove Ecosystems Based on 137 Cs and 210 Pb

Accretion rates were measured in fringe and basin mangrove forests in river and tidally dominated sites in Terminos Lagoon, Mexico, and a basin mangrove forest in Rookery Bay, Florida, USA. Accretion rates were determined using the radionuclides210Pb and137Cs. Consolidation-corrected accretion rates for the Rookery Bay cores, ranged from 1.4 to 1.7 mm yr−1, with an average rate of 1.6 mm yr−1. Rates at the Mexico sites ranged from 1.0 to 4.4 mm yr−1, with an average of 2.4 mm yr−1. Determination of rates in these mangrove forests was greatly affected by the consolidation corrections which decreased the apparent accretion rate by over 50% in one case. Accretion rates at basin sites compare favorably with a reported 1.4 to 1.6 mm yr−1 rate of sea-level rise, indicating little or no subsidence at inland locations. Accretion rates in fringe sites are generally greater than basin sites, indicating greater subsidence rates in these sediments over longer time intervals.

Litter Production and Turnover in Basin Mangrove Forests in Southwest Florida

Litterfall, litter standing crop, and leaf decomposition of basin mangrove sites with mixed associations of Avicennia germinans, Rhizophora mangle, and Laguncularia racemosa adjacent to bay waters were compared to monospecific stands A. germinans located inland of the mixed associations. The objective was to determine whether basin mangroves with low tidal amplitude are characterized by lower litter productivity, longer litter residence times, and increased nitrogen recycling. Litterfall rates for the two mixed forests averaged 8.10 Mg°ha—1°yr—1 compared to 4.44 Mg°ha—1°yr—1 in the three monospecific sites. Peak litterfall occurred from August to October after increases in soil water salinity during June and July. Seasonal changes in surface litter mass occurred only in the monospecific forests and corresponded with higher leaf decomposition rates when tidal inundation frequency increased. As a result, surface leaf litter in a monospecific site > 200 m from the bay had a longer residence time than in two monospecific sites < 100 m inland. The rates of dry mass loss and organic carbon leaching of R. mangle leaves were lower than those for A. germinans, resulting in higher residence times of leaf litter in mixed (0.5 yr) than monospecific (0.2 yr) forests located <100 m from the bay. Leaf nitrogen decreased during senescence, and absolute nitrogen increased in leaf litter during decomposition on the forest floor. As a result, turnover rates of nitrogen in surface litter were lower than for dry mass. A comparison of litter dynamics and nitrogen recycling among riverine, fringe, and basin mangroves suggests that the relative influence of export and decomposition on litter dynamics depends on the magnitude of tidal inundation. Inland basin mangroves have low nitrogen recycling efficiency in litterfall, but higher internal recycling of litter on the forest floor, due in part to a longer litter residence time, nitrogen retranslocation prior to leaf senescence, and nitrogen immobilization during litter decomposition and peat deposition.

The exchange of organic carbon in basin mangrove forests in a southwest Florida estuary

The magnitude and seasonality of organic carbon exchange was estimated for two basin mangrove forests in Rookery Bay, Florida. Runoff and tidal inundation in the forests were seasonal with half the annual total of each occurring from August to October. In each forest there were 152 tides yr −1 with a cumulative depth of about 12 m. Total organic carbon increased in bay waters exporting from the mangroves following a flood tide and peak concentrations were associated with export due to rainfall. The amount of net export from each basin forest was similar, although the concentration of organic carbon in each were different. Monthly net organic carbon export was proportional to the cumulative tidal amplitude within the forest. Total organic carbon export was 64 gC m −2 yr −1 and DOC was 75% of the total. A comparison of organic carbon export among riverine, fringe and basin mangroves suggests that tidal hydrology influences the proportion of litter fall that is exported from mangroves; and the magnitude of this organic carbon export from mangroves is related to the cumulative tidal amplitude within the forests.

Studies of a mangrove basin, Tuff Crater, New Zealand: III. The flux of organic and inorganic particulate matter

Water samples were collected at 15 min intervals over 11 tidal cycles from a tidal creek draining the mangrove-covered basin of Tuff Crater, Auckland, New Zealand. The samples were filtered and total suspended sediment (TSS), inorganic suspended sediment (ISS) and organic suspended sediment (OSS) were determined. Variation in TSS was high, the concentration varied over a tidal cycle and during over-bank flows concentrations were lowest at or near slack high water. Covariance between TSS concentrations and velocity and discharge meant that the calculation of particulate matter flux over tidal hemicycles was particularly dependent on the method of estimating tidal flux. The hypsometrically-based volumetric method was found to be inappropriate, predicting a positive budget (import) more often than observed. Instead particulate matter budgets were calculated by means of the velocity-area method and indicate a net export of TSS, ISS and OSS. Floating macrodetritus was observed on both the flood and ebb tides, but a net export was found on the two tides monitored. It is considered that on an annual basis floating macrodetritus export accounts for less than 2% of the detrital production in the basin, and organic suspended sediment export from the basin is less than 3 kg C ha −1 day −1 and is below the rate of detrital production. It is implied that a proportion of the organic detritus produced in this basin is degraded and recycled in situ.

Studies of a mangrove basin, Tuff Crater, New Zealand: I. Mangrove biomass and production of detritus

The mangrove, Avicennia marina var. resinifera in a tidally-flooded explosion crater, Tuff Crater, near the southern latitudinal limit of mangroves in New Zealand adopts two distinct growth forms, taller tree-like mangroves up to 4 m tall along the banks of the tidal creek, and low stunted shrub mangroves less than 1 m tall on the mudflats. Twelve trees were felled and on the basis of a biomass/height relationship for the taller trees and a biomass/canopy width relationship for the lower, above-ground biomass (excluding pneumatophores) was estimated. Average above-ground biomass for the taller mangrove was estimated to be 104·1 t ha −1 and for the lower 6·8 t ha −1. While the value for the taller mangroves is similar to figures reported for more complex tropical mangroves, the fact that 94% of the basin is covered by low generally sparse mangroves means that total biomass for the basin is estimated to be 153 t, an average of only 7·6 t ha −1. Litter-fall beneath the taller mangroves is estimated as 7·6±2·5 t ha −1 a −1 and beneath the lower mangroves 3·3±0·5 t ha −1 a −1. The value for the taller mangroves is similar to that reported from mangroves in many other parts of the world, but because of the extensive low sparse mangroves the total for the basin is estimated as 53·7 t a −1, an average rate of 2·7 t ha −1 a −1, a very low rate of litter-fall when compared with elsewhere. Decomposition of mangrove leaves occurs relatively rapidly with leaves losing half their dry weight in 10 weeks and then continuing to degrade but at a slower rate. Substrate sediment samples contain high organic matter content, and although some organic matter appears to be exported via the tidal creek, a proportion of the detrital production is evidently recycled in situ.

Studies of a mangrove basin, Tuff Crater, New Zealand. I. Mangrove biomass and production of detritus : Woodroffe, C.D., 1985. Estuar. coast. Shelf Sci., 20(3):265–280

Studies of a mangrove basin, Tuff Crater, New Zealand. I. Mangrove biomass and production of detritus : Woodroffe, C.D., 1985. Estuar. coast. Shelf Sci., 20(3):265–280