Scientific Report to Naucrates
Biology of Mangroves and GIS Mapping
Jennifer Morse and Mirco Boschetti
Research Assistants, July – August 2002
Mangroves are the main coastal wetlands in tropical and subtropical regions of the world (Mitsch and Gosselink 2000). Mangroves occupy important transition zones between terrestrial and aquatic environments and between marine and fresh waters. They are essentially terrestrial environments dominated by plants that are particularly adapted to the stresses of saltwater and tidal flooding. Mangroves occur along coasts with warm ocean currents (latitudes ~ 35？N or S), because they usually
cannot tolerate freezing temperatures (Hogarth 1999). They are found in shallow, low wave energy environments, such as protected shores or along rivers and tidal creeks.
Tidal flooding in mangroves creates extreme chemical conditions (low oxygen and salinity) that require special adaptation by plants. Many mangrove species have evolved pneumatophores (air-roots) that are adapted for gas exchange and aid in stabilizing the trees against flooding. To deal with salinity, most mangrove species have thick, nearly impermeable leaves and special membranes to exclude salt; some species also have salt-secreting glands in their leaves to get rid of excess salt. Most mangroves have a unique reproductive strategy, vivipary, that produces live propagules that begin germinating while still on the parent tree (Tomlinson 1984).
Trees dominate the mangrove ecosystem. The most abundant mangrove species in Thailand are the Rhizophora, recognized by their exceptional stilt roots (Tomlinson 1984). Different patterns of tree associations are formed in response to abiotic factors such as salinity and flooding gradients, geomorphology, and soil type, and through interspecific competition. The natural progression from young to mature forest (succession) also influences the distribution of species (Johnstone 1983).
Intact mangroves provide many ecosystem services. The waters sheltered by their roots provide nursery grounds for many commercial and non-commercial fisheries. Mangroves provide coastal protection, reducing coastal erosion and protecting low-lying areas from flooding and storm surges. Coral reefs also benefit from this reduction in erosion, as silt deposited on reefs kills the coral by smothering it; in turn, dead reefs result in decreased fish diversity abundance. Important biogeochemical processes in mangroves are the conversion of carbon dioxide to oxygen by photosynthesis, the removal of nutrients and pollutants from water, and the burial of organic matter in sediments (Hogarth 1999; Mitsch and Gosselink 2000). Mangrove products provide many benefits to local communities, such as Nypa palm
fronds for roofing thatch, many plants with medicinal uses, and shellfish and fish harvests (Aksornkae et al. 1985).
The overall aim of the preliminary botanic survey of the mangrove forest near the research station at Golden Buddha Beach Resort was to lay a foundation for ongoing ecological research on mangroves of Phra Thong Island. The objectives of the first field season were to develop and implement methodologies for 1) plant identification, 2) location and monitoring of sample plots, 3) data collection and input and 4) mangrove restoration areas, with a long-term study in mind. With this baseline information and methods, monitoring can be expanded to other areas of the island and perhaps to animal communities, to understand the natural dynamics of biodiversity and ecology, such as succession, expansion or mortality with changing sea level or storms, and human-induced changes such as clearing, cutting, or restoration.
In line with Naucrates’s conservation goals, we sought to interact with different communities of the island,
by giving presentations on mangroves to schoolchildren at the three schools on the island, to the Thai staff and to guests of the resort. We also wished to build a working relationship with Thai researchers from the Ranong Coastal Resources Research Station (RCRRS).
2Koh Phra Thong is a 100 km island (15 km long x 7 km wide), located about 5 km from the western
coast of Thailand in the Andaman Sea (9.03-9.17？N, 98.25-98.33？E; Figure 1). The western coast of the
island is primarily a high-energy environment with narrow strip of sandy beach, composed of marine sediments and bordered by sparse beach vegetation; the other shorelines are protected, low-energy environments characterized by muddy alluvial substrates and dominated by mangroves. The island’s
interior is an arid, savannah-like grassland with sandy soils and clusters of Melaleuca spp. trees. A tidal
channel named Khlong Ko Khat bisects the island from North to South. A tidal creek (~1.5 km) on the northwest corner of the island, near the Golden Buddha Beach Resort, was the site of intensive preliminary sampling during July and August 2002.
The island is largely undeveloped, and its infrastructure is limited to a minor network of unpaved tracks; there is no island-wide water, sewer, telephone, or electrical system. The island is experiencing development for tourism, primarily along the north-west shore.
The climate on Koh Phra Thong is influenced by the seasonal monsoon, resulting in a tropical savannah climate with three seasons: rainy or southwest monsoon (May to October), winter or northeast monsoon (November to February), and summer (March to April). General climatic data for the western coast of Thailand were obtained from the Thai Meteorological Department (Table 1; TMD 2003).
Table 1. Climatic data for the southwest coast of Thailand (TMD 2003). Rainy Season Winter Summer
27.3 26.8 28.4 Mean temperature (？C) Mean rainfall (mm) 1,914.7 429.5 380.0 Mean humidity (%) 84 77 76
To prepare for species identification, we became familiar with local mangrove plants through preliminary surveys and reference books, mainly Aksornkae et al. (1992), Tomlinson (1994), and Lovelock (1999). Staff from RCRRS provided guidance and assistance with plant identification. We used characteristics of root systems, leaf morphology, bark texture and color, propagules, and flowers (when present) to identify species.
Permanent Monitoring Plots
The tidal creek near the research station was designated for the preliminary survey of the mangrove ecosystem and as the first location for permanent monitoring plots. A rough, ground-based map of the channel area was first sketched by hand, using a compass; the map was then corrected and refined using precise coordinates obtained using a Garmin III GPS unit (Figure 1). The tidal creek was accessed by kayak, and interior areas of the mangrove forest were surveyed on foot during low tide.
The sampling method was developed in collaboration with researchers from RCRRS, to enable data sharing and comparisons with their monitoring efforts. We also consulted Bullock (1996), Küchler and Zonneveld (1988), and Snedaker and Snedaker (1984) for information on vegetation sampling. Three permanent monitoring belt transects were established perpendicular to the creek and extending to the mangrove/upland border on either side (Figure 1), to capture the longitudinal variability from ocean to inland and laterally from bank to upland. Each transect consisted of 10 m x 10 m plots extending from the bank to the mangrove/upland border or 50 m, whichever was encountered sooner. The corners and center point of each 10 m x 10 m plot were marked with labeled stakes. The landward limit of transects was
established a posteriori in the field, after ground observations showed little change in community +composition between 50 and 100 meters to the upland border. Transects were numbered with respect to their position along the channel (T01, T02, and T03, increasing away from the ocean), and each plot was assigned a code corresponding to its position on the hydrographic right or left of the channel and distance from the bank (RA, RB, RC; LA, LB, LC; increasing inland). Each plot, therefore, had a unique identifier: e.g., T01RE. We established a total of 26 plots.
In each 10 m x 10 m plot, each tree (defined as having a diameter at breast height, DBH > 4 cm) was identified to the species level; its diameter was measured directly with a caliper or estimated as circumference with a measuring tape then converted to diameter; and its height was estimated to ， 0.5 m.
Trees with multiple stems were treated as single individuals; the major stem was identified, and its diameter was measured at breast height or 5-10 cm above the highest prop root, where feasible. For the two palm species (Nypa fruticans and Phoenix paludosa, diameter was deemed an unreliable and rather
hazardous metric, because P. paludosa has long, sharp spines; only height was measured for these plants. In a 5 m x 5 m subplot at the left, inland corner of the 10 m x 10 m plot, we identified each small tree or sapling (defined as DBH < 4 cm and height > 1 m), measured its DBH, and estimated its height. In a 1 m x 1 m subplot, each seedling (defined as height < 1 m) was identified and measured. Observations of epiphytic plants, fauna, soil characteristics, visible human impacts, and dead trees were also recorded. From the center of each plot, canopy cover was estimated to the nearest 10%, and where signal reception was possible, GPS coordinates were also obtained.
2Trees: 100 m Landward ； 2Saplings: 25 m 2Seedlings: 1 m Toward creek ？ Figure 2. Schematic representation of a sampling plot
A database was developed in MS Access 2000 (Mangrove.mdb) to compile and analyze the data from field measurements. A mangrove species list for the intensive study area, including presence/absence in each sampling plot, was generated. We also compiled a list of casually observed fauna across all sample plots; no effort was made to seek out benthic fauna. Standard calculations of community structure, such as species richness, ecological dominance (calculated two ways: using basal area and height), species importance, Shannon-Weiner diversity index, and species evenness, were performed for each plot and over all plots. Calculating dominance and species importance in two ways made it possible to obtain values for N. fruticans despite the lack of meaningful diameter measurements to determine basal area.
Calculations for dominance, density, and species importance included trees and saplings (height > 1 m); calculations for species richness, Shannon-Weiner diversity index, and species evenness included all age/size classes.
1) Relative density (Smith 1966)
a. number of individuals of species A / total number of individuals in plot X
2) Relative dominance (Smith 1966)
a. total basal area of species A in plot X / total basal area of all species in plot X
b. total height of species A in plot X / total height of all species in plot X
If one species has the highest dominance by basal area and by height, then the species is dominant; if
maximum dominance by basal area and by height represent different species, then species are co-
3) Species importance (Smith 1966)
a. Importance value = relative density + relative dominance (by basal area)
b. Importance value = relative density + relative dominance (by height)
If one species has the highest IV by basal area and by height, then the species is dominant; if maximum IVs
by basal area and by height represent different species, then species are co-dominant.
4) Species richness
a. The total number of species per plot
5) Shannon-Weiner diversity index (H’) (Rickleffs 1993)
a. H = - ; (p)(ln p) , where p is the proportion of individuals of all species i that belong to species i iiii = 1 and s is the number of species
6) Species evenness (J’)
a. J = H / H , where H = ln s , where s is the number of species and H is determined above. maxmax
With ArcView 3.1, we created maps of mangrove vegetation characteristics in the tidal creek, displaying species dominance, species importance, and species richness data by transect and sampling plot (Figures 5-7). For Figures 5 and 6, each sampling plot was represented by one color or two colors combined as shown in Table 2. Figure 7 represents species richness by using a color gradient to show increasing number of species.
Table 2. Legend construction for Figures 5 and 6. Dominant species
are represented by a single color. The background color and the
stripping are combined to represent co-dominant species.
BC and CT BC (Background color) CT (Foreground strips)
GPS Survey and GIS Mapping of Koh Phra Thong
An accurate map of the island was prepared to provide a base map for the field survey. We obtained a +Landsat ETM (130/54) satellite image of Koh Phra Thong on 15 January 2002. A bathymetric map of the island produced in circa 1960 was scanned, digitized, and georeferenced to represent landforms in the geographic information system (GIS).
We surveyed different ecological zones of the island by foot, jeep, and long-tail boat. The survey was intended to be a coarse-resolution characterization of the different habitats and to provide an estimate of the areal extent of mangroves on the island. We surveyed most of the island’s west coast on foot; the interior of the island was explored by jeep and on foot; the north and east coasts, and the main north-south channel were visited by boat and on foot. Our ground surveys focused especially on savannah areas within 5 km of the Golden Buddha Beach Resort and on mangrove areas in the main tidal channel and at several locations on the north coast. We obtained GPS coordinates at regular intervals or to note a change in the ecological gradient; at each point, we took digital and 35-mm photographs and recorded general observations on the topography, landform features, soils, dominant vegetation, other species present, visual estimates of percent canopy cover, and descriptions of human impacts.
Field data were compiled in a MS Access 2000 database (FieldSurvey.mdb) and related to the base map using ArcView 3.1. Field data and site photographs are thus linked to spatial locations in the GIS database, providing the ability to produce many different maps and spatial analyses. We created a map to
show the locations of different vegetation zones and land units (Figure 8). The field survey database and GIS provide a way to integrate this preliminary survey data with data from future monitoring efforts.
Throughout the study period, we collected representative specimens from mangroves and mangrove-associates, for inclusion in the herbarium reference collection. We laid the specimens on newspaper and pressed them between thin wooden boards weighted with rocks. We did not have access to a dry or air-conditioned room to preserve our samples. Exposure to high humidity and heat during the rainy season probably enhanced the rate of fungal growth on our samples. We determined that under these field conditions, assembling and preserving a viable herbarium collection was unrealistic.
As an alternative, we used MS Access 2000 to develop a searchable database (Herbarium.mdb) with digital images, essentially a virtual herbarium, containing descriptions (family, genus, species, habitat, etc.) and photographs of characteristics for each species (growth form, roots, bark, flowers, fruit, and leaves). This database has a greater likelihood of survival and utility under the conditions at Koh Phra Thong, compared to a traditional herbarium collection.
Mangrove Nursery and Restoration
Our restoration activities included the establishment of a mangrove nursery and a revegetation experiment. We established a mangrove nursery by planting propagules of different species in two zones near the mouth of the tidal creek (rocky erosional environment and a backwater area). We also conducted a more structured revegetation experiment according to stratified random block design: we planted six species’
propagules in two treatment areas, an open mudflat and an adjacent mudflat occupied by a mostly dead Rhizophora mucronata, and crossed by two flooding treatments (high zone and low zone), to see if there was any relation between seedling success and tidal flooding, and between seedling success and openness of habitat (Figure 3). We monitored the plots one week and three weeks after planting. Future monitoring should report presence/absence, evidence of predation or other damage, number of leaves, condition, and height.
Roots (treatment) Open (control)
high zone ?3-4 m? high zone ?3-4 m?
1 2 3 6 1 2 5 6 1 4 5 6 3 4 5 1 2 3 6 1 2 5 6 1 4 5 6 3 4 5
4 5 6 3 4 5 2 3 4 1 2 3 6 1 2 4 5 6 3 4 5 2 3 4 1 2 3 6 1 2 4-5 m low zone ?3-4 m? low zone ?3-4 m?
1 2 3 6 1 2 5 6 1 4 5 6 3 4 5 1 2 3 6 1 2 5 6 1 4 5 6 3 4 5
4 5 6 3 4 5 2 3 4 1 2 3 6 1 2 4 5 6 3 4 5 2 3 4 1 2 3 6 1 2
1 Rhizophora apiculata 3 Avicennia marina 5 Rhizophora mucronata
2 Bruguiera cylindrica 4 Ceriops tagal 6 Nypa fruticans
Figure 3. Schematic representation of the revegetation experimental design.
We prepared informational posters and an instructional board game based on the mangrove food web. In collaboration with staff from RCRRS, we presented short lessons to students, from kindergarten to middle school, at the three schools on the island. We also explained the importance of mangroves and conservation to GBBR staff and guests.
Results and Discussion
Our intensive sampling in the tidal creek and our more general survey of mangrove areas throughout the island yielded a list of 39 mangrove and mangrove-associate species, presented in Table 3 according to Family and by presence/absence in each monitoring plot. The two-letter symbols we use to refer to species in figures below are also given in Table 3. We feel reasonably confident in most of the species identifications, with the following known exceptions, usually related to the lack of flowering or fruiting structures:
1) Lumnitzera littorea and Lumnitzera racemosa are such tall trees that examining their leaves and
flowers (when present) was impossible;
2) Distinguishing between Acanthus ilicifolius and Acanthus ebreactus is difficult, particularly
because both species have varying leaf morphologies;
3) Bruguiera species, especially when young seedlings, were difficult to identify without their
distinctly recognizable propagules or flowers;
4) Ceriops decandra may have been misidentified as Ceriops tagal throughout the field study
(Neither species was in bloom during July-August).
Given that this was a preliminary study, we are confident that any discrepancies will be discovered and corrected in the course of ongoing monitoring and with more experience. Staff from RCRRS were helpful in identifying species, but the best tools will be a reliable herbarium reference collection and the acquisition of Aksornkae et al. (1992) and Tomlinson (1984) for the project’s permanent collection.
These two sources are a good beginning, but they do not include enough detailed descriptions of all the species encountered: other reference books should also be sought.
Permanent Monitoring Plots
For each plot, we recorded soil type, general observations, evidence of human impacts, and any animals seen or heard (Table 4). In general, we found soils to be muddier closer to the creek and sandier farther from the creek. We estimated canopy cover in 13 of 26 sampling plots. Our estimates of canopy cover ranged from 20% at T03RA to 80% at T03RE, with an average of 50% cover. Human impacts were of two types: litter and cut trees. Litter was primarily coconuts, clam shells, polystyrene, and plastic bags, either dumped directly or washed in by tidal flooding. Cut trees were often Ceriops spp. and N. fruticans.
It is well known that several mangrove species, in particular N. fruticans, are used by Thai villagers as
building and roofing materials, as well as for food and medicinal purposes. Cutting activities were more significant than litter in terms of impact to the mangrove community. It appeared that young trees were sometimes cut and left behind; perhaps they were cut to gain access to a larger tree. We did not encounter more than one or two instances of large cut trees. The removal of small trees or parts of Nypa palms
(particularly when the heart is not damaged), is likely to have a relatively minor impact on the mangrove community, compared to the removal of a large, dominant tree.
Our observations of animals were not intended to be quantitative; rather they were haphazard, and thus biased toward easily visible and recognizable animals. However, we noted animal activities that shape the mangrove community and merit further study. For example, mounds created by the mud lobster (Thalassina spp.) create major local differences in elevation, altering the extent of flooding and soil aeration. We noted that Phoenix paludosa tends to grow in these raised areas. Mud crabs and fiddler
crabs were almost ubiquitous; they influence soil characteristics by aerating the soil with their burrows
Table 3. Mangrove and associate species are listed by family. Presence is indicated by “P;” absence is indicated by a blank cell.
T01L T01R T02L T02R T03L T03R yyy D E A B C D E A A B C D E A B C D E A B C D E A B CFamily Genus Species Abbr
Acanthaceae Acanthus ebreactus AE P Acanthaceae Acanthus ilicifolius AV P P P P P P P P P P P P P P Acanthaceae Acanthus volubilis AI P X Apocynaceae Cerbera odollamCO Asclepiadaceae (Periplocaceae) Finlaysonia maritima FM P P P P P P P P P P Avicenniaceae Avicennia alba AA P P Avicenniaceae Avicennia marina AM P P P P x Avicenniaceae Avicennia officinalisAO Combretaceae Lumnitzera littorea LR P P P Combretaceae Lumnitzera racemosa LL P Combretaceae Lumnitzera spp. Lsp P Ebenaceae Diospyros areolata DA P Euphorbiaceae Excoecaria agallocha EA P P P P P P P P P P P P P x Lecythidaceae (Barringtoniaceae) Barringtonia racemosaBR x Leguminosae – Caesalpinoidae Caesalpinia cristaCC x Leguminosae – Caesalpinoidae Intsia bijugaIB Leguminosae – Papilionoidae Dalbergia candenitensis DC P P P P P Leguminosae – Papilionoidae Derris indica DI P Leguminosae – Papilionoidae Derris trifoliata DT P P P P P P P P P P P P P x Malvaceae Hibiscus tiliaceusHT Meliaceae Xylocarpus granatum XM P P P P P P P P Meliaceae Xylocarpus molluccensis XG P Myrsinaceae Aegiceras corniculatum AC P P P P P P Palmae Nypa fruticans NF P P P P P y y y P P P P Palmae Phoenix paludosa PP P P P P P P P P P y y y P P P Plumbaginaceae Aegialitis rotundifolia AR P x Pteridaceae Acrostichum aureumAA2 Rhizophoraceae Bruguiera cylindrica BC P P P P P P P P P P P P P x Rhizophoraceae Bruguiera gymnorrhizaBG x Rhizophoraceae Bruguiera parvifloraBP x Rhizophoraceae Bruguiera sexangulaBS Rhizophoraceae Bruguiera spp. Bsp P P x,zRhizophoraceae Ceriops decandra CD zRhizophoraceae Ceriops tagal CT P P P P P P P P P P P P P P P P P P y y y P P P P Rhizophoraceae Rhizophora apiculata RA P P P P P P P P P P P Rhizophoraceae Rhizophora mucronata RM P P P P Rubiaceae Scyphiphora hydrophyllacea SH Rutaceae Atalantia monophylla AM2 P x Sterculiaceae Heritiera littoralisHL x Tiliaceae Brownlowia tersaBT Verbenaceae Clerodendrum inerme CI P xyzThis species was observed but did not occur in a sampling plot. Plots (T03LC-E) were estimated to be similar to plot T03LB in composition. C. decandra may have been mistaken for C. tagal.
and directly impact mangroves by feeding on propagules and seedlings. Mudskippers (Periopthalmus
spp.) and the sounds of pistol shrimp were common also. In the turbid waters of rising tides, we sometimes saw yellow and black spotted puffer fish, small red fish, and small blue fish, but this is not useful for species determination. We only observed one mammal species: we commonly encountered macaques throughout the tidal creek area and at one sampling plot (T01LA). In fact, the macaques were very displeased by our presence and both adolescent and larger males harassed us by screeching, baring teeth, and shaking nearby trees. We noted that macaques digging in crab burrows create a disturbance in the soil. There was much evidence of leaf herbivory – most mangrove trees seemed to sustain significant
grazing – but we did not record any herbivorous insects. Occasionally, we observed birds such as hornbills or kingfishers, but it is well known that they are not obligate residents of mangroves in Thailand.
Future surveys could be expanded to include benthic invertebrates, amphibians, reptiles, fish, and tree-dwelling insects. It would be interesting to couple data from faunal surveys with vegetation data and a more quantitative determination of environmental factors (such as soil type and texture, salinity, flood duration and extent, and elevation), to obtain a comprehensive picture of habitats and communities. We might then be able to identify patterns and associations between fauna, abiotic factors, and vegetation.
We identified and measured each tree, sapling, and seedling in each permanent monitoring plot, except for plots T03LC, T03LD, and T03LE, where we visually estimated that species composition was similar to plot T03LB. Summary statistics, including values that are displayed in Figures 4-7, are shown in Table 5.
The density of trees and saplings was highest at intermediate distances from the tidal creek and highest in the transect (T02) in the intermediate position along the coastal-to-inland gradient (Figure 4). This presents an interesting pattern, suggesting that mangroves are more abundant in zones that are sheltered from the coast or more successful in zones of intermediate salinity. There are many other possibilities too, such as local geomorphology, disturbance history, or competition between species, but our data are not extensive enough to draw meaningful conclusions. It would be helpful to collect more data along a salinity gradient in similar tidal creeks.
Species dominance also appeared to have some spatial patterns, but not based on distance from the creek (Figure 5; Table 5). We found a high degree of heterogeneity in this mangrove area, as adjacent plots had different dominant species, plots on different sides of the same transect were markedly different, and there were important differences along the coastal-to-inland gradient. The co-dominance of Ceriops spp.
and N. fruticans in the two transects farthest inland is an emergent characteristic, which can be easily hypothesized by observation in the field. One striking result of these calculations, however, is the small number of plots in which Rhizophora spp. are dominant or co-dominant. This fact calls attention to a
methodological problem, as we explain below.
We encountered two difficulties in applying traditional forest census methods to mangroves, both related to basal area. Species dominance is traditionally determined using basal area (through a measurement of diameter at breast height – DBH) to establish which species occupies the most space in an area.
Measuring basal area for the two species of palm in our study area does not apply, because there is no true stem. They must be included, however, as they represent a large proportion of biomass in many of the plots, particularly farther inland. Therefore, we determined species dominance in two ways, based on basal area and on height. The second problem is related to the massive, multi-trunked Rhizophora spp.,
which have aerial roots branching from stems over 3 m from the ground and often have new stems growing from aerial roots.
Table 4. General observations and descriptions of soil, human impacts, and fauna were recorded in each permanent
monitoring plot. Percent canopy cover was estimated in 13 of 26 plots.
Code Substrate % Cover Animals Observed Human Impacts Observations T01LA Muddy, rocky, mollusks mudskipper, macaques 1 cut CT interrupted by hostile macaques T01RA Muddy sand, slightly organic 20 mud lobster (mounds), mudskipper, 1 cut CT (1.5m) heard bird songs, saw clam and fiddler crab periwinkle shells, transparent fish (red and blue) T01RB surface mud, coarser lower mud lobster (mounds), hornbill (flying 2 RA (1.5m tall) cut; plastic large dead stump down overhead), polychaete, clam (shells debris, cut top of another RA, observed), mudskipper polystyrene
T01RC Muddy sand mud crab, mud lobster (mound), 1 cut tree and 1 cut B spp., 1 dead tree mudskipper, clam rubbish, 7 cut and left behind, 1 cut palm
T01RD Muddy sand 60 mud crab, small fish, mud lobster 2 cut CT, rubbish (mound), mudskipper
T01RE Muddy sand 80 moth, mud lobster (mound) cut trees (some newly cut) T02LA thin layer of mud darker 30 fiddler crab, mud crab, mudskipper, cut NF and RM; plastic bags black below cicadas (heard), ants
T02LB mud, sulfur smell mud crab, mud lobster (mounds) cut NF; garbage lot of FM ground cover; tidal creek T02LC Sandy 30 mud lobster (mounds), mudskipper cut CT, other cut trees T02LD Sandy 40 mudskipper, mud lobster (mounds) cut CT, other trees, coconuts T02LE Sandy, leaf litter 50 mud crab, mudskipper, mud lobster cut CT, lots of cut trees (mound), ants, mosquitoes
T02RA muddy sand mosquitoes, mudskipper, pistol shrimp (heard), mud lobster (mounds), butterfly, ants, mud crab
T02RB muddy sand mud lobster (mound), pistol shrimp CT cut X spp; a big Rhiz tree struck by (heard) lightning? (107 cm girth) T02RC muddy sand 60 clam, mud crab, fish, butterfly polystyrene; cut tree tree dead (of natural causes?) T02RD sand and mud 60 mud lobster (mounds), fish, butterfly, CT cut; PP cut big LL dead clam, mud crab
T02RE Sand 2 cut CT; litter T03LA Muddy 30 T03LB Muddy trash T03LC Muddy butterfly, crickets, mudskipper, mud lobster (mounds), mud crab, clam
T03LD Muddy crickets, mudskipper, butterfly, mud lobster (mounds), clam
T03LE Muddy snail, clam, butterfly, mudskipper T03RA Muddy 70 fish, mud lobster (mound), mudskipper, clam, mud crab, pistol shrimp (heard)
T03RB Muddy spider, moth, mudskipper, mud lobster coconut; polystyrene; cut trees (very tall mound), mud crab, fish, ants, (2 CT DBH 40 cm; 2 palms) puffer fish
T03RC Muddy T03RD mud with organic sand 60 cut palms underneath
T03RE muddy sand 50 cut palms
Average canopy cover 50%