General
Based on satellite
imagery, an attempt was made to assess the various vegetation
types / ecosystems present within the park boundaries. Once
established, the main ecosystems were visited and a species
assessment made.
Vegetation/Ecosystems
In the most important
ecosystems, standardized vegetation transects were established
in order to assess species composition and vegetation structure.
To facilitate the identification of the maximum number of
species, multiple visits were made to the transects (wet
season / dry season).
The methodology
used for the vegetation transects has been adapted from
the methodology used by the Forest Planning and Management
Project in Belize (Shawe, 1997). This methodology involved
the opening of a 200 meter long (and in this study, straight)
line through the vegetation under study. Care will be taken
not to remove any of the trees along the transect. The cut
line only serves to facilitate access. The actual transect
consists of a 4 m wide band along the cut line (2 m to the
left, 2 m to the right). For practical purposes, the 200
m long transect is divided into 20 separate, 10 m long segments.
In these segments, all trees with a diameter at breast height
(dbh) of more than 10 cm are counted, dbh
measured and where possible identified. Also per 10
m segment, notes will be taken on: soil type, slope, canopy
height and canopy cover.
With the data
thus obtained, several biodiversity indices were calculated
for each transect: these indices included a) the number
of species (N0 ), b) the number of abundant species (N1),
c) the number of very abundant species (N2), d) the Shannon's
diversity index (H') in which a higher figure indicates
a higher diversity, e) the level of evenness (E5) which
looks at the number of individuals per species and in which
a high evenness (=1) indicates a high diversity and un-even
communities receive a figure < 1. and finally f) the
rarefraction at sample size of 50 trees which is the number
of species had the sample size been 50. All these biodiversity
data are useful when comparing different sites. In conjunction
with these biodiversity indices, the dominant tree species
(> 10% of total) were noted.
Also per transect
a number of structural data were abstracted such as a) the
average stem dbh, b) the number of multi-stemmed trees,
c) the number of dead trees and d) the space per living
tree in m2. These data also give some indication on the
dynamics of the transect (large dbh and no dead trees: static;
many multi-stemmed and dead trees: dynamic).
Birds
General walk-over
surveys of the site and adjacent areas were conducted both
during the daytime (from before daybreak) as well as after
dusk. Identification was both by visual and vocal characteristics.
Amphibians and
Reptiles
Amphibians were
difficult to assess within the given timeframe of the REA.
Typically, amphibians (and more specifically frogs and toads)
are monitored at the breeding sites during times of mating
activity that usually takes place in the months of June
through September. Outside these months, reliable amphibian
monitoring is not possible and dependent on opportunistic
observations as is the case for reptiles.
Mammals
Mammals were assessed
on an opportunistic basis by all of the teams. Interviews
will be held with users of the area to assess the presence
of the more conspicuous species.
Bats received
special attention. For this purpose, some "harp"
traps and mist nets were set up in favorable locations.
Additionally multiple
acoustic monitoring on several unattended monitoring
sites was carried out. This provided the most complete survey
possible for all family of bats.
Literature
Shawe, K. 1997.
Ecological Survey - Sampling Strategy and Method. Draft
report to the Forest Planning and Management Project, Forest
Department, Belmopan. 10 pp.
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