2.2. Sampling plot selection and species composition
Field studies were undertaken from August 2010 until December
2011. Five study sites were selected. The first was in a typical
primary forest (PF) in the Kog Ma Experimental Watershed area
(Fig. 1). The next two were in secondary forests, which had been
cultivated and then abandoned approximately 30 years previously:
an abandoned area far from villages in an area that had not been disturbed after abandonment (AFV) and an abandoned area near a
village where people still collected non-timber forest products
(ANV). The final two sites were in enrichment plantation forests:
a plantation of mixed species (PMS) and a plantation of one species
(PPS). The enrichment plantation species were C. acuminatissima, B.
alnoides, C. iners, D. glandulosa, and T. gymnanthera at the PMS site
and B. alnoides at the PPS site. The planted saplings were about 1 m
in height, and the forest canopies were about 10 m high at the time
of plantation. Both enrichment plantations were planted 15 years
after being abandoned for cultivation, and they were 30 years old
at the time of our study. They were planted in a random manner
at a density of approximately 500 stems per hectare. None of the
planted species had reached seed-producing size at the time of
our study (Table 1; Forest Herbarium, 2011).
For each site, we established a 1-ha (100 m 100 m) permanent
plot, which was divided into 10 m 10-m quadrats, generating
a total of 100 quadrats. At the corner of each 10 m 10-m
quadrat, we established a 2 m 2-m sub-quadrat generating a total
of 100 sub-quadrats per site. We enumerated adult trees [diameter
at breast height (DBH)P2 cm] in every 10 m 10-m quadrat,
and saplings (DBH < 2 cm; height > 1.30 m) and seedlings
(height < 1.30 m) in every 2 m 2-m sub-quadrat. All the trees,
saplings, and seedlings (including planted individuals) were tagged
and the species identified. We identified species by collecting leaf
specimens and comparing them with standard specimens in the
herbarium of the Center of National Park, Wildlife and Plant Conservation
Department (BKF). The nomenclature followed the flora
of Thailand (Forest Herbarium, 2011) and Gardner et al. (2000).
We recorded the location of trees along the x and y axes (both x
and y coordinates had a value of 0–100, inside the 1-ha plots)
and measured the DBH (1.30 m from ground level) for all trees,
while only the number of saplings and seedlings for each species
were recorded.
2.2. Sampling plot selection and species compositionField studies were undertaken from August 2010 until December2011. Five study sites were selected. The first was in a typicalprimary forest (PF) in the Kog Ma Experimental Watershed area(Fig. 1). The next two were in secondary forests, which had beencultivated and then abandoned approximately 30 years previously:an abandoned area far from villages in an area that had not been disturbed after abandonment (AFV) and an abandoned area near avillage where people still collected non-timber forest products(ANV). The final two sites were in enrichment plantation forests:a plantation of mixed species (PMS) and a plantation of one species(PPS). The enrichment plantation species were C. acuminatissima, B.alnoides, C. iners, D. glandulosa, and T. gymnanthera at the PMS siteand B. alnoides at the PPS site. The planted saplings were about 1 min height, and the forest canopies were about 10 m high at the timeof plantation. Both enrichment plantations were planted 15 yearsafter being abandoned for cultivation, and they were 30 years oldat the time of our study. They were planted in a random mannerat a density of approximately 500 stems per hectare. None of theplanted species had reached seed-producing size at the time ofour study (Table 1; Forest Herbarium, 2011).For each site, we established a 1-ha (100 m 100 m) permanentplot, which was divided into 10 m 10-m quadrats, generatinga total of 100 quadrats. At the corner of each 10 m 10-mquadrat, we established a 2 m 2-m sub-quadrat generating a totalof 100 sub-quadrats per site. We enumerated adult trees [diameterat breast height (DBH)P2 cm] in every 10 m 10-m quadrat,and saplings (DBH < 2 cm; height > 1.30 m) and seedlings(height < 1.30 m) in every 2 m 2-m sub-quadrat. All the trees,saplings, and seedlings (including planted individuals) were taggedand the species identified. We identified species by collecting leafspecimens and comparing them with standard specimens in theherbarium of the Center of National Park, Wildlife and Plant ConservationDepartment (BKF). The nomenclature followed the floraof Thailand (Forest Herbarium, 2011) and Gardner et al. (2000).We recorded the location of trees along the x and y axes (both xand y coordinates had a value of 0–100, inside the 1-ha plots)and measured the DBH (1.30 m from ground level) for all trees,while only the number of saplings and seedlings for each specieswere recorded.
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