Growth performance and heritability were studied in a progeny trial of Acacia crassicarpa in Chacheongsao province, eastern Thailand in order to provide information on suitable families for seed improvement and production. A randomized complete block design (originally 8 blocks, 80 family plots/ block, 4 trees/plot) of the best 80 half-sib families selected from 7 provenances was thinned at ages 2.5, 4 and 5 years based on growth and tree form and so that there was one tree/ plot remained at the stage of present study. All remaining trees were measured for diameter at breast height (DBH), tree height (H), individual volume (VOL) and stem form (straightness and forked height) at ages 12, 12.5, 13 and 13.5 years, respectively. Narrow sense heritability (h 2 ) based on family was estimated for each characteristic. Analysis of variance showed that there were highly significant differences among families at the four ages for DBH, H and VOL. Stem straightness and forked height were not significantly different among families. The heritability of DBH was increased as trees were mature (h 2 = 0.236, 0.285, 0.288, and 0.291) but those of H and VOL were a little decreased. The heritability of stem straightness was very low (0.013) and that of forked height was also low (0.138). The results implied that the tree breeding of A. crassicarpa could improve DBH, H and VOL considerably. Further selection testing is required to increase the heritability of stem form. The measured data would be useful for tree improvement and seed orchard establishment of Acacia crassicarpa.

Abstract. Oo Y, Suanpaga W, Muenpong P. 2021. Assessment of forest degradation condition in Natmataung National Park Watershed, Myanmar. Biodiversitas 22: 1354-1362. Natmataung National Park (NTNP) is an important biodiversity hotspot in Myanmar, yet it is threatened by various anthropogenic activities, leading to deforestation and forest degradation. As such, the park needs to be restored to bring back its main function of conserving biodiversity. Ecological restoration in NTNP needs assessment of forest restoration potential through forest degradation condition. This research aimed: (1) to assess forest stand parameters of tree density, basal area, Above Ground Biomass (AGB), and Above Ground Carbon (AGC) at plot level and study area level through sampling with fixed area in the NTNP watershed, (2) to compare the accessed forest stand parameters of old-growth forest (OF) and secondary forest (SF) (per plot individual level and per stem individual level) and tree species richness and diversity of OF and SF (per plot individual level only) in order to know the forest degradation condition. A total of 69 square plots were sampled to achieve such aims. This study found two main results: (1) the estimation of stand parameters in both OF and SF at the plot level and study area level had acceptable statistical proration: (2) stand parameters at stem level had significant differences in which OF had overall higher values of parameters than in SF. Based on the results of this study, we recommend that the OF sites should be conserved through sustainable forest management, while the SF sites should be restored to mimic condition in OF through the implementation of assisted natural regeneration (ANR) with highest dominant native tree species, and the abandoned fallow lands should be restored using pioneer native tree species.

The objective of this research was to analyzed the relationship of vegetation index and biomass of mangrove forest plantation in in Don Sak national reserved mangrove forest, Don Sak district, Surat Thani province. The methodology was conducted by analysis relationship between the five vegetation indices, and five reflectances calculated from LANDSAT 8 satellite imagery which has a resolution of 30 meters and the data from field biomass survey. The proportional stratified sampling system classified by the age class; tree aged between 1-19 years, 14 age classes, three sample plots per age class, plot size 15x15 meters. The diameter and height of all trees in sample plot were collected for biomass calculation by using allometric equation. The result of this study found that the general linear and quadratic relationship of green radiance (G) and biomass were significant (Biomass = -1,318.715*(G) + 129.191, R 2 = 0.702; Biomass = 462.134 -9,002.43(G) + 43,823.11(G 2 ) , R 2 = 0.786) Meanwhile, there was no relationship between other vegetative indexes and biomass. Index Terms-Biomass, LANDSAT 8, mangrove, vegetative index.