Showing papers on "Excoecaria agallocha published in 2007"

Impact of solid shrimp pond waste materials on mangrove growth and mortality: a case study from Pak Phanang, Thailand

Abstract: One of the most serious threats to tropical mangrove ecosystems caused by shrimp farming activities is the poor management of pond waste materials. We hypothesise that mangroves can tolerate chemical residues discharged from shrimp farms and can be used as biofilters, but the capability of mangroves to cope with solid sediments dredged from shrimp ponds is limited. Our study in Pak Phanang, Thailand, confirmed that the excess sediments discharged from nearby shrimp ponds reduced mangrove growth rates and increased mortality rates. A series of transformed multi-temporal satellite images was used in combination with the field data to support this claim. In addition, a comparison between four dominant mangrove species revealed that Avicennia marina could tolerate sedimentation rates of >6 cm year−1, while Bruguiera cylindrica tolerated sedimentation rates of 5 cm year−1 (total sediment depth = 25 cm) before dying, while Excoecaria agallocha and Lumnitzera racemosa performed intermediate. This outcome implied that in our situation A. marina and to lesser extent E. agallocha and L. racemosa could be more effective as biofilters than B. cylindrica, as they may survive the sedimentation longer in the disposal areas. Further studies on the impact of sedimentation and chemical pollution of shrimp farm wastes on mangrove mortality and growth are required.

Biological Diversity Assessment of Tok Bali Mangrove Forest, Kelantan, Malaysia

Abstract: This paper attempts to give information about the structure of mangrove distribution at Tok Bali, Kelantan in order to initiate for management and rehabilitation program. A study was conducted in July to November 2006 to determine the species composition, diversity index and above-ground biomass in 15.8 ha Mixed Mangrove Forest. A transects forest profile length of 30 meter and 20 plots were established, a Diameter Breast Height (DBH) and height were measured and recorded, and also diversity index and above-ground biomass were determined. A total of 10 species consisting of nine exclusive and one non-exclusive mangrove were recorded. The common species found were Sonneratia alba (1,170 trees/ha, 330 saplings/ha and 22,680 seedlings/ha) followed by Ceriops decandra, Excoecaria agallocha, Avicennia alba, Bruguiera cylindrica, B. sexangula, Rhizophora apiculata, Aegiceras corniculatum, Nypa fruticans and Derris trifoliata. From the results an average of 595 trees/ha, 598 saplings/ha and 646 seedlings/ha represented a moderate good condition and regeneration potential. Total above-ground biomass was 2664.57 kg/ha and S. alba also recorded the highest because the of wide range of diameter and height. Mangrove trees showed total average of species richness (S) was 8.0, eveness (E) was 0.793 and diversity (H’) was 1.603.

Biological Diversity Assessment of Tok Bali Mangrove Forest, Kelantan, Malaysia

Abstract: This paper attempts to give information about the structure of mangrove distribution at Tok Bali, Kelantan in order to initiate for management and rehabilitation program. A study was conducted in July to November 2006 to determine the species composition, diversity index and above-ground biomass in 15.8 ha Mixed Mangrove Forest. A transects forest profile length of 30 meter and 20 plots were established, a Diameter Breast Height (DBH) and height were measured and recorded, and also diversity index and above-ground biomass were determined. A total of 10 species consisting of nine exclusive and one non-exclusive mangrove were recorded. The common species found were Sonneratia alba (1,170 trees/ha, 330 saplings/ha and 22,680 seedlings/ha) followed by Ceriops decandra, Excoecaria agallocha, Avicennia alba, Bruguiera cylindrica, B. sexangula, Rhizophora apiculata, Aegiceras corniculatum, Nypa fruticans and Derris trifoliata. From the results an average of 595 trees/ha, 598 saplings/ha and 646 seedlings/ha represented a moderate good condition and regeneration potential. Total above-ground biomass was 2664.57 kg/ha and S. alba also recorded the highest because the of wide range of diameter and height. Mangrove trees showed total average of species richness (S) was 8.0, eveness (E) was 0.793 and diversity (H') was 1.603.

Mangrove resources and conservation in Guangxi

Abstract: The mangroves distribute in Hepu county,Beihai City,Qingzhou City and Fangchenggang City in GuangxiThe total area is about 8 3749 hm2There are 15 mangrove species found in Guangxi coastOf which,11 species are true mangrove,5 species semi-mangrove,and Sonneratia apetala is the introduced plantThe mangroves could be classified into 8 formations and 15 community types,which consist mainly of 8 species such as Avicennia marina,Aegiceras corniculatum,Kandelia candel,Rhizophora stylosa,Bruguiera gymnorrhiza,Excoecaria agallocha,Acanthus ilicifolius and Heritiera littoralisThe mangroves are important oceanic resources in Guangxi,and characterized by the great potentialities of plant and animal resources,high value of ecotourism and good sites for ecological aquacultureIn order to protect the mangrove resources rationally,some suggestions were put forward in this paper

Study on the antibacterial and attifubgal activities of mangrove fungl endophytes

Abstract: Objective To isolate and screen fungal endophytes with antibacterial and antifungal activities from mangrove plantsMethods The antibacterial and antifungal activities test of fungal endophytes from mangrove plants were used by paper disc methodResults Sixty strains of endophytic fungi were isolated from Aegiceras corniculatum,Excoecaria agallocha,Kandelia candel,Bruguiera gymnorrhiza,Avicennia mariana,Heritiera littoralisThe result of the antibacterial and antifungal assay shows that thirty five strains of the endofungi(583% of total tested strains) have antibacterial activities,the active strains mostly belong to sterile groups(514 % of active strains),Penicillium(86%),Aspergillus(86%),Fusarium(86%);forty nine strains(817% of total tested strains) have antifungal activites,most of them belong to sterile groups(449 % of active strains),and Gloeosporium(171%)Conclusion Mangrove fungal endophytes were potential and rich resources of antimicrobial compounds,which need to explore further

Comparisons of leaf chloride content and leaf traits between true mangrove plants and semi-mangrove plants

Abstract: Aims Mangrove plants are usually categorized as true mangrove plants and semi-mangrove plants on the basis of their distribution in inter-tidal regions. However, the identification of some fringe mangrove species found mainly on the landward transitional zones is controversial. Specific leaf area (SLA, leaf area per unit dry mass) and mass- and area-based leaf nitrogen concentrations (Nmass and Narea) are important leaf traits for plants, but relevant comparative research on true and semi-mangrove plants is unavailable. Our objective was to determine differences between the two groups and to classify the controversial species according to their leaf traits. Ultimately, this will assist in the management, protection and utilization of mangrove forest. Methods Three individuals in similar growth sites were chosen for each species from Hainan Island. Fully expanded mature leaves were sampled from the upper canopy of all plants. Succulence (water content per unit leaf area), SLA, Nmass and Narea of mature leaves were studied for 33 species, representing all but three of the mangrove species in China. Important findings True mangrove plants accumulated more Cl and water per unit leaf area than semi-mangrove plants, except for Pemphis acidula, Hernandia sonora and Clerodendrum inerme. Cl and water content per unit leaf area of true mangrove plants were generally 2.5 mg·cm-2 and 2.4 g·dm-2, respectively. Cl concentrations were positively related to succulence for all mangrove species. True mangrove plants had low SLA (100 cm2·g-1) and high Narea; however, semi-mangrove plants had high SLA (mean of 160.4 cm2·g-1). Pemphis acidula had much lower SLA than other semi-mangrove species. Our study suggested that there are significant differences between true mangrove plants and semi-mangrove plants in leaf Cl concentration, succulence, SLA, Nmass and Narea. Heritiera littoralis, Excoecaria agallocha, Acrostichum aureum and Acrostichum speciosum are better classified as semi-mangrove plants, while Acanthus ilicifolius and Acanthus ebrecteatus are classified as true mangrove plants, and Xylocarpus granatum needs further research.

Antifungal and antibacterial activities of methanol extracts from mangrove plants

Abstract: The inhibition activities of methanol extracts from fifteen species of mangrove plants against Fusarium oxysporum fspNiveum,Pestalotia calabae Westond,Thielaviopsis paradoxa(de Seynes) VHohnel,Glorosprium musarum Cookeet Mass,Alternaria kikuchiana(Fr) Keissl,Mycosphaerella sentina (Fr) Schroeter,Sphaceloma fawcettii Jenkins,and Xanthomonas axonopodis pvcitri(Hasse) Dye were measured in laboratory by growth rate methodThe results showed that Pongamia pinnata(L) Merr,Clerodendron inerme(L) Gaertn,Aegiceras corniculata(Linn) Blanco,Excoecaria agallocha Linn,Lumnitzera racemosa Willd,Myoporum bontioides(Siebet Zucc) AGray,and Cerbera manghas Lhad significant inhibition on the pathogenic fungiAmong them,Myoporum bontioides(Siebet Zucc) AGray was the best,the EC50 values of its methanol extract for the above seven species of fungi were 332,104,257,144,163,266 and 125 mg·ml-1,respectively