Responses of the mangrove Rhizophora mucronata to high salinities and low osmotic potentials

The effect of solutions of seawater or non-saline polyethylene glycol (PEG)-6000 on dry mass, tissue water potential, stomatal resistance and inorganic solute uptake were investigated in the mangrove, Rhizophora mucronata Lam. Plants were treated with solutions of seawater or PEG-6000 at osmotic potentials of −0,05, −0,5, −1,2 and −2,4 MPa for three weeks. Generally, effects of salinity and PEG-6000 were similar. Low external osmotic potentials decreased root mass, lowered tissue water potentials, increased stomatal resistance and influenced distribution of Na, K, Ca and Mg in tissues. The similarity of the responses of the plants to salinity and PEG-6000 suggests that the effects of salinity are mediated primarily through low osmotic potentials and not by salinity per se

Physiology of Salt Excretion in the Mangrove Avicennia marina (Forsk.) Vierh

Diurnal and long‐term excretion by leaves of Avicennia marina seedlings growing in aqueous culture was correlated with substrate salinity and transpiration. Excretion was greater in 100% than 50% seawater but the reverse was true for transpiration. The diurnal excretion pattern, with exudation minimal during the day and maximal during the night, showed a negative correlation with the daily transpiration pattern. The total amount of salt excreted, however, showed a positive correlation with the total amount of water transpired. Root and xylem sap salinities were linearly related to substrate salinity but leaf Na+ increased to a maximum, indicating that control of leaf salt content is at the foliar, rather than the root level

Coastal Zones of the Arid Tropics and Pastoral Systems: Focusing on Human-Camel Relationship

The purpose of this paper is to establish a general framework within which to consider pastoral systems in the coastal zones of the arid tropics, focusing on humancamel relationships. Points at issue were determined by reviewing literature related to three topics: 1) pastoral systems in the arid tropics; 2) pastoralists living in its coastal zones; 3) human-camel relationships. As a results of these analyses, I set up twelve topics for discussion: 1) What kinds of water do one-humped camels and camel pastoralists drink to live in the coastal zones of the arid tropics? 2) Which species of plants do one-humped camels graze there? 3) What are the differences in pasture utilization between one-humped camels and other livestock there? 4) Which species of biological resources in addition to plants do camel pastoralists utilize there? 5) How do the coastal physical environments determine biological resource utilization of camel pastoralists? 6) What kinds of niches do onehumped camels occupy in the coastal ecosystems in terms of resource patch accessibility and availability? 7) How do camel pastoralists refer to the physical environments and how do they classify them? 8) How do camel pastoralists refer to the biological environments and how do they classify them? 9) How do camel pastoralists refer to the one-humped camel and how do they classify them? 10) Which species of biological resources of the coastal zones of the arid tropics are traded, and to what extent are they traded? 11) What roles do one-humped camels play in the broader network building and inter-ethnic relationships? 12) How do the natural environments and pastoral systems of the coastal zones of the arid tropics affect the survival of ethnic groups? Finally, I summarize my discussion on some basic data from a case study of the Beja on the Red Sea coast in Eastern Sudan, and propose a direction for my study of pastoral systems in the arid tropics

Respon Pertumbuhan Dan Komposisi Isoprenoid Semai Acanthus Ilicifolius Linn

The purpose of this study is to analyze growth of A. ilicifolius seedling in response to salinities and its isoprenoid composition. The mangrove seedling were grown under different salinities for 5 mounth. The maximum growth of A. ilicifolius seedlings was in 0.5 % salinity and this elevation appeared to be attenuated by increasing of salinity. The results showed the composition of the isoprenoid in A.ilicifolius were consist of four phytosterols namely stigmasterol, campesterol, β-sitosterol, cycloartenol, and six triterpenoids : taraxerol, β-amyrin, germanicol, betulin, α-amyrin and lupeol. This research may provide information the characterization of triterpenoid and phytosterol of A. ilicfolius seedlings

Karakterisasi Senyawa Isoprenoid Dan Pertumbuhan Semai Mangrove Avicennia Alba Bl.

This study aims to determine the characterization of isoprenoid compounds in the mangrove A. alba and seedling growth of A. alba at different levels of salinity. The results showed the total lipids in the leaves of A. alba (21 mg) was higher than that in the roots (11,7 mg). Total Non Saponifiable Lipids (NSL) content in the leaves of A. alba (1,1 mg) greater than that in the roots (0,6 mg). NSL composition of A. alba consists of 3 major factions namely triterpenoids, phytosterols, and other compounds. Phytosterol composition in the leaves and roots of A. alba showed the presence of compounds such as campesterol, stigmasterol and β-sitosterol. As frase for the composition triterpenoid found the presence of β-amyrin, germanicol, betulin, lupeol and α-amyrin. Phytol, cholesterol, and squalene were also found as the other compounds. The content of the NSL triterpenoid was higher than phytosterol in the leaves and roots of A. alba. The results also showed that phytol compounds had the highest content of leaves of A. alba (71.4 %) and the β-sitosterol had the highest content of root A. alba (27.8 %). Based on the analysis of the effect of salinity on seedling growth of A. alba showed that the salinity of 2% significantly affected the seedling height and diameter of 3 months of A. alba

Respon Pertumbuhan Dan Biomassa Semai Rhizopora Apiculata BI Terhadap Salinitas Dan Kandungan Lipidanya Pada Tingkat Pohon

Growth and biomass Rhizopora apiculata BI seedlings under varied salinities and their lipid content at tree stage. The research was conducted at Green house, Faculty of Agriculture and Research Laboratory, Faculty of Pharmacy, University of North Sumatra from August 2011 to July 2012. This study aims to determine the effect of salinity on the growth and biomassa of mangrove non secreter R. apiculata seedlings level and lipid and NSL (Nonsaponifiable Lipids) content at tree level. Five levels of salinities of 0%, 0.5%, 1.5%, 2%, 3% were treated and seedlings were planted for 5 months. The results showed that maximum growth of R. apiculata seedling at 1.5% concentration, leaf number and leaf area were in the salinity of 0.5%. Stem and root biomass achieved in 1.5%, while the leaf biomass in the salinity of 0.5%. The content of total lipid and NSL obtained from the leaves and the roots R. apiculata tree. The content of total lipid R. apiculata trees in the leaves (9.60 mg) were more amounts than in the roots (6.40 mg). NSL content of R. apiculata trees in the roots (0,226 mg) were more than in the leaves (0.10 mg). The results of this study may provide information to the rehabilitation program in order to obtain R. apiculata seedlings growing best based on their salinities

Pertumbuhan Dan Komposisi Rantai Panjang Polyisoprenoid Pada Mangrove Avicennia Marina (Forsk). Di Bawah Cekaman Salinitas

Mangrove plants have ability to remove excess of salt and contain secondary metabolite to adapt to wide salinity. The purpose of this study was to determine the best salinity level for growth of A. marina seedlings and to evaluate the effect on long-chain polyisoprenoid composition. A. marina seed was used with 5 treatments,-i.e 0%, 0.5%, 1.5%, 2%, and 3% grown for 3 months. Results showed that the optimum growth characterized by height, number of leaves, wet weight of root, wet weight of shoot, dry weight of root, dry weight of shoot, and ratio of shoot to root of A. marina seedlings in 2% concentration. The optimum of diameter was in 0% salinity. Polyisoprenoid showed that A. marina seedlings in 3% salinity was higher content than control. Key Words : Mangrove, Avicennia marina, Salt Salinity, Polyisoprenoid, Secondary Metabolite

Mosquito production and hydrological capacity of southeast Florida impoundments used for wastewater retention.

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How South Pacific mangroves may respond to predicted climate change and sea level rise

In the Pacific islands the total mangrove area is about 343,735 ha, with largest areas in Papua New Guinea, Solomon Islands, Fiji and New Caledonia. A total of 34 species of mangroves occur, as well as 3 hybrids. These are of the Indo-Malayan assemblage (with one exception), and decline in diversity from west to east across the Pacific, reaching a limit at American Samoa. Mangrove resources are traditionally exploited in the Pacific islands, for construction and fuel wood, herbal medicines, and the gathering of crabs and fish. There are two main environmental settings for mangroves in the Pacific, deltaic and estuarine mangroves of high islands, and embayment, lagoon and reef flat mangroves of low islands. It is indicated from past analogues that their close relationship with sea-level height renders these mangrove swamps particularly vulnerable to disruption by sea-level rise. Stratigraphic records of Pacific island mangrove ecosystems during sea-level changes of the Holocene Period demonstrate that low islands mangroves can keep up with a sea-level rise of up to 12 cm per 100 years. Mangroves of high islands can keep up with rates of sea-level rates of up to 45 cm per 100 years, according to the supply of fluvial sediment. When the rate of sea-level rise exceeds the rate of accretion, mangroves experience problems of substrate erosion, inundation stress and increased salinity. Rise in temperature and the direct effects of increased CO2 levels are likely to increase mangrove productivity, change phenological patterns (such as the timing of flowering and fruiting), and expand the ranges of mangroves into higher latitudes. Pacific island mangroves are expected to demonstrate a sensitive response to the predicted rise in sea-level. A regional monitoring system is needed to provide data on ecosystem changes in productivity, species composition and sedimentation. This has been the intention of a number of programs, but none has yet been implemented