The Avicennia And Rhizophora Mangrove Habitats In Iran Biology Essay

This survey investigates the physico-chemical fluctuations of surface H2O and dirt within Rhizophora mangle home ground and their influence processes in the Hormozgan state, South of Iran. Point trying method within transect was used for a period of one twelvemonth started from September 21th 2008. The fortnightly H2O sampling and seasonally dirty trying were conducted in Avicennia marina and Rhizophora mucronata home grounds. The comparing of average values utilizing t-test indicated that there is significantly differences among all variables including EsC, pH, EC, TSS and salt ( p & lt ; 0.01 ) , excepting DO ( p & gt ; 0.05 ) . The dirt tested besides showed important difference between two home grounds for available K, organic C, per centum of clay and silt at deepness of 0-20 centimeter, and organic C, pH, EC and per centum of sand and silt at deepness of 20-40 centimeter ( p & lt ; 0.05 ) . The consequences showed that H2O and dirt features are the most of import environmental factors straight impacting mangrove productiveness and construction. The consequences besides illustrated that the magnitude and cyclicity of the coastal systemA forces such as complex climatic conditions ( temperature ) , the handiness of H2O, physico-chemical features of environment such as EC, pH and other features related to H2O and dirt, may find the flowered and faunal composing in mangrove countries and the energy signature. Furthermore, the survey showed that deficiency of perennial flow of freshwater territory may be the ground for uniformity in dirt texture within mangrove woods. The sedimentA textureA exerts strong control on other factors such as conduction, pH, Ca carbonate, organic C, available P and available K.

Keywords: Environmental features, Seasonal alterations, Mangrove, Iran

Introduction

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The Rhizophora mangles normally occur in the intertidal zone ( Naidoo, 2009 ) within tropical and semitropical coastal rivers, estuaries and baysA of the universe ( Zhou et al. , 2010 ) , in sheltered saline to brackish environments ( Augustinus, 1995 ) . They act as a buffer between near shore and coastal/estuarine/bay environments with respect to the influence of salt government ( Ramanathan, 1997 ) . In add-on, they act as a transitional zone between land and sea, where they may have organic stuffs from estuarine or pelagic ecosystems ( Rajkumar et al. , 2009 ) .

Since the magnitude and cyclicity of the coastal systemA forces such as tides, foods, hydro-period and emphasiss such as cyclones, drouth and salt accretion may largely find the flowered and faunal composing in mangrove countries and the ‘energy signature ‘ ( Saravanakumar et al. , 2008 ) . Therefore, it has been suggested that mangrove functional and structural belongingss are influenced by a composite of climatic conditions, the handiness of H2O, dirt construction and some environmental physico-chemical features such as temperatures, EC, pH and others related to H2O and dirt ( Augustinus, 1995 ) .

On the other manus, distribution of foods and organic stuffs, which are chiefly based on season, tidal conditions and fresh water flow, find the birthrate potency and good health of Rhizophora mangle ecosystems ( Bragadeeswaran et al. , 2007 ; Saravanakumar et al. , 2009 ) . Therefore, it has been proposed that the magnitude alterations in the microclimate matched with season are finally reflected in the environmental parametric quantities ( and microhabitat besides ) , which have a direct or indirect influence over the alimentary rhythm, abiotic and biotic procedures in coastal environments ( Bala Krishna Prasad & A ; Ramanathan, 2009 ) , which in bend have an of import consequence over the craniate and spineless population. Therefore, appraisal of environmental quality is an of import facet of developmental activities of the Rhizophora mangle parts ( Saravanakumar et al. , 2008 ) . Although a figure of writers have studied the physical and chemical features of some Persian estuaries and Rhizophora mangles ( Danehkar, 1994 ; Safa, 2006 ) , such surveies have non been attempted in the Hormozgan seashore of Persian Gulf and Oman Sea, and merely small information is available on the physico-chemical facets of the Hara Protected Area ( HPA ) and Gaz River and Hara River Deltas ( GHRD ) Rhizophora mangle woods ( Danehkar & A ; Jalali, 2005 ) . Hence, the present probe attempted to enter some important physio-chemical variables of the Rhizophora mangle surroundings of Hormozgan state in the HPA and GHRD.

Similarly, Rhizophora mangles are particularly adapted to last conditions of high salt, low dirt H2O potency and waterlogging ( Naidoo, 1985 ) , therefore, the fluctuation in flora construction along environmental gradients is a common happening in mangrove systems ( Naidoo, 2009 ) . Two mangrove species of Avicennia marina and Rhizophora mucronata occur in the southern seashore of Iran within Persian Gulf and Oman Sea ( Safiari, 2002 ) . These two sorts of Rhizophora mangles display typical morphological, structural, physiological and floristic features ( Mendez Linares et al. , 2007 ; Naidoo, 1985 ) . Avicennia is normally the innovator of the Rhizophora mangle association and characteristically occupies the offshore part of the swamp. While, Rhizophora occurs at mid-tidal degree. Rhizophora normally occurs along the brook and ooze channels because it requires good saturated, but non excessively saline dirts ( Naidoo, 1985 ) . Furthermore, type of Avicennia appears to turn on land less waterlogged than does Rhizophora, nevertheless, in some countries there are assorted bases of both sorts. Therefore, it is by and large considered that type of Rhizophora mangle might besides be associated to alterations in environmental status such as H2O and dirt parametric quantities. It besides seems clear that the alterations in microhabitat due to construction of floras exert a controlling function on maps. Furthermore, fluctuations in microclimate of Avicennia and Rhizophora Rhizophora mangle woods are of involvement because both affect providing nutrient resources, shelter, nesting and perching sites for broad scope of species and may besides do alterations in comparative copiousness of waterbird species composing.

Since differences in construction of home grounds have been attributed to a assortment of environmental factors such as H2O parametric quantity and dirt variable ( Naidoo, 2009 ) , the purpose of this probe was to find the differences of H2O and dirt feature, individually in two types of Rhizophora mangle home ground.

MATERIAL AND METHODS

Study Area. This survey was conducted at two types of Rhizophora mangle forest home ground in Hormozgan Province, Iran. Avicennia marina is the pure base in the Hara Protected Area ( HPA ) Rhizophora mangle wood, which is situated at 26Es 23I„ – 26Es 59I„ N and 55Es 32I„ – 55Es 48I„ E. Rhizophora mucronata is located in the Rhizophora mangle woods of Gaz and Hara Rivers Delta ( GHRD ) in 26Es 30I„ – 26Es 50I„ N and 57Es 00I„ – 57Es 40I„ Tocopherol.

Hara Mangrove Reserve or ‘Khouran Passs ‘ is located in the southern Persian Gulf between the part of the Mehran River and Kol River deltas and the island of Qeshm, within quarter-circle of 26Es 23I„ – 26Es 59I„ N and 55Es 32I„ – 55Es 48I„ E. Within the passs, there are 100,000 hour angles of low-lying islands, Rhizophora mangle, mudflats and brook which constitute much of the largest mangrove/mudflat ecosystem in Iran. The average lower limit and maximal temperature are 2EsC and 48EsC, severally. The average one-year temperature is 27.6EsC, over a 30 twelvemonth period ( 1975-2005 ) at the Qeshm meteoric station. The average one-year rainfall in the Hara Protected Area ( HPA ) is about 80.3 millimeters and chiefly occurs in the winter. The average monthly comparative humidness is 83.4 % and the scope of high tide is 4.33 m from the Port of Shahid Rajaee, nearest to the survey site.

The Gaz River and Hara River Deltas ( GHRD ) international wetland, with 15000 ha country, is a big country of intertidal mudflats, mangrove swamps and flaxen beaches at the oral cavities of two rivers on the eastern shore of the Straits of Hormoz, at the entryway to the Persian Gulf ( Danehkar, 1994 ) . The oral cavity of the Gaz River is situated at 26A°50I„N 57A°40I„E while the oral cavities of Hara ( Hivi ) River is situated at 26A°30I„N 57A°00I„E. The average lower limit and maximal temperature are 3.5EsC and 49.6EsC severally. The average one-year temperature is 26.5EsC, in a 30 twelvemonth period ( 1975-2005 ) at the Minab meteoric station. The average one-year rainfall is about 40.6 millimeters and besides the lowest average monthly rainfall ( 0 millimeter ) occurred over 6 months, between April and October. The highest monthly rainfall ( 19.6 millimeter ) occurred in January, while the average one-year comparative humidness is 77.9 % .

Sampling Design. Point trying method ( within transects ) were used in our survey. Each site was divided by many intertidal channels. A sum of three transects had been detected on the map indiscriminately within 3 chief channels. Transects were run parallel to creek at the pre-decided locations distributed in each country. A sum of 35 point count Stationss ( 300 m apart from each other ) were established within transect 1, 30 points in transect 2 and 32 points in transect 3, indiscriminately in the HPA. Similar tendencies spread on GHRD, which 30 points were established within each transect.

The survey was conducted from 22 September 2008 to 21 September 2009. Sampling was carried out over 12 months or four seasons including autumn ( 22 September-21 December ) , Winter ( 21 December- 20 March ) , spring ( 21 March- 20 June ) , summer ( 21 June- 21 September ) .

Survey Design. Surface H2O was collected in situ from the surface, at 10 – 25 centimeter deepness at 3 random places per secret plan, 2 times in the every month ( semiweekly ) . The physico-chemical factors of surface H2O, including the rate of temperature ( A°C ) , sourness ( pH ) , dissolved O ( DO ; g L-1 ) , electrical conduction ( EC ; dS cm-1 ) , turbidness ( TSS ; mg L-1 ) and salt ( g L-1 ) were measured in situ with three reproduction in each trying points in each visit utilizing a portable trial Horiba ( theoretical account Horiba U-10 Multi parametric quantity Water Quality Meter ) and a digital salt metre ( theoretical account Koi Medic Salinity Meter ) . All H2O samples were collected from the surface, at 10 – 25 centimeter deepness at 3 random places per secret plan. This methodological analysis was explained by Campbell ( 2008 ) , Morimoto ( 2010 ) , and Omo-Irabor et al. , ( 2008 ) .

Sediment sampling was performed seasonally at low tide from the upper deposit bed ( 0 to 20 centimeter ) and lower deposit bed ( 20 to 40 centimeter ) in each point of the survey countries utilizing a nucleus sampling station of 10 centimeter diameter. Collected dirt samples were put into closed labeled plastic bags to minimise sample taint and set into an ice thorax at low temperature during transit and were brought to the research lab of Azad University of Bandar Abbas for immediate processing. Samples were air-dried at room temperature and exhaustively assorted before oppressing by utilizing a mechanical bomber ( A10 manufactured by 1 KA-Labor proficient ) and sieved through 2 millimeters mesh. The major physical and chemical belongingss of the dirts were soil texture ( % of silt, clay and sand ) , electrical conduction ( EC ) , sourness ( pH ) , organic C ( OC ) , calcium carbonate ( CC ) , absorbable K ( K+ ) and absorbable P ( AP ) . The deposit trying methodological analysis was followed as described by Andreoni et Al. ( 2004 ) , Ferreira et Al. ( 2007 ) , and Liu et Al. ( 2008 ) .

Data Analysis. The scope of mean, maximal, minimum and one-year agencies ( A±SE ) for each parametric quantity was measured. A one-way analysis of discrepancy ( ANOVA ) followed by a station hoc multiple comparing ( Tukey ‘s trial ) was employed to prove any important differences in all parametric quantities between seasons. A t-student trial was applied to look at any important differences betweenA A. marinaA and R. mucronata home grounds. All statistical analyses were performed with SPSS version 16.0, and graphs were established utilizing Excel 2007.

RESULT AND DISCUSSION

Water parametric quantity. The average values of EsC, pH, DO, EC, TSS and Salinity were measured 26.18A±0.22 A°C, 7.09A±0.02, 6.64A±0.04 g L-1, 42.78A±0.11 dScm-1, 112.28A±0.66 milligram L-1 and 34.72A±0.27 g L-1 severally for HPA. While for GHRD were 24.6A±0.23 A°C, 7.27A±0.03, 6.6A±0.03 g L-1, 44.38A±0.14 dScm-1, 119.61A±0.76 mgL-1 and 37.3A±0.12 gL-1 severally.

The consequences of comparing average values of variables utilizing t-test at HPA and GHRD showed that there was a important difference ( p & lt ; 0.01 ) among all variables including EsC ( t= 4.91, P & lt ; 0.01 ) , pH ( t= -5.48, P & lt ; 0.01 ) , EC ( t= -8.97, P & lt ; 0.01 ) , TSS ( t= -7.30, P & lt ; 0.01 ) and salt ( t=-23.41, p & lt ; 0.01 ) , except DO ( t= 0.86, P & gt ; 0.05 ) . Furthermore, the consequences of t-test showed that during non-migratory seasons, in the spring, there was a important difference on the EC ( t=-3.88, p & lt ; 0.01 ) and TSS ( t= -2.95, P & lt ; 0.01 ) , while there was no important difference for DO ( t=0.07, p & gt ; 0.05 ) merely in the summer between two sites. Furthermore, during migratory seasons there was important difference in the autumn for all parametric quantities ( P & lt ; 0.01 ) , excepting EC ( t=-0.82, p & gt ; 0.05 ) , while in the winter there was important difference for all parametric quantities ( P & lt ; 0.05 ) .

On a planetary graduated table, temperature is the most important determiner for the scope of zoology and vegetation within home grounds ( Augustinus, 1995 ; Blasco et al. , 1996 ) . Mangroves growing in tropical and sub-tropical latitudes, where the mean sea surface temperature is 24 EsC ( Hogarth, 2001 ) , though the climax growing of Rhizophora mangles has been reported merely under tropical conditions where atmospheric temperature during the coldest months is greater than 20EsC and the seasonal fluctuation does non transcend 5EsC ( Kathiresan & A ; Bingham, 2001 ) . Temporal conditions were similar in the Rhizophora mangle woods of Hormozgan state.

The tendency of alterations in H2O parametric quantities in the sites illustrated that surface H2O temperature varied from 18.1 to 32.8 EsC at HPA and 16.7 to 31.4 EsC at GHRD. The consequences of comparing average values of temperature showed a important difference ( p & lt ; 0.01 ) among seasons at HPA and GHRD. The average values of temperature lessening from autumn to winter, with low temperatures of 21.12A±0.16 and 19.69A±0.18 recorded during winter at HPA and GHRD severally, and they bit by bit increase from winter to spring and summer, top outing during the summer ( September in both home grounds ) ( Fig. 1 ) .

In general, the strength of solar radiation, vaporization and H2O flow from next neritic Waterss have an consequence on surface H2O temperature ( Govindasamy et al. , 2000 ; Perumal et al. , 2009a ) . In the current probe, non-migratory troughs and particularly summer extremums for air and surface H2O temperature were noticed. In situ observations showed a positive correlativity between air and surface H2O temperature during seasons for all trying points in both home grounds.

Fig. 1 The tendency of alterations in surface H2O temperature during four seasons

Salinity varied from 28 to 41 g L-1 at HPA and 31 to 45 g L-1 at GHRD. There was a somewhat addition in the salt from autumn to summer, while low salt of 33.22A±0.15 g L-1 and high salt of 34.45A±0.19 g L-1 were recorded during winter and summer severally in the HPA. The recorded values in GHRD for winter and summer were 36.81A±0.25 g L-1 and 37.69A±0.2 g L-1 severally ( Fig. 2 ) . The minimal salt was likely due to the influence of rainfall and the attendant river run-off, which is a regular one-year event in these countries during autumn and winter ( migratory season ) .

Salinity plays as a restricting factor in the distribution of life beings ( Perumal et al. , 2009 ) . By and large, salt of Rhizophora mangle home grounds is influenced by the inflow of fresh water from land and run off by tidal fluctuations. Saravanakumar et Al. ( 2008 ) reported a negative correlativity with rainfall and a positive correlativity with temperature. In our survey, salt in the both study countries was high during summer season and low during the winter season. Higher values during summer might be affected by high grade of vaporization or because of neritic H2O influx from unfastened sea, rainfall and the consequent fresh water influx from the land ( Perumal et al. , 2009 ) . In add-on, the fluctuations of salt in both home grounds were chiefly influenced by the entry of neritic H2O influx from the unfastened sea ( field obs. ) and entry of fresh water from the land by Kol and Mehran rivers at HPA and the rivers of Gaz and Hara ( Hivi ) at GHRD, which would hold reasonably reduced the salt.

Fig. 2 The tendency of salt alterations during four seasons

In the present survey, the Hydrogen ion concentration ( pH ) varied from 5.4 to 8.0 at HPA and 5.0 to 8.8 at GHRD. The seasonally average values of pH were high ( 7.29A±0.34 ) during the spring and low ( 6.95A±0.36 ) during the autumn and winter seasons at HPA. While it remained alkalic throughout the survey period in the surface Waterss of GHRD, with the minimal value ( 7.19A±0.07 ) happening in the winter season and upper limit values ( 7.30A±0.05 ) happening on spring and autumn seasons ( Fig. 3 ) .

By and large, factors like remotion of CO2 by photosynthesis through hydrogen carbonate debasement, decomposition of organic affair and decrease of salt and temperature are really of import in the fluctuations in pH values during different seasons of the twelvemonth ( Perumal et al. , 2009a ; Saravanakumar et al. , 2008 ) , and in this survey statistical analysis showed that salt had extremely important negative correlativity with the extremum of photosynthesis.

Fig. 3 The tendency of alterations in pH during four seasons

The dissolved O values were high ( 2.80 mg L-1 ) during the spring and low ( 8.90 mg L-1 ) during the summer. Fig. 4 gives the tendency of DO alterations during the four seasons in the HPA and GHRD mangrove woods. The higher values of DO concentration ( 6.92A±0.07 in the HPA and 6.74A±0.05 in the GHRD ) were recorded during migratory seasons ( autumn and winter ) , which could be chiefly due to decreased turbulency of coastal Waterss in the Rhizophora mangle home ground. However, there was no important difference among seasons in both home grounds ( P & gt ; 0.05 ) .

It is good known that disintegration of O is influenced by salt and temperature in the sea H2O ( Saravanakumar et al. , 2008 ; Vijayakumar et al. , 2000 ) . As can be seen, season-wide observation of DO illustrated an reverse tendency against temperature, salt and turbidness.

The current survey showed no important difference among DO between seasons for both home grounds, which might be due to the cumulative consequence of higher air current speed in the summer coupled with rainfall in the winter and the attendant H2O commixture. Saravanakumar et Al. ( 2008 ) and Perumal et Al. ( 2009a ) attributed seasonal fluctuation of DO concentration chiefly to entry of fresh water from the land and the ferruginous impact of deposits in Rhizophora mangles. In add-on, during a survey of the Rhizophora mangles in Kachchh-Gujarat in India there was no important fluctuation between Stationss and seasons ( Saravanakumar et al. , 2008 ) .

Fig. 4 The tendency of DO alterations during four season in the HPA and GHRD

Furthermore, it is good known that tendencies of EC are chiefly influenced reciprocally by temperature and salt ( Vijayakumar et al. , 2000 ) . In the present survey, the above findings are supported by the higher electrical conduction ( EC ) found in H2O samples from HPA and GHRD. Fall season had the highest conduction in HPA ( 44.51A±0.27 dS cm-1 ) , followed by winter ( 42.36A±0.15 dS cm-1 ) , spring ( 42.19A±0.2 dS cm-1 ) and summer ( 42.07A±0.11 dS cm-1 ) . A similar tendency with similar seasonal alterations was observed in the GHRD, which recorded the highest in the autumn ( 44.83A±0.26 dS cm-1 ) and the lowest in the summer ( 43.66A±0.26 dS cm-1 ) ( Fig. 5 ) .

Fig. 5 The tendency of EC alterations during four season in the HPA and GHRD

TSS varied from 79 to 148 g L-1 at HPA and 75 to 155 g L-1 at GHRD. There was a smooth fluctuation in the tendencies of TSS from autumn to summer, where low TSS of 107.92A±1.53 g L-1 for HPA and 115.87A±1.49 g L-1 for GHRD were recorded in winter at both sites ( Fig. 6 ) .

The minimal TSS was likely due to the influence of rainfall and the attendant river run-off, which is a regular one-year event in the countries during fall and winter. TSS followed by salt, DO and EC are all restricting factor in the distribution of life beings in the H2O by restricting light eloquence in deeper H2O ( Perumal et al. , 2009b ) . By and large, Saravanakumar et Al. ( 2008 ) reported positive correlativity between TSS and salinity/DO. In our survey, salt in both survey countries was high during summer season, which might be caused by a higher rate of vaporization, and low during the winter season due to neritic H2O influx from the unfastened sea, rainfall and the consequent fresh water influx from the land ( pers. Ob. ) which would hold reasonably reduced the TSS.

Fig. 6 The seasonal alterations of TSS in the H2O in adjacent of Rhizophora mangle wood at HPA and GHRD

Soil parametric quantity. The interactions of Rhizophora mangles with dirt and associated microorganisms are a major factor in explicating why Rhizophora mangles are extremely productive woods ( Alongi, 2002 ) . Dirt or deposit characters are known as one of the major controls on Rhizophora mangle distribution ( Perry & A ; Berkeley, 2009 ) , which must get by with a harsh, waterlogged environment. Furthermore, there has been increasing involvement in developing methods which are indexs ofA soilA wellness and sustainability, reflecting alterations in dirt belongingss ( Wang et al. , 2006 ) .

The different physiographic places occupied by the Rhizophora mangle forests in this survey look to take to of import differences in dirt composing and physicochemical conditions. This subdivision hence inside informations the forms of different constituent seen in dirt profiles from two sites. The focal point has switched from simple chemical attacks to more incorporate biological attacks including consequence of dirt conditions on the waders nutrient resources and so on the density/diversity of waterfowls in Rhizophora mangle ecosystems, in add-on to the microhabitat, which are first-class campaigners to reflect alterations in dirt conditions.

In this survey, the average values of sediment texture in footings of silt, clay and sand were 52.7A±0.88 ( % ) , 36.42A±0.68 ( % ) and 10.87A±0.47 ( % ) at deepness of 0-20 centimeter and 42.9A±0.63 ( % ) , 36.94A±0.57 ( % ) , and 16.09A±0.54 ( % ) at deepness of 20-40 centimeter for HPA. In add-on, these were 49.73A±0.72 ( % ) , 39.46A±0.79 ( % ) and 11.23A±0.35 ( % ) at deepness of 0-20 centimeter, and 50.13A±0.52 ( % ) , 37.75A±0.53 ( % ) and 12.12A±0.79 ( % ) at deepness of 20-40 centimeter for GHRD. The dirt texture corresponded to a Silty-Clay-Loam texture based on the USDA textural trigon category at the both sites and deepnesss. Soil texture revealed laterality of silt in both deepnesss of both home grounds with no much fluctuation among them, which it may be attributed to the absence of moving ridge induced sand conveyance from unfastened sea and besides faning activity of deposit conveyance system. Rajkumar et Al. ( 2009 ) indicated that deficiency of perennial flow of freshwater territory may be the ground for uniformity in dirt texture within Rhizophora mangle woods, and Clarke and Kerrigan ( 2000 ) found that sedimentA textureA exerts strong control on conduction, pH, organic affair, entire P, entire N and entire S along environmental gradients ofA Rhizophora mangles in Northern Australia.

Based on the information obtained in the HPA, the average values of pH, EC, Ca carbonate, organic C, available P and available K in the deepnesss of 0-20 centimeters were measured 7.09A±0.04, 47.26A±0.57, 37.3A±0.3, 1.83A±0.24, 207.41A±3.24 and 8.72A±0.35 severally, and in the deepnesss of 20-40 centimeters were measured 7.2A±0.05, 49.28A±0.62, 37.37A±0.48, 1.72A±0.03, 204.07A±3.02 and 9.14A±0.3 severally. While, the consequences of dirt profiles collected from GHRD showed 6.99A±0.05, 45.49A±0.72, 37.53A±0.42, 1.51A±0.04, 204.42A±4.09 and 9.74A±0.37 in the deepnesss of 0-20 centimeter, and 6.97A±0.06, 43.6A±0.51, 37.59A±0.36, 1.33A±0.05, 205.87A±2.51 and 9.35A±0.23 in the deepnesss of 20-40 centimeter severally ( Fig 7 ) .

The dirt tested showed significantly difference between the two sites study sites for available K ( t= -2, P & lt ; 0.05 ) , organic C ( t=5.74, P & lt ; 0.01 ) , clay ( t= -2.88, P & lt ; 0.01 ) , silt ( t=2.6, p & lt ; 0.05 ) at deepnesss of 0-20 centimeter, and organic C ( t=6.69, P & lt ; 0.01 ) , pH ( t=3, P & lt ; 0.01 ) , EC ( t=6.87, P & lt ; 0.01 ) , sand ( t=4.18, p & lt ; 0.01 ) and silt ( t=-3.87, p & lt ; 0.01 ) at deepnesss of 20-40 centimeter. Furthermore, the dirt tested showed important difference ( p & lt ; 0.05 ) among seasons merely for absorbable K at a deepness of 20-40 centimeter ( F3,48=3.23, P & lt ; 0.05 ) , and EC in the same deepness ( F3,48=3.6, P & lt ; 0.05 ) .

Mangrove deposits are in general comparatively rich in organicA C ( Kristensen et al. , 2008 ) . Since most mangrove woods occur along sedimentary coastlines in big estuaries and deltas, big measures of suspended organicA carbonA brought in by tides or rivers are deposited along with local Rhizophora mangle debris ( Victor et al. , 2004 ) . The organic C content at deepness of 0-20 centimeters varied from 1.78 ( in the spring ) to 1.89 ( in the autumn ) in the HPA, and from 1.48 ( in the spring ) to 1.55 ( in the winter ) in the GHRD. The determination of this survey showed the highest rate of organic C occurred in the migratory seasons ( autumn for HPA and winter for GHRD ) . Additionally, the findings showed how the distribution of organic C ( particularly in the deepnesss of 0-20 centimeter ) closely followed the distribution of deposit type ( i.e. , sediment low in clay content was low in the organic C and as the clay content increased, the organic C content besides increased ) as reported by Saravanakumar et Al. ( 2009 ) .

In the present survey the highest average value of organic C at deepnesss of 0-20 centimeter was recorded in the migratory seasons ( autumn and winter ) in both sites, nevertheless in the HPA was significantly higher than GHRD during all seasons.

The consequences showed low rate of organic C concentration during non-migratory seasons ( spring and summer ) and high during migratory season ( autumn and winter ) . Sverdrup et Al. ( 1942 ) reported that an abundant supply of organic affair in the H2O column, comparatively rapid rate of accretion of all right grained inorganic affair and low O2 content of the H2O instantly above the bottom deposits would prefer high organic affair and organic C in the bottom deposits. Looking into studies byA Bouillon et Al. ( 2003 ) and Kristensen et Al. ( 2008 ) based on the isotope composing of sediment organicA carbonA from Rhizophora mangle systems where important sums of C4 flora occurs in the catchment countries, illustrates the possible importance of riverine-transported tellurian stuff in mangrove systems. The available planetary estimations ofA carbonA accretion are chiefly calculated by difference utilizing litter autumn, export and ingestion rates ( Jennerjahn & A ; Ittekkot, 2002 ) , nevertheless, Kristensen et Al. ( 2008 ) indicated that a representative planetary estimation ofA carbonA content is likely to be near to 2.2 % .

A one manner ANOVA trial on the consequences showed important differences in average value of organic C among seasons in the HPA ( F ( 3,60 ) = 3.56, p=0.02 ) , while there was no significantly difference in the average value of OC among seasons in the GHRD ( F ( 3,60 ) = 0.13, p=0.94 ) . It is hard to construe, nevertheless it may be affected by deficiency of neritic H2O influx from the unfastened sea in the GHRD instead than HPA, or may reflect a variable part by otherA carbonA beginnings. Besides, it is now recognized that forage and feeding activities of Rhizophora mangle zoology can act upon the belongingss and handiness of organicA C ( Kristensen et al. , 2008 ) . Furthermore, foods are considered to be the major determiners ofA mangrove environment, act uponing distribution, growing, reproduction and metabolic activities of biotic constituents. The foods distribution within Rhizophora mangles is chiefly influenced by season, tidal conditions and fresh water flow from land beginning ( Saravanakumar et al. , 2009 ) .

Available Phosphorus ( AP ) concentrations in the dirt samples taken atA depthsA of 0 to 20 and 20-40 centimeter in both home grounds confirmed some interesting consequences as good. A one manner ANOVA trial showed that there was no important difference in average value of available phosphorus contents among seasons in the HPA for deepnesss of 0-20 centimeter ( F ( 3,60 ) = 0.35, P & gt ; 0.05 ) and 20-40cm ( F ( 3,60 ) = 0.28, P & gt ; 0.05 ) and in the GHRD for deepnesss of 0-20 centimeter ( F ( 3,60 ) = 0.15, P & gt ; 0.05 ) and 20-40 centimeter ( F ( 3,60 ) = 0.2, P & gt ; 0.05 ) . In add-on, a t-student trial on the consequences of dirt samples taken atA HPA and GHRD showed no important differences among home grounds in the deepness of 0-20 centimeter ( t= 0.58, P & gt ; 0.05 ) and 20-40 centimeter ( t= -0.44, P & gt ; 0.05 ) .

In the HPA, available Phosphorus was highest at winter ( 211.25 A± 9.11 m-equiv L-1 ) , followed by spring and autumn ( 208.81A±5.49 and 207.56A±3.26 m-equiv L-1, severally ) in the dirt samples taken atA a depthA of 0 to 20cm. In contrast, high value of available Phosphorus in dirt samples taken atA depthA of 20-40 centimeter in the winter and spring in the sites could be attributed to the regeneration and release of P from bottom clay into the surface bed, which measured at 208.19A±3.77 m-equiv L-1 and 204.31A±5.17 m-equiv L-1 in the winter and spring severally. Similar tendencies are observed in the dirt of GHRD. The fluctuation may be caused by the assorted procedures, such as phosphorus adsorption-desorptionA procedures and/or buffering action of deposits in Rhizophora mangle home grounds under unstable environmental conditions, as defined by Rajasegar ( 2003 ) .

In the present survey, entire available Potassium ranged between 6.20 and 18.3 m-equiv L-1. In the HPA atA depthA of 0 to 20 centimeter, K+ was lowest in the autumn ( 8.44A±0.63 m-equiv L-1 ) and highest in summer ( 10.78A±0.66 m-equiv L-1 ) . The rate of K+ at winter and spring were 9.19A±0.71 and 10.57A±0.83 m-equiv L-1 severally. Furthermore, the sum of available Potassium in the dirt samples taken at the HPA at depthsA of 20-40 centimeter during autumn, winter, spring and summer were measured at 9.48A±0.59, 7.94A±0.29, 10.38A±0.87 and 8.74A±0.32 m-equiv L-1 severally. Likewise, at the GHRD at deepnesss of 0 to 20cm, K+ was lowest in the autumn ( 8.44A±0.63 m-equiv L-1 ) and highest in summer ( 10.78A±0.66 m-equiv L-1 ) followed by 9.19A±0.71 m-equiv L-1 and 10.57A±0.83 m-equiv L-1 in winter and spring severally. Furthermore, the sums obtained atA depthA of 20-40 centimeter during autumn, winter, spring and summer were given as 8.62A±0.35, 8.71A±0.42, 9.94A±0.6 and 10.12A±0.34 m-equiv L-1 severally. Therefore, there was a gradual addition in the rate of available K ( K+ ) near the surface in sites from fall to summer. However, there was a fluctuation in the concentration of K+ in the deepness scope of 20-40 in the HPA. A higher concentration of K was observed during the summer season in the 0-20 centimeter bed at both home grounds, which may be due to dead organic affair from the top bed and low values observed in the fall may be related to remotion of top bed deposits by heavy inundations.

Calcium carbonateA ( CaCO3 ) is one of the cardinal factors act uponing the concentration of beings such as mollusk in the Rhizophora mangles. The per centum of CaCO3 in the HPA at 0-20 was a small spot higher in summer ( 37.69A±0.5 % ) , with values runing between 34.6 and 42.3 % . CaCO3 was besides measured at 36.85A±0.85 % , 37.14A±0.44 % and 37.51A±0.53 % during autumn, winter and spring severally. The CaCO3 contents at 20-40 centimeter were besides really different, with the highest values matching to winter ( 38.51A±0.74 % ) , followed by spring ( 37.4A±0.78 % ) , autumn ( 37.31A±1.07 % ) and summer ( 36.23A±1.21 % ) . The CaCO3 contents of GHRD dirts at 0-20 centimeter were besides higher in the summer ( 38.25A±0.73 % ) than others ( 37.82A±0.62 % , 36.68A±1.04 % and 37.4A±0.93 % during autumn, winter and spring severally ) . The contents at 20-40 centimeter were calculated with values runing between 37.25A±0.98 % ( in the autumn ) and 38.48A±0.46 % ( in the summer ) . Perry & A ; Berkeley ( 2009 ) reported that the loss of Ca carbonate from intertidal deposits mostly consequences from the acidic pore Waterss associated with organic-matter mineralization. One hypothesis for the clear deficiency of carbonate disintegration in the intertidal deposits is the continual production of carbonate and/or ambient sedimentary carbonate degrees presently staying sufficiently high to buffer acid generated during microbic decomposition of organic-matter, therefore heightening bioclast saving ( Barbieri, 2001 ) . An alternate hypothesis is that acerb production is limited by hapless sediment oxygenation ( Perry & A ; Berkeley, 2009 ) .

The pH in the upper bed deposits at HPA Stationss was about 6.99A±0.14 ( spring ) to 7.2A±0.11 ( summer ) whereas at GHRD the recorded pH was 6.87A±0.1 in the autumn to 7.08A±0.09 in the spring. The highest pH values were 8.10 ( at deepness of 0-20 centimeter ) and 8.7 ( at deepness of 20-40 centimeter ) in HPA and at GHRD were 7.6 ( at deepness of 0-20 centimeter ) and 7.8 ( at deepness of 20-40 centimeter ) . Since Rhizophora mangle dirts are typically waterlogged, so changes in dirt pH are closely related to alterations in surface H2O pH, while pore H2O sourness may increase as a map of Rhizophora mangle age ( Marchand et al. , 2004 ) . The sourness of dirt influences the chemical transmutation of most foods and their handiness to workss ( Kristensen et al. , 2008 ) . Most mangrove dirts are good buffered, holding a pH in the scope of 6 to 7. Wang et Al. ( 2006 ) demonstrated thatA biological activities in dirt were sensitive toA pH change.A They reported how pH was the most of import factor act uponing dirt biological activities by testingA scopes of pH fromA pHA 4.74 to 6.88 or 7.27 for high or low metalA dirt severally. In add-on, they tested to see whether reducingA pHA had important negative impact onA soilA microbic activity, such as biological activities in rhizosphere enzymes, such asA the enzyme of soilA alkaline phosphatase which removes a phosphate group from dirt into aA phosphateA ion, or nitrification potency which significantly reduces after dirt acidification.

The EC content of dirt was consistent with the consequences obtained for the EC of H2O. The entire EC contents ranged from 39.40 to 68.30 at deepness of 0-20 centimeter and 42.60 to 69 at deepness of 0-20 centimeter at HPA, whereas in GHRD the figures were 33.10 to 60 and 30.60 to 54.2 severally. The measuring of EC has been used as a rapid agencies of measuring the possible impact of extra organic input to marine deposit ( Pearson and Stanley, 1979 ) . Reliable measurings of EC require great attention to minimise exposure of the dirt sample to air ( English et al. , 1997 ) . The findings of this survey showed how the EC of dirt was influencedA by the EC of H2O ( likelyA with pH ) and aeration of a tidal brook.

Fig. 7 Seasonal alterations of CaCO3, Organic Carbon, and pH in the Rhizophora mangle wood at HPA and GHRD

Fig. 8 Seasonal alterations of Available Potassium and P and EC in the Rhizophora mangle wood at HPA and GHRD

Decision

Therefore, this survey illustrated that microclimate variables are the major control on Rhizophora mangle construction, distribution and spacial extent. For case, salt has a important consequence on the growing and zonation of Rhizophora mangle woods. ToA evaluate ecosystemsA is in footings ofA wellness and productiveness, it is necessary to supervise of dirt and every bit good as environing H2O beginnings. Several literatures have come out with contradictory findings about importance of H2O and dirt in Rhizophora mangle woods ( Kathiresan & A ; Bingham, 2001 ; Saravanakumar et al. , 2009 ) . However, far excessively small attending has been paid to the Rhizophora mangles of Iran ( Danehkar & A ; Jalali, 2005 ) . The present survey was designed to find the environmental status due to four seasons of twelvemonth in the A. marina and R. mucronata Rhizophora mangle wood in Iran. These woods are flooded twice daily under natural conditions with salt H2O that consequence in extremist alterations in the dirt features. This facet of the topic has already been argued by Tomlinson ( 1999 ) and Saravanakumar et Al. ( 2009 ) . Dirt features are one of the most of import environmental factors straight impacting mangrove productiveness and construction. Therefore, this survey illustrated that H2O and dirt variables are the major control on Rhizophora mangle construction, distribution and spacial extent. For case, salt has a important consequence on the growing and zonation of Rhizophora mangle woods.

On the other manus, this survey suggested that mangrove loss will besides cut down coastal H2O quality, cut down biodiversity and nursery home ground. Fertility and good health of Rhizophora mangle environment is reflected in productiveness of plankton communities, including phyto/zoo as primary/secondary manufacturers, which they are the cardinal participants in commanding nutrient webs in Rhizophora mangle Waterss and they are reflected in copiousness of mollusk and fishes.