Marina Trees Research Articles

First report of Streblote solitaria (Lepidoptera: Lasiocampidae) damage on Avicennia marina trees in southern mangroves of Iran

Nowadays, Streblote spp. is one of the destructive polyphagous pest in central and southern parts of Iran. During forest monitoring (2017–2018), the larvae of a lepidopteran species were observed to damage a large number of grey mangrove trees (Avicennia marina) located in Khamir port (Hormozgan province, Iran). So following intensive feeding of larvae on different portions of the canopy, severe dieback was observed on the trees in the study area. The objective of this research was first report of pest causing damage on A. marina trees in southern mangroves of Iran. To identify the pest, larvae and pupae were collected and transferred to the laboratory. The following characteristic observation were taken, (i) morphological characteristics and (ii) DNA barcoding. Regarding the results, the larvae and mature moth were identified as Streblote solitaria (Lepidoptera, Lasiocampidae) on the basis of morphological characteristics, and identification through DNA barcoding. The sequence was deposited in NCBI GenBank under accession number MH414968.1. This is the first report of the presence of S. solitaria in this forest in southern Iran and subsequent mangrove damage. More researches and proper management in this area is recommended to efficient control of this pest and inhibiting the disaster in this valuable mangrove forests.

Coastal Landform Constrains Dispersal in Mangroves

Mangrove forests are dynamic ecosystems found along low-lying coastal plains along tropical, subtropical, and some warm-temperate coasts, predominantly on tidal flats fringing deltas, estuaries, bays, and oceanic atolls. These landforms present varied hydrodynamic and geomorphological settings for mangroves to persist and could influence the extent of within-site propagule transport and subsequent local regeneration. In this study, we examined how different landform characteristics may influence local genetic diversity, kinship, and neighborhood structure of mangrove populations. To do so, we considered independent populations of Avicennia marina, one of the most abundant and widespread mangrove species, located in estuarine and coastal bay environments spread across the Western Indian Ocean region. A transect approach was considered to estimate kinship-based fine-scale spatial genetic structure using 15 polymorphic microsatellite markers in 475 adult A. marina trees from 14 populations. Elevated kinship values and significant fine-scale structure up to 30, 60, or 90 m distances were detected in sheltered systems void of river discharge, suggesting a setting suitable for very local propagule retention and establishment within a neighborhood. Slopes of a linear regression over restricted distance within 150 m were significantly declining in each sheltered transect. Contrastingly, such a spatial structure has not been detected for A. marina transects bordering rivers in the estuarine systems considered, or alongside partially sheltered creeks, suggesting that recruitment here is governed by unrelated carried-away mixed-origin propagules. South African populations showed strong inbreeding levels. In general, we have shown that A. marina populations can locally experience different modes of propagule movement, explained from their position in different coastal landforms. Thus, the resilience of mangroves through natural regeneration is achieved by different responses in coastal landforms characterized by different hydrodynamic conditions, which can be important information for their management and protection within the variety of coastal environments.

Connectivity of Avicennia marina populations within a proposed marine transboundary conservation area between Kenya and Tanzania

Threatened ecosystems such as intertidal mangrove forests often span political boundaries and require cross-border conservation planning initiatives. Population connectivity is key to establish transboundary collaborative actions. In this study, we assessed genetic diversity and connectivity of mangrove populations in a proposed transboundary conservation area (TBCA) between Kenya and Tanzania, where human demography exerts increasing pressure on biodiversity and ecosystem services. East African mangrove ecosystems comprise a complex pattern of estuaries and coastal bays, with Avicennia marina as a major mangrove component. Our main objective was to test a hypothesis of overall migration directionality reflecting regional ocean surface current flows. Fourteen microsatellite markers in 670 A. marina trees revealed no overall significant difference in allele or gene diversity levels between populations but showed an overall effect of geographic distance with a gradient of admixed gene pools. Migration tests and Approximate Bayesian computations supported a customized stepping-stone model of overall south to north migration with bidirectional gene flow and admixture between adjacent bays near the Kenya-Tanzania border. Observed patterns of gene flow suggest an important effect of large rivers and connections via creeks. Our results indicate that relevance for conservation and management of mangroves areas may remain largely within a hydrological connectivity context of each bay, despite prevailing genetic estimates reflecting historically well-connected mangroves between bays. For sustainable management, populations must be considered complementary and not redundant. Hence, transboundary regions must primarily adhere to local contemporary conservation and management, and not solely rely on the assumption of strong regional connectivity built historically.

Channel network structure determines genetic connectivity of landward-seaward Avicennia marina populations in a tropical bay.

Mangrove ecosystems along the East African coast are often characterized by a disjunct zonation pattern of seaward and landward Avicennia marina trees. This disjunct zonation may be maintained through different positions in the tidal frame, yielding different dispersal settings. The spatial configuration of the landscape and coastal processes such as tides and waves is expected to largely influence the extent of propagule transport and subsequent regeneration. We hypothesized that landward sites would keep a stronger genetic structure over short distances in comparison with enhanced gene flow among regularly flooded seaward fringes. We tested this hypothesis from densely vegetated A. marina transects of a well‐documented mangrove system (Gazi Bay, Kenya) and estimated local gene flow and kinship‐based fine‐scale genetic structure. Ten polymorphic microsatellite markers in 457 A. marina trees revealed no overall significant difference in levels of allele or gene diversities between sites that differ in hydrological proximity. Genetic structure and connectivity of A. marina populations however indicated an overall effect of geographic distance and revealed a pronounced distinction between channels and topographic setting. Migration models allowed to infer gene flow directionality among channels, and indicated a bidirectional steppingstone between seaward and nearest located landward stands. Admixed gene pools without any fine‐scale structure were found within the wider and more exposed Kidogoweni channel, suggesting open systems. Elevated kinship values and structure over 5 to 20 m distance were only detected in two distant landward and seaward transects near the mouth of the Mkurumuji River, indicating local retention and establishment. Overall, our findings show that patterns of A. marina connectivity are explained by hydrological proximity, channel network structure, and hydrokinetic energy, rather than just their positioning as disjunct landward or seaward zones.

Stunted Mangrove Trees in the Oligotrophic Central Red Sea Relate to Nitrogen Limitation

Mangroves are important coastal ecosystems of warm climatic regions that often grow in shallow saline or brackish waters of estuaries and river mouths affected by wide tidal intervals and receive abundant nutrient supply. However, mangroves also occur in areas of little tidal influence and devoid of riverine inputs, where they can develop a stunted plant form. Here we report that Avicennia marina trees in the fringe of the Red Sea have maximum heights toward the lower range of that reported elsewhere (average maximum canopy height of 4.95 m), especially in the central region, where mangroves are stunted with an average tree height of 2.7 m. Maximum tree height and chlorophyll a concentration correlated positively with nitrogen concentration in the leaves of A. marina. We conclude that the stunted nature of mangrove trees in the central Red Sea is likely driven by nitrogen limitation.

The heavy metal of cuprum (Cu) and lead(Pb) content in Avicennia marina and Rhizophora mucranata

Various types of mangrove plants found in coastal areas have a specific strategy to deal with pollution conditions from heavy metals. One of the several strategies used by mangroves is by accumulating various kinds of heavy metals in various parts of the tree. Most species of mangroves such as Avicennia marina, Rhizophora mucronata, Sonneratia caseolaris, Bruguiera gymnorhyza and others apply this strategy. Avicennia marina and Rhizophora mucronata are pioneer mangrove species that are able to accumulate heavy metals in the roots, stems and leaves. These species are also act as indicator of the sustainability of mangrove ecosystems. The presence of heavy metals will reduce water quality subsequently will decline the overall condition of the ecosystem. How big is the ability of Avicenia marina and Rhizopohora mucronata mangroves to absorb copper (Cu) and Lead (Pb) metals and how the conditions of the aquatic environment surrounding mangroves during heavy metal stress are need to be studied. Analysis of Cu and Pb heavy metals contents were carried out at the Chemistry Laboratory of the USU Medan Pharmacy Faculty. The mangrove species used for the analysis of Cu and Pb heavy metals were A.marina and R. mucronata that grew in Muara Sungai coastal areas from April to August 2018. The results showed heavy metal content of Cu was greater than Pb in wire roots, stems and leaves of A. marina trees. Analysis of roots, leaves and bark of R. mucronata also found greater content of Cu heavy metals than Pb.

Environmental drivers of stem radius change and heterogeneity of stem radial water storage in the mangrove Avicennia marina (Forssk.) Vierh.

The dynamics of stem water storage can provide insight on a tree's capacity to face imbalances between water supply and demand, and thus maintain hydraulic function and growth under fluctuating environmental conditions. Recent work on the mangrove Avicennia marina (Forssk.) Vierh showed that stem radius change (SRC) is highly heterogeneous due to the structure of A. marina wood, composed of multiple reticulate cambia. The heterogeneity of short and long-term SRC in trees with reticulate cambia, common in dry environments, complicates the study of environmental drivers of stem water storage.In order to find the environmental drivers of stem water storage and understand the nature of this heterogeneity we analysed high-resolution SRC of A. marina for one and a half years. Nine point dendrometers measured SRC in upper, lower and mid stem of three A. marina trees in northern New Zealand. Stem radius change was detrended for growth to obtain water-related shrinking and swelling only (ΔW).Despite heterogeneity in SRC measurements, ΔW changes in A. marina still had seasonal trends of high winter and low summer diel amplitudes and strong responses to mean diel environmental conditions. Environmental drivers of ΔW were more apparent once the data was standardized to show relative changes, and segregated by upper and lower stem tiers. Moving window correlations showed stem contraction was correlated with atmospheric water demand and precipitation, whilst stem swelling was correlated with light sums more often than with measures of water availability. The correlation of stem water storage with light seen in our work provides backing for the hypothesized role of carbohydrates in the mechanism behind daytime stem swelling of A. marina water storage tissues. Our work highlights the importance of sensor locations and data analysis approaches if we are to use established SRC technologies in a larger diversity of environments and species.

Physical and chemical characteristics of mangrove soil under marine influence. A case study on the Mangrove Forests at Egyptian-African Red Sea Coast.

The present study provides an analysis the growth performance of mangrove forests (Avicennia marina and Rhizophora mucronata) and the concentrates on the environmental factors (soil) that affect on the mangroves along Egyptian-African Red Sea coast. The growth performance of R. mucronata was higher in association with A. marina than in pure stands. Moreover, A. marina trees growing in association with R. mucronata were taller than plants growing in pure community. Plants growing (size index) at high tide attained the highest values of growth attributes. In comparison, A. marina growth attributes differed between the three locations of the three tide levels. The highest values of the growth parameters were recorded for A. marina growing at the medium tide in pure stands. However, the growth values of A. marina growing in mixture with R. mucronata were higher at low tide than those at either high or medium tides. The total mean of Soil Bulk Density (SBD) of the A. marina (1.24 g cm³) was higher than that of the R. mucronata (1.16 g cm³) and mixed stands (1.12 g cm³). The results shows that both ordination techniques clearly indicated that electric conductivity, CaCO3, K+, Ca++, Cl-, Na+ and Mg++ were the most important parameters determining the current distribution of mangrove pattern in the Egyptian Red Sea coast. The results showed that there is a similarity between the soil samples in different of the study locations as whole area is a coastal. In the current study the variability of ecosystem structure and function is generally a product of interactions between its different components. In the extreme arid environmental conditions of arid lands these interactions are of high significance, so that slight irregularities in one component of the ecosystem are likely to lead to substantial variations in others, so creating distinct micro habitats.

Hydraulic redistribution of foliar absorbed water causes turgor-driven growth in mangrove seedlings.

Although foliar water uptake (FWU) has been shown in mature Avicennia marina trees, the importance for its seedlings remains largely unknown. A series of experiments were therefore performed using artificial rainfall events in a greenhouse environment to assess the ecological implications of FWU in A.marina seedlings. One-hour artificial rainfall events resulted in an increased leaf water potential, a reversed sap flow, and a rapid diameter increment signifying a turgor-driven growth of up to 30.1±5.4μm. Furthermore, the application of an artificial rainfall event with deuterated water showed that the amount of water absorbed by the leaves and transported to the stem was directly and univocally correlated to the observed growth spurts. The observations in this process-based study show that FWU is an important water acquisition mechanism under certain circumstances and might be of ecological importance for the establishment of A.marina seedlings. Distribution of mangrove trees might hence be more significantly disturbed by climate change-driven changes in rainfall patterns than previously assumed.

Structural characterization, reproductive phenology and anthropogenic disturbance of mangroves in Costa do Sol, Bons Sinais Estuary and Pemba-Metuge from Mozambique

ABSTRACTMangrove forests are among the most important ecosystems with high ecological and economic value. In order to better understand and conserve this ecosystem, we aim to provide an overview of mangrove structure along the southern, central and northern parts of Mozambique, in Costa do Sol (CS), Bons Sinais Estuary (BSE) and Pemba-Metuge (PM), respectively. A total of 10 plots/site (10 × 10 m) along a transect perpendicular to the seashore were used. Inside the plots, the stem diameter and height were measured, and the species identified. The phenology and deforestation were categorized, and dead stumps were identified by species and its diameter measured. A total of five mangrove species were observed at BSE, four at PM and three at CS. BSE presented the greatest mean height at 3.3 m, as well as the highest complexity at 22.7. Avicennia marina was identified as the most ecologically important species in all the study sites. During May, A. marina trees were mainly dormant, while those of Ceriops tagal and Rhizophora mucronata were flowering and fruiting. Intact trees were dominant in all the study sites. This study will contribute in designing and implementation of sustainable strategies for conservation of mangrove forests in Mozambique.

Direct uptake of canopy rainwater causes turgor-driven growth spurts in the mangrove Avicennia marina.

Mangrove forests depend on a dense structure of sufficiently large trees to fulfil their essential functions as providers of food and wood for animals and people, CO2 sinks and protection from storms. Growth of these forests is known to be dependent on the salinity of soil water, but the influence of foliar uptake of rainwater as a freshwater source, additional to soil water, has hardly been investigated. Under field conditions in Australia, stem diameter variation, sap flow and stem water potential of the grey mangrove (Avicennia marina (Forssk.) Vierh.) were simultaneously measured during alternating dry and rainy periods. We found that sap flow in A. marina was reversed, from canopy to roots, during and shortly after rainfall events. Simultaneously, stem diameters rapidly increased with growth rates up to 70 μm h-1, which is about 25-75 times the normal growth rate reported in temperate trees. A mechanistic tree model was applied to provide evidence that A. marina trees take up water through their leaves, and that this water contributes to turgor-driven stem growth. Our results indicate that direct uptake of freshwater by the canopy during rainfall supports mangrove tree growth and serve as a call to consider this water uptake pathway if we aspire to correctly assess influences of changing rainfall patterns on mangrove tree growth.

Investigating chlorophyll and nitrogen levels of mangroves at Al-Khor, Qatar: an integrated chemical analysis and remote sensing approach.

Mangroves are unique ecosystems that dominate tropical and subtropical coastlines around the world. They provide shelter and nursery to wide variety of species such as fish and birds. Around 73 species of mangroves were recognized around the world. In Qatar, there is only one mangrove species Avicennia marina that is predominant along the northeastern coast. Assessing the health of these valuable ecosystems is vital for protection, management, and conservation of those resources. In this study, an integrated approach of chemical and remote sensing analysis was implemented to investigate the current status of the mangrove trees in Al-Khor, Qatar. Fifteen different A. marina trees from different locations in the mangrove forest were examined for their chlorophyll and nitrogen content levels. Soil analysis was also conducted to understand the effect of moisture on nitrogen availability. Results shows that currently, mangroves are in a good status in terms of nitrogen availability and chlorophyll levels which are related and both are key factors for photosynthesis. Remote sensing techniques were used for chlorophyll prediction. The results showed that these methods have the potential to be used for chlorophyll prediction and estimation.

Mangrove expansion and population structure at a planted site, East London, South Africa

Avicennia marina (Forrsk.) Vierh. was planted in 1969 at Nahoon Estuary, East London, followed a few years later by the planting of Bruguiera gymnorrhiza (L.) Lam. and Rhizophora mucronata (L.) among the larger A. marina trees. This study tested the hypothesis that mangroves have expanded and replaced salt marsh over a 33-year period (1978–2011). It provides important information on mangroves growing at higher latitudes, where they were thought to not occur naturally due to lower annual average temperatures. It further provides insights on future scenarios of possible shifts in vegetation types due to climate change at one of the most southerly distribution sites worldwide. The expansion of mangroves was measured using past aerial photographs and Esri ArcGIS Desktop 10 software. In addition, field surveys were completed in 2011 to determine the population structure of the present mangrove forest and relate this to environmental conditions. The study showed that mangrove area cover increased linearly at a rate of 0.06 ha y−1, while the salt marsh area cover also increased (0.09 ha y−1) but was found to be variable over time. The mangrove area is still relatively small (<2 ha) and expanded mostly over a bare sandflat area. Avicennia marina was the dominant species and had high recruitment (seedling density was 33 822 ± 16 364 ha−1). Only a few Bruguiera gymnorrhiza and Rhizophora mucronata individuals were found (<10 adult trees), although observations indicate that some young plants are becoming established away from the parent plants. The site provides opportunities for studies on mangrove/salt marsh interactions in response to a changing climate. Mangroves should not be planted in non-native areas as they may become invasive outside their natural range. However, future increases in temperature will certainly lead to a southerly expansion of mangoves in South African estuaries.

What regulates crab predation on mangrove propagules?

Crabs play a major role in some ecosystems. To increase our knowledge about the factors that influence crab predation on propagules in mangrove forests, we performed experiments in Gazi Bay, Kenya in July 2009. We tested whether: (1) crab density influences propagule predation rate; (2) crab size influences food competition and predation rate; (3) crabs depredate at different rates according to propagule and canopy cover species; (4) vegetation density is correlated with crab density; (5) food preferences of herbivorous crabs are determined by size, shape and nutritional value. We found that (1) propagule predation rate was positively correlated to crab density. (2) Crab competitive abilities were unrelated to their size. (3) Avicennia marina propagules were consumed more quickly than Ceriops tagal except under C. tagal canopies. (4) Crab density was negatively correlated with the density of A. marina trees and pneumatophores. (5) Crabs prefer small items with a lower C:N ratio.Vegetation density influences crab density, and crab density affects propagule availability and hence vegetation recruitment rate. Consequently, the mutual relationships between vegetation and crab populations could be important for forest restoration success and management.

Effects of experimental sedimentation on the phenological dynamics and leaf traits of replanted mangroves at Gazi bay, Kenya.

Sedimentation results in the creation of new mudflats for mangroves to colonize among other benefits. However, large sediment input in mangrove areas may be detrimental to these forests. The dynamics of phenological events of three mangrove tree species (Avicennia marina, Ceriops tagal, and Rhizophora mucronata) were evaluated under experimental sediment burial simulating sedimentation levels of 15, 30, and 45 cm.While there was generally no shift in timing of phenological events with sedimentation, the three mangrove tree species each responded differently to the treatments.Partially buried A. marina trees produced more leaves than the controls during the wet season and less during the dry season. Ceriops tagal on the other hand had higher leaf loss and low replacement rates in the partially buried trees during the first 6 months of the experiment but adapted with time, resulting in either equal or higher leaf emergence rates than the controls.Rhizophora mucronata maintained leaf emergence and loss patterns as the unaffected controls but had a higher fecundity and productivity in the 15-cm sedimentation level.The results suggest that under incidences of large sedimentation events (which could be witnessed as a result of climate change impacts coupled with anthropogenic disturbances), mangrove trees may capitalize on “advantages” associated with terrestrial sediment brought into the biotope, thus maintaining the pattern of phenological events.

How to catch the patch? A dendrometer study of the radial increment through successive cambia in the mangrove Avicennia.

Successive vascular cambia are involved in the secondary growth of at least 200 woody species from >30 plant families. In the mangrove Avicennia these successive cambia are organized in patches, creating stems with non-concentric xylem tissue surrounded by internal phloem tissue. Little is known about radial growth and tree stem dynamics in trees with this type of anatomy. This study aims to (1) clarify the process of secondary growth of Avicennia trees by studying its patchiness; and (2) study the radial increment of Avicennia stems, both temporary and permanent, in relation to local climatic and environmental conditions. A test is made of the hypothesis that patchy radial growth and stem dynamics enable Avicennia trees to better survive conditions of extreme physiological drought. Methods Stem variations were monitored by automatic point dendrometers at four different positions around and along the stem of two Avicennia marina trees in the mangrove forest of Gazi Bay (Kenya) during 1 year. Patchiness was found in the radial growth and shrinkage and swelling patterns of Avicennia stems. It was, however, potentially rather than systematically present, i.e. stems reacted either concentrically or patchily to environment triggers, and it was fresh water availability and not tidal inundation that affected radial increment. It is concluded that the ability to develop successive cambia in a patchy way enables Avicennia trees to adapt to changes in the prevailing environmental conditions, enhancing its survival in the highly dynamic mangrove environment. Limited water could be used in a more directive way, investing all the attainable resources in only some locations of the tree stem so that at least at these locations there is enough water to, for example, overcome vessel embolisms or create new cells. As these locations change with time, the overall functioning of the tree can be maintained.

Radiocarbon dating and wood density chronologies of mangrove trees in arid Western Australia.

Mangrove trees tend to be larger and mangrove communities more diverse in tropical latitudes, particularly where there is high rainfall. Variation in the structure, growth and productivity of mangrove forests over climatic gradients suggests they are sensitive to variations in climate, but evidence of changes in the structure and growth of mangrove trees in response to climatic variation is scarce. Bomb-pulse radiocarbon dating provides accurate dates of recent wood formation and tree age of tropical and subtropical tree species. Here, we used radiocarbon techniques combined with X-ray densitometry to develop a wood density chronology for the mangrove Avicennia marina in the Exmouth Gulf, Western Australia (WA). We tested whether wood density chronologies of A. marina were sensitive to variation in the Pacific Decadal Oscillation Index, which reflects temperature fluctuations in the Pacific Ocean and is linked to the instrumental rainfall record in north WA. We also determined growth rates in mangrove trees from the Exmouth Gulf, WA. We found that seaward fringing A. marina trees (∼10 cm diameter) were 48±1 to 89±23 years old (mean ± 1σ) and that their growth rates ranged from 4.08±2.36 to 5.30±3.33 mm/yr (mean ±1σ). The wood density of our studied mangrove trees decreased with increases in the Pacific Decadal Oscillation Index. Future predicted drying of the region will likely lead to further reductions in wood density and their associated growth rates in mangrove forests in the region.

Aboveground Biomass, Litterfall, and Forest Structure in the Mangroves of Hormozgan Province, Iran

ABSTRACT: Mangrove communities usually occur in the intertidal zone within tropical and subtropical coastal zones in sheltered saline to brackish environments. It is difficult to monitor and manage mangroves due to a lack of baseline data on the mangrove stmctural properties in the Persian Gulf and Oman Sea. This study investigated the structure of mangrove forests in the Hormozgan province, south of Iran. This study was performed in the Hara Protected Area (HPA) and Gaz and Hara Rivers Delta (GHRD), using random 5-m x 5-m quadrates. A total of 101 Avicennia marina trees in HPA and 172 Rhizophora mucronata trees in GHRD were measured. The average density, tree height, diameter at breast height, crown spread, canopy index, above ground biomass, and litterfall were 1005 ± 68.11 stem ha-1, 2.51 ± 0.17 m, 17.44 ± 0.8 cm, 1.97 ± 0.16 m, 56.06 ± 2.85 (%), 72 ± 9.8 t ha-1 and 9.4 ± 8.5 t ha-1 yr-1 for the A. marina stands, respectively, while 1110.77 ± 182.58 stem ha-1, 2.78 ± 0.46 m, 11.73 ± 1.50 cm, 1.39 ± 0.0...

Effect of environmental pollution on the proteins, allergenic bands, ontogeny and structure of Avicennia marina (Forsk.) Vierh (Avicenniaceae) pollen grains

In Bushehr province of Iran, Avicennia marina trees have grown in Bordekhoon (Mond Protected Area) and Assaluyeh (Marine National Park of Nayband). Contrary to Bordekhoon, Assaluyeh is a petrochemical region with environmental pollution. This study was aimed to studying protein profiles, allergenic bands, ontogeny, structure and elemental composition of tectum of A. marina pollens in Assaluyeh and Bordekhoon. Pollens were collected from two regions and extracted in PBS, and protein profiles of pollens were determined by sulfate–polyacrylamide gel electrophoresis (SDS-PAGE). As an experimental model, 20 female 6–8-week-old Balb/C mice were divided into two groups. The mice of first and second groups were sensitized by Bordekhoon and Assaluyeh pollen extracts, respectively, and mice serum samples were used for immunoblotting. Pollen characteristics were studied using light and scanning electron microscopes. SDS-PAGE showed some differences between pollen protein profiles of two regions. Immunoblotting assay detected that pollens have two allergenic bands and the protein band at 100 KD is the common allergenic protein in two regions. Light microscopy revealed that the development of anther wall was basic type and some abnormalities were observed in microspores and pollens of Assaluyeh. Scanning electron microscopy studies showed that the apertures in considerable numbers of Assaluyeh pollens were closed. The comparison of elemental composition of pollen tectum between two regions showed that pollens of Assaluyeh have accumulated Cu on their tectum. Results obtained indicated that environmental pollution can affect protein profile, allergenic bands, structure and elemental composition of tectum of A. marina pollens.

Temporal stability of a mosaic of two competitively exclusive arboreal ants in a tropical mangrove forest

We report on the distribution, behaviour, interspecific competition and temporal persistence over 4 years of arboreal ants in a mangrove forest within which patches of habitat ranged from single isolated trees to groups of interlocking trees. Two ants, an undescribed species of Crematogaster and Anonychomyrma itinerans, were common but only one ever occurred within any occupied patch. Sampling of the same 108 trees in May 2008, December 2009 and May 2012 showed very little temporal change in occupancy by both species. In manipulative experiments where the branches of closely adjacent pairs of neighbouring Avicennia marina trees containing these different species were clamped together, the ants fought and one species succeeded in taking over both trees. Thirteen of 20 clamped pairs were taken over by Crematogaster and seven by A. itinerans. Occupancy of conjoined patches did not change during the following year, which suggests that the ant species present is not determined by any inherent heterogeneity among patches. Since ants can affect herbivory, community composition and tree health, we suggest that the success of attempts to restore or conserve mangroves may be improved by long-term comparative studies of the effects of ants, including possible differences among species, in natural and artificially planted mangrove forests.