| publications-501 |
PEER REVIEWED ARTICLE |
2013 |
M. N. I. Khan , S. Sharma , U. Berger , N. Koedam , F. Dahdouh-Guebas , A. Hagihara |
How do tree competition and stand dynamics lead to spatial patterns in monospecific mangroves? |
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10.5194/bg-10-2803-2013 |
Simulation & Modeling |
Natural Water Bodies |
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Abstract. Information on mangrove stand development is rare because long-term monitoring data is often lacking. Such information is important in order to plan management measures effectively. Novel approaches based on existing datasets are required to bridge this gap of knowledge. This study uses a unique combination of field data analyses with simulation experiments in order to demonstrate how information on mangrove dynamics can be extracted if data are sparse. The paper provides a baseline characterization of stand development in a monospecific pioneer mangrove stand of Kandelia obovata. Point pattern analyses revealed that in the young stage, self-thinning has started but has not yet lead to a regularity of spatial tree distribution in the entire stand, and trees located in smaller clumps hinder each other in growth but do not lead to a significant size class differentiation. However, after ca. 2 decades the self-thinning and the size class differentiation start to become more visible. A mutual inhibition of growth was observed within 2 m circular distance (r) in the young stage and within 3 m distance after two decades of stand development as confirmed by the negative values of mark correlation function. As a stand grows older the spatial pattern of individuals become more regular from a clustered pattern. In order to understand and predict the future stand development, simulation experiments were carried out by means of the individual-based model KiWi. |
247514 |
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| publications-502 |
PEER REVIEWED ARTICLE |
2012 |
Ward Appeltans , Shane T. Ahyong , Gary Anderson |
The Magnitude of Global Marine Species Diversity |
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10.1016/j.cub.2012.09.036 |
Simulation & Modeling |
Natural Water Bodies |
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No abstract available |
247514 |
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| publications-503 |
PEER REVIEWED ARTICLE |
2012 |
Katrien Quisthoudt , Nele Schmitz , Christophe F. Randin , Farid Dahdouh-Guebas , Elisabeth M. R. Robert , Nico Koedam |
Temperature variation among mangrove latitudinal range limits worldwide |
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10.1007/s00468-012-0760-1 |
Data Management & Analytics |
Uncategorized |
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No abstract available |
247514 |
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| publications-504 |
PEER REVIEWED ARTICLE |
2012 |
Ruth Reef , Nele Schmitz , Britt A. Rogers , Marilyn C. Ball , Catherine E. Lovelock |
Differential responses of the mangrove Avicennia marina to salinity and abscisic acid |
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10.1071/fp12178 |
Data Management & Analytics |
Uncategorized |
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Salinisation of the soil can cause plant water deficits, ion and nutrient imbalances and toxic reactions. The halophyte, Avicennia marina (Forssk.) Vierh., is a mangrove that tolerates a wide range of soil salinities. In order to understand how salinity affects plant growth and functioning and how salinity responses are influenced by the water deficit signalling hormone abscisic acid (ABA) we grew A. marina seedlings under two non-growth limiting salinities: 60% seawater and 90% seawater and with and without exogenously supplied ABA. We measured growth, photosynthesis, sap flow, aquaporin gene expression, hydraulic anatomy and nutrient status as well as sap ABA concentrations. ABA addition resulted in a drought phenotype (reduced sap flow, transpiration rates and photosynthesis and increased water use efficiency and aquaporin expression). In contrast, growth in high salinity did not lead to responses that are typical for water deficits, but rather, could be characterised as drought avoidance strategies (no reduction in sap flow, transpiration rates and photosynthesis and reduced aquaporin expression). Tissue nutrient concentrations were higher in seedlings grown at high salinities. We did not find evidence for a role for ABA in the mangrove salinity response, suggesting ABA is not produced directly in response to high concentrations of NaCl ions. |
247514 |
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| publications-505 |
PEER REVIEWED ARTICLE |
2012 |
Nadia S. Santini , Nele Schmitz , Catherine E. Lovelock |
Variation in wood density and anatomy in a widespread mangrove species |
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10.1007/s00468-012-0729-0 |
Data Management & Analytics |
Uncategorized |
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No abstract available |
247514 |
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| publications-506 |
PEER REVIEWED ARTICLE |
2012 |
N. Schmitz , J. J. G. Egerton , C. E. Lovelock , M. C. Ball |
Light-dependent maintenance of hydraulic function in mangrove branches: do xylary chloroplasts play a role in embolism repair? |
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10.1111/j.1469-8137.2012.04187.x |
Data Management & Analytics |
Uncategorized |
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Summary To clarify the role of branch photosynthesis in tree functioning, the presence and function of chloroplasts in branch xylem tissue were studied in a diverse range of mangrove species growing in Australia. The presence of xylary chloroplasts was observed via chlorophyll fluorescence of transverse sections. Paired, attached branches were selected to study the effects of covering branches with aluminium foil on the gas exchange characteristics of leaves and the hydraulic conductivity of branches. Xylary chloroplasts occurred in all species, but were differently distributed among living cell types in the xylem. Covering stems altered the gas exchange characteristics of leaves, such that water‐use efficiency was greater in exposed leaves of covered than of uncovered branches. Leaf‐specific hydraulic conductivity of stems was lower in covered than in uncovered branches, implicating stem photosynthesis in the maintenance of hydraulic function. Given their proximity to xylem vessels, we suggest that xylary chloroplasts may play a role in light‐dependent repair of embolized xylem vessels. |
247514 |
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| publications-507 |
PEER REVIEWED ARTICLE |
2012 |
Nele Schmitz , Elisabeth M.R. Robert , Nico Koedam , Hans Beeckman , Gerald Koch , Uwe Schmitt |
A Structural and Compositional Analysis of Intervessel pit Membranes in the Sapwood of some Mangrove Woods |
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10.1163/22941932-90000091 |
Data Management & Analytics |
Uncategorized |
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Intervessel pits are prominent wall structures involved in the water transport mechanism of land plants. The role of their intra-tree variation in the regulation of water transport, however, remains enigmatic. The hypothesis was tested that pit membrane thickness and degree of impregnation with phenolic substances increase along the stem axis with increasing tension on the water column as an adaptation to the higher risk for cavitation. Wood samples were taken at different heights from the mangrove tree Rhizophora mucronata growing at Gazi Bay (Kenya). Additional samples were taken along the stem radius to distinguish height from age effect, and from six other mangrove species growing in the same forest. Intervessel pit membranes were studied via transmission and scanning electron microscopy and cellular UV-microspectrophotometry. The hypothesis of pit membrane thickness and composition as a static adaptation to the hydrostatic conditions during vessel differentiation could be refuted. Instead, our findings point to a more dynamic pit membrane appearance with seasonal changes in thickness and chemical composition. |
247514 |
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| publications-508 |
PEER REVIEWED ARTICLE |
2012 |
Dennis J.R. De Ryck , Elisabeth M.R. Robert , Nele Schmitz , Tom Van der Stocken , Diana Di Nitto , Farid Dahdouh-Guebas , Nico Koedam |
Size does matter, but not only size: Two alternative dispersal strategies for viviparous mangrove propagules |
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10.1016/j.aquabot.2012.06.005 |
Simulation & Modeling |
Uncategorized |
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No abstract available |
247514 |
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| publications-509 |
PEER REVIEWED ARTICLE |
2012 |
Behara Satyanarayana , Preetika Bhanderi , Mélanie Debry , Danae Maniatis , Franka Foré , Dawda Badgie , Kawsu Jammeh , Tom Vanwing , Christine Farc |
A Socio-Ecological Assessment Aiming at Improved Forest Resource Management and Sustainable Ecotourism Development in the Mangroves of Tanbi Wetland National Park, The Gambia, West Africa |
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10.1007/s13280-012-0248-7 |
Simulation & Modeling |
Uncategorized |
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No abstract available |
247514 |
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| publications-510 |
PEER REVIEWED ARTICLE |
2012 |
Rodrigo Méndez-Alonzo , Humberto Hernández-Trejo , Jorge López-Portillo |
Salinity constrains size inequality and allometry in two contrasting mangrove habitats in the Gulf of Mexico |
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10.1017/s0266467412000016 |
Simulation & Modeling |
Uncategorized |
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Abstract:The competition for resources increases size inequality in trees, particularly under low abiotic stress. Because mangrove communities are subject to site-specific salinity (and therefore abiotic stress) gradients, these habitats should differ in height–diameter allometry and size inequality. The size inequality (by the Gini Coefficient, G) and maximum potential height (Hmax from a height–diameter asymptotic model) were determined within the mangrove forest of a coastal lagoon in Veracruz, Mexico in 20 0.25-ha plots, 10 in interdistributary basins (IBs, lower salinity) having Avicennia germinans, Laguncularia racemosa and Rhizophora mangle and 10 in mudflats (MFs, higher salinity) dominated by A. germinans. Size inequality was significantly higher in IBs (G = 0.59 ± 0.02 vs. 0.39 ± 0.03). Due to their significant intercorrelation G, total basal area and density were synthesized in one PCA axis accounting for 67% of total variance and inversely correlated with salinity (R = −0.65, P = 0.003). The height–diameter scaling model reached a stable asymptote (Hmax range: 16–21 m; coefficient of variation CV: 7.7) in IBs, suggesting that trees can still increase their diameter after achieving maximum height. In MFs, no stable asymptote was reached (Hmax range: 11–26 m; CV: 32.5), suggesting a lower growth rate of diameter in the MF trees when compared with IB trees. |
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