1,738 publications from this institution
In this paper we identify adaptation enabling variables, and components that can be adapted, in a setting specific to Digital Talking Books. We then propose an evolution to our Digital Talking Book builder framework, to enable the production of adaptive books.
As coastal plants that can survive in salt water, mangroves play an essential role in large marine ecosystems (LMEs). The Red Sea, where the growth of mangroves is stunted, is one of the least studied LMEs in the world. Mangroves along the Central Red Sea have characteristic heights of ~2 m, suggesting nutrient limitation. We assessed the nutrient status of mangrove stands in the Central Red Sea and conducted a fertilization experiment (N, P and Fe and various combinations thereof) on four-week-old seedlings of Avicennia marina to identify limiting nutrients and stoichiometric effects. We measured height, number of leaves, number of nodes and root development at different time periods as well as the leaf content of C, N, P, Fe and Chl a in the experimental seedlings. Height, number of nodes and number of leaves differed significantly among treatments. Iron treatment resulted in significantly taller plants compared with other nutrients, demonstrating that iron is the primary limiting nutrient in the tested mangrove population and confirming Liebig's law of the minimum: iron addition alone yielded results comparable to those using complete fertilizer. This result is consistent with the biogenic nature of the sediments in the Red Sea, which are dominated by carbonates, and the lack of riverine sources of iron.
Georeferenced database on the spatial properties of all individual shallow-water tropical coral reefs worldwide. The dataset was obtained by processing and analyzing the global-scale coral reef benthic data provided by the Allen Coral Atlas (ACA), a publicly available dataset of high-resolution satellite imagery and machine learning-based coral reef classifications. The original data, already divided into different coral provinces, was segmented to identify the individual reefs of each province using a label assignment algorithm. This allows to analyze several spatial properties of coral reefs such as the size distribution, area-perimeter relationship, fractal dimensions and shape measures. The dataset contains measures of area, perimeter, fractal dimension, compactness and elongation index (diameter ratio) for each individual reef in each coral province.
MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 221:117-124 (2001) - doi:10.3354/meps221117 Retrospective estimates of net leaf production in Kandelia candel mangrove forests Sarah C. Coulter1,*, Carlos M. Duarte2, Mai Sy Tuan3, Nguyen Hoang Tri3, Hoang Thi Ha3, Le Huong Giang3, Phan Nguyen Hong3 1University of Victoria, PO Box 3025, Victoria, British Columbia V8W 3P2, Canada 2Instituto Mediterráneo de Estudios Avanzados (IMEDEA), CSIC-Universidad illes Balears, C/ Miquel Marqués 21, 07190 Esporles Mallorca, Islas Baleares, Spain 3Mangrove Ecosystem Research Division, Centre for Natural Resource and Environment Studies, Vietnam National University, Hanoi, So 7, Ngo115, Pho Nguyen Khuyen, Hanoi, Vietnam *Present address: Box 633, Invermere, British Columbia V0A 1K0, Canada. E-mail: scoulter@uvic.ca ABSTRACT: A new, inexpensive, and time-saving method for the estimation of the net production of leaves and reproductive structures of mangroves was applied to 2 Vietnamese stands of Kandelia candel. The method combines the allometric relationship between the number of meristems in trees and their diameter with knowledge of the number of leaf pairs and reproductive structures each meristem develops annually to calculate the net leaf and inflorescence production of each tree in the stand. Each apical meristem of K. candel produced about 6 leaf pairs and 1.3 to 1.9 inflorescences annually, with the number of meristems in each tree increasing to the square of their girth. The size distribution of K. candel was highly skewed at all sites, with an exponential decline in the number of plants as the size increased. The net leaf production (dry wt), calculated by scaling the production per meristem to that of individual trees and then to the entire stand, ranged from 176.5 to 1338.7 g m-2 yr-1 among stands, with an estimated total inflorescence production ranging from 0.91 to 101 g m-2 yr-1. The largest individuals, comprising 10 % of the population, contributed the majority of the stand production. The approach demonstrated overcomes serious deficiencies in the traditional litter-fall method, particularly when applied to developing mangrove stands, and should be applicable to other mangrove species as long as they display clear nodes, leaf, flower and fruit scars, as do other members of the Rhizophoraceae family. KEY WORDS: Mangrove · Primary production · Litterfall · Kandelia candel · Rhizophoraceae · Vietman Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 221. Online publication date: October 18, 2001 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2001 Inter-Research.
Data from 69 Florida lakes were used to test 15 empirical models that were developed from a worldwide data base to describe the biomass and cover of aquatic macrophytes in lakes. Ten of the models failed to provide useful predictions in Florida because the models did not adequately reflect the limnological characteristics of Florida lakes. Submerged and emergent biomass in the Florida lakes was predicted by the models that estimated these parameters from the areal cover of submerged and emergent vegetation. Total macrophyte cover in Florida lakes could be predicted from a model based on lake size, annual irradiance at the surface, and the mean annual irradiance within the mean depth of the lake. Even the best models, however, overestimated submerged plant biomass and cover in highly colored (>400 Pt–Co units) lakes and lakes with steep (slope >15%) littorals. This suggests that the influence of light (quantity and quality) and littoral slope on the abundance of aquatic macrophytes needs additional research before improved empirical models can be developed for lakes located in limited geographic regions.
Abstract. Transparent exopolymer particles (TEP) are the most ubiquitous gel particles in the ocean and form abiotically from dissolved precursors. Although these particles can accumulate at the ocean surface, being thus exposed to intense sunlight, the role of solar radiation on the assembly and degradation of TEP is unknown. In this study, we experimentally determined the effects of visible and ultraviolet B (UVB) radiation on (1) TEP degradation (photolysis experiments), (2) TEP assembly from dissolved polymers (photoinhibition experiments) and (3) TEP release by microorganisms. Solar radiation, particularly in the UVB range, caused significant TEP photolysis, with loss rates from 27 to 34% per day. Dissolved polysaccharides did not increase in parallel. No TEP were formed under UVB, visible or dark conditions, indicating that light does not promote TEP assembly. UVB radiation enhanced TEP release by microorganisms, possibly due to cell deaths, or as a protective measure. Increases in UVB may lead to enhanced TEP photolysis in the ocean, with further consequences for TEP dynamics and, ultimately, sea-air gas exchange.
