Allometry, biomass, and productivity of mangrove forests: A review

We review 72 published articles to elucidate characteristics of biomass allocation and productivity of mangrove forests and also introduce recent progress on the study of mangrove allometry to solve the site- and species-specific problems. This includes the testing of a common allometric equation, which may be applicable to mangroves worldwide. The biomass of mangrove forests varies with age, dominant species, and locality. In primary mangrove forests, the above-ground biomass tends to be relatively low near the sea and increases inland. On a global scale, mangrove forests in the tropics have much higher above-ground biomass than those in temperate areas. Mangroves often accumulate large amounts of biomass in their roots, and the above-ground biomass to below-ground biomass ratio of mangrove forests is significantly low compared to that of upland forests (ANCOVA, P < 0.01). Several studies have reported on the growth increment of biomass and litter production in mangrove forests. We introduce some recent studies using the so-called “summation method” and investigate the trends in net primary production (NPP). For crown heights below 10 m, the above-ground NPP of mangrove forests is significantly higher (ANOVA, P < 0.01) than in those of tropical upland forests. The above-ground litter production is generally high in mangrove forests. Moreover, in many mangrove forests, the rate of soil respiration is low, possibly because of anaerobic soil conditions. These trends in biomass allocation, NPP, and soil respiration will result in high net ecosystem production, making mangrove forests highly efficient carbon sinks in the tropics.     

荞麦愈伤组织分化与过氧化物酶活性及其同工酶关系的研究

在附加不同外源激素的培养基中,龙山荞的子叶愈伤组织表现出不同的分化状态:(1)不分化;(2)分化根;(3)分化芽;(4)分化全苗。四种愈伤组织的过氧化物酶活性的相对比值为1:1.47:5.95:7.78,并且过氧化物酶同工酶谱也存在明显差异。酶带4'为分化愈伤组织所特有;酶带2'为未分化和分化愈伤组织所共有;在分化根和未分化愈伤组织中缺少酶带1';未分化愈伤组织比分化愈伤组织多出酶带3'。     

Inferences from Common Species Communities for Selecting Conservation Areas

We aimed at identifying probabilistic areas of high biodiversity value over a large spatial scale, e.g., an entire country (France) within the temperate region, that could work as valuable conservation areas for both rare and common species. We aimed at identifying areas where four measures on bird community overpass a selected threshold value, by using probability interpolation models. The four variables considered were the rare species number, and three measures related to common bird community: relative abundance, estimated species richness and composition originality. For the latter, we developed an indicator that discriminates original from more ordinary compositions of common bird communities, accounting for the number of representatives in each species. This indicator was positively correlated to rare breeding species number, so that original composition of common bird communities allows us to identify areas also supporting the rarest species. Areas with high probabilities of two indicators reaching their threshold values represented 2.9% of continental France. Most double-indicator areas were those with high species richness and high relative abundance, then with original communities and high rare species number. The originality indicator was revealed valuable to identify the most suitable areas that could ensure the preservation of both rare and common species, at a national scale. By preserving sites supporting original common bird communities, conservationists would ensure the protection of rare and common species.     

The analysis of stratified 2 x 2 contingency tables

We consider the problem of testing for independence against the consistent superiority of one treatment over another when the response variable is binary and is compared across two treatments in each of several strata. Specifically, we consider the randomized clinical trial setting. A number of issues arise in this context. First, should tables be combined if there are small or zero margins? Second, should one assume a common odds ratio across strata? Third, if the odds ratios differ across strata, then how does the standard test (based on a common odds ratio) perform? Fourth, are there other analyzes that are more appropriate for handling a situation in which the odds ratios may differ across strata? In addressing these issues we find that the frequently used Cochran–Mantel–Haenszel test may have a poor power profile, despite being optimal when the odds ratios are common. We develop novel tests that are analogous to the Smirnov, modified Smirnov, convex hull, and adaptive tests that have been proposed for ordered categorical data. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Cerebellar localization of the NO-receptive soluble guanylyl cyclase subunits-α2/β1 in non-human primates

Nitric-oxide-sensitive guanylyl cyclase (NO-sGC) plays a pivotal role in many second messenger cascades. Neurotransmission- and neuropathology-related changes in NO-sGC have been suggested. However, the cellular localization of NO-sGC in primate brains, including humans, remains unknown. Biochemical evidence has linked the α₂-subunit of NO-sGC directly to neurotransmission in rodents. Here, we have used a recently characterized subunit-specific antibody for the localization of the α₂-subunit on sections from the cerebelli of the common marmoset (Callithrix jacchus; New World monkey) and macaque monkeys (Macaca mulatta, M. fascicularis; Old World monkeys). In contrast to the more ubiquitous cytoplasmic presence of subunit-β₁, the α₂-subunit is mainly confined to the somato-dendritic membrane including the spines of the Purkinje cells. Only limited colocalization with presynaptically localized synaptophysin has been seen under our staining conditions, indicating a higher abundance of subunit-α₂ at the postsynaptic site. This localization indicates that subunit-α₂ links NO-sGC to neurotransmission, whereas subunit-β₁ may act as a cytoplasmic regulator/activator by contributing to active heterodimer formation via translocation from the cytoplasm to the cell membrane. The last-mentioned action may be a prerequisite for generating nitric-oxide-dependent, subcellular, and postsynaptically localized cGMP signals along neuronal processes.This study was supported by the Deutsche Forschungsgemeinschaft.     

Low support for separate species within the redpoll complex (Carduelis flammea-hornemanni-cabaret) from analyses of mtDNA and microsatellite markers

The redpoll complex, consisting of three currently recognized species (Carduelis flammea, C. hornemanni and C. cabaret), is polytypic in biometry, morphology, physiology and behaviour. However, previous genetic work has not revealed any indications of genetic differentiation. We analysed sequence variation in the mtDNA control region, and allele frequencies of supposedly faster evolving microsatellites (n=10), in an attempt to detect molecular genetic support for the three species, as well as two subspecies of C. flammea (ssp. flammea and rostrata), within this complex. We used samples from two subspecies of the twite (Carduelis flavirostris, ssp. flavirostris and rufostrigata) as outgroup. We found no structure among redpoll individuals in mtDNA haplotypes or microsatellite allele frequencies, and only marginal differences between redpoll taxa in analyses of molecular variance (AMOVAs) of predefined groups. In contrast, the two twite subspecies constituted two well-supported monophyletic groups. Our study thus strengthens previous indications of low genetic support for current redpoll taxa. Two major alternative interpretations exist. Either redpolls form a single gene pool with geographical polymorphisms possibly explained by Bergmann's and Gloger's rules, or there are separate gene pools of recent origin but with too little time elapsed for genetic differentiation to have evolved in the investigated markers. Future studies should therefore examine whether reproductive isolation mechanisms and barriers to gene flow exist in areas with sympatric breeding.     

Geographic variation in malarial parasite lineages in the common yellowthroat (<Emphasis Type="Italic">Geothlypis trichas</Emphasis>)

Our current understanding of migration routes of many birds is limited and researchers have employed various methods to determine migratory patterns. Recently, parasites have been used to track migratory birds. The objective of this study was to determine whether haemosporidian parasite lineages detect significant geographic structure in common yellowthroats (Geothlypis trichas). We examined liver tissue or blood from 552 birds sampled from multiple locations throughout the continental United States, southern Canada, and the Bahamas. We found a 52.7% overall prevalence of haematozoan infection. We identified 86.1% of these infections to genus: 81% were Plasmodium; 5% were Haemoproteus; and 0.1% were Leucocytozoon. There were significant differences in the prevalence of different parasite genera among regions (χ² = 36.82, P < 0.0001) and in the proportion of Plasmodium infections versus other parasites among regions (χ² = 35.52, P < 0.0001). Sequence information identified three Haemoproteus lineages, two Leucocytozoon lineages, and thirteen Plasmodium lineages. Due to the low number of Haemoproteus and Leucocytozoon, only Plasmodium lineages were used in the geographic comparison of lineages. Six Plasmodium lineages were found in eight or more birds and the prevalence of these varied significantly among regions (χ² = 172.33, P < 0.0001). Additionally, 45 juvenile birds were sampled to determine what parasites could be obtained in the breeding grounds and we found only one lineage. In conclusion, parasite lineages show some geographic structure, with some lineages being more geographically specific than others, but are not useful for determining migratory connectivity in this species. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. The U.S. Government’s right to retain a non-exclusive, royalty-free license in and to any copyright is acknowledged.