Using expert knowledge and modeling to define mangrove composition, functioning, and threats and estimate time frame for recovery

Mangroves are threatened worldwide, and their loss or degradation could impact functioning of the ecosystem. Our aim was to investigate three aspects of mangroves at a global scale: (1) their constituents (2) their indispensable ecological functions, and (3) the maintenance of their constituents and functions in degraded mangroves. We focused on answering two questions: “What is a mangrove ecosystem” and “How vulnerable are mangrove ecosystems to different impacts”? We invited 106 mangrove experts globally to participate in a survey based on the Delphi technique and provide inputs on the three aspects. The outputs from the Delphi technique for the third aspect, i.e. maintenance of constituents and functions were incorporated in a modeling approach to simulate the time frame for recovery. Presented here for the first time are the consensus definition of the mangrove ecosystem and the list of mangrove plant species. In this study, experts considered even monospecific (tree) stands to be a mangrove ecosystem as long as there was adequate tidal exchange, propagule dispersal, and faunal interactions. We provide a ranking of the important ecological functions, faunal groups, and impacts on mangroves. Degradation due to development was identified as having the largest impact on mangroves globally in terms of spatial scale, intensity, and time needed for restoration. The results indicate that mangroves are ecologically unique even though they may be species poor (from the vegetation perspective). The consensus list of mangrove species and the ranking of the mangrove ecological functions could be a useful tool for restoration and management of mangroves. While there is ample literature on the destruction of mangroves due to aquaculture in the past decade, this study clearly shows that more attention must go to avoiding and mitigating mangrove loss due to coastal development (such as building of roads, ports, or harbors).Arcadia Mandat d'Impulsion Scientifique. Grant Number: 1765914 National Science Foundation (FNRS) CREC. Grant Number: 247514 Vrije Universiteit Brussel (VUB) Fonds Wetenschappelijk Onderzoek (FWO) Mangrove Ecology, Functioning and Managemen

IBD risk loci are enriched in multigenic regulatory modules encompassing putative causative genes.

GWAS have identified >200 risk loci for Inflammatory Bowel Disease (IBD). The majority of disease associations are known to be driven by regulatory variants. To identify the putative causative genes that are perturbed by these variants, we generate a large transcriptome data set (nine disease-relevant cell types) and identify 23,650 cis-eQTL. We show that these are determined by ∼9720 regulatory modules, of which ∼3000 operate in multiple tissues and ∼970 on multiple genes. We identify regulatory modules that drive the disease association for 63 of the 200 risk loci, and show that these are enriched in multigenic modules. Based on these analyses, we resequence 45 of the corresponding 100 candidate genes in 6600 Crohn disease (CD) cases and 5500 controls, and show with burden tests that they include likely causative genes. Our analyses indicate that ≥10-fold larger sample sizes will be required to demonstrate the causality of individual genes using this approach

Allometric relationships for predicting the stem volume in a Dalbergia sissoo Roxb. plantation in Bangladesh

Allometric relationships for estimating stem volumes of Dalbergia sissoo Roxb. (Sissoo) trees were investigated in monoculture plantations in Bangladesh. The various allometric relationships between stem volume and different dimensions were tested and the coefficient of determination R2 values were used to compare the strength of the relationships. Although the allometric equations were highly significant (P<0.01) there was considerable variation among them as indicated by the R2 values. Our results suggested that tree volume is more correlated with basal area than with simple D (stem diameter at 1.3 m height above the ground). The allometric relationships of stem volume to the tree diameter at 10% of tree height (D0.1) did not improve the allometric strength in comparison with simple D as reported in case of some other tree species. The multiplication of tree height H with D in the allometric equation gives a little improvement in the degree of fitness of the allometric equations. However, for the Sissoo plantations studied the stem dbh alone showed a very strong accuracy of estimation (R2 = 0.997) especially when used as D2. It is concluded that the use of tree height in the allometric equation can be neglected for the species, as far as the present study area is concerned. Therefore, for estimating the stem volume of Sissoo, the use of D2 as an independent variable in the allometric equation with a linear or quadratic equation is recommended. The paper describes details of tree volume allometry, which is important in silviculture and forest management