Conversion and recovery of Puerto Rican mangroves: 200 years of change

Human activities have dramatically reduced the world’s area of mangroves just as the ecological services they provide are becoming widely recognized. Improving the conservation tools available to restore lost mangroves would benefit from a better understanding of how human activities influence the conservation of these ecosystems. We took advantage of historical information and long-term landscape analyses to relate land use change with the area of mangroves in Puerto Rico. We found that mangroves experienced dramatic changes over the last 200 years, and four distinct eras of change were visible. During the agricultural era (1800–1940) the area of mangroves declined 45%. As the economy changed to industrial in the late 1940s the area of mangrove increase due to reduced land use pressure on the wetlands. Nevertheless, urban expansion between 1960s and 1970s produced another decline. Public concern for mangrove conservation resulted in the legal protection of all the mangroves in 1972, and since then their area has expanded. We found that past human activity altered the original proportion of mangrove species. The number and size of mangrove-forest fragments was impacted by land use, and urban areas had fewer and smaller fragments than vegetated areas. Uncontrolled expansion of urban areas emerged as a major threat to mangrove conservation. Mangroves are resilient and recover quickly when given an opportunity if the geomorphological and hydrological features of the habitat are not changed by their use. The key to conservation appears to be a combination of the type of human activity in mangrove watersheds combined with strong legal protection. The following steps are recommended: (1) identify the areas that satisfy the ecological requirements of mangrove development; (2) incorporate better zoning regulations to maintain these areas natural and to protect the fluxes of water, nutrients, and organisms in and out of the system; and (3) monitor results.     

Temperature, the GacS/GacA system, and host metabolites regulate the type VI secretion system of Pseudomonas syringae pv. phaseolicola

The recently discovered type VI secretion system (T6SS) is implicated in the pathogenic and/or virulence processes of diverse bacteria. The expression pattern of the T6SS differs among different organisms and also depends on several environmental factors. We initiated a study of the conditions that influence T6SS gene expression in Pseudomonas syringae pv. phaseolicola NPS3121. Our results indicate that low temperatures and plant extracts impact the expression of T6SS genes and that the process is subject to regulation by the GacS/GacA two-component system.     

Phylogenetic Variation of Chelonid Alphaherpesvirus 5 (ChHV5) in Populations of Green Turtles Chelonia mydas along the Queensland Coast,Australia

Abstract

Sea turtle fibropapillomatosis (FP) is a disease marked by the proliferation of benign but debilitating cutaneous and occasional visceral tumors, likely to be caused by chelonid alphaherpesvirus 5 (ChHV5). This study presents a phylogeny of ChHV5 strains found on the east coast of Queensland, Australia, and a validation for previously unused primers. Two different primer sets (gB-1534 and gB-813) were designed to target a region including part of the UL27 glycoprotein B (gB) gene and part of UL28 of ChHV5. Sequences obtained from FP tumors found on juvenile green turtles Chelonia mydas (<65 cm curved carapace length) had substantial homology with published ChHV5 sequences, while a skin biopsy from a turtle without FP failed to react in the PCRs used in this study. The resulting sequences were used to generate a neighbor-joining tree from which three clusters of ChHV5 from Australian waters were identified: north Australian, north Queensland, and Queensland clusters. The clusters reflect the collection sites on the east coast of Queensland with a definitive north–south trend.

Received October 22, 2016; accepted May 7, 2017 Published online July 26, 2017     

Fluorine‐18 fluorodeoxyglucose positron emission tomography imaging exhibits increased SUVmax at the level of the spinal intumescence in normal dogs

Positron emission tomography (PET) imaging utilizing fluorine‐18 labeled fluorodeoxyglucose is a relatively new imaging modality in veterinary medicine that is becoming more common for oncological staging and for musculoskeletal imaging. Thus, it is important to identify the normal variations on PET imaging that may be mistaken for pathology. Variation in standardized uptake values (SUVmax) have been anecdotally identified in the spinal cord of dogs undergoing fluorodeoxyglucose (FDG) PET–CT examinations for oncological staging, with notable increase in SUVmax values identified in the region of the cervical and lumbar spinal intumescences. The aim of this retrospective, analytical study was to compare the SUVmax values at four different locations throughout the spinal cord (C3, C5‐T1, T13, and L3‐S1) of a group of dogs with no evidence of neurologic disease and compare those findings to histologic specimens from dogs euthanized for unrelated disease. SUVmax values were significantly higher at the cervical and lumbar intumescences in comparison to the control regions (P < .0001 and P < .0001, respectively). Neuronal count and spinal cord gray matter area were also significantly greater at the cervical and lumbar intumescences (neuronal count P = .0025 and P = .0001; area P = .0004 and P = .0009, respectively) while overall neuronal density was lower (P = .003 and P = .028, respectively). We presume the increased SUVmax values at the spinal cord intumescences are the result of overall increased neuron count, increased proportion of gray matter, and increased spinal cord gray matter area. These findings will aid in the interpretation of future PET–CT studies and hopefully prevent the misdiagnosis of spinal cord disease in normal canines.     

Generalized glycogenosis in Brahman-derived breeds: diagnosis and prevalence in Argentina

Tropical Animal Health and Production - Generalized glycogenosis is a lethal autosomal recessive disease caused by a deficient activity of the acidic 1,4-α-glucosidase enzyme and characterized...     

Saproxylic species are linked to the amount and isolation of dead wood across spatial scales in a beech forest

Context

Dead wood is a key habitat for saproxylic species, which are often used as indicators of habitat quality in forests. Understanding how the amount and spatial distribution of dead wood in the landscape affects saproxylic communities is therefore important for maintaining high forest biodiversity.

Objectives

We investigated effects of the amount and isolation of dead wood on the alpha and beta diversity of four saproxylic species groups, with a focus on how the spatial scale influences results.

Methods

We inventoried saproxylic beetles, wood-inhabiting fungi, and epixylic bryophytes and lichens on 62 plots in the Sihlwald forest reserve in Switzerland. We used GLMs to relate plot-level species richness to dead wood amount and isolation on spatial scales of 20–200 m radius. Further, we used GDMs to determine how dead wood amount and isolation affected beta diversity.

Results

A larger amount of dead wood increased beetle richness on all spatial scales, while isolation had no effect. For fungi, bryophytes and lichens this was only true on small spatial scales. On larger scales of our study, dead wood amount had no effect, while greater isolation decreased species richness. Further, we found no strong consistent patterns explaining beta diversity.

Conclusions

Our multi-taxon study shows that habitat amount and isolation can strongly differ in the spatial scale on which they influence local species richness. To generally support the species richness of different saproxylic groups, dead wood must primarily be available in large amounts but should also be evenly distributed because negative effects of isolation already showed at scales under 100 m.