Potential effects of sea-level rise on plant productivity: species-specific responses in northeast Pacific tidal marshes

Coastal wetland plants are adapted to varying degrees of inundation. However, functional relationships between inundation and productivity are poorly characterized for most species. Determining species-specific tolerances to inundation is necessary to evaluate sea-level rise (SLR) effects on future marsh plant community composition, quantify organic matter inputs to marsh accretion, and inform predictive modeling of tidal wetland persistence. In 2 macrotidal estuaries in the northeast Pacific we grew 5 common species in experimental mesocosms across a gradient of tidal elevations to assess effects on growth. We also tested whether species abundance distributions along elevation gradients in adjacent marshes matched productivity profiles in the mesocosms. We found parabolic relationships between inundation and total plant biomass and shoot counts in Spartina foliosa and Bolboschoenus maritimus in California, USA, and in Carex lyngbyei in Oregon, USA, with maximum total plant biomass occurring at 38, 28, and 15% time submerged, respectively. However, biomass of Salicornia pacifica and Juncus balticus declined monotonically with increasing inundation. Inundation effects on the ratio of belowground to aboveground biomass varied inconsistently among species. In comparisons of field distributions with mesocosm results, B. maritimus, C. lyngbyei and J. balticus were abundant in marshes at or above elevations corresponding with their maximum productivity; however, S. foliosa and S. pacifica were frequently abundant at lower elevations corresponding with sub-optimal productivity. Our findings show species-level differences in how marsh plant growth may respond to future SLR and highlight the sensitivity of high marsh species such as S. pacifica and J. balticus to increases in flooding.Keywords: Root-to-shoot ratio, Zonation, Plant biomass, Tidal wetlands, Marsh organ

Stress gradients structure spatial variability in coastal tidal marsh plant composition and diversity in a major Pacific coast estuary

Understanding the drivers of variability in plant diversity from local to landscape spatial scales is a challenge in ecological systems. Environmental gradients exist at several spatial scales and can be nested hierarchically, influencing patterns of plant diversity in complex ways. As plant community dynamics influence ecosystem function, understanding the drivers of plant community variability across space is paramount for predicting potential shifts in ecosystem function from global change. Determining the scales at which stress gradients influence vegetation composition is crucial to inform management and restoration of tidal marshes for specific functions. Here, we analyzed vegetation community composition in 51 tidal marshes from the San Francisco Bay Estuary, California, USA. We used model-based compositional analysis and rank abundance curves to quantify environmental (elevation/tidal frame position, distance to channel, and channel salinity) and species trait (species form, wetland indicator status, and native status) influences on plant community variability at the marsh site and estuary scales. While environmental impacts on plant diversity varied by species and their relationships to each other, overall impacts increased in strength from marsh to estuary scales. Relative species abundance was important in structuring these tidal marsh communities even with the limited species pools dominated by a few species. Rank abundance curves revealed different community structures by region with higher species evenness at plots higher in the tidal frame and adjacent to freshwater channels. By identifying interactions (species–species, species–environment, and environment–trait) at multiple scales (local, landscape), we begin to understand how variability measurements could be interpreted for conservation and land management decisions

Congenital and childhood atrioventricular blocks: pathophysiology and contemporary management

Atrioventricular block is classified as congeni- tal if diagnosed in utero, at birth, or within the first month of life. The pathophysiological process is believed to be due to immune-mediated injury of the conduction system, which occurs as a result of transplacental pas- sage of maternal anti-SSA/Ro-SSB/La antibodies. Childhood atrioventricular block is therefore diagnosed between the first month and the 18th year of life. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited progressive car- diac conduction disorders. Indications and techniques of cardiac pacing have also evolved to allow safe perma- nent cardiac pacing in almost all patients, including those with structural heart abnormalities

Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF

M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe

Common benthic algae and cyanobacteria in southern California tidal wetlands

Benthic algae and photosynthetic bacteria are important components of coastal wetlands, contributing to primary productivity, nutrient cycling, and other ecosystem functions. Despite their key roles in mudflat and salt marsh food webs, the extent and patterns of diversity of these organisms is poorly known. Sediments from intertidal marshes in San Diego County, California host a variety of cyanobacteria, diatoms, and multi-cellular algae. This flora describes approximately 40 taxa of common and notable cyanobacteria, microalgae and macroalgae observed in wetland sediments, principally from a small tidal marsh in Mission Bay. Cyanobacteria included coccoid and heterocyte and non-heterocyte bearing filamentous genera. A phylogenetically-diverse assemblage of pennate and centric diatoms, euglenoids, green algae, red algae, tribophytes and brown seaweeds was also observed. Most taxa are illustrated with photographs

Common benthic algae and cyanobacteria in southern California tidal wetlands

Benthic algae and photosynthetic bacteria are important components of coastal wetlands, contributing to primary productivity, nutrient cycling, and other ecosystem functions. Despite their key roles in mudflat and salt marsh food webs, the extent and patterns of diversity of these organisms is poorly known. Sediments from intertidal marshes in San Diego County, California host a variety of cyanobacteria, diatoms, and multi-cellular algae. This flora describes approximately 40 taxa of common and notable cyanobacteria, microalgae and macroalgae observed in wetland sediments, principally from a small tidal marsh in Mission Bay. Cyanobacteria included coccoid and heterocyte and non-heterocyte bearing filamentous genera. A phylogenetically-diverse assemblage of pennate and centric diatoms, euglenoids, green algae, red algae, tribophytes and brown seaweeds was also observed. Most taxa are illustrated with photographs

Functional Diversity and Composition of Microalgae and Photosynthetic Bacteria in Marine Wetlands: Spatial Variation, Succession, and Influence on Productivity

Phylogenetically diverse benthic producers (e.g., diatoms, green algae, cyanobacteria, and anoxygenic photobacteria) inhabit the sediments of coastal wetlands and mediate numerous ecosystem functions, including a substantial fraction of total ecosystem productivity. Despite their ubiquity and functional importance, spatia-temporal patterns in the distribution of major taxonomic groups and diversity­ related effects on function are poorly understood. Using a photopigment-based approach I investigated the composition of microproducer communities at two coastal sites in southern California and addressed (1) the temporal development of assemblages in a restored wetland, (2) the spatial distribution of major functional groups across various habitats, and (3) the influence of functional group diversity and dominance on primary productivity.Within a large restoration site at Tijuana Estuary, pigment concentrations suggested rapid recovery of assemblage biomass (< 1yr) and at least partial recovery of taxonomic composition by 0.2 yr in restored mudflats. In Spartina-dominated salt marsh, however, composition and diversity took longer to mirror natural marsh communities (-1.5-2.2 yr). In Mission Bay, study of an older restoration site (6.3 yr) also suggested differences in rates of habitat development, with Spartina marsh and creek-banks probably preceding mixed species marsh. In a spatial analysis of communities, I found that natural sediments from vegetated marshes in Mission Bay were enriched in cyanobacteria and anoxygenic photobacteria, and had higher diversity, relative to unvegetated sediments, but no mudflat versus marsh difference was evident at Tijuana Estuary. In several independent studies of diversity and productivity, including a manipulation of functional richness in lab cultures, I found no effect of variation in functional diversity on rates of oxygenic photosynthesis and only minor increases in microproducer standing stocks in more diverse assemblages. However, results also tentatively suggest unique community roles for green algae (high oxygenic production rates) and anoxygenic photobacteria (enhancement of community biomass), supporting the notion that composition may be more important than absolute diversity to function.These data re-enforce the idea that study of composition in microproducer assemblages is necessary in addition to simple measures of chlorophyll a. The functional consequences of altered diversity and composition should be further investigated in this cryptic but important flora

Functional Diversity and Composition of Microalgae and Photosynthetic Bacteria in Marine Wetlands: Spatial Variation, Succession, and Influence on Productivity

Phylogenetically diverse benthic producers (e.g., diatoms, green algae, cyanobacteria, and anoxygenic photobacteria) inhabit the sediments of coastal wetlands and mediate numerous ecosystem functions, including a substantial fraction of total ecosystem productivity. Despite their ubiquity and functional importance, spatia-temporal patterns in the distribution of major taxonomic groups and diversity­ related effects on function are poorly understood. Using a photopigment-based approach I investigated the composition of microproducer communities at two coastal sites in southern California and addressed (1) the temporal development of assemblages in a restored wetland, (2) the spatial distribution of major functional groups across various habitats, and (3) the influence of functional group diversity and dominance on primary productivity.Within a large restoration site at Tijuana Estuary, pigment concentrations suggested rapid recovery of assemblage biomass (< 1yr) and at least partial recovery of taxonomic composition by 0.2 yr in restored mudflats. In Spartina-dominated salt marsh, however, composition and diversity took longer to mirror natural marsh communities (-1.5-2.2 yr). In Mission Bay, study of an older restoration site (6.3 yr) also suggested differences in rates of habitat development, with Spartina marsh and creek-banks probably preceding mixed species marsh. In a spatial analysis of communities, I found that natural sediments from vegetated marshes in Mission Bay were enriched in cyanobacteria and anoxygenic photobacteria, and had higher diversity, relative to unvegetated sediments, but no mudflat versus marsh difference was evident at Tijuana Estuary. In several independent studies of diversity and productivity, including a manipulation of functional richness in lab cultures, I found no effect of variation in functional diversity on rates of oxygenic photosynthesis and only minor increases in microproducer standing stocks in more diverse assemblages. However, results also tentatively suggest unique community roles for green algae (high oxygenic production rates) and anoxygenic photobacteria (enhancement of community biomass), supporting the notion that composition may be more important than absolute diversity to function.These data re-enforce the idea that study of composition in microproducer assemblages is necessary in addition to simple measures of chlorophyll a. The functional consequences of altered diversity and composition should be further investigated in this cryptic but important flora

Control of brown rot and shot hole in almond: 2009 field trial

We conducted a field trial to evaluate the efficacy of a synthetic fungicide (Pristine; boscalid and pyraclostrobin) and two organic fungicides (Regalia; extract of Reynoutria sachilinensis and JMS Stylet-oil; paraffinic oil) for management of two foliar diseases in almond. Pristine and Pristine alternated with Regalia effectively reduced symptoms of both brown rot and shot hole following three applications from red bud to post-bloom. JMS Stylet-oil and Regalia alone did not control the diseases

Chemical and biological control of grape powdery mildew: 2008 field trials

Powdery mildew is one of the most significant diseases affecting grape (Vitis vinifera) production around the world. The disease is caused by the hyaline ascomycete, Erysiphe necator, a pathogen capable of rapid proliferation under optimal environmental conditions. Disease onset begins in the spring with the release of ascospores from over-wintering chasmothecia (Gubler and Hirschfelt 1992). Once initial colonies are established, the fungus can asexually propagate via large numbers of conidia that disperse and re-infect additional leaves and developing fruits. Powdery mildew effects on the host include reduction in berry mass, potential cracking of berries, and increased susceptibility to berry rots (Gubler and Hirschfelt 1992, Calonnec et al. 2004, Gadoury et al. 2007). Economically, the disease may be damaging to California’s grape industry because of lost yield, a shortened shelf life for table grapes, and alterations in wine flavor (Gubler and Hirschfelt 1992, Gadoury et al. 2007).In California, powdery mildew is principally controlled via periodic application of foliar fungicides, including sulfur and synthetic materials such as demethylase inhibitors and strobilurins (California Department of Pesticide Regulation 2004). A wide range of materials show at least some reduction in disease levels under field conditions (Janousek et al. 2007, Adaskaveg et al. 2008). We continued our annual powdery mildew trials during 2008 to evaluate the efficacy of various fungicide products, including registered synthetic materials of varied chemical classes, oils, and biocontrol products. We present the results of five trials conducted in a Chardonnay vineyard at Herzog Ranch in Sacramento County, California