In nutrient-poor landscapes, external nutrient subsidies are important for sustaining local production. Seabirds can transport marine nutrients in the form of guano to terrestrial and coastal ...ecosystems where they can relieve nutrient limitation. We assessed whether seabirds provide nutrient subsidies to mangrove islands that are strongly limited by phosphorus (P) in the Yucatan Peninsula. Our hypotheses were: (1) seabirds transport nutrients to mangrove islands, (2) mangroves use marine-derived nutrients and (3) nutrient inputs are higher during the nesting season. We chose 6 mangrove islands within a coastal lagoon: 2 with no birds, 2 with temporary birds and 2 with permanent bird colonies. On each, we measured forest structure and soil characteristics (P, pH, salinity and organic matter) for 3 seasons (dry, wet and trade wind season). We collected leaves (green and senescent) to determine P content and resorption efficiency as a measurement of nutrient limitation. Green leaves were also sampled for δ13C and δ15N to determine nutrient origin. Results show that islands with permanent bird colonies have the highest soil nutrients, which are used by the mangrove trees and relieve some of their nutrient limitation. Nutrient inputs were homogenously distributed through the sediment column, although a decrease in P and an increase in the N:P ratio in the first 20 cm suggests bacterial consumption. Bird nutrient inputs are seasonal, with highest inputs during the nesting season. This study shows an example in which marine-derived nutrients could be important for production of coastal mangrove islands.
Green stormwater infrastructure is a common feature of urban cities which is mostly designed for hydrological and water quality purposes. The last decade has seen a rise in research on the ...environmental impact assessment of vegetated water sensitive urban design (WSUD) technologies. However, the added ecosystem benefits of these systems, such as carbon sequestration, have received less attention. In this study, the life cycle net carbon footprint of various vegetated WSUD technologies namely green roofs, rain gardens, bioretention basins, vegetated swales and stormwater ponds, have been reviewed and analysed including their carbon sequestration potential. The carbon footprint of each vegetated WSUD technology was evaluated through the four phases of the life cycle assessment (LCA): material production, construction, operation and maintenance and end-of-life phases. The results of this study show that the initial embodied carbon associated with production, transportation and construction phases is the major contributor to the carbon footprint for most of the vegetated WSUD technologies. Rain gardens are shown to provide the highest carbon sequestration potential which offsets its carbon footprint. Carbon sequestration of bioretention basins, green roofs, vegetated swales and stormwater ponds can mitigate approximately 70%, 68%, 45% and 8% of their carbon footprint respectively. This study demonstrates the significant role of carbon sequestration in mitigating the carbon footprint from the assigned life time of the vegetated WSUD technologies. The results presented in this study will allow designers and policymakers to include the carbon implication in their WSUD strategies.
Mangroves are among the most carbon-dense ecosystems on the planet. The capacity of mangroves to store and accumulate carbon has been assessed and reported at regional, national and global scales. ...However, small-scale sampling is still revealing 'hot spots' of carbon accumulation. This study reports one of these hotspots, with one of the largest-recorded carbon stocks in mangroves associated with sinkholes (
) in the Yucatan Peninsula, Mexico. We assessed soil organic carbon (SOC) stocks, sequestration rates and carbon origin of deep peat soils (1 to 6 m)
We found massive amounts of SOC up to 2792 Mg C ha
, the highest value reported in the literature so far. This SOC is primarily derived from highly preserved mangrove roots and has changed little since its deposition, which started over 3220 years ago (±30 BP). Most
are owned by Mayan communities and are threatened by increased tourism and the resulting extraction and pollution of groundwater. These hot spots of carbon sequestration, albeit small in area, require adequate protection and could provide valuable financial opportunities through carbon-offsetting mechanisms and other payments for ecosystem services.
•This study explores relationships between spatial complexity and form of aquatic macrophytes, and epiphytic algal on a tropical floodplain.•Our study indicates greater algae biomass on macrophytes ...with high structural complexity.•Our results also suggest shape and alignment of macrophytes, rather than surface area or biomass, result in greater epiphytic attachment.•Water quality conditions within patches is influenced by the structure and density of the dominant macrophyte type.•A layer of submerged macrophyte below the clear water surface, function in a similar way to the littoral zone to boosts epiphyte algal production.
Tropical floodplains are highly productive because of seasonal replenishment of water and nutrients, which substantially boost primary productivity. This study examined how the architecture of aquatic macrophytes affect the light and water quality and consequently the attachment and biomass of epiphytes on a floodplain in northern Australia. Results show that macrophyte structural complexity is not only important for water column light penetration but also for the development of epiphytes on macrophytes. Emergent grasses with simple vertical structure and high plant densities, limit light penetration and consequently the development and biomass of epiphytic algae. In contrast, submerged macrophytes growing just below the water surface, allow greater light penetration. The complex architecture of submerged macrophytes also provides a large surface area for the development of a dense covering of epiphytic algae. Other plant structural forms (e.g., plants with floating leaves) have a simple structure, variable light penetration and low epiphytic algae biomass. The emergent grass Pseudoraphis spinescens (R.Br.) Vickery also had low light penetration but the horizontal alignment of stems across the water surface allow greater exposure to sunlight of the stems and the consequent development of epiphytic algae. We conclude that (1) the complex structure of submerged plants effectively creates a “false bottom” in deeper waters so that they function similarly to the floodplain's littoral zone, and (2) that their extremely large surface area for attachment allows greater production of epiphytic algae than would occur on the sediment surface.
Mangroves are considered ideal ecosystems for Blue Carbon projects. However, because of their short stature, some mangroves ('scrub' mangroves, less than 2 m) do not fulfil the current definition of ...'forests', which makes them ineligible for emission reduction programmes such as REDD+. Short stature mangroves can be the dominant form of mangroves in arid and nutrient-poor landscapes, and emissions from their deforestation and degradation could be substantial. Here, we describe a Blue Carbon project in the Gulf of California, Mexico, to illustrate that projects that avoid emissions from deforestation and degradation could provide financial resources to protect mangroves that cannot be included in other emission reduction programmes. The goal of the project is to protect 16 058 ha of mangroves through conservation concessions from the Mexican Federal Government. The cumulative avoided emissions of the project are 2.84 million Mg CO
over 100 years, valued at $US 426 000 per year (US$15 per Mg CO
in the California market). The funds could be used for community-based projects that will improve mangrove management, such as surveillance, eradication of invasive species, rehabilitation after tropical storms and environmental education. The strong institutional support, secure financial status, community engagement and clear project boundaries provide favourable conditions to implement this Blue Carbon project. Financial resources from Blue Carbon projects, even in mangroves of short stature, can provide substantial resources to enhance community resilience and mangrove protection.
Mangroves are one of the few woody ecosystems that grow in hot-arid climates. They can survive extreme conditions of low precipitation, high solar radiation, wide temperature fluctuations and ...hypersalinity. These unique mangroves have distinct geomorphology, hydrology, forest structure, tree physiology, and soil biogeochemistry. In this review, supported by field data from Australia and Mexico, we explore the characteristics of mangroves in arid climates of the world. These mangroves are mostly tide-dominated with freshwater flows restricted to groundwater and sporadic tropical storms. They form dense forests with stunted growth dominated mainly by trees of the genus Avicennia that co-occur with salt marshes in the high intertidal. Their soils have low nutrient and carbon concentrations, and high soil δ15 N and δ13C values compared to subhumid and humid mangroves. Mangroves in arid climates have relatively low human pressure due to sparse human settlements. Key threats to these mangroves, which often persist at the edge of their physiological tolerances, include extreme drought, reductions in groundwater inputs, altered hydrology, sea-level fluctuations and increases in nutrient loading. Restoration of mangroves in arid climates should focus on restoring their hydrology. Mangroves in arid zones are under-represented in global maps and assessment programs, as they may not be consistent with countries’ definition of “forests”. Improved global representation and understanding of the ecology of mangroves in arid climates could help sustain their valuable ecosystem services.
•In arid climates, mangroves live in extreme conditions of temperature, radiation, and salinity.•They form short, dense forests of Avicennia and are dominated by tidal inputs.•They have low soil C and N, and high δ15N and δ13C values.•A major threat to these mangroves is hydrological modifications that cause hypersalinity.•Mangroves in arid climates are underrepresented in global assessments.
Offsetting carbon (C) emissions and reducing nitrogen (N) pollution have been goals of mangrove restoration programs around the world. There is a common, yet dubious expectation that mangrove ...restoration will result in immediate and perpetual delivery of ecosystem services. There are expected time lags between mangrove clearing and C and N losses, and between restoration and C and N gains. Obtaining accurate rates of losses and gains requires frequent and long-term sampling, which is expensive and time consuming. To address this knowledge gap, we used a chronosequence of mangrove forests in mangroves in Matang Mangrove Forest Reserve (MMFR) in Malaysia, a region with one of the most C dense forests in the world. In this site, we assessed the ecosystem C and N stocks, including soil, downed wood, downed litter, and trees. The objective was to measure C and N changes through time. After mangrove clearing, C and N losses in soil and downed wood were rapid, with stocks halved after just one year. In the first 10 years after replantation, the forest recovered quickly, with rates of C accumulation of 9.5 Mg C ha−1 yr−1. After ten years, the rate of accumulation decreased to 2.8 Mg C ha−1 yr−1. However, 40 years after replantation, mangroves were still about 26% lower in C and 15% lower in N compared to our reference forest. The trajectory of recovery of C and N stocks in these forests was different among mangrove components: forest litter recovered rapidly, but downed wood and soil recovered much slower. Programs aimed at reducing C emissions and N pollution should consider that there are temporal lags and ecosystem trade-offs when assessing the effectiveness of mangrove protection and restoration as climate change mitigation strategies.
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•One year after clearing, mangroves lost half of their C and N stock.•After replantation, recovery rates were high at 9.5 Mg C ha−1 yr−1.•After ten years, accumulation rates decreased to 2.8 Mg C ha−1 yr−1.•Planted mangroves at 40 years were lower in C and N than the reference forest.•Restoration programs should consider lags between clearing, plantation, and provision of ecosystem services.
Coastal wetlands are essential for regulating the global carbon
budget through soil carbon sequestration and greenhouse gas (GHG – CO2, CH4, and N2O) fluxes. The conversion of coastal wetlands to
...agricultural land alters these fluxes' magnitude and direction
(uptake/release). However, the extent and drivers of change of GHG fluxes are
still unknown for many tropical regions. We measured soil GHG fluxes from
three natural coastal wetlands – mangroves, salt marsh, and freshwater tidal
forests – and two alternative agricultural land uses – sugarcane farming and
pastures for cattle grazing (ponded and dry conditions). We assessed
variations throughout different climatic conditions (dry–cool, dry–hot, and
wet–hot) within 2 years of measurements (2018–2020) in tropical Australia.
The wet pasture had by far the highest CH4 emissions with 1231±386 mgm-2d-1, which were 200-fold higher than any other site.
Dry pastures and sugarcane were the highest emitters of N2O
with 55±9 mgm-2d-1 (wet–hot period) and 11±3 mgm-2d-1 (hot-dry period, coinciding with fertilisation), respectively. Dry
pastures were also the highest emitters of CO2 with 20±1 gm-2d-1 (wet–hot period). The three coastal wetlands measured had
lower emissions, with salt marsh uptake of -0.55±0.23 and
-1.19±0.08 gm-2d-1 of N2O and CO2, respectively, during the dry–hot
period. During the sampled period, sugarcane and pastures had higher total
cumulative soil GHG emissions (CH4+N2O) of 7142 and 56 124 CO2-eqkgha-1yr-1 compared to coastal wetlands with 144 to
884 CO2-eqkgha-1yr-1 (where CO2-eq is CO2 equivalent). Restoring unproductive sugarcane
land or pastures (especially ponded ones) to coastal wetlands could provide
significant GHG mitigation.
The Mexican consensus on non-cardiac chest pain Gómez-Escudero, O; Coss-Adame, E; Amieva-Balmori, M ...
Revista de Gastroenterología de México (English Edition),
2019 Jul - Sep, 20190701, Volume:
84, Issue:
3
Journal Article
Peer reviewed
Open access
Non-cardiac chest pain is defined as a clinical syndrome characterized by retrosternal pain similar to that of angina pectoris, but of non-cardiac origin and produced by esophageal, musculoskeletal, ...pulmonary, or psychiatric diseases.
To present a consensus review based on evidence regarding the definition, epidemiology, pathophysiology, and diagnosis of non-cardiac chest pain, as well as the therapeutic options for those patients.
Three general coordinators carried out a literature review of all articles published in English and Spanish on the theme and formulated 38 initial statements, dividing them into 3 main categories: (i)definitions, epidemiology, and pathophysiology; (ii)diagnosis, and (iii)treatment. The statements underwent 3rounds of voting, utilizing the Delphi system. The final statements were those that reached >75% agreement, and they were rated utilizing the GRADE system.
The final consensus included 29 statements. All patients presenting with chest pain should initially be evaluated by a cardiologist. The most common cause of non-cardiac chest pain is gastroesophageal reflux disease. If there are no alarm symptoms, the initial approach should be a therapeutic trial with a proton pump inhibitor for 2-4weeks. If dysphagia or alarm symptoms are present, endoscopy is recommended. High-resolution manometry is the best method for ruling out spastic motor disorders and achalasia and pH monitoring aids in demonstrating abnormal esophageal acid exposure. Treatment should be directed at the pathophysiologic mechanism. It can include proton pump inhibitors, neuromodulators and/or smooth muscle relaxants, psychologic intervention and/or cognitive therapy, and occasionally surgery or endoscopic therapy.
Heritable symbionts have diverse effects on the physiology, reproduction and fitness of their hosts. Maternally transmitted
are one of the most common endosymbionts in nature, infecting about half of ...all insect species. We test the hypothesis that
alter host behaviour by assessing the effects of 14 different
strains on the locomotor activity of nine
host species. We find that
alter the activity of six different host genotypes, including all hosts in our assay infected with
Ri-like
strains (
Ri,
Suz and
Aur), which have rapidly spread among
species in about the last 14 000 years. While
effects on host activity were common, the direction of these effects varied unpredictably and sometimes depended on host sex. We hypothesize that the prominent effects of
Ri-like
may be explained by patterns of
titre and localization within host somatic tissues, particularly in the central nervous system. Our findings support the view that
have wide-ranging effects on host behaviour. The fitness consequences of these behavioural modifications are important for understanding the evolution of host-symbiont interactions, including how
spread within host populations.
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