Spatially non-continuous relationships between biological invasion and fragmentation of mangrove forests

Rapid and large-scale biological invasion results in widespread biodiversity loss and degradation of essential ecosystem services, especially in mangrove forests. Recent evidence suggests that the establishment and dispersal of invasive species may exacerbated in fragmented landscape, but the influence of mangrove fragmentation on coastal biological invasion at landscape scale remains largely unknown. Here, using the derived 10-m resolution coastal wetland map in southeast coast of China, we examine the relationships between fragmentation of mangrove forests and salt marsh invasion magnitude and quantify the geographical variations of the relationships across a climatic gradient. Our results show that mangrove forests with small size, large edge proportion, and regular boundary shape tend to suffer more serious salt marsh invasions, indicating a positive correlation between mangrove fragmentation and its invaded magnitude. In particular, such fragmentation-invasion relationships in subtropics are shown to be more intensive than in tropic. Our findings provide the first spatially explicit evidence of the relationships between mangrove fragmentation and biological invasion on a landscape scale, and highlight an urgent need for conservation and management actions to improve mangrove connectivity, which will increase resistance to invasions, especially for small-size subtropical mangrove forests.

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Extreme Precipitation and Flooding Contribute to Sudden Vegetation Dieback in a Coastal Salt Marsh

Plants ◽

10.3390/plants10091841 ◽

2021 ◽

Vol 10 (9) ◽

pp. 1841

Author(s):

Camille LaFosse Stagg ◽

Michael J. Osland ◽

Jena A. Moon ◽

Laura C. Feher ◽

Claudia Laurenzano ◽

...

Keyword(s):

Salt Marsh ◽

Extreme Precipitation ◽

Large Scale ◽

Coastal Wetland ◽

Global Climate ◽

Elevation Gradient ◽

Climate Extremes ◽

Climate Conditions ◽

Extreme Precipitation Events ◽

Baseline Climate

Climate extremes are becoming more frequent with global climate change and have the potential to cause major ecological regime shifts. Along the northern Gulf of Mexico, a coastal wetland in Texas suffered sudden vegetation dieback following an extreme precipitation and flooding event associated with Hurricane Harvey in 2017. Historical salt marsh dieback events have been linked to climate extremes, such as extreme drought. However, to our knowledge, this is the first example of extreme precipitation and flooding leading to mass mortality of the salt marsh foundation species, Spartina alterniflora. Here, we investigated the relationships between baseline climate conditions, extreme climate conditions, and large-scale plant mortality to provide an indicator of ecosystem vulnerability to extreme precipitation events. We identified plant zonal boundaries along an elevation gradient with plant species tolerant of hypersaline conditions, including succulents and graminoids, at higher elevations, and flood-tolerant species, including S. alterniflora, at lower elevations. We quantified a flooding threshold for wetland collapse under baseline conditions characterized by incremental increases in flooding (i.e., sea level rise). We proposed that the sudden widespread dieback of S. alterniflora following Hurricane Harvey was the result of extreme precipitation and flooding that exceeded this threshold for S. alterniflora survival. Indeed, S. alterniflora dieback occurred at elevations above the wetland collapse threshold, illustrating a heightened vulnerability to flooding that could not be predicted from baseline climate conditions. Moreover, the spatial pattern of vegetation dieback indicated that underlying stressors may have also increased susceptibility to dieback in some S. alterniflora marshes.Collectively, our results highlight a new mechanism of sudden vegetation dieback in S. alterniflora marshes that is triggered by extreme precipitation and flooding. Furthermore, this work emphasizes the importance of considering interactions between multiple abiotic and biotic stressors that can lead to shifts in tolerance thresholds and incorporating climate extremes into climate vulnerability assessments to accurately characterize future climate threats.

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Biotic homogenization can decrease landscape-scale forest multifunctionality

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1517903113 ◽

2016 ◽

Vol 113 (13) ◽

pp. 3557-3562 ◽

Cited By ~ 103

Author(s):

Fons van der Plas ◽

Pete Manning ◽

Santiago Soliveres ◽

Eric Allan ◽

Michael Scherer-Lorenzen ◽

...

Keyword(s):

Large Scale ◽

Biodiversity Loss ◽

Landscape Scale ◽

Biotic Homogenization ◽

Ecosystem Functions ◽

Negative Consequences ◽

Β Diversity ◽

Spatial Turnover ◽

Α Diversity ◽

Ecosystem Multifunctionality

Many experiments have shown that local biodiversity loss impairs the ability of ecosystems to maintain multiple ecosystem functions at high levels (multifunctionality). In contrast, the role of biodiversity in driving ecosystem multifunctionality at landscape scales remains unresolved. We used a comprehensive pan-European dataset, including 16 ecosystem functions measured in 209 forest plots across six European countries, and performed simulations to investigate how local plot-scale richness of tree species (α-diversity) and their turnover between plots (β-diversity) are related to landscape-scale multifunctionality. After accounting for variation in environmental conditions, we found that relationships between α-diversity and landscape-scale multifunctionality varied from positive to negative depending on the multifunctionality metric used. In contrast, when significant, relationships between β-diversity and landscape-scale multifunctionality were always positive, because a high spatial turnover in species composition was closely related to a high spatial turnover in functions that were supported at high levels. Our findings have major implications for forest management and indicate that biotic homogenization can have previously unrecognized and negative consequences for large-scale ecosystem multifunctionality.

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Winter climate change and coastal wetland foundation species: salt marshes vs. mangrove forests in the southeastern United States

Global Change Biology ◽

10.1111/gcb.12126 ◽

2013 ◽

Vol 19 (5) ◽

pp. 1482-1494 ◽

Cited By ~ 187

Author(s):

Michael J. Osland ◽

Nicholas Enwright ◽

Richard H. Day ◽

Thomas W. Doyle

Keyword(s):

Climate Change ◽

United States ◽

Salt Marshes ◽

Coastal Wetland ◽

Southeastern United States ◽

Foundation Species ◽

Mangrove Forests ◽

Winter Climate ◽

Winter Climate Change

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Accumulation patterns of soil organic matter in forests as a legacy of historical charcoal burning

10.5194/egusphere-egu21-5161 ◽

2021 ◽

Author(s):

Anna Schneider ◽

Alexander Bonhage ◽

Florian Hirsch ◽

Alexandra Raab ◽

Thomas Raab

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Large Scale ◽

Soil Surface ◽

Landscape Scale ◽

Legacy Effects ◽

Charcoal Production ◽

Study Region ◽

Land Use Legacies

Human land use and occupation often lead to a high heterogeneity of soil stratigraphy and properties in landscapes within small, clearly delimited areas. Legacy effects of past land use also are also abundant in recent forest areas. Although such land use legacies can occur on considerable fractions of the soil surface, they are hardly considered in soil mapping and inventories. The heterogenous spatial distribution of land use legacy soils challenges the quantification of their impacts on the landscape scale. Relict charcoal hearths (RCH) are a widespread example for the long-lasting effect of historical land use on soil landscapes in forests of many European countries and also northeastern USA. Soils on RCH clearly differ from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal. The properties of RCH soils have recently been studied for several regions, but their relevance on the landscape scale has hardly been quantified.We analyse and discuss the distribution and ecological relevance of land use legacy soils across scales for RCH in the state of Brandenburg, Germany, with a focus on soil organic matter (SOM) stocks. Our analysis is based on a large-scale mapping of RCH from digital elevation models (DEM), combined with modelled SOM stocks in RCH soils.&#160;The distribution of RCH soils in the study region shows heterogeneity at different scales. The large-scale variation is related to the concentration of charcoal production to specific forest areas and the small-scale accumulation pattern is related to the irregular distribution of single RCH within the charcoal production fields. Considerable fractions of the surface area are covered by RCH soils in the major charcoal production areas within the study region. The results also show that RCH can significantly contribute to the soil organic matter stocks of forests, even for areas where they cover only a small fraction of the soil surface. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEM can contribute to improving such approaches.

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NATURE-BASED COASTAL PROTECTION: WAVE DAMPING BY FLEXIBLE SALT MARSH VEGETATION

Coastal Engineering Proceedings ◽

10.9753/icce.v36v.management.9 ◽

2020 ◽

pp. 9

Author(s):

Thomas J van Veelen ◽

Harshinie Karunarathna ◽

William G Bennett ◽

Tom P Fairchild ◽

Dominic E Reeve

Keyword(s):

Salt Marsh ◽

Salt Marshes ◽

Large Scale ◽

Coastal Vegetation ◽

Coastal Protection ◽

Coastal Zones ◽

Wave Damping ◽

Marsh Vegetation ◽

Efficient Manner ◽

Wave Energy Dissipation

The ability of coastal vegetation to attenuate waves has been well established (Moller et al., 2014). Salt marshes are vegetated coastal wetlands that can act as nature- based coastal defenses. They exhibit a range of plant species, which have been shown to differ in the amount of wave damping they provide (Mullarney & Henderson, 2018). Recent studies have shown that plant flexibility is a key parameter that controls wave energy dissipation (Paul et al., 2016). Yet, no model exists that includes plant flexibility in computationally efficient manner for large-scale coastal zones. Therefore, we have developed a new model for flexible vegetation based on the key mechanisms in the wave-vegetation interaction and applied it to an estuary with diverse salt marsh vegetation.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/AjnFx3aFSzs

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How do zooplankton respond to coastal wetland restoration? the case of newly created salt marsh lagoons in La Pletera (NE Catalonia)

Limnetica ◽

10.23818/limn.38.42 ◽

2019 ◽

Vol 38 (2) ◽

pp. 721-741

Author(s):

Santiago Cabrera ◽

Jordi Compte ◽

Stéphanie Gascón ◽

Dani Boix ◽

David Cunillera-Montcusí ◽

...

Keyword(s):

Salt Marsh ◽

Wetland Restoration ◽

Coastal Wetland

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Climate changes in mangrove forests and salt marshes

Brazilian Journal of Oceanography ◽

10.1590/s1679-875920160919064sp2 ◽

2016 ◽

Vol 64 (spe2) ◽

pp. 37-52 ◽

Cited By ~ 22

Author(s):

Yara Schaeffer-Novelli ◽

Eduardo Juan Soriano-Sierra ◽

Claudia Câmara do Vale ◽

Elaine Bernini ◽

André Scarlate Rovai ◽

...

Keyword(s):

Salt Marsh ◽

Early Warning ◽

Salt Marshes ◽

Regional Scale ◽

Level Energy ◽

Mangrove Forests ◽

Coastal Zones ◽

Coastal Habitat ◽

Ecological Processes ◽

Salt Marsh Species

Abstract This synthesis is framed within the scope of the Brazilian Benthic Coastal Habitat Monitoring Network (ReBentos WG 4: Mangroves and Salt Marshes), focusing on papers that examine biodiversity-climate interactions as well as human-induced factors including those that decrease systemic resilience. The goal is to assess difficulties related to the detection of climate and early warning signals from monitoring data. We also explored ways to circumvent some of the obstacles identified. Exposure and sensitivity of mangrove and salt marsh species and ecosystems make them extremely vulnerable to environmental impacts and potential indicators of sea level and climate-driven environmental change. However, the interpretation of shifts in mangroves and salt marsh species and systemic attributes must be scrutinized considering local and setting-level energy signature changes; including disturbance regime and local stressors, since these vary widely on a regional scale. The potential for adaptation and survival in response to climate change depends, in addition to the inherent properties of species, on contextual processes at the local, landscape, and regional levels that support resilience. Regardless of stressor type, because of the convergence of social and ecological processes, coastal zones should be targeted for anticipatory action to reduce risks and to integrate these ecosystems into adaptation strategies. Management must be grounded on proactive mitigation and collaborative action based on long-term ecosystem-based studies and well-designed monitoring programs that can 1) provide real-time early warning and 2) close the gap between simple correlations that provide weak inferences and process-based approaches that can yield increasingly reliable attribution and improved levels of anticipation.

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Benthic Habitats and the Effects of Fishing

Benthic Habitats and the Effects of Fishing ◽

10.47886/9781888569605.ch6 ◽

2005 ◽

Keyword(s):

Fisheries Management ◽

Large Scale ◽

Scale Effects ◽

Ecosystem Processes ◽

Fishing Effort ◽

Habitat Types ◽

Benthic Habitats ◽

Management Actions ◽

Ecosystem Effects ◽

Ecosystem Based Fisheries Management

Abstract. We review the impacts of towed gears on benthic habitats and communities and predict the consequences of these impacts for ecosystem processes. Our emphasis is on the additive and synergistic large-scale effects of fishing, and we assess how changes in the distribution of fishing activity following management action are likely to affect production, turnover time, and nutrient fluxes in ecosystems. Analyses of the large-scale effects of fishing disturbance show that the initial effects of fishing on a habitat have greater ecosystem consequences than repeated fishing in fished areas. As a result, patchy fishing effort distributions have lower total impacts on the ecosystem than random or uniform effort distributions. In most fisheries, the distribution of annual fishing effort within habitats is more patchy than random, and patterns of effort are maintained from year to year. Our analyses suggest that many vulnerable species and habitats have only persisted in heavily fished ecosystems because effort is patchy. Ecosystem-based fisheries management involves taking account of the ecosystem effects of fishing when setting management objectives. One step that can be taken toward ecosystem-based fisheries management is to make an a priori assessment of the ecosystem effects of proposed management actions such as catch controls, effort controls, and technical measures. We suggest a process for predicting the ecosystem consequences of management action. This requires information on habitat distributions, models to predict changes in the spatial distribution of fleets following management action, and models of the impacts of trawling disturbance on ecosystem processes. For each proposed management action, the change in disturbance affecting different habitat types would be predicted and used to forecast the consequences for the ecosystem. These simulations would be used to produce a decision table, quantifying the consequences of alternative management actions. Actions that minimize the ecosystem effects of fishing could then be identified. In data-poor situations, we suggest that management strategies that maintain or maximize the patchiness of effort within habitat types are more consistent with the precautionary approach than those that lead to more uniform fishing effort distributions.

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