Dendrochronological analysis of baldcypress (Taxodium distichum) responses to climate and contrasting flood regimes

2012 ◽  
Vol 42 (3) ◽  
pp. 423-436 ◽  
Author(s):  
Richard F. Keim ◽  
J. Blake Amos
Keyword(s):  
Mississippi River ◽  
Taxodium Distichum ◽  
Growth Responses ◽  
Ecological Processes ◽  
Ecosystem Responses ◽  
Local Climate ◽  
Dendrochronological Analysis ◽  
Key Species ◽  
Climatic History

Baldcypress (Taxodium distichum (L.) Rich.) has been used extensively for dendrochronological reconstruction of climate and is a key species in globally important wetlands with complex, poorly understood relationships between hydrological and ecological processes. To better understand ecosystem responses to changing climate and hydrology and to test whether hydrological or climatological variables are most reflected in chronologies, we developed tree-ring chronologies for six stagnant or riverine swamps in the Mississippi River deltaic plain and modeled growth responses to historical hydrology (51 years of data) and climate (111 years of data). Decoupled flooding and local climate in this deltaic setting allowed for relatively independent assessments of the roles of hydrology and climate in baldcypress growth. Depth of annual flooding was positively correlated with growth that year but negatively correlated with growth in the ensuing year for both riverine and stagnant swamps. Depth of 10-year mean flooding was positively correlated with growth in riverine swamps but negatively correlated with growth in stagnant swamps. Results corroborate previous findings that long-term, stagnant flooding reduces productivity, but growth at these deltaic sites was less correlated with climatic variables than elsewhere. At least in these frequently flooded sites, baldcypress tree rings appear to be a better long term record of hydrological history than of climatic history.

scholarly journals Patterns of genetic connectivity in invertebrates of temperate MPA networks

2013 ◽  
Vol 4 (2) ◽  
pp. 138 ◽  
Author(s):  
Patricia Marti-Puig ◽  
Federica Costantini ◽  
Luca Rugiu ◽  
Massimo Ponti ◽  
Marco Abbiati
Keyword(s):  
Benthic Invertebrates ◽  
Deep Understanding ◽  
Coastal Development ◽  
Genetic Connectivity ◽  
Environment Design ◽  
Ecological Processes ◽  
Temperate Reefs ◽  
Marine Habitats ◽  
Key Species

Temperate reefs are among the most threatened marine habitats due to impacts caused by high density of human settlements, coastal development, pollution, fisheries and tourism. Networks of marine protected areas (MPAs) are an important tool for ensuring long-term health and conservation of ecological processes in the marine environment. Design of the MPA network has to be based on deep understanding of spatial patterns of species distribution, and on the make-up of connectivity among populations. Most benthic invertebrates are sessile and/or sedentary in the adult phase, and their dispersal relies mainly on the gametes and/or larval behaviours. Genetic markers allow us to quantify gene flow and structuring among populations, and to infer patterns of genetic connectivity. Based on the information available in the peer reviewed literature on genetic connectivity in benthic invertebrates of temperate MPAs, we provide a comment about the gaps and the needs. Moreover, we propose a rationale to plan and optimise future studies on this topic. A conceptual framework for planning effective studies on genetic connectivity in an MPAs network is provided, including general recommendations on sampling design, key species and molecular markers to use.

scholarly journals Urban Ecological Restoration

2010 ◽  
Vol 5 (3) ◽  
pp. 227-230 ◽  
Author(s):  
Paul H. Gobster
Keyword(s):  
Ecological Restoration ◽  
Urban Areas ◽  
Indigenous Species ◽  
Reference Sites ◽  
Urban Context ◽  
Ecological Processes ◽  
Fixed Set ◽  
Natural Diversity ◽  
Urban Ecological Restoration

What does ecological restoration mean in an urban context? More than half of the world’s population now lives in cities, and in response to the dynamic patterns of urbanization, a growing number of ecologists, land managers, and volunteers are focusing their efforts in and around cities to restore remnants of natural diversity (Ingram 2008). Ecological restoration is still a quite youthful field, yet many scientists and practitioners hold a relatively fixed set of criteria for what defines a successful restoration project, irrespective of where sites are located. Among the criteria commonly stated, sites should be composed of indigenous species, have a structure and diversity characteristic of currently undisturbed or historically documented “reference” sites, and be maintained through ecological processes such as fire that ensure long-term sustainability with minimal human assistance (Ruiz-Jaén and Aide 2005; SER International 2004). Application of these criteria has led to many ecologically successful restorations, but some ecologists in the field have begun to question whether the same standards can be realistically applied to sites such as those within urban areas that have been radically altered by past human activity (e.g., Martínez and López-Barerra 2008) or are being influenced by novel conditions that result in unpredictable trajectories (Choi 2007). Perhaps more significantly, it is becoming increasingly recognized that the broader viability of restoration projects, especially those in urban areas, hinges on how socially successful they are in gaining public acceptance for restoration activities and practices, building constituencies to assist with implementation and maintenance, and addressing a broader set of sustainability goals that reach beyond the protection of native biodiversity (e.g., Choi et al. 2008; Hobbs 2007; Rosenzweig 2003).

scholarly journals Long-term UVB exposure promotes predator-inspection behaviour in a fish

2017 ◽  
Vol 13 (12) ◽  
pp. 20170497 ◽  
Author(s):  
Simon Vitt ◽  
Janina E. Zierul ◽  
Theo C. M. Bakker ◽  
Ingolf P. Rick
Keyword(s):  
Gasterosteus Aculeatus ◽  
Stratospheric Ozone ◽  
Ultraviolet B ◽  
Antipredator Behaviour ◽  
Uvb Radiation ◽  
Ecological Processes ◽  
Predator Prey ◽  
Natural Sunlight ◽  
Predator Inspection

Ultraviolet-B radiation (UVB) reaching the earth's surface has increased due to human-caused stratospheric ozone depletion. Whereas the harmful effects of UVB on aquatic organisms are well studied at the molecular and cellular level, recent studies have also begun to address behavioural changes caused by sublethal amounts of UVB. However, the behavioural consequences of long-term exposure to ecologically relevant UVB levels over several life stages are virtually unknown, particularly with regard to predator–prey behaviour. We found increased predator-inspection behaviour together with a smaller body length in three-spined sticklebacks ( Gasterosteus aculeatus ) after fish were exposed for about seven months to natural sunlight conditions with enhanced UVB, compared with full siblings exposed to natural sunlight only. The observed change in antipredator behaviour may reflect a direct behavioural response mediated through UVB-induced oxidative stress during development. Alternatively, the smaller body size in UVB-exposed fish may result in an increased inspection effort allowing them to spend more time foraging. Our findings suggest that, within the scope of environmental change, UVB radiation constitutes an important stress factor by eliciting behavioural responses that influence crucial ecological processes, such as predator–prey interactions.

scholarly journals A floristic description of the Afromontane fynbos communities on Platberg, Eastern Free State, South Africa

Koedoe ◽  
2008 ◽  
Vol 50 (1) ◽  
Author(s):  
Robert F. Brand ◽  
Pieter J. Du Preez ◽  
Leslie R. Brown
Keyword(s):  
Natural Resources ◽  
Plant Communities ◽  
Conservation Management ◽  
Alien Invasive Species ◽  
Ecological Processes ◽  
The North ◽  
Shrub Community ◽  
Management Plans ◽  
Twinspan Classification

Within the Platberg area and the wider Drakensberg region, the shrinking natural resources and the threat posed to biodiversity are of concern to conservation management and require an understanding of long-term ecological processes. The vegetation of Platberg was investigated as part of an ecological survey to establish Afromontane floristic links to the Drakensberg as well as for the management of natural resources. From a TWINSPAN classification, refined by the Braun-Blanquet method, four main plant communities were identified, which were subdivided into fynbos, wetland, a woody/shrub community and grassland. A classification and description of the fynbos are presented in this article.The analysis showed the fynbos divided into two communities comprising four sub-communities and seven variants. The fynbos community had an average of 28.34 species per relevé, ranging from 14 to 54 species per sample plot. Twenty-four endemic or near-endemic Drakensberg Alpine Centre (DAC) species and 22 exotic (alien-invasive) species were recorded. Numerous floristic links with the DAC, Cape flora fynbos and grassland bioregions to the north and west were also found. The description of the fynbos plant communities can serve as a basis for the formulation of management plans for the area.

scholarly journals Hurricanes as a Major Driver of Coastal Erosion in the Mississippi River Delta: A Multi-Decadal Analysis of Shoreline Retreat Rates at Bay Champagne, Louisiana (USA)

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1480 ◽  
Author(s):  
Marianne Dietz ◽  
Kam-biu Liu ◽  
Thomas Bianchette
Keyword(s):  
Mississippi River ◽  
Average Rate ◽  
Landsat Imagery ◽  
Mississippi River Delta ◽  
Coastal Lake ◽  
Shoreline Retreat ◽  
The Past ◽  
Coastal Features ◽  
Mexico Coast

The Louisiana shoreline is rapidly retreating as a result of factors such as sea-level rise and land subsidence. The northern Gulf of Mexico coast is also a hotspot for hurricane landfalls, and several major storms have impacted this region in the past few decades. A section of the Louisiana (USA) coast that has one of the highest rates of shoreline retreat in North America is the Caminada-Moreau headland, located south of New Orleans. Bay Champagne is a coastal lake within the headland that provides a unique opportunity to investigate shoreline retreat and the coastal effects of hurricanes. In order to examine the influence of hurricanes on the rate of shoreline retreat, 35 years (1983–2018) of Landsat imagery was analyzed. During that period of time, the shoreline has retreated 292 m. The overall rate of shoreline retreat, prior to a beach re-nourishment project completed in 2014, was over 12 m per year. A period of high hurricane frequency (1998–2013) corresponds to an increased average shoreline retreat rate of >21 m per year. Coastal features created by multiple hurricanes that have impacted this site have persisted for several years. Bay Champagne has lost 48% of its surface area over the last 35 years as a result of long-term shoreline retreat. If shoreline retreat continues at the average rate, it is expected that Bay Champagne will disappear completely within the next 40 years.

scholarly journals A vegetation description and floristic analyses of the springs on the Kammanassie Mountain, Western Cape

Koedoe ◽  
2004 ◽  
Vol 47 (2) ◽  
Author(s):  
G. Cleaver ◽  
L.R. Brown ◽  
G.J. Bredenkamp
Keyword(s):  
Plant Communities ◽  
Western Cape ◽  
Ecological Processes ◽  
Mountain Catchment ◽  
Habitat Factors ◽  
Management Plans ◽  
Twinspan Classification ◽  
Geological Origin ◽  
The Difference

The Kammanassie Mountain is a declared mountain catchment area and a Cape mountain zebra Equus zebra zebra population is preserved on the mountain. The high number of springs on the mountain not only provides water for the animal species but also contributes to overall ecosystem functioning. Long-term conservation of viable ecosystems requires a broader understanding of the ecological processes involved. It was therefore decided that a classification, description and mapping of the spring vegetation of the Kammanassie Mountain be undertaken. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 11 major plant communities that could be related to geological origin. Habitat factors associated with differences in vegetation include topography, soil type and grazing. Descriptions of the plant communities include diagnostic species as well as prominent and less conspicuous species of the tree, shrub and herbaceous layers. The results also indicate a high species richness compared to similar regions and the difference between plant communities of wet and dry springs. This data is important for long-term monitoring of the spring ecosystems as well as for the compilation of management plans.

scholarly journals Metabolic plasticity can amplify ecosystem responses to global warming

2021 ◽  
Author(s):  
Rebecca Kordas ◽  
Samraat Pawar ◽  
Guy Woodward ◽  
Eoin O'Gorman
Keyword(s):  
Global Warming ◽  
Body Size ◽  
Predictive Models ◽  
Chronic Exposure ◽  
Ecosystem Respiration ◽  
Short Term ◽  
Ecosystem Responses ◽  
Metabolic Plasticity ◽  
Ecosystem Level

Abstract Organisms have the capacity to alter their physiological response to warming through acclimation or adaptation, but empirical evidence for this metabolic plasticity across species within food webs is lacking, and a generalisable framework does not exist for modelling its ecosystem-level consequences. Here we show that the ability of organisms to raise their metabolic rate following chronic exposure to warming decreases with increasing body size. Chronic exposure to higher temperatures also increases the sensitivity of organisms to short-term warming, irrespective of their body size. A mathematical model parameterised with these findings shows that metabolic plasticity could account for an additional 60% of ecosystem energy flux with just +2 °C of warming. This could explain why ecosystem respiration continues to rise in long-term warming experiments and highlights the need to embed metabolic plasticity in predictive models of global warming impacts on ecosystems.

Sign in / Sign up

Export Citation Format

Share Document