Ecotoxicity of Nitroaromatics to Aquatic and Terrestrial Species at Army Superfund Sites

2009 ◽  
pp. 117-117-13 ◽  
Author(s):  
PS Hovatter ◽  
SS Talmage ◽  
DM Opresko ◽  
RH Ross
Keyword(s):  
Superfund Sites ◽  
Terrestrial Species

Vulnerability of species to climate change in the Southwest: terrestrial species of the Middle Rio Grande

2013 ◽  
Author(s):  
Megan M. Friggens ◽  
Deborah M. Finch ◽  
Karen E. Bagne ◽  
Sharon J. Coe ◽  
David L. Hawksworth
Keyword(s):  
Climate Change ◽  
Rio Grande ◽  
Terrestrial Species ◽  
Middle Rio Grande

Pores versus spores: competition between photosynthesis and reproduction is constrained by leaf mass per unit area (LMA) in ferns

2020 ◽  
Author(s):  
K G Srikanta Dani ◽  
Jose Mathew ◽  
T M Nila-Mohan ◽  
Raju Antony ◽  
S Suresh ◽  
...  
Keyword(s):  
Life Histories ◽  
Resource Constraints ◽  
Time Window ◽  
Unit Area ◽  
Stomatal Density ◽  
High Fertility ◽  
Leaf Lifespan ◽  
Trade Off ◽  
Terrestrial Species ◽  
Leaf Mass

Abstract Diversity in plant life histories is primarily that found in the rate and duration of photosynthetic (vegetative) and reproductive growth. However, direct evidence for an anticipated trade-off between photosynthesis and reproduction is lacking in any plant lineage. Ferns allocate leaf space and resources to both photosynthesis and reproduction, potentially leading to competition for leaf resources between stomatal pores and reproductive spores. We hypothesized that a trade-off between stomatal density (StD; a proxy for photosynthetic capacity) and sporangial density (SpD; a measure of fertility) has evolved in monomorphic ferns due to the common space, time and resource constraints imposed by a highly conserved and globally low leaf mass per unit area (LMA) in ferns, where any increase in LMA indicated greater construction cost and longer leaf lifespan. We measured LMA, StD and SpD in 40 fern species in India that represented both monomorphic and dimorphic conditions from both terrestrial and epiphytic habits. Both StD and SpD showed a 50-fold range in monomorphic species whereas LMA was more conserved (six-fold range). LMA of terrestrial ferns was significantly lower than that of epiphytic ferns. Linear regression between LMA and StD was significantly positive in dimorphic terrestrial ferns (showing the lowest LMA among all ferns) and significantly negative in monomorphic epiphytic ferns (showing the highest LMA among all ferns). Dimorphic terrestrial ferns were highly fecund on their fertile leaves and showed a significantly higher StD to LMA ratio on their sterile leaves compared to monomorphic terrestrial ferns. Dimorphic ferns seem to maximize both StD and SpD by physical separation of photosynthesis and reproduction, and their characteristically low LMA (shorter leaf lifespan = smaller time window) potentially selects for high StD and high fertility. The regression between StD and SpD in monomorphic ferns was significantly linear and positive, although comparisons among closely related species (within families) showed negative correlations when both StD and SpD were high, captured also by a significant quadratic regression between StD and SpD in monomorphic ferns. Monomorphic terrestrial species bearing more spores per stomata showed relatively low LMA whereas those producing fewer spores per stomata possessed leaves with relatively high LMA. Monomorphic epiphytes produced as many spores as terrestrial species but showed significantly low StD for their high LMA. We discuss the evolutionary reasons behind these trends and conclude that monomorphic terrestrial ferns with high LMA (long leaf lifespan) tend to prioritize photosynthesis over reproduction, while monomorphic epiphytes (always high LMA) are significantly more fertile for lower photosynthesis. The role of LMA in framing the rules of competition between stomata and sporangia in monomorphic ferns provides a template for how photosynthesis may directly or indirectly influence reproductive strategies (and vice versa) in all land plants.

scholarly journals Trophic interactions and ecosystem management at the New Zealand Subantarctic Islands

2021 ◽  
Author(s):  
◽  
Sean David Cooper
Keyword(s):  
New Zealand ◽  
Stable Isotope ◽  
Biodiversity Loss ◽  
Marine Environments ◽  
Management Planning ◽  
Terrestrial Species ◽  
Marine Communities ◽  
Subantarctic Islands ◽  
Stable Isotope Signatures

<p>Ecosystem-based management (EBM) has become an increasingly popular concept for government agencies to incorporate into management planning strategies. The basic idea behind EBM is that an ecosystem remains intact, resilient and productive in the long-term, to provide for ecological, social, cultural and economic benefits. The problem that decision makers face is that there is often little information regarding the structure and functioning of ecosystems upon which to base meaningful decisions. A further complication is that governance of the environment is highly sectoral both across government and within agencies. This often leads to fractured management between the terrestrial, freshwater and marine environments, potentially risking biodiversity loss and the stability of ecosystems.  Small oceanic islands may potentially be model ecosystems for undertaking ecological studies, due to their constrained spatial extent and often unmodified condition. The New Zealand Subantarctic Islands, which are remote and largely unmodified, provide a natural laboratory to study the structure and functioning of ecosystems. I undertook stable isotope and water nutrient sampling to describe the trophic structure, trophic interactions and the drivers of the Antipodes and Bounty Islands, two of the islands in New Zealand’s Subantarctic region. These islands have high conservation value and are an important area for breeding seabirds and marine mammals, but there have been no studies at these islands to understand how they function and what the connections are between the terrestrial and marine environments.  Using the stable isotope signatures of nitrogen (δ¹⁵N) and carbon (δ¹³C) from a wide range of common marine and terrestrial species at both islands, I described the trophic structure of each island. I found that the islands had a similar number of trophic levels and that omnivory was present beyond secondary consumers and below top level predators. Antipodes Island had a more complex food web than the Bounty Islands, but both islands showed strong linkages between the terrestrial and marine environments at both a local scale and with habitats beyond the sovereignty area of New Zealand.  A basic two-source mixing model was used to determine the carbon sources that were important at each island. It was found that the Antipodes Island marine communities were influenced by phytoplankton, but that kelp was also an important contributor of carbon to consumers’ diets. In contrast, at the Bounty Islands, phytoplankton was the sole carbon source in marine communities. Terrestrial species at both islands had a marine-derived carbon component to their diets, with Antipodes Island terrestrial species incorporating a combination of terrestrial-derived and marine-derived carbon. The Bounty Islands’ terrestrial species were completely reliant on marine-derived carbon that was linked to phytoplankton. To further test the diets of species, Isosource was used to reconstruct the diets of the most common marine invertebrates and terrestrial species, again demonstrating strong marine-terrestrial links.  To determine if there was any correlation between the distance from shore, water nutrient concentrations and phytoplankton stable isotope signatures, samples were collected in open ocean sites across the Campbell Plateau and within 12 nautical miles of each island. It was found that the nitrate levels of Antipodes Island water samples decreased with distance towards the island and that nitrate and dissolved reactive phosphorous levels increased with distance towards the Bounty Islands.  This research has clearly demonstrated that there is a strong link between the marine and terrestrial realms at both islands and at spatial scales beyond the islands. The current management of the islands requires this new information to be taken into consideration in future management planning, so that trophic connections are maintained across realms. Further work is required across government and within agencies to bring legislation, policy and science into an integrated framework across sectors. This will allow environmental managers to reduce threats at the ecosystem level to minimise biodiversity loss and the risk of degradation of ecosystems, to protect New Zealand’s long-term biodiversity, social, cultural and economic prosperity.</p>

scholarly journals Environmental exposures among gravidae living near Superfund sites has altered placental metagenomic and metabolomic profiles

2022 ◽  
Vol 226 (1) ◽  
pp. S520-S521
Author(s):  
Sohini Banerjee ◽  
Melissa Suter ◽  
Bhagavatula Moorthy ◽  
Kjersti M. Aagaard
Keyword(s):  
Environmental Exposures ◽  
Superfund Sites
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