scholarly journals Two new terrestrial species of Talitrus (Amphipoda: Talitridae) from Tasmania

1979 ◽  
Vol 113 ◽  
pp. 85-98
Author(s):  
JA Friend
Keyword(s):  
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>

Diversity patterns of seasonal wetland plant communities mainly driven by rare terrestrial species

2016 ◽  
Vol 25 (8) ◽  
pp. 1569-1585 ◽  
Author(s):  
David C. Deane ◽  
Damien A. Fordham ◽  
Fangliang He ◽  
Corey J. A. Bradshaw
Keyword(s):  
Plant Communities ◽  
Wetland Plant ◽  
Terrestrial Species ◽  
Diversity Patterns ◽  
Seasonal Wetland ◽  
Wetland Plant Communities

Skin folds in the gekkonid lizard genus Rhacodactylus: a natural test of the damage limitation hypothesis of mite pocket function

1990 ◽  
Vol 68 (6) ◽  
pp. 1196-1201 ◽  
Author(s):  
Aaron M. Bauer ◽  
Anthony P. Russell ◽  
Norman R. Dollahon
Keyword(s):  
Tissue Damage ◽  
Host Response ◽  
Terrestrial Species ◽  
Damage Limitation ◽  
Selective Forces ◽  
Natural Test

The hypothesis that lizard mite pockets have evolved as a host response to limit damage by ectoparasites is tested. Evidence from the New Caledonian geckos of the genus Rhacodactylus does not support the hypothesis. Putative pockets in popliteal position are present in all taxa examined, but are infested by trombiculid chiggers only in Rhacodactylus auriculatus, a partially terrestrial species. Tissue damage results from the formation of a stylostome within the host pocket. No mechanisms for host amelioration of parasite effect are evident. At least in Rhacodactylus, chiggers appear to facultatively exploit skin folds or pockets, which may have evolved and been maintained as a result of selective forces unrelated to ectoparasite damage limitation.

Ecotoxicological Evaluation Of Titanium Silicon Oxide Nanoparticules With Terrestrial Species

2014 ◽  
Vol 229 ◽  
pp. S201
Author(s):  
Sirine Bouguerra ◽  
Ana Gavina ◽  
Mohamed Ksibi ◽  
Maria da Graça Rasteiro ◽  
Teresa Rocha-Santos ◽  
...  
Keyword(s):  
Silicon Oxide ◽  
Terrestrial Species ◽  
Ecotoxicological Evaluation ◽  
Titanium Silicon

Distribution of seabirds at sea in the Gulf of Carpentaria, Australia

1994 ◽  
Vol 45 (3) ◽  
pp. 445 ◽  
Author(s):  
SJM Blaber ◽  
DA Milton
Keyword(s):  
Food Availability ◽  
Coastal Waters ◽  
Common Tern ◽  
Terrestrial Species ◽  
Water Currents ◽  
The Common ◽  
Roseate Tern ◽  
Sooty Tern ◽  
North Western ◽  
Seabirds At Sea

The distribution and abundance of seabirds was documented at sea in the Gulf of Carpentaria in December 1990 and November 1991. Of the 17 species recorded, only the crested tern, least frigatebird, brown booby and streaked shearwater were widespread. The first three species were seen mainly in coastal waters; streaked shearwaters were seen only in the central north-western gulf. The common tern, roseate tern, little tern, sooty tern, black-naped tern, common noddy and greater frigatebird were either sparsely distributed or uncommon. The list includes five terrestrial species. The distribution of the seabirds is discussed in relation to proximity to breeding and roosting sites, food availability, the effects of discards from prawn trawling, and water currents.

scholarly journals Comparison of the transcriptomes of two tardigrades with different hatching coordination

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuki Yoshida ◽  
Kenta Sugiura ◽  
Masaru Tomita ◽  
Midori Matsumoto ◽  
Kazuharu Arakawa
Keyword(s):  
Gene Expression ◽  
Embryonic Development ◽  
Juvenile Hormone ◽  
Extreme Environments ◽  
Regulation Mechanism ◽  
Egg Hatching ◽  
Terrestrial Species ◽  
Juvenile Hormone Analog ◽  
Hormone Analog ◽  
Multiple Species

Abstract Background Tardigrades are microscopic organisms, famous for their tolerance against extreme environments. The establishment of rearing systems of multiple species has allowed for comparison of tardigrade physiology, in particular in embryogenesis. Interestingly, in-lab cultures of limnic species showed smaller variation in hatching timing than terrestrial species, suggesting a hatching regulation mechanism acquired by adaptation to their habitat. Results To this end, we screened for coordinated gene expression during the development of two species of tardigrades, Hypsibius exemplaris and Ramazzottius varieornatus, and observed induction of the arthropod molting pathway. Exposure of ecdysteroids and juvenile hormone analog affected egg hatching but not embryonic development in only the limnic H. exemplaris. Conclusion These observations suggest a hatching regulation mechanism by the molting pathway in H. exemplaris.

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