103 research outputs found
Volume 2, Chapter 14-3: Ground-Dwelling Anurans
https://digitalcommons.mtu.edu/bryo-ecol-subchapters/1119/thumbnail.jp
Chapter 14 - Amphibians
Explore the contents of Bryophyte Ecology, Volume 2, Chapter 14 - Amphibians by clicking the links above. For the Contents section of this ebook, as well as Volumes 1 through 5, please visit the Bryophyte Ecology Main Page.
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Ebook sponsored by Michigan Technological University and the International Association of Bryologists.https://digitalcommons.mtu.edu/bryophyte-ecology2/1013/thumbnail.jp
Volume 2, Chapter 14-2: Anuran Conservation Issues
https://digitalcommons.mtu.edu/bryo-ecol-subchapters/1118/thumbnail.jp
Volume 2, Chapter 14-1: Amphibians: Anuran Adaptations
https://digitalcommons.mtu.edu/bryo-ecol-subchapters/1117/thumbnail.jp
Volume 2, Chapter 14-4: Anurans: Waterfalls, Treefrogs, and Mossy Habitats
https://digitalcommons.mtu.edu/bryo-ecol-subchapters/1120/thumbnail.jp
Changes in geothermal vegetation at Myvatn, Iceland, and comparisons to other geothermal areas
We sampled 207 plots from 15 transects at the Myvatn geothermal area
in Iceland in 1985, one year after the September 1984 eruption of Krafla, and again
in 1987, and compared the species and community structure to that of other sites
we had visited in Japan and New Zealand. We found 5 lichen, 47 bryophyte, and 28
tracheophyte species at Myvatn. Overall Shannon diversity (Hâ) was high at 4.34,
with Brillouin (information-theory-based) species diversity (Hâ) being very similar
at 4.32. The greatest diversity occurred at > 25â35°C surface temperature and the
least at > 60°C. Zones are defined mostly by temperature and humidity, with
Cyanobacteria closest to the vents in the hottest zones, followed by bryophytes,
then lichens, then tracheophytes. Bryum argenteum, Ceratodon purpureus, and
Fossombronia sp. 1 (probably immature F. foveolata) occupied the highest
temperatures near the vents in 1985. Lichens tended to avoid hot soils with high
humidity. Soil chemistry most likely plays a role, but with so many variables and
many values at unquantifiable levels, we considered it premature to determine their
individual effects. By 1987, Bryum argenteum, a near-vent species, had almost
totally disappeared, along with the steam emissions where they had thrived. The
geothermal areas in cold climates could serve as refugia for more temperate species
that may have existed prior to the Ice Age, or they may simply be suitable habitats
for northern extensions of the species. This study gives us a glimpse of potential
vegetational changes resulting from climate changes as demonstrated in three
regions of the world
An ancient and conserved function for armadillo-related proteins in the control of spore and seed germination by abscisic acid
Armadilloârelated proteins regulate development throughout eukaryotic kingdoms. In the flowering plant Arabidopsis thaliana, Armadilloârelated ARABIDILLO proteins promote multicellular root branching. ARABIDILLO homologues exist throughout land plants, including earlyâdiverging species lacking true roots, suggesting that earlyâevolving ARABIDILLOs had additional biological roles. Here we investigated, using molecular genetics, the conservation and diversification of ARABIDILLO protein function in plants separated by c. 450 million years of evolution. We demonstrate that ARABIDILLO homologues in the moss Physcomitrella patens regulate a previously undiscovered inhibitory effect of abscisic acid (ABA) on spore germination. Furthermore, we show that A. thaliana ARABIDILLOs function similarly during seed germination. Earlyâdiverging ARABIDILLO homologues from both P. patens and the lycophyte Selaginella moellendorffii can substitute for ARABIDILLO function during A. thaliana root development and seed germination. We conclude that (1) ABA was coâopted early in plant evolution to regulate functionally analogous processes in sporeâ and seedâproducing plants and (2) plant ARABIDILLO germination functions were coâopted early into both gametophyte and sporophyte, with a specific rooting function evolving later in the land plant lineage
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