Aquatic insects in Alaska John, Kathy and Bob collaborated on this amazing publication—yet another in Armstrong’s rich library of self-published…2012 | John Hudson, Katherine Hocker, Robert Armstrong | 142 pages
In 2002, Discovery Southeast began a 2-year study of amphibian habitat, principally within half a mile of the Juneau road system, but in following years branching out to other parts of northern Southeast Alaska. We (Armstrong, Willson & Carstensen) soon noticed that toad, frog and newt stillwater breeding habitat could almost be considered the inverse of aquatic habitats selected by anadromous fish.
In consequence, while moving waters important to the Southeast ‘money-fish’ (salmon and trout) have been intensively researched for more than a century, the quiet spawning ponds of inedible (even toxic!) herps are almost completely unstudied, and even unclassified.
For our study, a geomorphic classification seemed most appropriate. In other words, what are the geological and biological agents of pond formation? Here they are, listed roughly in order from most recent (and rapidly changing) to most ancient (and successionally stable):
beaver created and actively maintained by beaver
glacial kettles, etc uncovered since peak of Little Ice Age
uplift Ï ponds on former tideland developed since Little Ice Age
fen ponds on gently sloping sedge/herb dominated peatlands
bog ponds in sphagnum-dominated peatlands
bedrock controlled by bedrock, includes larger lakes
Okay, got some answers to the caption questions? Principle control on this pond is the dam in center distance, which appears to step down toward the right, direction of stream flow. Almost all drowned spruces have sluffed their bark but retain medium-sized branches—class III decay—which takes a couple decades. Snags lacking branches are also broken-topped and on slightly higher ground, possibly remnants from an earlier impoundment.
In this section
Mysterious declines As most longtime Southeast residents are aware, we’ve suffered a major decline in western toad, recently renamed Anaxyrus…2014 | Richard Carstensen |
Final report on Discovery’s 2-year study of amphibian habitat relations. Population numbers, breeding pond origin types, and amphibian natural history…2003 | Richard Carstensen, Mary Wilson, Robert Armstrong | 77 pages