A visit to an old graveyard, particularly one that has not been cared for, will generally reveal tombstones covered in lichens. Lichens are composite organisms; they are a symbiotic relationship between a fungus and a green alga (or a cyanobacterium). The fungus provides the physical infrastructure and the algae do photosynthetic duty to supply sugars. [...]
Archive for March, 2009
Dating With Lichens
Posted in As Landscape, As Object, tagged lichen, moraines, tombstones on March 16, 2009 | Leave a Comment »
Hypoallergenic Flowers
Posted in As Kind, As Object, tagged allergy, hypoallergenic, pollen on March 15, 2009 | Leave a Comment »
“Horticulturalist Thomas Leo Ogren, author of Allergy-Free Gardening: The Revolutionary Guide to Healthy Landscaping, found that allergenic plants are often favored by landscapers: ‘School after school is landscaped with the most allergenic plants possible. Even at hospitals I see landscaping so explosively allergenic that it makes me shudder.’” (www.achooallergy.com)
Some allergy-sufferers, fearing a reaction, decline to [...]
Why Plants Are Where They Are
Posted in As Landscape, tagged biogeography, climax, succession on March 15, 2009 | Leave a Comment »
Why are there different plants in different places? If you revisit a place decades later, will the same plants still be there, only having grown larger? How do plants get where they are? All of these questions (and more) are asked by plant biogeographers. Many students of biology who pursue the subject in school out [...]
The Plant Succession Debate
Posted in As Landscape, tagged Clement, Gleason, pollen, succession on March 15, 2009 | 1 Comment »
The ecologist community of the 20th century divided over the nature of plant succession on both an ecological and a geological timescale. During the last glacial advance of the Pleistocene Epoch ice sheets covered nearly all of Canada and the northern third (more or less) of the United States. Beginning approximately 18,000 years ago, these [...]
