| BEN |
| BOTANICAL ELECTRONIC NEWS |
|---|
| ISSN 1188-603X |
| No. 426 May 27, 2010 | aceska@telus.net | Victoria, B.C. |
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In late November 2009 I noticed that all the leaves had finally fallen from the huge poplars (Populus sp.) at the corner of our property in the Saanich Peninsula. I picked up a random sample of leaves and tried to estimate the biomass of encysted Melampsora occidentalis Jacks. (a rust fungus) in the dead leaves. Of course, I wasn't being properly scientific about it. To begin with I estimated that the trees had 100,000 leaves: I was reasonably sure this was correct to one order of magnitude.
Some of the leaves still had uredinia (orange in colour) but every leaf I picked up had at least a few black spots of the telial stage of the rust, and most had more than 100 such areas, while some had about 1000. I estimated that the average leaf had about 5% fungal biomass (some much less, some much more). I weighed ten randomly chosen leaves, and was pleased to find that they weighed in at 10 grams, or 1 gram each, which simplifies the arithmetic tremendously. So - 100,000 grams = 100 kg of leaves.
5% of that is 5 Kg, or 11 pounds of fungal biomass. Now I looked at thin vertical sections of some of those black areas, and estimated that each of them contained about 500 (resting) telial cells.
Now for some real guesswork. I think that about 25% of the telial cells may be eaten by invertebrates during the winter, though they are heavily impregnated with a melanic substance, and may not be at all palatable.
Each teliospore should eventually give rise to a basidium, producing and discharging 4 basidiospores. So we can put together the following sequence: 100,000 (leaves) x 100 (telial areas) x 500 (telial cells) x 0.75 (some eaten) x 4 (basidiospores per cell) = 15,000,000,000 or 15 billion basidiospores.
My calculations should not be off by more than one order of magnitude, so the number of basidiospores floating in the air next spring will be enough to ensure that the needles of the conifer alternate host are well and truly infected. That's how the fungi work...
The circulation of water in nature takes place through the large and small water cycles. Humanity, through its activities and systematic transformation of natural land into cultured land, accelerates the runoff of rainwater from land. Limiting evaporation and the infiltration of water into the soil decreases the supply of water to the small water cycle. The equilibrium of the water balance in the small water cycle is thus disturbed and it gradually starts to break down over land. If there is insufficient water in the soil, on its surface and in plants, immense flows of solar energy cannot be transformed into the latent heat of water evaporation but are instead changed into sensible heat. The surface of the ground soon overheats, and as a result, a breakdown in the supply of water from the large water cycle arises over the affected land. Local processes over huge areas inhabited and exploited by human beings are changed into global processes and with processes that occur without the assistance of human beings; together they create the phenomenon known as global climate change. The part of global climate change caused by human activities then is largely based on the drainage of water from the land, the consequent rise in temperature differences triggering off mechanisms which cause a rise in climatic extremes. The disruption of the small water cycle is accompanied by growing extremes in the weather, a gradual drop in groundwater reserves, more frequent flooding, longer periods of drought and an increase in the water shortage in the region.
The part of climatic change which is the result of human activities (draining of a region), can be reversed through systematic human activity (the watering of a region). The watering of land can be achieved through saturation of the small water cycle over land by ensuring comprehensive conservation of rainwater and enabling its infiltration and evaporation. This can help achieve the renewal of the small water cycle over a region and fundamentally change the trend of changing climatic conditions: it can-to reverse the trend of regional warming-temper extreme weather events and ensure a growth in water reserves in the territory. The renewal of the small water cycle over an area, however, depends not only on the extent to which the area has been damaged but also on a number of other factors. In the case of Slovakia, we can expect visible results relatively soon (10 to 20 years) after implementation of these measures. The financial costs of these specific measures are moderate sums which can be allocated from state, public and private budgets. Support for the implementation of far-reaching measures should be linked pro rata to each 1 m3 of reservoir volume built in the ground or to anti-erosion measures carried out. The implementation of water conservation measures should, until the renewal of the small water cycle and the maximalization of a stable water balance in a region, replace previous investment measures, which only served to accelerate the runoff of water from a region.
The conservation of rainwater on land "in situ" and the conducting away only of the natural surplus of water in a region is "condicio sine qua non"-a condition essential for ensuring environmental security, global stability and the sustenance of economic growth. Fulfilling these conditions should be of interest to each individual and each community. This is the first time in the history of human civilization when the impact of mankind's activities on the water cycle and the decrease of amount of water in it will have to be evaluated. The statement of the Srí Lankan king, Parakramabahu the Great-"Not even a single raindrop should be allowed to flow into the sea without it first having been used for the benefit of the people..." -is the best summing up of the new water paradigm, a statement which, in the coming decades, should become a slogan for mankind calling for the preservation of civilization.
Available from: http://www.islandalpineflowers.ca
This full colour, water and tear-proof plant identification is being unique in being specifically about Vancouver Island's alpine flowers. Hans Roemer, Ph.D., brings to this publication more than 35 years of professional experience as a botanist/ecologist with the British Columbia Government and as a consultant. Also a mountaineer, Hans' succinct text about the usual habitats of these 86 species is distilled from his years of experience as a field botanist in our island mountains.
This pamphlet is one contribution towards inspiring and enabling awareness of our Vancouver Island alpine flora. The website is another active part of this project. It enables additions beyond the scope of the pamphlet. There is still much to be discovered about alpine plants and their distribution on Vancouver Island. Use your camera and GPS. Your participation is welcome! Write alpineflowers@gmail.com with your contributions, questions, or new records.
On one hand, the title of Cody's book belies a specific geographic focus, as it concerns entirely the small, inland islands in Barkley Sound, British Columbia. On the other hand, the quality of the data, particularly the unusually long period of collection (1981-2003), and the thoughtfulness and creativity of the analyses give this book a broad ecological applicability. Indeed, it should be considered a must-read for anyone involved in island biogeography research, and has important implications for theory on species invasions and dispersal patterns.
"Plants on Islands" begins with an excellent general description of the geology and ecology of the Barkley Sound area, as well as a review of Island Biogeography Theory in the context of the islands Cody surveyed. Following that is perhaps the most thorough analysis of island plant surveys yet published, using both conventional analyses familiar to most ecologists (species-area curves, incidence functions), and novel, finely-detailed analyses of many aspects of the Barkley Sound flora.
It is these details that are the major strength of the book. The analyses are very well explained, the figures are intuitive and well constructed, and the conclusions that are drawn are, in most cases, strongly supported. Some of the many important patterns revealed include: a somewhat lower extinction than colonization rate on the islands in general; non-random colonization and extinction patterns; species turnover in only part of the flora; and diminishment over time of some introduced species populations. The work on dispersal modes of species and their possible evolutionary consequences on islands is also excellent, and indicates an important area for further research. Finally, there is a small amount of work tying possible isolation-based evolutionary patterns in plants with those of island fauna, namely slugs and deer mice. Again, Cody provides the reader with many cross-disciplinary research ideas.
While there is risk in Cody's approach of overanalyzing data (i.e., finding spurious associations through sheer volume of analyses), this is mitigated somewhat by the fact that the patterns illustrated are backed up by volumes of data and realistic explanation. More importantly, had such an approach not been taken, and had only broad patterns been analyzed, key drivers of ecosystem dynamics would have remained unknown. Indeed, reading "Plants on Islands" in the context of MacArthur and Wilson's classic "Island Biogeography", is a humbling experience. It illustrates the need for careful scrutiny of the elegant but superficial theories we try to impose on nature. It also shows the wealth of knowledge that can come from detailed analysis by someone who is expert at both natural history and analytical methods. Cody's book poses as many questions as it answers, so it should be widely read by ecologists who are looking for research directions.
Information from the back cover:
"This thorough and meticulous study, the result of nearly a quarter-century of research, examines the island biogeography of plants on continental islands in Barkley Sound, British Columbia. Invaluable both because of its geographical setting and because of the duration of the study, Plants on Islands summarizes the diversity, dynamics, and distribution of the approximately three hundred species of plants on more than two hundred islands. Martin Cody uses his extensive data set to test various aspects of island biogeographic theory. His thoughtful analysis, constrained by taxon and region, elucidates and enhances the understanding of the biogeographic patterns and dynamics. He provides an overview of the basic theory, concepts, and analytical tools of island biogeography. Also discussed are island relaxation to lower equilibrium species numbers post-isolation, plant distributions variously limited by island area, isolation and climatic differences, adaptation to local abiotic and biotic environments within islands, and the evolution of different island phenotypes. The book concludes with a valuable consideration of equilibrium concepts and of the interplay of coexistence and competition. Certain to challenge, Plants on Islands is among the first books to critically analyze the central tenets of the theory of island biogeography."
The Junipers of the world (2nd Ed.) summarizes over 40 years of research by Prof. Adams on the genus Juniperus. The taxonomy and evolution of Juniperus species is supported by a synthesis of morphological, biochemical, bio-geographical, ecological and DNA sequence data that is presented for the reader to examine. The species description of each taxon contains: a distribution map, close-up photo of the leaves and seed cones, and plant habit photo. Chapters are: Introduction, Geographic Variation, Speciation by sections, Keys, Species Descriptions, Hybridization, Ecology, Cultivated Junipers, and Commercial Uses. In addition, a Cross Indexed Synonymy of Juniperus and Tables of Essential Leaf Oils compositions are presented.
The Junipers of the World contains a synthesis of data on evolution by examining: Geographic Variation: Pan-Arctic variation in Juniperus communis, etc. Speciation in sections of the genus: Species concepts, Speciation in Juniperus section Juniperus, etc. In addition, Keys to Juniperus are provided by region: Eastern Hemisphere, Europe (including Azores, Canary Islands, Asia Minor and Africa), Central Asia (Turkmenistan to western Himalayas), China, Far East (Japan, Korea, Sakhalin Island, Taiwan), Western Hemisphere, Continental North America, United States and Canada, Mexico and Guatemala, and the Caribbean.
This book supplements the web site www.juniperus.org and the reader will find literature citations, downloadable pdf files of the original literature. Prof. Adams has presented arguments for the recognition of species and varieties by showing how the data analyses led to taxonomic decisions.
The Junipers of the World, 2nd Ed. is now the authoritative reference for the genus Juniperus. In total, the book deals with 67 species, 34 varieties and 6 forms.
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