Our Gossamer Planet

Thursday, December 9, 2010

Poll result: What MOST bothers you about the effect of lead ammunitions on fauna and humans?

100% is bothered most by Lead poisoning in birds and mammals which feed on carcasses of hunted game animals.

No responses to the options of 'Lead poisoning in humans who ingest hunted game animals', 'Lead ammunitions do not cause any such effects. Ergo, this is all hogwash', and 'This issue is irrelevant and of no concern to me'.

Kissing the mistletoe goodbye?

Kissing under the boughs of mistletoe is an oft-observed Christmas tradition, especially in the UK and the US. But, according to the UK’s National Trust, the years are fast approaching by when we may be kissing the UK mistletoe goodbye.

The parasitic European Mistletoe, Viscum album, thrives on fruit

trees such as the domestic apple tree and also other hosts such as lime, poplar, and hawthorn. Its heartland is the counties of Somerset, Gloucestershire, Herefordshire, and Worcestershire. However, since the mistletoe’s main habitat, the traditional orchards, have declined dramatically in the past 60 years, there is a looming threat that, in twenty years, yuletide revellers would have to import mistletoe from mainland Europe (a trend which has been, nonetheless, slightly increasing over the past few years). The solution offered by the National Trust is to purchase mistletoe from ‘sustainable home or local’ sources. The charity, in association with Natural England, had also launched a project last year which aims at restoring traditional orchards supporting small cottage industries. It must be mentioned that a common end effect of mistletoe infestation (apart from reduced growth) is death for the host and it remains to be seen how many traditional orchard owners would be keen on not excising the mistletoe bunches in their trees.

Mistletoe has a degree of ecological importance for it is an ecological keystone species (Watson, 2001). Since the plant provides food (especially during winter) and habitat for wildlife, it could be considered as having a positive effect on biodiversity.

The plant is also believed to have medicinal properties: lowering blood pressure and heart rate, easing anxiety, relieving headaches, improving concentration ability, and in the treatment of cancer (Ernst et al, 2003). In Germany, more than US $30 million is spent on mistletoe extracts, with a yearly sales increase of 20%.

Mistletoe’s anti-cancer properties remain a bone of contention (Ernst et al, 2003; Horneber et al, 2008). For instance, there are positive results (such as Hajto et al demonstrating that mistletoe’s ß-Galactoside-specific Lectin activated monocytes in the peripheral human blood, resulting in the secretion of Tumor Necrosis Factor a, Interleukin 1, and Interleukin 6, all of which can inhibit tumour growth; or, Büssing et al’s results which suggests that it could be used in the treatment of lymphoma and lymphocytic leukemia due to its property of inducing apoptosis in human lymphocytes), as well as negative (Steuer-Vogt et al, 2001; Gabius et al 2001). An exhaustive review of all randomised clinical trials (Ernst et al, 2003) illustrated that the published work had failed to demonstrate the efficacy of this therapy in cancer patients –in fact, it even had the potential to cause harm (as seen in Gabius et al’s study in which clinically relevant low doses of mistletoe lectin where shown to stimulate tumour proliferation in cell lines and histotypic cultures). Furthermore, there are grave concerns since lectins tend to sediment the erythrocytes.

Reverting to the gist of this post, our mango trees (here in Trivandrum, Kerala) have mistletoes (Loranthus sp) as well. And despite the unwelcome visitor’s virtues, we tend to care more about the potential mangoes, and hence excise the sprigs- and never fail to admire its tenacity when it springs back to life. In any case, due to the lack of a market for mistletoes in the country, there isn't any utility in retaining/cultivating these except during the Advent tradition of hanging up the mistletoe (and are probably a minority in following this tradition in the region). Ergo, I would to like to know the stance of the ‘traditional orchard’ owners. And, admittedly, during my years in Oxbridge (+London), I've noticed far more mistletoe in other trees than in apple.
Nonetheless, one does hope that the National Trust’s information on the mistletoe’s impending doom in the UK isn’t a case of crying wolf. Or is it indeed a legitimate concern?

Photo credit: sumeja

References:
http://www.nationaltrust.org.uk/main/w-global/w-news/w-latest_news/w-news-campaign-launched-to-give-mistletoe-the-kiss-of-life.htm

Horneber MA, Bueschel G, Huber R, Linde K, & Rostock M (2008). Mistletoe therapy in oncology. Cochrane database of systematic reviews (Online) (2) PMID: 18425885

Ernst E, Schmidt K, & Steuer-Vogt MK (2003). Mistletoe for cancer? A systematic review of randomised clinical trials. International journal of cancer. Journal international du cancer, 107 (2), 262-7 PMID: 12949804

Gabius HJ, Darro F, Remmelink M, André S, Kopitz J, Danguy A, Gabius S, Salmon I, & Kiss R (2001). Evidence for stimulation of tumor proliferation in cell lines and histotypic cultures by clinically relevant low doses of the galactoside-binding mistletoe lectin, a component of proprietary extracts. Cancer investigation, 19 (2), 114-26 PMID: 11296616

Steuer-Vogt MK, Bonkowsky V, Ambrosch P, Scholz M, Neiss A, Strutz J, Hennig M, Lenarz T, & Arnold W (2001). The effect of an adjuvant mistletoe treatment programme in resected head and neck cancer patients: a randomised controlled clinical trial. European journal of cancer (Oxford, England : 1990), 37 (1), 23-31 PMID: 11165126

Watson, DM (2001), Mistletoe-A Keystone Resource in Forests and Woodlands Worldwide, Annual Review of Ecology and Systematics 32, pp.219-249.
http://www.annualreviews.org/doi/abs/10.1146/annurev.ecolsys.32.081501.114024

Büssing A, Suzart K, Bergmann J, Pfüller U, Schietzel M, & Schweizer K (1996). Induction of apoptosis in human lymphocytes treated with Viscum album L. is mediated by the mistletoe lectins. Cancer letters, 99 (1), 59-72 PMID: 8564930

Hajto, T., Hostanska, K., Frei, K., Rordorf, C., and H-J Gabius (1990). Increased Secretion of Tumor Necrosis Factor a, Interleukin 1, and Interleukin 6 by Human Mononuclear Cells Exposed to ß-Galactoside-specific Lectin from Clinically Applied Mistletoe Extract1. Cancer Res 50, pp. 3322

Monday, September 20, 2010

One flood. Three days -> One canyon.

We often get glimpses into the overwhelming power of nature. One such was in June-July 2002 in Texas: Fearing the worst during torrential rains, the waters of Canyon Lake (a reservoir on the Guadalupe River) were diverted into an emergency spillway. The consequential flood event, with a flow rate of over 1450 cubic metres per second and duration of six weeks, destroyed a bridge and trees, and carved a 2.2 km long, 7 m (average) deep canyon into the limestone bedrock. This new Canyon Lake Gorge is highlighted by Michael Lamb (Caltech) and Mark Fonstad (Texas State University) in their paper published in Nature Geosciences on the ‘Rapid formation of a modern bedrock canyon by a single flood event’.

Deep river canyons are considered to have formed gradually over the millions of years as a result of moderate and recurring flow of water. Megaflood events too results in similar canyons and channels, except that these are formed more rapidly, as in the case of the Canyon Lake Gorge. In this event, it is undeniably known that the erosion happened during the flood and the more destructive episode happened over a time span of just three days.

Using pre and post data and techniques (aerial photographs/images, models, flood measurements) Lamb and Fonstad analysed the formation of the canyon, identified the characteristics, and reconstructed the hydraulics of the flood. The important findings are:

- The rate of gorge erosion/formation was rapid, limited only by the amount of sediments carried by the floods. About 460,000 cubic metres of materials were dislodged, almost half of which were rocks. Even boulders with a size of 1m were plucked and moved downstream.

- The very creation of the canyon was dependent on the nature/characteristics of the bedrock. For instance, the aforementioned plucking of the 1m limestone boulders was facilitated by the fractures (horizontal bedding planes and vertical cracks probably due to tectonic movements) which were already present in the layered limestone bedrock.

- The rock type determined the resultant morphology of the canyon. The first part features 10-12m high waterfalls, channels, and terraces due to the plucking of the boulders. The latter part features sediment islands which are considered to be characteristic of large flood events.

Caveat: Is this a really megaflood (floods with a flow of1 million cubic metres per second) per se?

References:
Lamb, M., & Fonstad, M. (2010). Rapid formation of a modern bedrock canyon by a single flood event Nature Geoscience, 3 (7), 477-481 DOI: 10.1038/ngeo894

http://media.caltech.edu/press_releases/13357

Thursday, September 16, 2010

Gossamer Webs 1.5

How acidic oceans are posing problems for fishes by affecting their ability to smell:
http://www.telegraph.co.uk/science/7896681/Acidic-oceans-cause-fish-to-lose-ability-to-smell-danger.html

Is climate change affecting phytoplankton?- Review of 'Global phytoplankton decline over the past century' in Nature (Daniel Boyce, Marlon Lewis, and Boris Worm of Dalhousie University)
http://takluyver.wordpress.com/2010/08/06/is-climate-change-affecting-phytoplankton/

The effect of acidification in the lakes of Adirondack mountains of New York State- Review of ‘Acidification in the Adirondacks: Defining the Biota in Trophic Levels of 30 Chemically Diverse Acid-Impacted Lakes’ (Sandra Nierzwicki-Bauer, Charles Boylen, Lawrence Eichler and James Harrison) published in Environmental Science and Technology
http://www.conservationmagazine.org/2010/07/acid-test/

The Horton Plains Slender Loris is not extinct after all!
http://www.telegraph.co.uk/earth/wildlife/7897057/Horton-Plains-Slender-Loris-pictured-for-first-time.html

EU and ‘clean driving’:
http://www.telegraph.co.uk/motoring/news/7906313/Brussels-plans-to-test-drivers-on-environmental-friendliness.html

Poll result: Which of the following game (if any) have you eaten?

The options provided were deer/venison, boar, quail, pheasant, partridge, ptarmigan, grouse, woodpigeon, woodcock, snipe, plover, goose, duck, rabbit, hare, squirrel, elk, and frog.

100% of the survey participants had consumed deer/venison, 75% had eaten duck, 50% had consumed quail, and 25% had partaken boar, pheasant, partridge, goose, rabbit, and hare.

New poll added.

On a sidenote, I wouldn't be surprised if the quiet countryside of England and the formal halls of Oxbridge contributed to the results above :p

Tuesday, August 17, 2010

The modest Vetiver

Bountiful Nature certainly holds the antidote to many anthropogenic and natural problems.

One such is Vetiver (Chrysopogon zizanioides), formerly known as Vetiveria zizanioides, a xerophytic and hydrophytic perennial clump grass of the Poaceae family with fast-growing tough root system and the ability to grow very tall with rigid stems and leaves. Since it is native to India, we tend to be quite familiar with its myriads of uses as listed below.

Vetiver roots’ aromatic and cooling properties
Vetiver’s roots are highly aromatic, with a pleasant, cool, refreshing, and earthy smell.
1. The roots are added to water in earthen pots in order to impart a distinctive flavour as well as a cooling effect.
2. The roots are kept in cupboards so that the clothes have a ‘fresh’ smell (similar to how we use sachets of lavender).
3. The fragrant essential oil from the roots is widely used in perfumery.
4. Mats and fans made of woven Vetiver roots are used to cool rooms during summer.
5. Other handicrafts made of Vetiver roots are popular due to the subtle aroma.

Medicinal property
Vetiver is often used in Ayurveda, the traditional (and viable) Indian system of medicine.
1. Water is purified by adding the roots.
2. Infusion of the roots can help in allaying fever, inflammation, and tummy problems.
3. It is effective in normalising, moisturising, and rejuvenating the skin. Apparently, it is also effective in removing acne and can be applied on irritated, wounded, and inflamed skin for speedier healing.
4. When applied regularly, the oil can prevent stretch marks (especially during pregnancy).
5. Due to its beneficial effects on the central nervous system, applying the oil also helps in psychological and emotional balance- i.e. helps in overcoming depression, stress, tension, anxiety, nervousness, and even insomnia.
6. When applied locally, it is effective in countering rheumatism, back pain, headaches, and sprains.
7. And apparently, the oil is also an aphrodisiac.

Vetiver roots’ decontaminating property
1. Vetiver decontaminates the polluted/contaminated soil.
2. As mentioned before, the roots have the property of purifying water. Being a hydrophyte, the plant can be used in treating wastewater.

For addressing environmental problems
Vetiver’s roots are unique- these grow very deep downwards and are thick with high tensile strength. As a result, it has the following uses:
1. For controlling erosion: Vetiver is very effective in preventing soil erosion when planted on the boundaries of agricultural lands, dikes, bunds, embankments, slopes, or on stream and river banks.
2. Runoffs are mostly blocked and spread in the surrounding areas. As a result, not only are the soil, sediments, and agricultural fertilisers trapped (thus enriching the land), but the soil moisture is also conserved (which the plants use during times of water scarcity).
3. Groundwater recharge- apparently, groundwater levels have increased in areas where vetiver is widely used.
4. Since Vetiver grows in clumps, weed invasion is prevented.

Vetiver requires minimal maintenance and has very sturdy characteristics. It is highly tolerant of adverse climatic conditions and variations (including droughts, floods, submergence, and extreme temperatures from -14ºC to +55ºC), pH (from 3.3 to 12.5), salinity, frosts, herbicides, pesticides, and pollutants. Its sturdy stems can withstand deep and heavy water flows. It is also noninvasive, propagating by small offsets instead of stolons or rhizomes. Should there be any fires or heavy grazing (or any other hazard), the new shoots easily develop from the underground crown. Interestingly, Vetiver is intolerant to shade which may result in a reduction of growth or even its elimination.

Vetiver is thus a low-cost effective solution to myriads of problems, including soil erosion which otherwise results in great expenses. For the farmers, this is a very beneficial tool which evidently results in increased crop yields, irrespective of adverse weather conditions. Furthermore, flooding risks are greatly reduced and runoffs of agricultural chemicals (into streams/rivers) are restricted. Even the rest of us are blessed by this modest grass!

Photo: by treesftf