next message in archive
next message in thread
previous message in archive
Index of Subjects
Hi Dave P. & All, Apr 13, 2013
Was this effect of Ca on tree productivity established by experiment,
e.g. application of Gypsum, or by association ? Genuine Ca deficiency is, as
I recall, just about unknown apart from extreme conditions such as
Serpentine soils or solution culture.
In an interesting experiment reported by Reich et al. (Ecology Letters
(2005) 8:811-818),14 tree species were grown for 30 years in replicated
plots of 'uniform' initial soil and a converse effect was demonstrated;
species with high Ca in their leaf litter significantly increased soil Ca
and soil pH.
[BTW, soil pH usually increases as soil Ca increases (there is only so
much exchange capacity to go around) but the two can be manipulated
independently, e.g. Gypsum will increase soil Ca while having almost no
effect on pH.]
Yt, Dave Webster, Kentville
----- Original Message -----
From: "David Patriquin" <patriqui@DAL.CA>
To: <naturens@chebucto.ns.ca>; "Mary Macaulay" <marymacaulay@hotmail.com>
Cc: <naturens@chebucto.ns.ca>
Sent: Thursday, April 11, 2013 12:35 PM
Subject: Re: [NatureNS] tree biomass fuel ... calcium loss also critical in
NS
> In addition to concerns raised by the Nature article, a multi-authored
> paper published in the Policy Forum of Science in 2009 pointed out that
> there is a critical accounting error in the Kyoto Protocol that allows
> biomass energy to be treated as carbon neutral, regardless of the source.
> The error is very large for forest biomass.
>
> Searchinger. T.D. et al T.D. et al., 2009. Fixing a Critical Climate
> Accounting Error Science 23 October 2009: Vol. 326. no. 5952, pp. 527-528
>
> In addition, we should be concerned about calcium losses in NS. NS
> forests are the most or amongst the most intensively harvested in Canada,
> half or more of our soils by area are very calcium poor and highly
> susceptible to soil acidification, and the area is stressed by acid rain.
> There are worrying signs that for large areas of Nova Scotia (esp in the
> SW), significant declines in productivity or other effects of low calcium
> may be only 1 or 2 rotations away, if not already beginning to happen.
> Further, climatic warming can be expected to exacerbate these stresses,
> e.g., because the deciduous species expected to be favoured have higher
> calcium requirements than softwood.
>
> Intensive forest harvesting can only exacerbate this problem, both by
> direct removal of nutrients and though increased losses from leaching.
>
> Loss of salmon from many of our rivers is attributed to acid rain but
> also reflects reduced levels of calcium in the upland soils.
>
> Birds are also affected, see
> http://news.psu.edu/story/155790/2011/09/15/research-shows-soil-calcium-limits-forest-songbirds
>
> ...we have many reasons to be concerned about continued clearcutting in
> NS, and the obscurification of this issue by the current government.
>
>
>
>
>
>
>
>
>
>
> Quoting Mary Macaulay <marymacaulay@hotmail.com>:
>
>> One of The Economist leaders this week warns against the trend toward
>> using forest biomass as fuel (they call it environmental lunacy). It's a
>> great article on page 71 for those who subscribe
>> or at this link
>> http://www.economist.com/news/business/21575771-environmental-lunacy-europe-fuel-future
>>
>> Please circulate this widely. It's nice to see this highly respected
>> journal calling an axe an axe.
>>
>> Mary Macaulay
>
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2013.0.3272 / Virus Database: 3162/6236 - Release Date: 04/10/13
>
next message in archive
next message in thread
previous message in archive
Index of Subjects