Date: Fri, 2 Feb 2001 13:02:41 +0000 (GMT Standard Time)
From: Keeley Louise Bignal <K.L.Bignal@Bradford.ac.uk>
To: bryonet-l@mtu.edu
BRYONET
Dear All
I am a research student investigating the impact of
vehicular emmissions on lichens and bryophytes.
I am exposing a no. of species to diesel exhaust fumes in
solar domes and screening for sensitivity (the levels are
typical roadside concentrations). The moss material
consists of individual shoots from 2.5 cm in length to 70
cm, depending on the species. I hope to measure growth
(hence the individual shoots).
Polytrichum commune is in glass jars half filled with
water. Dicranum scoparium, D. majus and Mnium hornum are
packed into small transparent beakers filled with sand with
capillary matting extending to a reservoir of water. After
6 weeks exposure, all of the aforementioned species look
quite healthy despite some browning of the uppermost
leaves. Material in the controls also shows signs of damage
which is probably do to dessication.
The following species are the ones I am having the most
trouble with: Plagiothecium undulatum, Brachythecium
rutabulum, Rhytidiaedelpus squarrosus, Eurynchium
praelongum, Hylocomium splendens and Hypnum cupressiforme
are laid out as individual shoots on sand in pots. The
material in the controls is not healthy, with bleaching and
loss of pigment. However, the material in the pollution
domes has died/turned brown.
The plants are watered 3x week with artificial rainwater
solution. They cannot be watered more often as the domes
are 200 miles from where I study so I have to rely on other
people to water them.
Obviously I am having problems with the material drying
out and the plants are not coping as well with dessication
in the pollution domes. I need the material to survive for
longer than 6 weeks so that I can take some growth
measurements. I was wondering if any of you have any tips
on stopping the bryophytes from drying out and how to
maintain them. Does anyone have experience of exposing small
sections of material to air pollutants in controlled
conditions.
I would be very grateful for any comments/ideas on how to
proceed.
Regards,
Keeley Bignal
K.L.Bignal@bradford.ac.uk
------------------------------------------------
Subject: Re: culturing bryophytes in controlled conditions
Date: Fri, 2 Feb 2001 11:30:19 -0800
From: davidhwagner <davidhwagner@home.com>
To: <bryonet-l@mtu.edu>
BRYONET
It is my experience that cultivation of most bryophytes under glass faces
the difficult problem of maintaining high humidity and AT THE SAME TIME
adequate air flow. One without the other is a source of problems. It is
not hard to get high humidity, but adequate air flow is then a challenge.
and vice versa. On top of this, most bryophytes like to have water flow
that rivals air flow. Still water is as inhibiting as still air. Dead air
+ dead water = dead plants.
David H. Wagner
davidHwagner@home.com
Northwest Botanical Institute
P.O. Box 30064
Eugene OR 97403-1064
U.S.A.
---------------------------
Subject: Re: culturing bryophytes in controlled conditions
Date: Fri, 02 Feb 2001 15:26:34 +0100
From: H.J.During <H.J.During@bio.uu.nl>
To: bryonet-l@mtu.edu
BRYONET
Dear Keeley,
Are these solar domes translucent & closed? in that case, your plants might
simply get too hot, and you might think of the old solution for greenhouses
in summer - spray some calcium carbonate solution over the dome to make it
less translucent and reflect some of the incoming light. This may help to
prevent temperatures getting too high and will reduce evaporation rates of
the plants.
It is difficult to say from a distance whether nutrient shortage may partly
cause the bleaching, but you might consider to occasionally spray a dilute
nutrient solution over the pleurocarps and see whether that improves their
appearance.
Good luck!
Heinjo During
H.J. During
Department of Plant Ecology
F.A.F.C. Went Building, P.O. Box 800.84
NL-3508 TB Utrecht, The Netherlands
Tel. +31 30 2536847
Fax +31 30 2518366
e-mail h.j.during@bio.uu.nl
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