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January 2010
353
MASHONALAND CALENDAR
Sunday, January 17th: 11 Blue Haze Lane, Umwinsidale area
Our venue for the first outing of 2010 is the home of Fred and Renate
Winch, a place we visited for the December 2008 Christmas Social and where
we found, during a short walk, a number of interesting woody and herbaceous
species.
Directions: From town take the Enterprise Road. Turn left into Umwinsidale
Road and follow the Pat Mavros signs, cross the river and up the hill,
then turn right into Haslemere Road (tarred). Take the first right turn
past Mick Fleet's house, into Blue Haze Lane, go about 200 meters and
turn right into No 11 right at the end of the lane. We will meet at 9.30
am.
Please bring a chair and your lunch.
*** NOTE: EXTRA EVENT ***
Saturday, January 23rd: Visit to the National Herbarium
As a follow-up to the successful appeal for the fumigation of the National
Herbarium, we have organised an afternoon visit to the herbarium for Tree
Society members and people who donated to the appeal.
The purpose of the visit will be to show people the Herbarium and what
it does.
The Head of the Herbarium, Christopher Chapano, will be there to give
us a guided tour of about 30 minutes in length. Afterwards, we will arrange
some tea (ZESA willing) and there will be an opportunity to look more
closely at the specimens and facilities.
This event will take place on Saturday 23rd January at 2.30 pm.
The entry to the National Herbarium is off 5th Street Extension, opposite
Downie Avenue. NOTE that this is not the place where we usually meet for
Tom’s walks. Please could those intending to attend let our Secretary,
Ruth Evans (petra@mango.zw) know in advance so that we have some idea
of the numbers who will be coming.
Letter to Tree Life
[Rob Burrett has sent us some comments that expand usefully on the themes
about Harare trees and history in the December Tree Life.
-Ed.]
Yes, for many years it has been known that the Harare hanging tree was
a myth. No one was hanged there ... certainly not Nehanda. It is a myth
that has been around for many years, but it got worse when that stamp
was issued (without the facts being checked with heritage specialists);
it also suits the current reinvention of nationalist heritage. National
Museums is fully aware of this myth. It is correct that Nehanda and the
others were hanged at what is now Harare Central – that section
that corners on Kenneth Kaunda Avenue. It has a large internal open space,
and it was probably there.
On the Miombo of Harare there are several points:
1. Most pictures are taken from the Kopje looking out over the vlei that
was around the stream that now runs under the palms of Julius Nyerere
Way. It was a large, open and grassy area that was chosen. Yes, damp in
places, but desirable for reason of defence for the Pioneers who were
concerned about potential Matabele attack. If they had gone on to Mount
Hampden, as was the aim, it would have been through problematic terrain
and treed relief – much too dangerous. The Miombo was there, but
it did not appear in the lens of those early photographers.
2. Vleis were also larger then as the watertables had not been drained,
something we have done so successfully in the last century. You know how
the margins of most of the remaining grass belts around Harare (Greystone
Park for example) have been invaded as we alter the watertable level.
This seems to be a general phenomenon and, with ten boreholes reportedly
being drilled in Harare every day, is a situation that can only worsen.
3. In addition, this area was occupied during the late pre-colonial period.
There were villages in the area, and the inhabitants would have used the
timber and opened fields.
4. I think we saw the re-emergence of Miombo through the colonial process.
It was there, but in pockets up on the more exposed highveld – hammered
by nature, humans and frost. Look at those old musasa in the Botanical
Gardens or at Saint George’s College. They must be a few hundred
years old. Regrowth and expansion took place successfully with our intervention.
5. A really good example of the changing cycles influenced by humanity
is the Epworth-Ventersburg area. In the 1890s, Alice Balfour painted rocks
and people just off the “Umtali Road”. The background is grassy
plain with few trees. Then it became private land, and the Miombo reasserted
itself, or it invaded so that a well-treed section was established along
the Marondera Road. I remember us going there when it was a leased commercial
farm some years back. It was good Miombo. Then came the expansion of informal
settlement and the ZESA challenges; the trees went, and we are back to
Balfour, albeit with maize and a LOT more people!
It would be interesting to see this analysed scientifically by someone.
Similar patterns occur in Bulawayo, Gweru and Marondera, where I have
early pictures.
R. Burrett
Faidherbia albida Promises to Revive African Soils
[One paper presented at last August’s 2nd World Congress of Agroforestry
in Nairobi received particular attention, and stories reporting its findings
were published widely. The one used here comes from Science Daily of August
26, 2009. (http://www.sciencedaily.com/releases/2009/08/090824182535.htm).
-Ed.]
With its nitrogen-fixing qualities, the tall, long-lived acacia tree,
Faidherbia albida (Mgunga in Swahili) could limit the use of fertilizers;
provide fodder for livestock, wood for construction and fuel wood, and
medicine through its bark, as well as windbreaks and erosion control to
farmers across sub-Saharan Africa. The tree illustrates the benefits of
growing trees on farms, said the scientists at today's meeting, and is
adapted to an incredibly wide array of climates and soils from the deserts
to the humid tropics.
"The future of trees is on farms," said Dennis Garrity, Director
General of the World Agroforestry Centre, or ICRAF, one of 15 centers
supported by the Consultative Group on International Agricultural Research
(CGIAR). The Center is hosting the Congress, which has convened about
800 global experts to discuss the importance of growing trees on farms
for humanity's survival.
"Growing the right tree in the right place on farms in sub-Saharan
Africa-and worldwide- has the potential to slow climate change, feed more
people, and protect the environment. This tree, as a source of free, organic
nitrogen, is an example of that. There are many other examples of solutions
to African farming that exist here already."
African farmland is severely degraded and African farmers, on average,
apply only 10 percent of soil nutrients used in the rest of the world.
Low-cost options are critical to reversing the continent's declining farm
productivity, the scientists said, as sharply increasing fertilizer prices
further limit the choices African farmers have to improve farm yields
while protecting forests from further clearing.
The Faidherbia acacia tree has the quality of "reverse leaf phenology,"
which drives the tree to go dormant and shed its nitrogen-rich leaves
during the early rainy season-when seeds are being planted and need the
nitrogen-and then to re-grow its leaves when the dry season begins and
crops are dormant. This makes it highly compatible with food crops because
it does not compete with them for light-only the bare branches of the
tree's canopy spread overhead while crops grow to maturity. Their leaves
and pods provide a crucial source of fodder in the dry season for livestock
when other plants have dried up.
Research on the tree began over 60 years ago when scientists observed
that farmers throughout the Sahelian region of Africa were retaining the
trees in their sorghum and millet fields. It is a frequent component of
farming systems of Senegal, Mali, Burkina Faso, Niger, Chad, Sudan, and
Ethiopia, and in parts of northern Ghana, northern Nigeria, and northern
Cameroon. The tree is growing on over 4.8 million hectares of land in
Niger. Half a million farmers in Malawi and in the southern highlands
of Tanzania grow the tree on their maize fields.
In Malawi, maize yields were increased up to 280 percent in the zone under
the tree canopy compared with the zone outside the tree canopy. In Zambia,
recent unpublished observations showed that unfertilized maize yields
in the vicinity of the Faidherbia trees averaged 4.1 tonnes per hectare,
compared to 1.3 tonnes nearby but beyond the tree canopy. Yield increases
have also been documented in unfertilized millets grown under the tree
in West Africa, for sorghum in Ethiopia, other parts of Africa, and in
India, in addition to groundnuts and cotton. Often, millet and sorghum
exhibit no further response to artificial fertilizers beyond that provided
by the tree's leaf fall.
Currently, the Departments of Agriculture in both Malawi and Zambia are
seeking to double maize production with the use of the tree. They recommend
that farmers establish 100 Faidherbia trees on each hectare of maize that
is planted.
Scientists at the conference noted some 700 published references to the
tree's history, ecology, and growing habits. "Knowledge of this tree
is farmer-driven," said Garrity. "We are now combining the scientific
knowledge base with the farmer knowledge base. There is sufficient research
on both sides to warrant dramatically scaling-up the planting of this
tree on farms across Africa through extension programs. The risks to farmers
are low; it requires very little labor, and delivers many benefits."
"Thus far we have failed to do enough to refine, adapt and extend
the unique properties of these trees to the more than 50 million food
crop farmers who desperately need home-grown solutions to their food production
problems," he continued.
A Green(ish) New Year’s Quiz
Happy New Year! You will have had Adele’s usual challenging quiz
at the Christmas social. Now, as a test of how much self-inflicted damage
you did to yourselves over the festive season, here is a baker’s
dozen for the new year. Bearing the theme in mind may prove helpful.
1. What two (large) birds are known to make therapeutic use of what widespread
local tree? And how?
2. Where do the original wild apples and apricots come from?
3. And in the same vein, what is the only fruit that we see regularly
on sale in many places that comes originally from southern Africa?
4. Of all vegetables, only three will routinely crop for several growing
seasons. All other vegetables must normally be replanted every year. What
are the three perennial vegetables?
5. In posh liquor stores, it is possible to buy pear brandy with a real
pear inside the bottle. The pear is whole and mature, and the bottle is
genuine, but has a neck much smaller than the pear. Neither bottle nor
pear has been cut in any way. How did the pear get in there?
6. Name the only vegetable that is never sold (at least in southern Africa)
frozen, canned, processed, cooked or in any other form except fresh.
7. Name the only fruit that has its seeds on the outside.
8. Name a fruit where you eat the stalk and treat the actual fruit with
great reserve at best.
9. A Russian novelist and Nobel Prize winner; a German Chancellor, and
an American filmmaker share common roots. What’s the connection?
10. Why would good gardeners celebrate the incoming of 2010 with the root
of a sedge, 2011 with the bluebells of Scotland, and 2012 with a tree
that drips blood?
11. What is reputed to be the second most frequent cause of accidental
death in the Comoros, after traffic accidents?
12. Where does the common name of the weed Chromolaena come from, and
why is it appropriate?
13. Finally, let’s see who knows their grasses:
a. Name five important food grasses.
b. How do grasses cause hay-fever?
c. What are marram grass and esparto grass used for?
d. Are pampas grass and bamboo true members of the grass family?
That’s it folks! Answers in February’s Tree Life.
COMMITTEE MEMBERS’
CONTACT TEL. NUMBERS
Harare
Mark Hyde Home 745263
Cell 091 233751
Ruth Evans Home 331198
Terry Fallon Home 481076
J-P Felu Home 304916
Eva Keller Home 339368
Richard Oulton Home 870540
Mimi Rowe Home 882719
Tree Life Editor Home 302812
or bkinsey@mango.zw
The Tree Society’s e-mail address is
petra@mango.zw (Ruth Evans)
The Tree Society web site is
http://www.lind.org.zw/treesociety/index.htm
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