NEWSLETTERS OF THE TREE SOCIETY OF RHODESIA FOR 1968
The following is a summary of the news, events and happenings of the Tree Society of Rhodesia from the records we have available for 1968
Tree Society of Rhodesia Newsletter March 1968 (no letters for January or February)
What do you want to read in “News” in Rhodesia Science News, generally, in these letters and in the Society’s “Notes”?
I have been told that items in the Notes would be better in the Letter and vice versa. The main point is, is a need being filled? Obviously the Notes should be about the activities or objects of the Society, but of general interest to all readers, and the Letter should be of particular interest to members. I believe that apart from trees as trees our members have heterogeneous interests, so often include matter only indirectly associated with trees. Are some interested all of the time and all interested some of the time?
Last month’s Notes dealt with two subjects without a break of sub-head between them, for which I have apologized and in return would point out that such a fault was not uncommon in the last issue. These are lesser matters compared with such things as contents lay out and printing. After a trial run of ten issues the Board of Management of the News, it consists of a representative from each subscribing society, has taken a hard look and is contemplating a number of changes in style and content.
Msasa and Bare Ground: The msasa we know steals an undue amount of water and nutrients from the soil but these are possibly only some of the reasons for bare ground beneath these trees. Overgrazing and trampling by cattle could be a cause but there is usually insufficient grass to attract them. Watching such rain as there has been this year has become a habit, and it appeared to me that both msasa and mnondo have a greater proclivity than over trees for a fleeting interception of rainfall and then its release as maximum sized drops. It even seemed to me that the battering the ground receives during rain was far more severe under these trees than in the open, with the exception of those wind driven large sized drops which occur in some of our storms. In the latter case the battering under the trees would be a little less than in the open.
Battering by rain drops is a major cause of erosion and surface compaction of bare soil. Trees are reputed to give some protection but I am now convinced that this does not always apply. The surface compaction of the soil greatly reduces infiltration of rain. This and the thirsty msasa roots mean insufficient water for the grass which disappears. I have in the past seen extreme cases, which I then attributed solely to overgrazing and fire, where msasa trees were dying back and I am now wondering if drip compaction was not the subsequent major factor which was killing them.
Drought induced Vegetation Cycles: The above item on trees suffering from lack of moisture in spite of the better rainfall of the high veld leads me to some thoughts on the low veld. The trees of course differ in species habit and water demand. Overgrazing causes a big increase in bush and scrub which is accentuated by indiscriminate fires. However, again, infiltration is reduced and whereas before most or all of the water penetrated during the intense storms common in the drier areas, much of it now runs off and is lost. With less water going in and more bush to extract it the soil dries out to depth and as a result after a series of drought years the bushes scrub and trees die back or may even perish. Big thorn trees which grow along the stream channels are killed by having their bark stripped by starving elephant.
All this sounds terrible but it is one of Nature’s methods of resting the balance between grass and trees. Branches from the dead trees and shrubs fall off and litter the ground to provide shelter under which grass seeds are protected and can germinate when rain does come. The grass plants are given some protection from grazing by the branches and form a source of seed which spreads over the veld. Under natural conditions the game would have trekked out of the area and recovery would take place in about two years. In fact, there might even be more grass than immediately before the succession of drought years. Do not feel too sorry for the trees, even in death they perform a useful function. They do not all die and many of the shrubs, in particular those which are good browse, sprout from the ground.
In the past grass and browse, and grazing and browsing animals were in the balance. Drought cycles helped maintain that balance in the low veld. In fact, if scrub became too thick the droughts could induce a vegetation cycle. We are apt to forget the extent to which browse provided food. Eland stand on their hand legs and use their horns to reach, and with a twist, pull down into their mouths branches up to 12 feet from the ground. Giraffe and elephant can reach much higher. There are few plants which are not eaten by one or more species of game.
When Man introduces cattle and drives out the game he creates the problems of scrub re-growth and bush encroachment. Last May I was a member of a party which made a rapid tour through the low veld to see the reported recovery due to good rains of previously long overgrazed and now destocked areas. On one stretch of about 50 miles, we saw grass only along the water courses, cover on the rest consisted of worthless annual weeds and some patches of thorn scrub.
Birds as Weather Forecasters: Rain, or the lack of it appears to be the topic of this letter. This season has focused my attention on the behavior of birds prior to rain. Most of us know the call of the Jacobean Cuckoo, Clamator jacobinus. It is black with white markings and one of our largest birds, the other two Clamators are brownish, perhaps a little larger, and equally noisy before rain but less common.
When a really wet spell is imminent they forecast it with a striking call, commencing with long whistles “koo wip” which gradually becomes shorter and closer spaced until it becomes a succession of “koo..s” which also shorten until it ends as a rattle. The whole call lasts about 20 seconds. Up to several days before rain or if the rain is going to be light only the first few whistles are given or the whole call is very much abbreviated. The long call is repeated frequently at the beginning of rain if there are to be heavy storms over the next few days. This last forecast, which proved to be correct, did not please me when I was once bogged down by an unexpected downpour. It became pitch dark while we tried unsuccessfully to dig out the car but the bird continued its clamour from a branch a few feet above us far into the night. It was not popular.
Perhaps our best songster, and according to a BBC recording an equal “world first” is Heuglin’s Robin or White-browed Robin Chat. This bird is almost silent during dry spells and sings most before and during rain, so is a short term forecaster.
Several different kinds of birds which live in my garden are more inclined to take a bath towards the end of a dry spell, up to about a day before it rains. I have often noticed them congregate under the spray the day before light rain, particularly manikins, waxbills, white-eyes, weavers and bulbuls, but they do not do this if the dry spell is to continue. If the birds are not there I soak the ground, if they are, I give it a short watering and then move the spray which they follow round.
The following incident which I saw in mid-January was almost certainly caused by lack of rain and natural food. It was a gathering of around a hundred bulbuls which moved slowly eastwards flying in small numbers from one tree to the next. Since then bulbuls have been few in the vicinity. It is known they move in family parties to new feeding grounds but I have no information of them moving in flocks. If they had not been making a call I have not heard before and so not attracted my attention, I would not have noticed this migration.
Next outing 10th March 1000 hrs. Dr.Ritchken’s Arboretum, Umwinsidale.
Douglas Aylen, President
Tree Society of Rhodesia Newsletter April 1968
The Annual General Meeting will be held on May 13th at 1945 hrs at the Auditorium of the Queen Victoria Museum. The main business will be the New Constitution and a copy of the Committee’s proposals will be reaching you at about the same time as you receive this.
The old constitution of which you will also receive was very sketchy. The Committee has attempted to include all the best features of all the Constitutions of similar Societies. It is hoped that only minor alterations will be needed to most of it.
There are, however, two major changes. The first is the Society’s year, because the Committee has it is far more convenient to use the Calendar Year. This means that you will be paying a year’s subscription for nine months. It is a fact at present that we are offering our members more than their money’s worth i.e. Science News, a Newsletter and, on request a free copy of the South African Tree Journal. There are the costs of running the Arboretum and also paper, stamps and phone calls.
The present subscriptions do not cover all these. Next year bulk supplies of Science News may cost less, we might decide to make a part charge for the S. A. Journal, in which case, it would not be necessary to raise subscriptions in 1969. It appears that the Society is about to expand and a bigger income would help solve this problem. Finances were not considered when deciding to change the Society Year, but it does give time to find out how we are going and how to balance income and expenditure.
Perhaps the only contentious alteration is the major one of reducing the number of Office Holders. This is in line with all other Societies. I think the original reason for having a President, two vice Presidents, a Chairman and a Vice Chairman and a large Committee was to have a large number of persons on whom one could call to do jobs, form subcommittees etc. This has not worked. A few do all the work. You will see that it would be possible under the New Constitution to co-opt any person for a special purpose which means, in an extreme case, that a sub-committee for a special task might consist of Committee members as its chairman with persons recruited outside the Society.
There are eight or more major tasks on which the Committee is working or proposed to work, about which you will hear in the Chairman’s report. It appears that after many years the Society is now going places. These are the reasons why we must have a comprehensive Constitution.
It could take days to discuss the New Constitution, so to reduce queries and their discussion to a minimum would all members please inform in writing, by return of their disagreements, approval, queries etc, on it. If we can have them in good time to discuss at the prior Committee meeting and then to process them, a very great deal of time can be saved at the meeting.
Douglas Aylen President
Tree Society of Rhodesia Newsletter June 1968
Future Outings: It has been decided to alternate distant and near places and that as far as possible they will be held on the second Sunday of the month. The reason being that frequently something arises at an outing of general interest on which we would like to comment in our notes in Science News. Further it gives the scribe or scribes some time to prepare these Newsletters and the subsequent stenciling and duplication.
Our next outing will be to see some hundreds of acres of natural park land, mainly in the fork formed at the confluence of the Makabusi and the Chiraura, that is the area bounded by Hillside, the Hillside road to the Imperial Tobacco Company residences and Factory and Chadcombe, Queensdale and Wilmington Park. The Municipal nursery where the swans from Lisbon are being acclimatized is adjacent to the eastern corner of the area.
The public recreational areas of greater Salisbury amount to only one fifteenth of the recommended area for other countries, which of course, include Natural Parks of which Salisbury has none. The Society’s aim is to protect existing trees and woodland and to see that trees are established on the bare area downstream of the Municipal Market.
Dates, Times and Places : June 9th at 0930 hours at the old Dirt Track, signposted, from the railway crossing opposite the Rhodesville Police Station, Umtali Road. We will explore the natural woodland mainly by car to vantage points, returning to the Dirt Track for tea and a discussion.
July 7th. This will be the annual outing to Ewanrigg. The Aloes are earlier this year, or at least, irregular in flowering. No fixed time, but the earlier the better if you wish to see birds. Meet with the tea you bring just before 1100 hours on the lawn when we will give you details of a Nature Quiz Competition, all answers can be found at Ewanrigg.
THE OUTING TO THE LEMON FOREST: The May outing was a great success. In spite of the distance over 40 adults attended as well as some children, but no young people. It is a most interesting area and was made even more so as we had the privilege of being lead by Dr. W. J. Jacobson, Chief Geologist of Mangula Mine, which is only a few miles away. Dr. Jacobson has made a particular study of the effect of copper and other heavy metals on the vegetation, and the use of vegetation in prospecting for these minerals. He knows this area and its flora extremely well.
The Lemon Forest gets its name from the many large wild Mazoe rough skinned lemons growing in it. In fact many of us sucked one of the huge lemons as soon as we arrived. There are, of course, introduced, not truly indigenous, but by whom it is uncertain, perhaps by Indians, Arabs or the Portuguese. There are still some of these lemons around the Mazoe Dam and they were used from the beginning as a stock for grafting sweet oranges.
Dr. Jacobson explained that a bar of rock had, by holding back water, created a swamp on which existed this riverine type evergreen forest. The rock around and below the actual site is a dolomite which after pulverization by a fault thrust had been partially leached, dolomite is a calcium magnesium carbonate or magnesia lime stone and therefore soluble, and refilled with silica, quartz, and was not a “chert”, impure flint. Strangely shaped boulders around the site and on a nearby kopje reminded one of the quartzite of Chimanimani.
The Lemon Forest which covers an area of 80 acres is one of the “relic” forests of Rhodesia and contains trees which a long time ago migrated from both the North and the South. Chirinda is another, and in other places which are favourable a single species or a few species may be found isolated by a great distance from other of the same species. This is strong evidence that during a pluvial period and before the erosion of the Zambezi Valley and the Limpopo created arid barriers there was a continuous link of conditions favourable to trees which require perennial moisture.
Evidence of a past link between our Eastern Border Mountains and the northern end of the Great Dyke will be seen on our August outing. The Raphia palms demonstrate a past link with countries northward of the Zambezi. A very much older link is that of the mountains along the length of the eastern edge of Africa, namely the mountains Kenya, Kilimanjaro, M’lange, Inyangani, Chimanimani and the Drakensburg. In this case the time has been adequate for the evolution of new species.
In all we spent about three hours wandering through the Lemon Forest listing the trees present and admiring particularly specimens. We saw one Acacia galpinii which had a butt over six feet across but it soon branched, and another with a high bole of over four feet across and which was perhaps over 100 feet high. There were many Khaya nyasica between 70 and 80 feet and Trichilia emetica from 50 to 60 feet high and several Albizia zimmermannii of the same size.
The best of the Khaya nyasica were killed a few years ago by, it is thought, flooding, though a few show signs of fire damage. Most must have been near the 150 feet mark. Bauhinia petersiana was more than a scandent large shrub, in fact one specimen had reached about 40 feet up an Acacia galpinii and another had gone out to the end of a very long branch of another Acacia galpinii. On our walk we searched for ripe fruits of Carissa edulis. There were many large bushes but the monkeys had been there before us and it was difficult to find a fruit ripe enough to eat.
Other trees seen above normal size were the Cap fig, Ficus capensis which was strangling a sausage tree, Kigelia pinnata and a Strychnos stuhlmanii with marble sized fruit which with the support of a large tree had reached the top. Some of the trees, unusual or rare in our area were Euclia schimperi, Adina microcephela, Maesa lanceolata, Croton gratissimus, Diospyros sinensis, a Clerodendrum species and a shrub, Synadenium kirkii, and the climber Dregea abyssinica. There was one baobab, Adansonia digitata.
We lunched in the shade of some huge Celtis africana and after the usual chat a party of us scrambled a kopje of the same “chert”. The rocks had separated in vertical fissures and the hard way would have been in places good practice for a climber, we took the relatively easy way. In one place a small hole was seen to widen into a well lit chamber some 50 feet down. Here we saw growing in small cracks on the solid rock a most beautiful Aloe. None of us knew the name. It had long narrow recurved leaves with a U cross section and of a purplish brown tint. The flowers were in a tall slender panicle and their colour was sealing wax red.
On this kopje we found Gyrocarpus americanus a Ficus ingens with a bole 9 feet in diameter and a spread of over 200 feet, Ficus pretoriae, a very large Kirkia acuminata and some more huge Albizia zimermannii. Also Sterculia quinqueloba and S.africana, Commiphora africana and C. marlothii and more big specimens of some of the trees already noted. On the summit were Schrebera tricolada and Markhamia acuminata. Ficus sycamorus was noted several times along the road.
Other trees seen in the area of the outing were Acacia goetzei, Acacia campylacantha, Cassia abbreviata, Cassia singueana, Dalbergia melanoxylon, Diospyros mespiliformis, Diospyros lycioides, Dichrostachys cinerea, Euclea divinorum, Euphorbia ingens, Ficus capensis, Flacourtia indica, Grewia flavescens, Grewia monticola, Lippia javanica, Lonchocarpus capassa, Maytenus senegalensis, Piliostigma thonningii, Phoenix reclinata, Popowia obovata, Rauvolfia caffra, Securinega virosa, Syzygium cordatum, Syzygium guineense, Ximenia caffra and Ziziphus mucronata. Some of us not only admired the flowers and fruit of Pterolobium stellatum but also encountered it!!
A NOTE BY DOUGLAS AYLEN ON ‘PLANTS AS INDICATORS OF METALS’
It was fortuitous that we had an opportunity of discussing with Dr. Jacobson the effect of heavy metals on vegetation as there was an article on this subject by Professor Wild in the May issue of Rhodesia Science News.
I received much help from Professor Wild when some years ago I studied the growth of plants on mine dumps. At first a puzzling phenomenon was the occurrence of the apparently most unlikely plants. This lead to a more general study of the tolerance of plants to an extremely adverse condition.
It became apparent that a number of plants can tolerate any one of a number of adverse conditions such as mineral toxicity, brack swamp, anaerobic soil, absence of plant nutrients or aridity provided other conditions are favourable to growth. Alternatively they might tolerate two or even three slightly adverse conditions.
The range of these tolerances varies from plant to plant, but under a certain combination of favourable and unfavourable conditions a certain group or association of plants could be expected to be present. However, the presence of a lesser number of plants in such an association could indicate quite different conditions. For example, two reliable indicators of copper, Becium homblei and Vellosia esquizoides, were found together on sterile sand deficient in copper.
For this reason prospectors lost faith in Geo-Botany. This would have been avoided if account had been taken of all conditions on the site and associations rather than single species had been used.
Generally the only item required to obtain a growth of plants on mine slime dumps is a mulch of vegetable matter. Introduced weeds and trees such as Toona, Jacaranda, Melia, swamp grasses such as cotton grass, also plants and trees thought to have been introduced long ago also then became established naturally. In one case pumpkin seed from compound refuse made the pioneer cover.
The problem on mine sand dumps is usually wind erosion. If not present or controlled the sequence can be couch grass to thatching grass.
Douglas Aylen, President
Tree Society of Rhodesia Newsletter August 1968
Though the date was chosen last year, the visit on the 11th August to the Raphia Palms comes at a very appropriate time. Firstly, as a result of the campaign to preserve an indigenous woodland within Salisbury, attention has been directed to the need to preserve representative samples of each plant association as well as areas where rare plants exit, perhaps hang on precariously. Secondly, there is the series of excellent articles on palms by Dr. Joseph Ritchken in the Rhodesia Science News. Thirdly, at its recent conference the Southern African Regional Committee for Conservation and Utilization of the Soil recommended that member countries should set aside “Witness Areas”, that is places where undisturbed plants could be a scientific witness for all time of the original vegetation type. The scientific information that these can provide ranges from the chromosomes of plants which may be lost to the genesis of the soil which is the primary reason for the interest of SARCCUS, but that body’s interest is also wide. For example, many years ago it promoted the planting of trees alongside main roads. Fourthly, thanks to the initiative of Rudyard Boulton a number of interested people were able to have dinner at Atlantica with Dr. E. B. Worthington, Scientific Director of the International Biological Programme, when he stopped here for a meeting with the Rhodesia I.B.P. Committee when on a flight from East Africa to the Republic.
The objects of I.B.P. might be described as the study of the future relationships of Man and the natural environment, or Ecology in the broadest sense or even the continued existence of Man. Conservation when defined as the development and use of natural resources so that they provided the maximum benefits for all people for all time would also cover the objects. Benefits meaning food utilities and amenities.
Nature Reservations provide both the means of obtaining scientific information which, contrary to much public opinion, if of practical value, immediately or ultimately and amenities such as the popular conception of Natural Parks. Both purposes may be present but to a varying degree. The meeting with Dr. Worthington attempted to sum up the position in Rhodesia and decided the country as regards preservation of our heritage of Flora and Fauna is comparatively progressive with a rich potential.
Our National Parks and Forest Reserves are large and include samples of all but a few plant associations and a fair representation of the associated wildlife. The Natural Resources Act provides for the declaration of Protected Areas in which it is then an offence to destroy, cut or remove any of the vegetation but there are no means for fencing or supervision. Two such areas will be visited on the trip to the Palms. Wild life can be protected by the Game Preservation Act and in areas declared there is then enough policing to minimize poaching.
However, the present concern is preservation of examples of all types of vegetation and maintenance of an ecological balance within the samples. The first exercise is to find adequate samples. As already conveyed samples of many perhaps most, already are within National Parks and Forest Reservations. Information would be welcomed on plant associations or rare plants which it is believed are adequately represented within areas where already there is good protection. The next exercise is the selection of the best sites not so covered.
As regards trees we are lucky. For example, in South Africa less than 1% of the country is now covered by natural forest. Members may have heard the radio discussions on the Addo Forest and its elephants which leads to a thought on Chirinda. Many years ago when I first visited Mt. Selinda Forest, as it was then called, my companion shocked me at first by stating that the Forest needed a herd of elephant through it. He explained that the underbush was choking the trees and preventing regeneration. This poses the questions, was there once a herd of forest elephant and what effect did they have on the vegetation and thus on the Fauna. The answers might provide the clue to the management of Addo.
This comparatively simple problem is quoted to illustrate the value of international co-operation. The far greater problems of how to increase food production sufficiently to prevent worldwide starvation remain largely unsolved. A million pounds can be spent cheerfully on experiments to find a better synthetic fibre but little is spent on “academic” research on plants. Actually we can only guess at what clues rare plants and associations might provide. In physics chemistry and mathematics for example there is tremendous research into the unknown for new knowledge with, at the time, little idea of the future use and value of the findings. There is a possible need for such research into biology.
Dichlorodiphenyltrichloroethane (DDT) was first synthesized in 1874. Notes on its poisonous properties to insects did not attract attention until 1939 and then DDT became our secret weapon to destroy the vectors of typhus and malaria. Ten years later it was coming under suspicion as the cause of death of certain animals but it was another 15 years before the process was revealed that the minutest traces could be collected by one organism and subsequently reconcentrated in successive stages e.g. algae micro-crustaceans, small fish, larger fish, fish eating birds. In 1956 a case was reported that spraying trees in summer with .25lb per acre of DDT resulted in the death six months later of trout. Recently it has been shown that birds are poisoned by the cycle DDT on tree leaves, leaf mould, fungi, insects, and birds. After nearly 100 years of biological research into the accumulative effects of DDT is either inadequate or not adequately publicized.
There is a great need for basic biological research but just what is the gap when even a horrific item such as DDT is minimized somewhere along the line.
The Raphia Palms: The palms are an outlying relic which was isolated when the Zambezi Valley was formed. It is probable that they were widespread in Rhodesia before the depressions created during the ice-age were drained hundreds of millions of years later by destruction of the greater part of the original plateau. The distribution of a great many other plants support the contention of the ancient continuity of plateau and climate.
It would appear that Raphia ruffia requires swampy conditions perhaps slightly alkaline, freedom from frost and a somewhat more humid climate than is the rule in Rhodesia. Elsewhere they form a fringe forest around swamps or along swampy river banks.
In Rhodesia they are found mainly around springs along the east side of the northern end of the Great Dyke and in the gap north of Penrose Farm, between the end of the Dyke and a subsidiary Dyke. Geological questions will be answered at the Outing. There are some specimens along streams below the springs and a few along streams to the west of Nyarasuswe Peak, N.W. corner of Penrose. It is my experience that these areas are rather prone to early morning mist.
The most concentrated area of palms and which is the main object of the Outing, gives the name “Palm Block” to the farming area.
At the time of my first visit the suitability of the area for farming was being investigated. It took some time to set in motion measures for the protection of the palms and when I next visited to erect temporary protection notices I found that a miner had commenced building a house in it. In fact he was about to put in the window frames.
However, the area already had value protection and his potential home was several miles away from his workings and the site had not been registered with the Mining Commissioner. I won the race to erect notices and get a Reserved, against mining, Area proclaimed.
I next met the Lands Department surveyor who excised some 40 acres from the prospective farms and on a later visit the professional surveyor who was mapping the farms. With his assistance plates were erected at the permanent survey beacons. The Muware Protected Area was now a reality and the farmer whose land adjoins, Mr. P. W. Atkinson, in due course, agreed to be the Honorary Warden.
The leaf stem, rachis, of Raphia ruffia is extremely strong and very light and it is possible to obtain a pole of from 20 to 30 feet for use as a rafter or the side of a ladder. On one trip I measured leaves of over 55 feet. The dead rachis make very good fuel but owing to its fibrous nature is best cut by a bush saw. The gardener’s tying material raffia, comes from this source but from countries where the palm is common.
At first there was some confusion as to the vernacular name of the palm which is Muwari, plural Miwari. A roof pole is mwari. God is Mwari and a nearby hill is called M’wari.
Like many palms growth is very slow at first. In this case they probably do not commence to make a bole for 10 to 20 years. It is then comparatively rapid until the bole is 15 to 25 feet high or in exceptional specimens up to 35 feet. It then flowers and fruits once and then dies. The leaves are more or less erect so that the total height of a good specimen is 75 feet plus. The inflorescence is produced near the growing point and the fruits which are rather like Nills bombs with a military leather colour and polish hang in a tight cluster from a stout stem.
On my first visit I attempted, or at least, had the intention for a time to collect an intact cluster of fruits. The climb up the bole was difficult as though the bases of the leaf stems remain attached they become rotten. It meant stripping off muddy pieces to get finger holds and kicking toe holds. I was removing spines from the bases of leaves when it became apparent I had entered the habitat of small hornets. I descended slowly without attracting their attention. It is more than possible the hornets are the pollinating agents.
My friend and I then attempted to cut through the stem of the fruits with shots from a .22 and my automatic pistol but even when literally only threads remained we could not break it off using a trimmed rachis as a long lever. Then an African appeared, took the pole from us and inserted the top end in the bunch of fruit and, standing immediately below, gave an upward heave. The hard fruit showered down, some bouncing off his head, but this did not deter him from continuing until we had collected a sack full. He must have received a dozen blows on top of his head. Incidentally the sack was too heavy for the three of us to carry and so had to be decanted into smaller loads.
Please arrange to give lifts to guests.
Douglas Aylen, President
Tree Society of Rhodesia Newsletter September 1968
I have little need to write this month as Tony Tanser has very kindly supplied some notes on the history of Cleveland Dam and the Reservation, while Trevor Gordon has written up the list of trees that will be seen in the area to be visited on 15th September.
We will meet at the car park near the dam wall at 1000 hours and then proceed by car about half a mile along a track which runs behind the Supervisor’s House, taking two right turns. This takes us to the woodland on the other side of the fence to the picnic area.
Eric Edwards invited me to take part in a discussion on trees on TV on the 26th August, and I took the opportunity to give some views on the Makabusi. I have also accepted an invitation to serve on the Salisbury City Tree Planting Advisory Panel. It is consulted not only on planting but also pruning and removal of trees. You may be assured that the protection of indigenous trees will not be overlooked.
I find that even the most casual acquaintances are taking more interest in trees. Members can give more help than perhaps is realized by ‘talking trees’ at every opportunity.
Douglas Aylen, President
SOME NOTES ON CLEVELAND DAM supplied by Mr. G. H. Tanser
Salisbury is where it is because of the Makabusi. The river was described as a strongly flowing stream with wide pools on September 11th 1880, the end of the dry season. Its headwaters were protected in that they were not surveyed as farms but remained the property of the B.S.A. Company.
In March 1881 a Makabusi pool was sufficiently large for the first aquatic sports to be held. A bottle of whisky at the bottom was the first prize for diving. Within a year erosion of banks had started and the river began to silt up. The water became undrinkable but was used for washing clothes.
The Sanitary Board leased plots at Hillside for the first laundry. The headwaters became a shooting preserve for the Administrator and his friends as wild duck and snipe were plentiful.
In 1900 a scheme for a dam on the Makabusi was proposed, the cost was £65,000 but it met with much opposition and was abandoned. Two years later the new Town Engineer recommended the installation of three windmills with 50 feet diameter sails to pump water from the Makabusi. But this scheme was also turned down.
In 1904 it was reported that an outbreak of enteric fever was due to the use of surface water and that the source of supply was a grave danger to the community.
In 1907 the townsfolk insisted on a swimming bath. The old bathing pool on the Makabusi was cleaned out and screened off with a reed fence. Trees were to be planted at the approach of the rainy season. The opening of the pool was soon followed by complaints of bilharzias. The M.O.H. conjectured the disease entered bodies while bathing and parents were warned against boys bathing. The first civic ‘swimming bath’ failed as an amenity.
In 1909 the MOH again fulminated against the water supply describing it as wholly inadequate, faulty and dangerous, but it was not until 1911 that the BSA Company decided to take action by offering 4000 acres of the Government Reserve to the Municipality as the catchment reservation for the Makabusi in which to construct a dam. A rubble masonry dam, to hold back 100 million gallons of water was proposed.
The Cleveland Dam, named after Councillor M. E. Cleveland, who had been Mayor during the discussions, was opened on May 24th 1913 when the water which was pumped to the first reservoirs at Harman Hill was turned on.
The provision of water led to improvements in gardens and to wide scale tree planting. The streets were watered to abate the dust nuisance.
A swimming bath was now possible and it was opened by the new Administrator Mr. Drummond Chaplin on January 30th 1915.
Despite the Cleveland Dam there were still water shortages. In 1916 the bath was closed and boreholes had to be sunk to increase the supply of water.
The years following were not so difficult though often restrictions had to be placed on supply. In 1922 it was decided to raise the dam wall by three feet. This was done but the next year on Friday July 9th the dam burst. The surging waters washed away the railway, filled the pools and in places changed the course of the stream. However, the wall was soon repaired.
As it was evident that water controlled the development of the town a private bill was passed to obtain water from the Hunyani River.
Cleveland Dam can store 200 000000 gallons of water. The purification plant which is situated just by the dam wall can deal with 750 000 gallons daily. The water is still used, being pumped to supply chiefly Donnybrook and Mabvuka townships though it also can be fed back into the main city reticulation system.
The Catchment Reservation of about six square miles is a bird and animal sanctuary and its waters are reserved by an angling society.
Tree Society of Rhodesia Newsletter November 1968
NEXT OUTINGS: Arboretum 17th November; Scout Park 15th December
It was just not possible to produce a Newsletter for October. Science News also ran into difficulties and came out a month after the ideal date. We know that both are valued by our country members. They are our means of communication with all members, and thus important.
The list of trees at the Arboretum is included as we have an Outing there on 17th November. It is hoped a good gang will turn up early in the morning with bush saws and pangas. Work will consist of cutting out Msasa scrub and some pruning. When it gets hot, or if it rains, there will be a discussion on the verandah of the hut. The hill slope becomes shaded soon after lunchtime and there will then be conducted tours.
The Department of National Parks is considering the need to develop the Lake Frontage from the Arboretum to the entrance to the Game Reserve. Recently during weekdays twelve cars on the average have parked along this frontage, and many more during the weekend, thus demonstrating the need here for a public convenience and other amenities. We considered this eventuality long ago, and so did Parks, however the “comfort station” had to be linked to the then only available water supply. Now a borehole is to be sunk near the Game Park entrance and when funds permit a convenience will be built about 200 yards in the direction of the Arboretum.
There will be, in due course, stand pipes delivering safe drinking water, permanent fire places etc. In fact a picnic area and parking area will be made between the Arboretum turn off and the Game Park Gate. This area is bare of trees and a considerable number must be planted to make it suitable for the purpose.
The triangle on the Arboretum side of this frontage, which is actually regarded as part of the Arboretum, still has only a few trees on it. It came last in our plans and has suffered from fires and, this year, frost. It is hoped that it can be planted fairly thickly with trees, in clumps mainly.
The weeping willow, Salix babylonica, has proved a failure, but the indigenous willow, Salix subserrata, has proved itself along the high water mark. Also self established are Acacia sieberiana and Acacia karroo. The wild date palm is quite resistant to frost though slow to make a bole, but when small it does possess defensive spines. Most high veld riverine and vlei trees are resistant to frost and can withstand seasonal extremes in water level. Could a dozen or more members each raise a score or more trees? Suggestions as to suitable species and supplies of seed would be welcome.
The Outing to the Scout Park on the 15th December completes a series of visits to places which have been afforded some protection. Thinking back, each place visited this year, and a number visited in previous years, has been afforded protection. The extent has been varied, and sometimes considerable damage occurred before the area was protected and occasionally whilst it has been protected. I will write on this matter of protection in the next Newsletter, but meanwhile readers might think over the problems involved, which are that in Nature, there is always change and it is quite impossible to achieve anything near perfect protection.
The 21st October we had a most interesting film show. In the three films there were many shots of extreme beauty and a great deal of information. It was a pity that the Shell Cinema was only two thirds full, due without doubt, to the breakdown in communications.
In one film it is stated that a glorious scene at Kirstenbosch was a few years ago a gulley. In Cape Town itself the formal gardens and modern buildings enhanced, set off, each other. What a contrast to Cecil Square and the impending concrete jungle flats in Salisbury’s residential avenues, but above all the contrast between the Makabusi River and the “wild” gardens and natural parks along streams in many towns in South Africa and Bulawayo!
There is a steadily growing interest in the Makabusi woodlands, and requests for talks and written accounts have been received, thus giving opportunities for gaining further support. Even as I write a member of the public has phoned to report the destruction by a builder of a large tree on the edge of the future road servitude. Another has commented on the elimination of trees in the new high density housing scheme behind Haddon’s Service Station on Jameson Avenue East. Here the conditions are adverse for horticulture, the land is almost flat, the soil is a black to yellow clay and the area is prone to frost. One hopes the authorities will proffer advice on trees, lawns and plants which are tolerant of these conditions.
This is the best time of year for bird song, even the commoner shrikes make canary like noises or whistle, sun birds sing like an European robin, the waxbills twitter cheerfully, the red wing starlings chortle, and if you are lucky your garden will have the prima donnas of the birds, Heuglin’s robin, thrushes, warblers, tit warblers and some fly catchers. An ever increasing variety of riverine and thicket birds visit the well wooded gardens on the higher ground in Greendale and Highlands, even the raucous purple crested lourie is often heard, and sometimes the flash of its crimson wings is seen.
There is no reason why some of these birds should not move into other areas made attractive to them. The first requirement is lines of easy communication between groups of trees, trees with dense foliage and small thickets of bushes, and the second, that as many as possible of these should provide food, e.g. berries or nectar. Insects in their various stages will provide the entire food needs of many birds, and seedeaters feed their young on juicy caterpillars, even some sunbirds live almost entirely on moths when they are available.
The fate of School Cadets is in the balance. Scouting and guiding are to become more venturesome. Rhodesia is blessed with National Parks of all types. The opportunity is there. It remains for us and our sister societies to attain the interest of more teachers, guiders, scouters and parents so that they may pass on that interest, which once started is bound to grow naturally and then youth can be entrusted without qualm to increase steadily the scope of adventure in the veld and on the mountains.
Acquisition of powers of observation cannot be commenced too early. There is much to observe in the smallest garden, and it is an art which can be acquired only by practice. I would again stress that the responsibility for the introduction to this art is that of the parent of the toddler, and then the young man will regard veld lore not as sissy but as he man stuff.
After that appeal to parents I would appeal to leaders in youth organizations, only a few are already doing what is now proposed which is to join an amateur naturalist society or if they have not the time for long hikes in the wild to take part in a venturesome sport such as rock climbing or small sailing boat racing, anything which brings them into contact with untamed Nature.
The Need for Books on Trees
Trees have been named by Trevor Gordon and Bob Drummond in school grounds in Salisbury, and the Lomagundi District. There has been a long delay in making the labels, but now Conex has got the job well in hand. We are not certain who will see that they are affixed. Trees were also named by Trevor Gordon at Admiral’s Cabin and by me at the Caravan Club Site, both in McIlwaine Park. Trees have been listed on our Arboretum but there are still a few to add. It is proposed to print the list when completed. Personally I would like to see a descriptive list of all trees in McIlwaine Park, but even better to production of a book similar to “Trees of the Kruger Park”.
The draft of a National Tree List is being prepared by Rud Boulton. This has necessitated consultation with authorities here and in South Africa. This bald statement does not imply the great amount of work involved. Only now is the confusion due to duplication of names being cleared up and there is still some dispute as to the order of families. Reference for each tree must be given to the type specimen, and technical works in which it is described.
When completed the draft will be submitted to all local authorities as a basis for discussion, which will also include the selection of a system of numeration suitable for computer processing.
Bundu Books 1 & 2 are approaching the “out of print” stage and I have asked for comment, particularly on the tree section in Book 1, with little success. Should this section be reprinted, revised, rewritten or should a separate book or books on trees be produced? There is a great need for an elementary book on trees, but the publishers first require to know what would prove most popular and the expected sales. Alternatively should separate books on trees, flowers and grasses be produced by a consortium of government departments? Would members please sound their friends and report to me as a member of the Bundu Book Committee.
The Societies activities
Some of us with the help of Bob Drummond commenced an exercise in Greenwood Park, the original Botanic Garden, planted from 1921 to 1926 and then sadly neglected for many years. The original records have been found but they were badly prepared. Some painstaking work is now required to identify each surviving tree with a position often inaccurate on the plan and its date of planting. The information when completed will be passed to the Municipality with every hope that a name plate, which would include the above information, be placed by each outstanding tree. Greenwood Park presents proof that many indigenous trees even when neglected, have a growth rate as good as the exotics and are at least as beautiful.
All must be aware that I, in particular, am interested in the development of waste and idle land along the Makabusi River. In this I have had the support of the Committee and also of various other societies and bodies. Our Society has taken action on several occasions to halt the destruction of the trees there.
The history is that a year ago the Natural Resources Society revived this subject but finding that they lacked technical knowledge and past experience of the area asked me to proceed with enquiries and formulation of proposals. A scheme for the development of the area was submitted to the City Council in 1960 but interest goes back much further than that. A recent letter from the Town Clerk states “I have to inform you that the Council has considered the matters to which you referred and others, and has accepted them for future development, subject only to the availability of finance”. The correspondence also included the need to plant trees on the main approach routes and the western side of the Civic Area.
The position except for obvious long delay would appear satisfactory from our point of view. There is, however, one important feature which is most alarming, that is a proposal to develop as a residential site the glorious natural park bounded by Hillside, the railway line, the ITC Factory and the Makabusi. My long experience leads me to believe that so much of this land is unfit for residential sub division that it is uneconomic for that purpose. Compared to American and South African standards Salisbury is woefully short of open spaces, particularly of the “wild” or natural type.
I submit that this piece meal approach is wrong and that instead account should be taken of the overall need and the overall economic and sociological benefits and that blue prints should be produced for a Five-Year Plan. I strongly recommend that all interested people should have a look at the potential natural park, the riverine land along the Makabusi and the approaches to our City and then compare this with the work done, for example, in Bulawayo, Que Que, Gwelo and Umtali. The approaches to most of the towns give the impression they are thriving and progressive, but Salisbury’s bare, idle or wasted areas must act as a deterrent to prospective industrialists, investors and residents when they see this neglect.
I have been informed that Que Que will seek the advice of the Society on the development of their new 500 acre nature sanctuary. Melsetter is resuscitating its Arboretum and we have had considerable correspondence with the organizers. We congratulate them and wish them every success.
The National Botanic Garden at Alexander Park has made astonishing progress. Even the most casual visitor must admire this great achievement and the beauty of the whole site. The curator, Mr. Tom Muller, has brought near miracles. The Society was able to achieve some publicity and support for the Ritchken Fund for the Garden. However, the scheme of a “Tree for a Child” has met with very little response. The idea was passed over to the Society by a roundabout route and the Rhodesia Herald then gave it some good publicity.
Funds for this purpose that is the commemoration of the birth of a child by having a tree planted and nominated for him/her, can be contributed to the Botanic Garden Fund. For your advice I find that prospective grandmothers are most likely to be receptive of this project.
Our publicity has increased from next to nothing to what could be described as fair but still very far from the “desideratum”. I can say the ice has been broken and with the exception of Rhodesia Science News and a section of the Press we still have to take the plunge. Trevor Gordon has talked to Garden Clubs and schools in his area. I had the opportunity to talk on radio and TV. There have been talks to a few schools. Above all have been the services mentioned earlier provided by Rhodesia Science News, our only difficulty here is that the Newsletter and Notes to be topical have to be written as late as possible, which means a high pressure on whoever types them. Perhaps someone other than the Secretary would undertake this typing.
During the year there has been only one response to a general request for suitable items and one suggestion of a topic. Surely some members must come across useful snippets in out of the ordinary journals or in the garden or veld or have strong views.
We have not yet fully achieved the liaison, coordination and cooperation with other Societies which we hoped the ASSR would bring about.
The Arboretum has been rather neglected except for the sterling work of Col. Mike Kemp. Here I do suggest that the new Committee should consider appointing one of its members to co-opt a strong and active sub-committee. We have lost Doug Newmarsh to Ft. Victoria, that is their gain, and he has said he will attempt to start a branch there. Without his help the Arboretum could scarcely come into being. It is possible that Triangle and Melsetter would link up, perhaps with Umtali as well, to form a regional branch. We can trust Doug Newmarsh to start the most in Fort Victoria.
On the Arboretum itself, we were faced with a heavy bill for repairs, happily it was reduced to one for service and replacement of minor items.
It has been suggested that we run a competition in schools for the now needed new insignia. I think this is a good idea.
The New Constitution
A proper Constitution was long overdue and a careful compilation of all the best of the constitutions of kindred societies has been presented for your approval. It is more than possible that amendments will be required next year either to the item on annual subscription or that on charges for publications. The Constitution has been gone into so thoroughly by the committee and with extra help from Rud Boulton and Jack Reid, that I cannot foresee the possibility of any major alterations. I submit it should be given a trial as it stands and any mild controversies left over until next year.
It was a unanimous decision to reduce the number of top posts so bringing our Society into line with all the others and so to reduce the number who can attend committee meetings. I would suggest this be kept in mind when electing the committee. We believe that a sound and comprehensive constitution will encourage all classes of membership as well as donations and legacies. It is with confidence that we commend it to you.
The other resolution, on charges for publications, has been put on the Agenda in order to get your views and I would propose that when this has been done it should be recommended to the attention of the committee. A decision now would require reassessment if, as I expect, the bulk cost of Science News is reduced. This could be enough to subsidize the Journal.
Without the untiring help of our secretary, Mrs. Ewing and John Hill this year’s spate of typing and duplicating would not have been possible. I am sure you will all second a resolution of special thanks to them. I must thank the members of the committee for their hard work and patience without which little would have been possible.
We are most grateful to the Curator and the Museum authorities for allowing us to use the well appointed Board Room and this comfortable Auditorium.
Douglas Aylen, President.
Tree Society of Rhodesia Newsletter December 1968
Future outings : 27th January 1969 2000 hours : Museum, “Bees and flowering Trees”. Slide lecture by Miss P. Papadopoulo; 16th February, 1969. 1000 hours. Gilnockie, Arcturus.
Date not yet fixed for Annual General Meeting
THE OUTING TO THE ARBORETUM: A happy day for a small party. Did the suggestion of doing a little work frighten people? We climbed the hill and part way up another to see two uncommon figs, Ficus soldanella, the rock-splitter, a small specimen but with most beautiful leaves and in fruit and Ficus pretoriae, the ‘wonderboom’, a fairly large specimen.
Jack Reid, with help from Trevor Gordon and Mike Kemp repaired the spray on the birdbath, and a small gang Trevor brought extended “fringe pruning” along the road. Mrs. Kemp invited us to a sumptuous tea, which coincided with the only shower.
How many members noticed that the very common tree Combretum molle slipped out of the revised check list? Please add.
SALISBURY’S STREET TREES The Tree Planting and Preservation Panel is adamant that the so called ‘Hanging Tree’ must stay. As a result of some rain it is looking quite vigorous in spite of its presumed age.
The other day I photographed the grotesque shapes into which many trees have been reduced by over pruning. Before utterly condemning the pruning it might be as well to have a look at the other side of the problem. The early plantings of street trees, especially Toonas, Jacarandas and other over large trees, conflict with lighting, pipes and cables, road widening, parking and high buildings close to the verge. Sometimes the tarmac is damaged by roots and in places the trees proved to be too closely planted.
The mistake, which could not be foreseen, was not commencing to prune to size and shape 25 years ago. There was pruning, of course, but it could not have been designed to meet the present conditions. Today there is considerable knowledge on many suitable trees and they can be tailored to fit a situation provided it is known in advance. Future plans of streets and information on the type of buildings to be permitted should be provided to the tree planter.
Central Squares are a photogenic feature of most large towns. They may be an expanse of concrete with fountains and statues and hardly a tree, formal Latin American tree shaded plazas’ or an adventurous garden with a non geometrical plan of trees, lawns and flower beds, but they all have one thing in common, an overall design in which the buildings harmonize, and the square and the buildings each set off the other.
Bearing in mind these two paragraphs on trees in towns, now cast your mind onto the problems which face the tree planter, say, at Cecil Square, the Civic Centre and the area of large flats in the residential Avenues.
Trees for harsh conditions. A few self established and thriving Acacias of four indigenous species do suggest that they would be useful street trees on clay soils in areas subject to frost. Some of the other indigenous trees might also be tried. Rhus lancea has done well but its shape may not suit all situations.
Ruwa Scout Park. Plant protectionists have had to change the concept of protection. Plant protection is not one of the functions of Ruwa, it is a Scout camping site, but effort has been made to prevent damage, especially to trees. Nevertheless there have been considerable changes in the vegetation, and similar changes could take place in parks and sanctuaries to an extent which would impair their purpose, even nullify the object. It is believed that much of value on plant preservation and ecology could be found by a study of Ruwa.
On Outings and at Shows we have seen how efforts for the complete protection of an area, a community or a single species so far have not been wholly successful. Some will also have read articles on the subject or attended lectures. We will run over these points at Ruwa, there is not space to do so here, except to remind the reader that alteration has occurred in every place to which at sometime Man has had access.
It would appear that at one time the vegetation of what is now Ruwa Park was typical of granitic sand on the Highveld, dry woodland, riverine forest and vlei. Prior to acquisition about 40 years ago it must have suffered severely from primitive agriculture and woodcutting. Recently camping on an increased scale has resulted in compaction of the soil, the grass has become shorter, and the bushy vegetation less and also the vleis have become hard and dry. Msasa is increasing to the detriment of other trees.
Not only have these factors wrought changes in the plant life, but they have increased the intensity of frosts, causing further changes. A change of a different type is the invasion of bare areas by the common ‘naturalized’ weeds. The agricultural development of surrounding areas must also have had a big effect.
There should be much to discuss at this Outing. We have the use of a meeting room in case of rain. Tea will be provided. Bring a swimming costume.
Slide Show. 27th January. Flowering trees with a talk by the Government Apiarist, Miss P. Papadopoulo, on their value as a source of honey and on bees in general.
Annual General Meeting. Required: 1. Information on achievements for the Report of the Year. 2. Thought on Officers and members of the Committee.
At the last meeting of the ASSR Committee it was agreed it was desirable that a Society’s Notes and Letters should be written by a variety of persons, as in the Rhodesia Science News editorial, which I heartily endorse.
Douglas Aylen, President