ESTUDIO II COOPERATIVA DE CAFICULTORES CAFICAICEDONIA LTDA.

geographically East-West* The sites in each of the sub-groups have a number of additional species in common*

5a South-West*

(Sites 427, 429, 430,, 431, 433, 436, 467) Andrepogon plumosus, Euolea schimperiy Euolea sp* 2072* Grewia mollis,_{^^ini-|-ii i v i-in -.ru uUJ4.m*^—-i.4-4iiuPljul *i- hji u.im..m>i.i i.ni i n WImii'idw iih, .1» » * . » . i<irjirj»^i>ic#iii»iip¥*»it*. «*** <»«?> *}

iefegrantlllj idibioissus' erytlir.odes.i'' Toelea nobilie, Yernonia braohyoalyx.

3b, Southo . -

(Sites'404,-408, 411,' 413,; 413, 4X7) Buelea- latldans Euoloa sp * 8078 * ■ Grovifla^sImll Is ,' Lantana salvlfolia,

Polypodium phymatodes , Bhoieissue erythrbfles, Bit chela

duohesnei, Scut la: rnyrf Ina* ■

3c South Bast ♦ • '

(Sites 458, 460., 468, 464). Qrewla. mollis, Bhoiclasus orythrodes*

34 East.

(Sitos 438 , 440 , 448 , 444 , 446 , 448 , 450) Hiiolea latldahs, Qrewla. slmilis, Hippo or at ©a- afrloana, Bit oho la

duohesnel, R* macroearpa, Becamcne platystigo.a, Toolea nobillaAII T»' tricliooarpa* Yernonia brachycalyx, Msiphus puhescens*

Those thickets occur on anthills and irAn soils* The anthill soils are similar in colour and texture-to the

surrounding soils, are deep, well aerated and drained, mostly crumb-*structured and friable though some valley anthills have larger aggregates* Organic- matter and rooting, are abundant

in the topsoil and are apparent at some depth. The analyses

of these soils (Appendix B) show topsoil pH-of between 5*34 and 7*8, subsbils from -4*8 to 8*1;' bases-* phosphate, carbon and nitrogen are abundant or adequate* The mean values for bases., carbon, and nitrogen are lower for the soils associated

overlap of the bond It Ions, of these two; subgroups... . (.Subgroups >;

So and Sd-were not sampled for analysis)* ;

Bites ’4:27, 430 and 451 of group 3a have -adequate bases,

carbon and nitrogen but deficient phosphate* The remaining

sites of group; Sa and group '5b -have--abundant', bases ? carbon

and nitrogen.and adequate or abundant phosphate. Acacia

heb e o I ad o id e s was' recorded from, sites 487. and 451 only ~

two of the T?less fertile** anthills'5 while the following {!

species: were recorded, from* two op more of. the' Tmore; fertile1*

ahthillss. Acacia eampylacantha. Acacia seyal var» •1YJ.--r r i T . - t- - r — ...T ■ irit|W■ ri ji ji^ H n y n n m m nun i/ip nr'n itfn irg 7 <w ^^w >»,r^mi>miiiium)| mi f w* ^ •.***■-uwi i Wm — iwjijii o m multi mJuga,& m r

Acacia sp*, Acalypha bipartita, Albissgia malacQphylla a

irt -n r.rt.^'i^rrrrrn :'.T-U-inrr.r.rt.t.Tir - ." Timfrii m iw>ii»*up -*>ni.yinflHfri .’rrr > ~ Ymy wirnT *•*<?»***+*■*/•#*»/{* '>»ti'»*■-'***’ *

Alchornea corAlfOllaV- Antidesiaa meioc’arpum. Asparagus paulls

m . T.irr/t- ~ t — i r~ T ir n n n " '-:,)“ ' ~rnnrnr: iirL-.i~n.rni i-r r rr “ ,t .t t t ~ t '“i— r T f ‘ t * * w»w>w*i nn' w hitM*# !*1» ik•! Ni* ■ * m

jguilelmii,. M ’iSrim.'7rr: n i r i :r n r a ir~r". rr n r * - " i r r v - ^ j - ; . — nvrn.nir-.nn i n r r W i y m i ^ W r T 'T I r [ ganomuiti. sp. ,-r“y— rftt. A ., Braohiarla ■y i,TTfn'iT“ : : i- r r r t r T - t~i'.‘T lr ‘Li i — br izanth'a, Bridella... ... f ********

br id e 1 ilfo 1 ia 9 Oapparla * aoutissima-, Olausena ©xiisata, Oombretum^

r r ^ _ T ^ TIT|ir.|r~ r . -irr7 r n -ii...i .[jnilii.iiiim ;i nr T r .iju f i * < phhii ******** j . r r r t m r r i j-rr-TT itn -.itri * r iiiH rtTiir,» ~ r r iir^ ~ in ~ -i-r ,'" r ^ - ‘Jr T j - r n r r - ' — r ; " r ;n “ ‘ i r ir r +

binderanmu, Pommeling afrlcana,, Domboya rotundifolla - Pucloa

latldans.,- Glorloba simplex* Prewitt .& Imlltel-• Lant'ana ..^alvifolia^H Moriscus mc.er , Opilia coltldifolia, Panioum maximum.

Piliostigma thonhihgil,•; Bitcheia1 duchesnel , - ¥anguorla . y; acutHob a , W. aplcnlaf a/ anci Poly-podium phyiaatodes* Pew of

these,- however* ' ooOufc7oh more' thesis5 out*: of the 0 -tsmora fertile! anthills. nevertheless, this list indicates a connection

between nutrlet.it -status and-the species lists of the thickets :ti; of. sub-groups 3a and 3b*

Tlio' VA! soils .associated with- the northern Ttrergre.en %

Thicket (:&roup B) are'more, aoid and have, less carbon and . •-

sites 543, 545 and 346* All these sites and site 415 have acute phosphate deficiency*

The northern Evergreen Thickets also differ in their overhead climate * They are located in an area which receives less rainfall per annum, which is less humid throughout the year, and has a longer and more intense dry season* On the other hand they occur oh the first full-height hills south of the Lake Kioga-Biver Nile water expanse which probably

receives a higher rainfall than the surrounding lands* La addition there are the observed daily morning mists which persist until about 9 a*m*

Furthermore, the Northern Evergreen Thickets are of large extent and are protected from fire at their edges by occurrences of shallow soils .and ironstone pavements*

These peculiarities of soils, climate, and burning account‘for the individuality of the Mort&ern Evergreen Thickets* More accurate information on the climate and additional sampling of the soils and vegetation would be required for a detailed analysis of the interrelationships

of these communities*

The main division of the Southern Evergreen Thickets is geographical* Certain species, however, are restricted to anthills in valleys whilst others oocur only on anthills away from valleys* (Species which occur on one site only have not been considered)*

Species restricted to valley anthills: Acacia.

oampylaeautha. A*- lie'beolMoitles, Acacia aft1., Brldella W III n! r J * UN*l* WI >1 Ulil ii I *4 * \ _ # ,, „ - „ , , , , t , t m

eoXerbneuroides * / Gomkellha: afficana, Bombeya • rotundifolla,

Grewla ■ mo Ills ■ (mostly valley)-, Marl a c u b mao ex** Bboeniy - - h;

reolinata (recorded from 1 site ■but • widely observed),

PiliostiCTa thonnih&ii* 3feiphus- •abyssinica, Z* mauritlana*

iifci.HiMMr M *******.'1**!!*1*.* * W m1ttlrtniiii>iimin)>inw»i»M -it « n in i~ ■ n r • ~ ~iiii'n rtnm np , 11- ,i ' <»>p<il>>l<|<>wt>WW»Wfc|W* u h*. x*Mu * m iwi hm j * W > . i *i «*ti <*■». n » 1111. >*>» i»ii i>» 111 mum* »i,h *

Species restricted to bill ant bills: M ramomum ~ sp* A *,

Bersama •abyss inloa, Br id.e 1 la,; br id el Ilf o 1 ia-, Gapparls rothii* .....;; Ficus ■ oaponsis; Haploooelum fo 1 iolosum; ■ Xpomoea grant 11 (mostly.,-... ; non-valley), Opilia celtidifolla, Phyllanthus disco idous'*,

Tlmxea aethiopica, Vltex-fisoberl.

• '■ The only,'-other differences between valley and bill w anthill sitee‘rire.; bbe seasonal -waterlogging of. the surrounding Valley soils compared with well drained soils -round bill

anthills, the siae.of the thickets and the intensity of burning-'" There-are no- signlfleant 'differences- in the base , phosphate,

carbon or .nitrogen- content of their soils-, and their pH ranges ■ , are almost identical. Textures and structures are:.similar,

though some-valley anthills-have-larger aggregates - nuts ■ and clods ** in the lower layers* • Drainage and- aeration are’ generally good t but one profile taken from near the edge of a

valley anthill (site 404) does show impeded drainage at a depth =•'•

of 86 inches. -h

■ *■ The valley anthills are surrounded by seasonally water: * logged, soils yet are themselves well-drained . We are therefore faced with the question of how- they are drained*

One possibility is that they are well-drained by virtue

of ■increased evapo-transpiration.from better..structured5 soils

and the different vegetation type* This , o.ould be coupled, with

improved drainage due to their microrelief * •• * •

(a) - gravity drainage - partly away from anthill*

( b ) m increased evapotranspirat ion *

i.However, this does not'account for the absence of water: slogging in anthills at some depth below the level of the

surroundihg' water-table, or the moisthess' of anthill soils in

ry season*'

A number, of valleys were observed = to have a layer of coarse sand beneath their clayey- subsoils:

fh &*15

Toe&o\i_ 0-2. P Fine

strrtby L

A

A(

SuBSolL Ft^e- £*rr<C>y CuAy

ton n,\r t — ) 2.

SA^S Z> •

Himerous. attempts ‘wore .made to bore-through anthills to . see. if they drained into this 'layer* The earliest of them; were unsuccessful. owing- -to .the depth of soil, over: the sandy layer-

starting a boring 'at' the bottom of a pit dug ih an anthill-

(Bite 460) * The sand' layer was reached bet ween 10 and XX feet

below the level of the'surfbunding valley after boring through a well-drained sandy clay loam*

Fig*14

• Woody species' are- absent "'from the more severely waters logged valleys (see group 11)* The hill thickets cover a number of anthills and the intervening ?S'A'9 soil* oh the other hand,, the valley•thickets are•restricted to single anthills* This difference is due to the waterlogging of the intervening valley soils*

There are two main reasons why the effects of burning are greater on valley thickets'than hill thickets and both are due to the waterlogging of. valley soils* First, the valley thickets are restricted to the area of well drained soil and s<

are more subject-to fire as their' area/edge ratios are less than those of the larger hill thickets* Second, the valley thickets are unable to fluctuate to an$ffro’*r'

The species restricted to valley anthills in the-south include Brldelia scleroneuroides, Grewla mollis, Zlsiphus

Northern*-.Declduotts. Thibket*. • The following.- species^ restricted to hill anthills, in -the south were found in the. Hortho3.n1

Evergreen Thicket.: Bridella brl&elilfolleu Crrewia -bIbxIIIs., and lilaploooelnm ,f o1iplosuffi*

The restriction of thickets to anthills in valleys Is due

in. part at least, to the-waterlogging of the surrounding soils However., the phenomenon is hot :. limited,-.:: to the- valleys;

thickets are also•concentrated about anthills .surrounded by well drained soils on hillsides and hilltops* Differences between the chemical and physical conditions of the soils of

anthills , and the .surrounding land. may •be ■.critical*

The analyses of each layer of the 11 anthill profiles sampled (sites’. 404, 400,/-411, 445., 41?-, 427, 429, 430, 431, 453, 456.) show more 0,11, Ca, Mg and K than the gorross

:ponding layers of the surrounding soils {sites 405, 407,.410, 412, 416, 426 j 425, 424., 428, 432, 455), with the following exceptions; .

404 has less •!% than- 405 in. the subsoil*. 408 has lose G than 407 .in the topsoil*

... 427' has les& }?g0g *. Oa than. 426 in the td.paoll* 4137 has loss ,0a*• .1C, than .426 in the subsoil* 436 has loss -Mg than 430 in the subsoil*.

... Also the anthill/soils .have .greater -porosity and better developed crumb structures* However,, thickets are not