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Impact of livestock grazing on forest structure, plant species composition and biomass in Southwestern Madagascar


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Background and aims – To contribute towards a better understanding of habitat utilization by livestock and its impact on biodiversity components in the dry ecosystems of Madagascar. Location – Southwestern Madagascar, in and around Tsimanampesotsa National Park. Methods – We quantified species composition, life forms, structure, and plant biomass of different vegetation formations in areas of four different grazing intensities: (1) ungrazed for four years prior to the study, (2) grazed by zebu during the dry season, (3) grazed by zebu at the end of wet season and during the dry season, and (4) grazed by goats during the wet and the dry season and by zebu at the beginning of the dry season. The food biomass available was compared with the food biomass required. Key results – Zebu feed on the east side of the National Park during the wet season as long as there is enough water in that area. When water becomes scarce, the zebus return to the western side of the park. Goats are restricted to the littoral zone year-round. As a result, goats and zebus occupy different proportions of the various vegetation types of our study area. Zebus also use the littoral forest, but only at the end of wet and during the dry season. Large parts of the spiny bush on the limestone massif and dry forest on ferruginous soil are not used regularly by zebu. Plant species richness and diversity varied in relation to grazing pressure and soil conditions. In the littoral and on red sand, plant diversity decreased with grazing pressure. This change was most pronounced in the littoral zone. Since grazing pressure increases during the dry season, grazing affects mostly woody species, since herbs are no longer available during the dry season. In contrast to the bush encroachment due to grazing in Africa, grazed areas in southwestern Madagascar contain fewer woody plant species than areas not used by livestock.
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Scripta Botanica Belgica 50: 82–92, 2013
African Plant Diversity, Systematics and Sustainable Development –
Proceedings of the XIXth AETFAT Congress, held at Antananarivo, Madagascar, 26–30 April 2010.
Natacha Beau, Steven Dessein and Elmar Robbrecht (eds)
Impact of livestock grazing on forest structure, plant species
composition and biomass in southwestern Madagascar
Rakotomalala Yedidya Ratovonamana1,2,*, Charlotte Rajeriarison1,
Edmond Roger1, Iris Kiefer3 & Jörg U. Ganzhorn2
1University of Antananarivo, Department of Plant Biology and Ecology, BP 906, Antananarivo, Madagascar
2University of Hamburg, Biocenter Grindel, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
3University of Bonn, Nees Institute for Biodiversity of Plants, Meckenheimer Allee 170, 53115 Bonn, Germany
*Author for correspondence:
In most dry regions of the world, livestock represents a very
important source of income and insurance against variation
in agricultural production due to climatic unpredictability
and erratic rainfall (Riginos & Hoffman 2003, Dickhoefer et
al. 2010). The dry regions of Madagascar are no exception.
In many parts of Madagascar grazing leads to the degrada-
tion of the natural ecosystems. While the degradation of for-
est and non-forest ecosystems due to grazing seems obvious
in many parts of south and southwestern Madagascar, quan-
titative data on livestock carrying capacity and indicators for
degradation or overgrazing are not available (ANGAP et al.
1999, Mahazotahy 2006). This lack of information hinders
the establishment of a monitoring program for habitat quality
and the implementation of a management plan for sustain-
able land use that reconciles the need for livelihoods of the
human population and conservation of Madagascar’s unique
Southwestern Madagascar is a prime example where
livestock is a most important cultural and economic com-
ponent (Sourdat 1970, Pannoux 1991, Razanaka et al. 2001,
Rakotoarison 2005, SuLaMa 2011) embedded in biologi-
cally unique ecosystems that are under high pressure from
human land use (Fenn 2003). Stockbreeders in southwestern
Madagascar face several problems. First, the region is char-
acterized by a long dry period with irregular rainfall includ-
ing years without rain. The insufcient water supply reduces
the range of cattle as the dry season progresses. Since cat-
All rights reserved. © 2013 National Botanic Garden of Belgium ISSN 0799-2387
Background and aims – To contribute towards a better understanding of habitat utilization by livestock
and its impact on biodiversity components in the dry ecosystems of Madagascar.
Location – Southwestern Madagascar, in and around Tsimanampesotsa National Park.
Methods – We quantied species composition, life forms, structure, and plant biomass of different
vegetation formations in areas of four different grazing intensities: (1) ungrazed for four years prior to the
study, (2) grazed by zebu during the dry season, (3) grazed by zebu at the end of wet season and during the
dry season, and (4) grazed by goats during the wet and the dry season and by zebu at the beginning of the
dry season. The food biomass available was compared with the food biomass required.
Key results – Zebus feed on the east side of the National Park during the wet season as long as there is
enough water in that area. When water becomes scarce, the zebus return to the western side of the park.
Goats are restricted to the littoral zone in the west year-round. As a result, goats and zebus occupy different
proportions of the various vegetation types of our study area. Zebus also use the littoral forest, but only at
the end of wet and during the dry season. Large parts of the spiny bush on the limestone massif and dry
forest on ferruginous soil are not used regularly by zebus. Plant species richness and diversity varied in
relation to grazing pressure and soil conditions. In the littoral and on red sand, plant diversity decreased with
grazing pressure. This change was most pronounced in the littoral zone. Since grazing pressure increases
during the dry season, grazing affects mostly woody species, since herbs are no longer available during
the dry season. In contrast to the bush encroachment due to grazing in Africa, grazed areas in southwestern
Madagascar contain fewer woody plants and plant species than areas not used by livestock.
Key wordsForest-pasture, transhumance, grazing effect, fodder biomass, Tsimanampesotsa National
Ratovonamana et al., Impact of livestock grazing on vegetation characteristics in Madagascar
tle have to stay close to water, more distant areas are grazed
only lightly with substantial amounts of plant biomass re-
maining at the end of the wet season (Bosser 1954). Second,
the pasture is dominated by herbaceous species of low forage
value, such as Cenchrus ciliaris, Panicum pseudovoeltzkowi,
Eragrostis cilianenensis and E. pilosa (Bosser 1954, Morat
1973). Third, parts of the pasture are transformed to agricul-
tural land (Sourdat 1970). Forth, Madagascar is extending
its protected area system, particulary forest ecosystems, thus
reducing the access to forest pasture during the dry season
(Borrini-Feyerabend & Dudley 2005a, 2005b).
Within this context, the goal of this study was to contrib-
ute towards a better understanding of the impact of livestock
on the vegetation in the driest ecosystem of Madagascar.
Within this framework, the specic objectives of this study
were to: (1) document grazing impact on structural vegeta-
tion characteristics, (2) determine the impact of grazing on
plant species composition, (3) identify plant species as indi-
cators for grazing pressure, and (4) measure the biomass of
fodder for livestock during different seasons.
Site description
The study was carried out in the northern and western part of
the Tsimanampesotsa National Park and at adjacent sites west
of the national park. The national park is located in south-
western Madagascar (24°03’ – 24°12’S, 43°46’ – 43°50’E)
on the escarpment of the Mahafaly Plateau. The park was ex-
tended from 43,200 ha to 203,000 ha in 2007. This extension
reduces access to forest pasture during the dry season. Tra-
ditionally, cattle use the forests during the dry season where
they browse on woody plant species. This is considered one
of the major threats to the biotic diversity of Tsimanampesot-
sa National Park (ANGAP et al. 1999, Goodman et al. 2002,
Mahazotahy 2006). The Tsimanampesotsa NP represents
Madagascar’s peculiar dry and spiny forest ecosystems and
covers a substantial portion of the Mahafaly Plateau. It sepa-
rates extensive grassland towards the east from the littoral
zone in the west. During the wet season all zebu around the
Tsimanampesotsa NP are brought to the east of the Mahafaly
Plateau into the region of Itomboina where extensive grass-
Figure 1 – Study area and seasonal migration (transhumance) of livestock between the western and eastern parts of the Mahafaly Plateau at
the beginning of the wet season. The migration is reversed at the end of the wet season.
Scripta Bot. Belg. 50
lands provide food. However, water is limited in this region.
When water becomes scarce, zebus cross the limestone pla-
teau on a traditional track of transhumance north of the Lac
Tsimanampesotsa at the end of the wet season (March) even
though the areas in the east still provide plenty of food. Then,
cattle remain on the coastal plain where water is available
year round, but food availability is low. With the progressing
dry season, cattle move into the national park. They return
to the east (region of Itomboina) at the end of the dry season
in November (g. 1). Goats remain in the littoral zone year
round. Thus, the number of livestock west of and within the
national park is highest during the dry season when herba-
ceous forage is not available. At this time of the year, woody
plant species (liana, shrubs and trees) provide food for the
animals (Le Houérou 1980).
Field research on grazing was carried out between March
2008 and March 2009. Vegetation descriptions have been
performed during the wet seasons. The study is part of a
more comprehensive study on the vegetation of Tsimanamp-
esotsa NP (Ratovonamana et al. 2011).
Based on long-term averages, the region can be character-
ized as a semi-arid tropical climate with eight dry months
(April–November) and four wet months (December–March).
Months are considered ‘dry’ when rainfall (R) is less than
twice the mean monthly temperature (R < 2T). During the
dry season, the temperature varies from 17.8°C to 32.6°C
and from 24°C to 35.5°C during the wet season (g. 2). The
average annual rainfall is less than 500 mm (range at Tulear
between 1951 and 1990: 166 – 719 mm / year; CNRE 1992),
but can be irregular with ‘wet’ seasons without rain.
The Tsimanampesotsa forest is part of the southwestern
spiny forest of Madagascar (Moat & Smith 2007). It contains
some of the most unique plant communities on the island and
harbors the highest level of plant endemism with 48% of the
genera and 95% of the species being endemic (Elmqvist et
al. 2007). The forest is characterized by many xerophytic
and drought tolerant woody species of the Didiereaceae and
Figure 2 Climate of the study area; (*) indicates dry months. Data
from 1950 to 2000 from DIVAGIS ( Data
for the study area were recorded from 2006 to 2009 with i-buttons
(temperature loggers; from Ratovonamana et al. 2011).
Euphorbiaceae. The littoral zone with sandy soil is charac-
terized by dry forest, degraded forest and different herba-
ceous layers. The limestone is covered by xerophytic bush
with dry forest on ferruginous soil (g. 3). Depressions on
the limestone plateau are lled with red, ferruginous soil (red
sand) and covered by forest that is similar to the littoral zone.
Degradation is the result of direct and indirect anthropogenic
pressure, such as collection of re and construction wood,
slash and burn agriculture, re and grazing. The different
vegetation types and their phenology have been described by
Ratovonamana et al. (2011).
Process of site selection
We started with an analysis of images available in Google
Earth to include the full range of degradation of vegetation
types, and to identify zebu trails crossing the Mahafaly pla-
teau. True migration routes were identied on the ground.
True trails were distinguished from false routes based on the
presence of dung. The map and area assessment occupied by
livestock have been analyzed with ArcGIS. Based on these
pilot studies, we selected an area of 7591 ha for more de-
tailed studies, located between 23°58’ – 24°02’S and 43°42’
– 43°47’E. Within this area, eleven sites were selected which
are subject to different forms of utilization by livestock (table
1, g. 4). The eleven sites included: dry forest on the littoral,
degraded dry forest on the littoral, herbaceous formations on
the littoral, dry forest on ferruginous soil, xerophytic bush on
limestone, degraded xerophytic bush on limestone, bare soil
and water, and herbaceous wetland formations.
Categories of grazing pressure
Since stocking rates were not known at the beginning of the
study, we assigned sites to grazing intensities ranging from 1
(lowest) to 4 (highest):
(1) Not used by livestock since 2006
(2) Used by zebu during the dry season
(3) Used by zebu at the end of wet season and during the
dry season
(4) Used by goats during the wet and the dry season and
by zebu at the beginning of the dry season.
Floristic and structural vegetation description
We measured maximum height (in m) and trunk diameter at
breast height (for trees, in cm) of woody plants within 15
× 15 m2 plots. Crown diameter (Cd) was measured by pro-
jecting the edges of the crown onto the ground and meas-
uring the diameter along two axis (maximum: Cdmax and
minimum: Cdmin crown diameter axis in meters) through
the crown center (Brack 1999). Crown radius (Cr) was calcu-
lated as Cr = (Cdmax + Cdmin) / 4. Crown volume (Cv) was
calculated by using the formula for the volume of a cylinder
with: Cv = (pi) × (Ch) × (Cr)2/4; Ch is the vertical extension
of the crown from the rst branch to the maximum height of
the tree.
The herbaceous cover was estimated per species in ve 1
m2 subplots within each 15 × 15 m2 plot following the system
Ratovonamana et al., Impact of livestock grazing on vegetation characteristics in Madagascar
Figure 3 – Vegetation types and location of study sites in areas of different grazing regimes. Categories of grazing and site numbers are listed
in table 1. Grazing pressure categories: category 1: site 1; category 2: sites 1, 2, 8, 9, 10; category 3: sites 7, 11; category 4: sites 3, 4, 5, 6.
of Braun-Blanquet. The percent coverage per species and
plot was averaged for the each of the ve 1 m2 subplots.
Plant specimens collected in the eld were identied
in the herbaria of the Département de Biologie et Ecologie
Végétales, FOFIFA ( and the Parc
Biologique et Zoologique de Tsimbazaza. Since scientic
names are being updated continuously, we used the names
listed by Tropicos (
aspx). For the time being, the specimens are kept in the of-
ce of the Arboretum d’Antsokay in Toliara.
Plant species richness and plant diversity were used to
characterize the effect of grazing on the different plant com-
munities. Species diversity was evaluated using species
richness (S) and specic richness (SR) (Shannon & Weaver
1949). Specic richness takes into account the number of
species and the number of individuals. The similarity of plant
composition for each zone under different grazing pressure
was evaluated with the Spearman correlation coefcient.
The relative importance of species was calculated to deter-
mine important species, considered as indicators for differ-
ent forms of grazing pressure. The importance index of each
species was calculated by adding relative frequency, relative
density and relative dominance (Evariste et al. 2008).
Vertical vegetation structure was used as a proxy for
degradation. For this, the vegetation was subdivided in ve
height classes (< 25 cm, 25–49.9 cm, 50–99.9 cm, 100–149.9
cm and ≥ 150 cm) and the percentage of individuals with
different life forms (tree, shrub, and liana) was measured.
Detailed analyses of the vertical structure were limited to
heights below 1.5 m as this is the height that can be reached
by livestock in the area.
Plant biomass available as food for livestock
Since we rst had to identify the most important food plant
species for zebu and goats, we could not establish a rigorous
sampling design to measure the productivity of the differ-
ent food plant species year-round. Rather, as a rst step, we
identied the most important food plants for a given season
and then measured their standing biomass which was avail-
able as roughage at the time the species was identied as an
important food species. For woody species, we measured
the crown volume of various individuals per species. Sub-
Scripta Bot. Belg. 50
Site name and site
Number of
15 × 15 m2
of grazing
Latitude S Longitude E Soil type and
Distance to
water source
Andranovao (1) 4, 4 1, 2 24°1’ 25.55” 43°44’ 9.21” Sand, Littoral 2500
Ambahatry (2) 4 2 24°2’ 7.61” 43°44’35.35” Sand, Littoral 4000
Saia (7) 4 2, 3 24°0’ 19.05” 43°44’ 45.02” Limestone 2220
De Gaule (8) 3 2 24°1’ 20.43” 43°44’ 48.99” Limestone 3110
Andolomitsanga (9) 2 2 24°1’ 59.65” 43°44’ 55.25” Limestone 4220
Ambolely (10) 10 2 24°1’ 31.80” 43°45’ 30.48” Read sand 4000
Maintilimy (3) 7 4 24°0’ 41.79” 43°43’ 10.10” Sand, Littoral 1600
Kilibory (4) 4 4 23°58’ 14.02” 43°43’ 3.28” Sand, Littoral 3600
Fijona (5) 10 4 24°0’ 7.69” 43°43’ 50.45” Sand, Littoral 600
Andemodemoky (6) 5 4 23°59’ 7.44” 43°43’ 43.07” Sand, Littoral 1900
Ankazomaneno (11) 9 3 23°59’ 0.62” 43°46’ 47.78” Read sand 5900
Table 1 Study sites; vegetation formations in the littoral and on red sand are formed by dry forest.
Low spiny bush is growing on limestone (Ratovonamana et al. 2011). Classication of grazing pressure: (1) not used by livestock since 2006,
(2) used by zebu during the dry season, (3) used by zebu at the end of wet season and during the dry season, (4) used by goats during the wet
and the dry season and by zebu at the onset of the dry season.
Figure 4 – Study sites in areas of different grazing intensities as described in table 1.
Ratovonamana et al., Impact of livestock grazing on vegetation characteristics in Madagascar
sequently, all edible parts (leaves and twigs to a diameter of
3 mm) were collected from the individual plant, dried and
weighted. For each species, the dry biomass of edible parts
was regressed against the crown volume with a linear re-
gression that describes the allometric relationship between
crown volume and food for livestock (Gregoire et al. 1995;
electronic appendix 3). For the estimation of herbaceous
biomass, all herbaceous plants were cut within the 1 m2
subplots, dried and weighted. Available food biomass was
summed for the different woody and herbaceous species and
extrapolated to kg/ha.
Livestock stocking rates and ranging patterns
Assessment of the stocking rates and the habitat utilization
by livestock is difcult as the number of livestock owned by
a person is an economic (and thus tax) issue. The number of
cattle and goats has been obtained from the ofcial admin-
istration of the Commune of Beheloke. Analyses of habitat
utilization patterns are hindered by the fact that livestock are
not supposed to use the national park, while goats and cattle
actually do use it. Therefore, the spatio-temporal patterns of
grazing are based primarily on information provided by our
long-term assistants from local villages based on their own
experience and interviews.
Grazing pressure and carrying capacity
The determination of the carrying capacity requires knowl-
edge about plant biomass production, consumption rate per
unit livestock per day and the stocking rate per unit time.
One livestock unit (head of cattle under tropical condi-
tions) is dened as an animal of 250 kg body mass (Unité
de Bétail Tropical: UBT). Its consumption is dened as 6.25
kg of dry plant biomass per day (Consommation Journalière;
Boudet 1975). One UBT is equivalent to one zebu or twelve
goats. The grazing pressure was determined by comparison
of the biomass production of the most important plant spe-
cies and the food requirement of livestock.
Statistical analysis
Measurements of plant and vegetation characteristics were
averaged per 15 × 15 m2 plot. The individual plots served
as unit for subsequent analyses. Data were tested for devia-
tion from normality. Data deviating from normality were
analyzed with non-parametric tests. All other variables were
analyzed with parametric tests followed by Tukey’s Hon-
est Signicant Difference test for multiple comparisons. All
tests were performed with the statistical package SPSS Base
for Windows 13.0. Differences were considered signicant
at p ≤ 0.05.
Plant species and vegetation types within the study area
In the 66 plots of 15 × 15 m2, we recorded 189 plant spe-
cies from 56 different plant families with 126 plant species
in the dry forest on sandy soil (littoral zone), 127 species on
ferruginous soil (red sand), and 78 species in the xerophytic
Littoral Limestone Red sand
Number of 15 ×15 m2
plots 38 9 19
Families 46 33 44
Life forms
T 24 15 26
S 54 43 60
L 17 8 18
H 30 12 23
P 1 0 0
Total 126 78 127
Table 2Number of 15 × 15 m2 plots, plant families, species and
life forms in the major habitat types.
T: tree; S: shrub; L: liana; H: herb; P: parasite.
bush on limestone (table 2). The different numbers of species
and families in the different formations cannot be compared
directly due to the different number of plots per formation.
The most important families are Fabaceae (29 species), Mal-
vaceae (thirteen species), Apocynaceae and Euphorbiaceae
(twelve species), Poaceae (ten species), Acanthaceae (nine
species), Burseraceae (eight species) and Brassicaceae (six
species). The different plant species, their growth forms,
mean abundance per plot and their index of relative impor-
tance in the different zones are shown in the electronic ap-
pendix 1.
Livestock distribution
Goats and zebus occupied different proportions of the dif-
ferent vegetation types (table 3). Goats use only the littoral
throughout the year. The animals leave the village every
morning to graze in the littoral forest, especially those that
are located around water points. Zebus also use the littoral
forest, but only at the end of wet and the beginning of the dry
season. Large parts of the spiny bush on the limestone massif
Vegetation types Study
area Goats Zebus
Dry forest in the littoral 601 472 596
Degraded dry forest
in the littoral 1356 1288 1356
Herbaceous formations
in the littoral 905 656 749
Dry forest on ferruginous soil 359 0 359
Xerophytic bush on limestone 434 0 55
Degraded xerophytic bush
on limestone 3726 0 835
Bare soil and water 162 0 0
Herbaceous wetland
formations 48 0 0
Total 7591 2416 3950
Table 3Surface (ha) of different vegetation types in the study
area and the area used by goats and zebu during the wet and the
dry season.
Scripta Bot. Belg. 50
and dry forest on ferruginous soil (16% of the study area) are
not used by zebus regularly (table 3, gs 1 & 4).
At the end of the dry season / beginning of the rainy sea-
son (November–December) the zebus west of Tsimanam-
pesotsa NP are brought to the eastern part of the limestone
massif to the region of Itomboina where extensive grasslands
provide good pasture. At the end of the wet season (March),
zebus cross the limestone plateau from east to west on a tra-
ditional track of transhumance in the northern part of Tsima-
nampesotsa NP. Initially, they remain on the coastal plain,
but start moving into the national park as food abundance de-
clines on the coastal plain during the dry season (gs 1 & 4).
Effects of grazing on the oristic composition and plant
life forms
Plant species diversity changes with different grazing pres-
sure and topographic position (table 4). In the littoral and on
red sand, the mean number of plant species decreases signi-
cantly with increasing grazing pressure. On limestone, the
species richness between sites with different grazing pres-
sure did not differ signicantly. The representation of differ-
ent life forms did not differ under different grazing pressure
in any of the habitats. An analysis of community similarity
based on Spearman correlations between the occurrences of
different plant species indicates that plant species composi-
tion is related more to the vegetation formation than to deg-
radation (g. 5).
In the littoral, the plots with low pressure (GP 1) are
dominated by higher plant individuals (height > 50 cm) than
the plots with medium (GP 2) and high (GP > 3) grazing
pressure (g. 6). In the limestone area, no signicant differ-
ences were observed. On red sand, the communities are char-
acterized by plants with heights below 25 cm, with a domi-
nance of herbaceous species and rarity of woody plant in the
100–150 cm height class.
Indicator species
Electronic appendix 2 shows the most important plant species
(dened by high values of relative importance) in relation to
grazing pressure in the different vegetation types. The littoral
plots with high grazing intensities (GP 3 and 4) were domi-
nated by Aerva javanica (Amaranthaceae), Setaria pumila
(Poa ceae) and Solanum hippophaeoïdes (Solanaceae). These
three species were absent in the plots not used by livestock.
Some shrubs were more abundant in grazed than in ungrazed
plots. These are Acacia rovumae, Alantsilodendron alluau-
dianum, Chadsia grevei, Mimosa delicatula (Fabaceae) and
Rhigozum madagascariense (Bignoniaceae). On limestone,
the plots not used by zebu during the dry season, were domi-
nated by Panicum mahafalense (Poaceae) and Xerophyta
tulearensis (Velloziaceae). These two species constitute the
main food source for cattle at the onset and during the dry
season. On red sand Aerva javanica (Amaranthaceae), Ja-
tropha mahafaliensis (Euphorbiaceae), Uncarina stelluli fera
(Pedaliaceae), Alantsilodendron alluaudianum (Fabaceae)
and Cucurbita sp. (Cucurbitaceae) were more abundant in
Figure 5Similarity of the oristic composition of plots in different
categories of grazing pressure in the different zones.
Zone N Total number of species Herb Liana Shrub Tree
GP 1 4 47 ± 14a6 ± 2 3 ± 2 22 ± 7a15 ± 4a
GP 2 8 23 ± 5b7 ± 3 3 ± 2 7 ± 4b5 ± 2b
GP 4 26 20 ± 6b8 ± 2 2 ± 1 8 ± 3b3 ± 2b
Chi-Square 11.78** 3.52 4.26 10.77** 16.51***
GP 1 5 33 ± 5 4 ± 1 4 ± 1 20 ± 3 6 ± 1
GP 2 2 23 ± 1 3 ± 1 2 ± 0 14 ± 1 5 ± 1
GP 3 2 28 ± 11 5 ± 1 3 ± 1 18 ± 7 3 ± 1
Chi-Square 2.96 1.54 2.82 2.90 5.83
Red sand
GP 1 6 45 ± 7a3 ± 1 7 ± 2a21 ± 4a15 ± 2a
GP 2 4 35 ± 4b3 ± 0 6 ± 1a15 ± 2b12 ± 2a
GP 3 9 19 ± 3c4 ± 4 2 ± 2b7 ± 3c4 ± 4b
Chi-Square 15.16*** 1.65 11.72** 15.48*** 14.51***
Table 4Effects of grazing on plant species numbers and different life forms in plots subject to different grazing pressure (GP, as
dened in table 1).
N: number of 15 × 15 m2 plots. Values are means ± standard deviations. Asterisks indicate signicance levels according to Kruskal-Wallis
analysis of variance: * p ≤ 0.05; ** p ≤ 0.01; *** p ≤ 0.001. Different letters indicate differences according to post-hoc tests.
Ratovonamana et al., Impact of livestock grazing on vegetation characteristics in Madagascar
plots with high grazing pressure (GP 3) than in plots with
low grazing pressure (GP 1) (electronic appendix 2).
Plant biomass
Table 5 shows the average biomass (dry plant material:
DPM) of the most important food species in the study area.
During the wet season (January–April) livestock used mainly
the littoral. At this time of the year the most important food
plants were: Aerva javanica (19.5–258.3 kg DPM/ha), Boer-
havia diffusa (4.8–206.4 kg DPM/ha), Dactyloctenium capi-
tatum (4.8–6.3 kg DPM/ha), Indigofera diversifolia (13.8 kg
DPM/ha), Panicum pseudovoeltzkowii (37.8–75.6 kg DPM/
Figure 6 – Vegetation structure under different grazing pressure.
Grazing pressure as described in table 1.
Littoral Littoral
and limestone
and red sand
Wet season Onset of the
dry season Dry season
Month of roughage biomass estimates Jan. Feb. Mar. Apr. May–Jun. Jul.–Dec.
Species Family
Panicum pseudovoeltzkowii Poaceae 75.6 37.8 34.1 - - -
Aerva javanica Amaranthaceae 258 50.4 19.5 - - -
Dactyloctenium capitatum Poaceae - 6.3 4.8 - - -
Boerhavia diffusa Nyctiginaceae - 12.6 4.8 206.0 - -
Tribulus cistoïdes Zygophyllaceae - 31.5 230.0 176.0 - -
Indetermined (‘Tirinkitroky’) Nyctiginaceae - - 12.9 189.0 - -
Indigofera diversifolia Fabaceae - - 13.8 - - -
Panicum subalbidum Poaceae - - - 17.6 - -
Panicum maximum Poaceae - - - 28.1 - -
Panicum mahafaliense Poaceae - - - - 232.4 -
Indigofera peltieri Fabaceae - - - - 1.5 -
Commiphora lamii Burseraceae - - - - 6.8 4.1
Commiphora marchandii Burseraceae - - - - 263.6 5.2
Plumbago aphylla Plumbaginaceae - - - - 3.4 0.9
Xerophyta tulearensis Velloziaceae - - - - 28.4 55.5
Mollugo decandra Aizoaceae - - - - - 6.1
Gyrocarpus americanus Hernandiaceae - - - - - 15.4
Total Biomass 333.9 138.6 319.9 617.5 536.1 87.2
Table 5 Average biomass of roughage per month of the most important food plant species during different times of the year.
Values are kg of dry plant material per ha. Biomass was measured for the areas used by livestock in the different months. Setaria pimula had
not been recorded in the standardized plots due to its patchy distribution, but represents an important fodder plant.
ha), Panicum subalbidum (176 kg DPM/ha), Panicum maxi-
mum (28.1 kg DPM/ha), Tribulus cistoïdes (50–365.2 kg
DPM/ha), ‘Tirinkitroky’ (20–300 kg DPM/ha). The highest
roughage biomass was recorded in April, at the end of the
wet season (607 kg DPM/ha). The minimum was measured
in February with 138.6 kg DPM/ha. The species Tribulus cis-
toïdes, Panicum pseudovoeltzkowii, and Aerva javanica were
the most important food species at this time of the year. The
average biomass available from these plant species per ha
and their monthly changes are listed in table 5.
At the beginning of the dry season zebu started moving
into the limestone area. During this time, roughage availabil-
ity was still high due to the shift from herbs to the annual
growth of trees and regenerating plants. Indigofera peltieri
(1.5 kg DPM/ha), Commiphora lamii (4.1–6.8 kg DPM/ha),
C. marchandii (263 kg DPM/ha), and Plumbago aphylla
(3.38 kg DPM/ha) were the most important species for the
littoral zone. Apart from these widely distributed species
there were some highly productive patches of Setaria pimula
(260 kg DPM/ha). Xerophyta tuleariensis (28.4 kg DPM/ha)
and Panicum mahafaliense (232 kg DPM/ha) were most im-
portant in the limestone area.
During the dry season most woody plants lose their
leaves and herbs disappear. In this season cattle were fre-
quently found in the Tsimanampesotsa NP. Their staple food
consisted almost exclusively of Xerophyta tuleariensis (55.5
kg DPM/ha), Mollugo decandra (6.1 kg DPM/ha), and Gyro-
carpus americanus (15.4 kg DPM/ha) (table 5).
Scripta Bot. Belg. 50
Plant biomass available and total food requirements of
The study area is stocked by the villages of Maromitilike,
Efoetse, Marojery and Ankilibory. According to ofcial
sources, their number of livestock was equivalent to 5009
UBT (4434 zebus + (6897 goats / 12) = 4434 + 574.75 UBT;
total of 5008.75 UBT). Table 6 summarizes a rough estimate
of the carrying capacity of the area where people of the vil-
lages listed above herd their livestock. The estimates are
based on the following assumptions:
1. Goats were limited to the littoral zone and range over
2416 ha (table 3).
2. Zebu used 2701 ha of the littoral zone at the end of the
wet season and included another 1249 ha on the limestone
and red sand after the onset of the dry season (table 3).
3. The number of animals was assumed to be constant
throughout the year, thus not taking into account
reproduction. This underestimates food requirements.
4. Since zebu moved into the limestone area at the end of the
dry season due to reduced food availability in the littoral
zone, we assumed that food availability in the littoral
zone is as low, or even lower than food availability in the
limestone area. For the estimate of the carrying capacities
we assumed that the same quantity of roughage would be
available in both areas during the dry season (87.2 kg/
ha). This overestimates food availability in the littoral
5. Food requirements per unit of livestock are set as 6.25 kg
roughage per day. This amounts to 187.5 kg of roughage
per month per unit of livestock.
During the wet season, livestock which does not partici-
pate in the seasonal migration uses mainly the littoral zone.
Here, the total biomass increased until the end of the wet sea-
son and decreased gradually during the dry season (table 6).
According to the comparison between plant biomass avail-
able and total food requirements of livestock, food availabil-
ity exceeded the needs of livestock during the six months be-
tween the wet and the onset of dry season. In contrast, food
requirements of the animals were higher than food availabil-
ity during the six dry months. At this time, livestock relied
heavily on the fodder produced within Tsimanampesotsa NP.
Grazing is a widespread form of land use in arid and semi-
arid region (Riginos & Hoffman 2003). It can modify the o-
ristic composition, spatial structure and representation of life
forms in plant communities either through direct impact or
to altered species interactions (Tielbörguer & Kadmon 2000,
Pykälä 2004, Cipriotti & Aguiar 2005, Jacobo et al. 2006,
Sankey 2007, Škornik et al. 2010). Our study showed that
species richness and diversity were affected differently by
different grazing intensities and in different vegetation for-
mations. In the littoral and on red sand, the plant diversity
decreased with grazing pressure. Plots that were not used
contained more woody plant species than area used by live-
stock at the end of wet season and during the dry season. The
change in woody plant species structure favors the growth
forms of herbaceous, desirable as well as unpalatable spe-
cies. This change was most pronounced in the littoral zone,
i.e. the area that is used by goats year-round and by zebu dur-
ing the dry season. In contrast, livestock grazing had no sta-
tistically signicant effect on species composition, diversity
or structure on limestone. It seems unlikely that grazing does
not have any effect on the plant communities on limestone.
But we simply could not measure any effect, either because
grazing intensity is actually very low or regeneration is so
slow that effects of unhindered regeneration are not measur-
able, not even after four years without grazing (our category
GP 1).
The effect of grazing on plant community structure and
plant diversity can be explained by the availability of herbs
and grass in the pasture area (Škornik et al. 2010). In our
study, the total fodder biomass increased until the end of
the wet season. It decreased gradually during the dry sea-
son. The comparison between plant biomass available and
total food requirements of livestock showed that the plant
biomass available exceeded the food requirements of the
animals which remain in the area until the onset of the dry
Wet season End of wet
Onset of dry
season Dry season
Livestock units: goats 574.75 574.75 574.75 574.75
Livestock units: zebu - 4434 4434 4434
Livestock units per ha of littoral: goats 0.238 0.238 0.238 0.238
Livestock units per ha of littoral: zebu - 1.642 - -
Livestock units per ha of littoral and limestone: zebu - - 1.122 1.122
Food requirements per unit livestock (goats)
per month occupying one ha 44.6 kg 44.6 kg 44.6 kg 44.6 kg
Food requirements per unit livestock (zebu)
per month occupying one ha - 307.9 kg 210.4 kg 210.4 kg
Total food requirements of livestock / ha 44.6 kg 352.5 kg 255 kg 255 kg
Available biomass of roughage
(kg of dry plant material / ha) 264 kg 617.5 kg 536.1 kg ≤ 87.2 kg
Table 6Available biomass of roughage and estimates of food requirements of goats and zebu in different zones used at different
times of the year.
Wet season: January-March; end of the wet season: April; onset of the dry season: May-June; dry season: July-December.
Ratovonamana et al., Impact of livestock grazing on vegetation characteristics in Madagascar
season. But during the dry season the food requirement of
the livestock exceeded the plant biomass available. By then,
cattle switch from grazing on herbs and grasses to brows-
ing on woody plants that still have leaves. The utilization of
woody forage depends on the animals that remain in the pas-
ture area. Goats eat a signicant proportion of leaves from
woody plants year-round, while zebu browse mainly during
the dry season when the herbaceous forage is not available
(Grouzis & Sicot 1980, Maiga 1995). Thus, the decline of
liana, shrub and tree species with increasing grazing pressure
indicate the dependence of livestock on woody species at the
end of the wet season and during the dry season when the
herbaceous plant species are not available. It should be kept
in mind that data on livestock and ranging pattern are prob-
ably underestimated because the numbers obtained from the
regional administration are unlikely to be complete. People
at the villages are afraid that the neighbouring villages will
know the number of their livestock. Furthermore, people use
the national park as pasture. Since people recognize this as
illegal, they are unwilling to reveal details about these activi-
ties and are hesitant to allow outside monitoring of their ac-
tivities. In addition, livestock reproduction and thus seasonal
changes in livestock numbers are not taken into account.
The increase of some species at high grazing intensities
could be used as indication for grazing pressure. The increas-
ing dominance of these plant species in grazed areas can be
explained by two processes. First, some of the species are
spread by livestock. These are Aerva javanica (Amaran-
thaceae), Setaria pimula (Poaceae), Solanum hippophae-
noïdes (Solanaceae), Alantsilodendron alluaudianum (Fa-
baceae), Erythrophysa aesculina (Sapindaceae), Poupartia
minor (Anacardiaceae), Uncarina stellulifera (Pedaliaceae)
and Cucurbita sp. (Cucurbitaceae). Second, others species
have a high regeneration capacity and are more resistant to
cattle trampling. These are Cedrelopsis grevei, Cedrelopsis
gracilis (Ptaeroxylaceae), Rhigozum madagascariense, Ste-
reospermum nematocarpon (Bignoniaceae), Chadsia grevei,
Acacia rovumae, Mimosa delicatula (Fabaceae) and Boscia
longifolia (Boraginaceae).
Apart from changes in species composition, we observed
a relatively large difference in the representation of growth
forms of plants across the different categories of grazing
pressure. In grazed plots the percentage of plants in the low-
est stratum increased in the littoral zone. This this is opposite
to the situation in many parts of Africa where grazing results
in bush encroachment (Skarpe 1990, Moleele & Perkins
1998). In southwestern Madagascar herbaceous vegetation
seems to increase with increasing grazing pressure. Yet, this
is not due to an actual increase of herbaceous vegetation, but
due to the reduction of trees and shrubs that are fed upon dur-
ing the dry season when herbaceous plants are absent. Thus,
the observed pattern is the outcome of the effect of grazing
during the dry season when animals feed on woody vegeta-
tion because herbs are absent.
In summary, vegetation characteristics (species rich-
ness, species composition, plant life forms and vegetation
structure) change with grazing pressure. The impact is most
pronounced in the littoral and the red sand where vegetation
cover is higher than on limestone. In the latter, grazing pres-
sure seemed too low to have a measurable effect on plant
diversity and structure. Contrary to expectation, grazing did
not result in bush encroachment as in many African coun-
tries, but favours herbs at the expense of woody vegetation,
because herb biomass exceeds livestock food requirement
during the wet season. During the dry season, herbs are no
longer present according to their annual cycle. At this time
of the year, livestock feeds extensively on woody vegetation
that does not match the food requirements of the livestock
at the present stocking rate and thus results in a decline of
woody vegetation.
Supplementary data are available in pdf at the Supplemen-
tary Data Site of publications from the National Botanic
Garden of Belgium ( > SBB50 >
folder 612) and consist of (1) mean abundance of different
plant species and their mean relative importance in the 15 ×
15 m2 plots of the different major habitat types in the study
area; (2) relative importance of species under different graz-
ing pressure; and (3) allometric calculation of edible plant
biomass for various woody species.
The study was carried out under the collaboration between
Madagascar National Parks (ex-ANGAP), the Departments
of Animal Biology and Conservation, Department of Plant
Biology and Ecology (Antananarivo University, Madagas-
car) and Department of Animal Ecology and Conservation
(Hamburg University, Germany). We thank Mark Fenn, Joce-
lyn Rakotomalala and Domoina Rakotomalala (MNP Toli-
ara, WWF Madagascar) Juliana Rasoma V. Rahantavololona,
Jacques Solofomalala Rakotondranary and Peggy Giertz for
their support. Special thanks go to our para-ecologists Mr.
Louis Fisy and Mr. Mahita for their help in the eld and for
their communication skills with the local communities. The
study was nanced by WWF Sweden / WWF Madagascar
with additional support from DFG/BMZ (Ga 342/15), VW
Foundation, DAAD, WWF Germany and SuLaMa/BMBF.
We highly appreciate the help and comments of Natacha
Beau and two reviewers. The participation of R.Y. Ratovona-
mana at the AEFTAT congress was supported by the Ham-
burger Universitätsvermögen.
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Electronic appendix 1 to:
Rakotomalala Yedidya Ratovonamana, Charlotte Rajeriarison, Edmond Roger, Iris Kiefer &
Jörg U. Ganzhorn (2013)
Impact of livestock grazing on forest structure, plant species composition and biomass in
southwestern Madagascar
Scripta Botanica Belgica 50
Appendix 1 Mean abundance of different plant species (AB) and their mean relative
importance (IR) in the 15 × 15 m² plots of the different major habitat types in the study
N = number of plots.
Red sand
Scientific name
Barleria humbertii
Blepharis calcitrapa
Blepharis sp
Hypoestes phyllostachya
Justicia spicata
Ruellia albopurpurea var. sulfureoviolacea
Mollugo decandra
Aerva javanica
Aerva madagassica
Aerva sp
Henonia scoparia
Operculicarya hyphaenoïdes
Poupartia minor
Stapelianthus insignis
Rhigozum madagascariense
Stereospermum nematocarpon
Boscia longifolia
Cadaba virgata
Androya decaryi
Commiphora humbertii
Commiphora mahafaliensis
Commiphora marchandii
Commiphora orbicularis
Opuntia monocantha
Terminalia disjuncta
Terminalia ulexoïdes
Cucurbitum sp
Didierea madagascariensis
Dioscorea fandra
Diospyros manampetsae
Acalypha decaryana
Croton cotoneaster
Croton geayi
Croton salviformis
Euphorbia stenoclada
Euphorbia tirucalli
Red sand
Scientific name
Givotia madagascariensis
Jatropha mahafalensis
Securinega seyrigyi
Croton sp8
Acacia bellula
Acacia rovumae
Alantsilodendron alluaudianum
Albizia mahalao
Albizia tulearensis
Chadsia grevei
Crotalaria androyensis
Crotalaria humbertiana
Indigofera sp
Mimosa delicatula
Mundulea micrantha
Mundulea sp2
Senna meridionalis
Tephrosia alba
Gyrocarpus americanus
Karomia microphylla
Capuronianthus mahafaliense
Grewia grevei
Grewia humblotii
Indetermined (Kotaky)
Megistostegium microphyllum
Sida acuta
Neobeguea mahafaliensis
Ximenia perrieri
Uncarina stellulifera
Plumbago aphylla
Panicum mahafalense
Setaria pumila
Polygala greveana
Cedrelopsis gracilis
Cedrelopsis grevei
Azima tetracantha
Salvadora angustifolia
Erythrophysa aesculina
Lycium acutifolium
Solanum hippophaenoïdes
Xerophyta tulearensis
Zygophyllum depauperatum
Electronic appendix 2 to:
Rakotomalala Yedidya Ratovonamana, Charlotte Rajeriarison, Edmond Roger, Iris Kiefer & Jörg U. Ganzhorn (2013)
Impact of livestock grazing on forest structure, plant species composition and biomass in southwestern Madagascar
Scripta Botanica Belgica 50
Appendix 2 – Relative importance of species under different grazing pressure: A, littoral; B, limestone; C, red sand.
Electronic appendix 3 to:
Rakotomalala Yedidya Ratovonamana, Charlotte Rajeriarison, Edmond Roger, Iris Kiefer & Jörg U. Ganzhorn (2013)
Impact of livestock grazing on forest structure, plant species composition and biomass in southwestern Madagascar
Scripta Botanica Belgica 50
Appendix 3 – Allometric calculation of edible plant biomass for various woody species. VPA: Crown volume in cm3; Wet biomass
in g.
... There were higher densities of shrubs in both crop-livestock system and livestock production system. The shifts in botanical composition arising from differential livestock utilization has been demonstrated by Ratovonamana et al., (2013). In their study, they found that changes in the structure of woody plant species resulting from browsing favours the growth of herbaceous and unpalatable species. ...
... On the basis of this evidence, it can be surmised that the higher densities of shrubs in both mixed farming system and livestock production system may be attributed to differential utilization by livestock. Ratovonamana et al., (2013) also found evidence that regeneration potential in livestock production zones depends on the browsing intensity and grazing pressure (Reed and Clokie, 2001;Sassenand Sheil, 2013) indicating that intensive grazing hampers forest regeneration. Thus, there is need to ensure appropriate stocking levels that will reduce the grazing pressure particularly in the livestock production system. ...
... The low tree heights in the mixed farming system were attributed to high demand for crop stakes which are used for supporting tomato crop, a major crop grown in the area. The low mean tree height in mixed farming systems and livestock production systems were further attributed to browsing, trampling and breakages resulting from grazing pressure (Ratovonamana et al., 2013). The livestock production system is dominated with herbaceous vegetation and shrubs which are generally short. ...
Full-text available
Riparian ecosystems are considered hotspots of carbon and nitrogen transformations. These biochemical transformations are driven by anthropogenic activities in the immediate riverine water catchments. The anthropogenic activities may include and not limited to extraction of goods such as agricultural products, wood products, honey, plant based pharmaceutical products, livestock products, firewood, water and grass for thatching homesteads. Riparian ecosystems also provide important tangible and intangible ecosystem services comprising spiritual and aesthetic functions, pollination, ecosystem detoxification functions, carbon and nitrogen sequestration and CO2 sinks for amelioration of climate change impacts among others. These ecosystems are increasingly threatened by degradation attributed to land use changes. Human perturbations such as crop farming on riparian land, overgrazing and population pressure on land resources influence degradation of riparian ecosystems, with profound effects on biodiversity conservation and local livelihoods. Evidence from the literature indicates that although there is a general understanding regarding the response of terrestrial and wetland ecosystems to human perturbations, there is a dearth of information on the response of African riparian ecosystems to ecologic and socio-economic impacts.
... However, the Fabaceae, Euphorbiaceae, Hypoxidaceae, and Scrophulariaceae were more common under continuously grazed grasslands in the COP and CF farms compared to the CMF farm. The Fabaceae was one of the most dominant families in heavy grazing plots in southwestern Madagascar [65]. They stated that legumes had a high capacity for regeneration and were resistant to trampling by animals. ...
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Grazing practices affect the soil and vegetation of grasslands, which further influence the provision of ecosystem services and the productivity of grasslands. We determined the ecosystem resilience of a mesic grassland under three grazing management systems in the Pakkies area, (30°33′08″ S, 29°25′22″ E), South Africa: cooperative (continuously grazed since 2017), commercial (rotationally grazed for >20 years), and communal (continuously grazed for >20 years) farms. This was carried out by measuring the penetration resistance and infiltration, soil nutrients, forage quality contents for livestock, veld condition, plant species composition and richness, and functional diversity. The soils had a higher penetration resistance in the continuously grazed communal farm, while water infiltration was highest in the continuously grazed cooperative farm. The plant species and functional diversity were greater in the rotationally grazed commercial farm than in the continuously grazed communal and cooperative farms. The continuously grazed cooperative farm had the highest veld condition score (97%), while the rotationally grazed commercial and the continuously grazed communal farms had 82% and 56% veld condition scores, respectively. The forage quality and soil nutrients were generally similar among all farms. The lower plant diversity observed with continuous grazing may indicate that the ecological system was not as resilient concerning this type of grazing. However, for forage quality, soil nutrients and veld condition, continuous grazing was resilient, which indicates that rotational grazing may not be better than continuous grazing for livestock production in this specific region. As long as a minimum level of ecological resilience can be retained, continuous grazing can sustain effective animal production, particularly for small-holder farmers.
... This implied that the number of saplings and seedlings increased with the declining presence of cow dung since livestock either browse or trample on them. This study (Yedidya Ratovonamana & Ganzhorn, 2013) indicated that livestock grazing in a forest degrades the ecosystem by altering the floristic composition and other research. Roberts et al. (2021) have also shown that seedlings and saplings are mostly damaged by trampling and grazing. ...
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Forest ecosystems provide livelihood opportunities such as medicines, fuelwood, timber, cash income and a reliable supply of groundwater. However, encroachment of forests by human settlement adjacent to conservation areas is associated with overharvesting of forest resources and uncontrolled livestock grazing leading to the destruction and disappearance of useful plant species in forest ecosystems which can significantly affect both biodiversity integrity and ecological functioning. Therefore, this study aimed to investigate the distribution, conservation status, and effects of threats on the relative abundance of Warburgia ugandensis in Katimok Forest Reserve, Baringo County in Kenya. Data collection was done using transect lines and quadrat methods. The data on the relative abundance of Warburgia ugandensis and indicators of threat were collected from quadrats and sub-quadrats located at 50 m, 350 m and 650 m from the forest edge. In addition, other measures of tree growth such as diameter at breast height (DBH) and heights of mature trees in the study blocks were made. One-way ANOVA was used to analyse the relative abundance of Warburgia ugandensis, indicators of threat and growth parameters. Pearson correlation results revealed a significant relationship between debarked and mature Warburgia ugandensis (r = 0.95; df=2, P=0.019), grazing intensities, and number of seedlings/saplings (r = 0.96; df=2, P=0.017) and other indicators of threats (stumps, defoliated leaves, broken twigs/branches) and the abundance of Warburgia ugandensis (r = 0.97; df=2, p=0.015). Therefore, there is an urgent need to map out the distribution of Warburgia ugandensis in the whole country to know where it is abundant in order to draw a national conservation and management plan for the tree species.
... One of the critiques of the study is that livestock grazing as a forest degradation driver was classified as both large and small scale with no actual numbers as operationalized by previous researchers to indicate grazing intensities. Ratovonamana et al. (2013) work was done in Madagascar and the researchers investigated the impact of livestock grazing on forest structure, plant species and composition in Madagascar. The work noted that plant diversity decreased with increase in livestock grazing pressure. ...
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Global Dynamics in Africa Editors: Maurice N. Amutabi and Dr. Linnet Hamasi Published by CEDRED Publications, Nairobi, Kenya ISBN 978-9966-116-53-6 Table of Contents Dedication ii Copyright iii Acknowledgement iv Introduction Maurice Nyamanga Amutabi 1 Chapter 1 The Medical Male Circumcision Practice as a Global Health Strategy for HIV and AIDS prevention in Uganda By Bernard Omukunyi 8 Chapter 2 Overview of Innovative Crop Production Strategies for Sustainable Food Security in Kenya By Alice Kosgei & Jones Agwata 22 Chapter 3 Role of Private Academies in Provision of Basic Education in Kenya: A Case of Kwanza Sub-County of Trans Nzoia County, Kenya By Aggrey Asitiba Okutu 38 Chapter 4 Gender Differentials in Borrowing of Loans and Effects of the Loans on Households’ Livelihood Improvements in Kenya By Jane Wanjiku Wanjihia, Lawrence Njoroge & Leah Wanjama 52 Chapter 5 Competency Based Curriculum: Launching and Perception of Primary Teachers on its Implementation: A Case study of Trans-Nzoia County, Kenya By David Wafula Wakoli 63 Chapter 6 Influence of Competitive Aggressiveness on the Performance of Youth-led Micro and Small Enterprise in Lake Basin Region, Kenya By Evelyn Bosire, Gregory Namusonge & Samson Nyang’au Paul 74 Chapter 7 Influence of Buyer-Supplier Collaboration on Organizational Performance in Food and Beverage Manufacturing Companies in Kenya By Bartoo Dorothy Chebichii, Gregory Namusonge & Elizabeth Nambuswa 86 Chapter 8 The Role of Learning Resource Project in Teacher Education in Kenya By Ezekiel Nyambega Omwenga & Omosa Elijah Mochama 106 Chapter 9 Use of information and Communication Technology tools for Capturing Indigenous Farming Knowledge for Sustainable Development By Anderson Kahindi Chai & Zipporah W. Gichuhi 122 Chapter 10 Towards Reducing Gender-Based-Violence within Higher Learning Institutions: The Case of St John’s University of Tanzania By Milka Otieno, Elizabeth Msoka & Sheila Mziray 132 Chapter 11 Public Procurement Ethics and Procurement Performance: The Case of Kakamega County Government, Kenya By Jackline Akoth Odero and Kelvin Mogere Machuki 152 Chapter 12 The Effect of Initiation Rituals on Secondary School Students’ Academic achievements in Chemba District, Tanzania By Munjori, Mwanahamisi, O & Elizabeth M. Msoka 170 Chapter 13 Influence of Flexible Workload Strategies on Performance of Nurses in Regional Hospitals in Tanzania By Elisifa Ezekiel Nnko, Samson Nyang’au & Romanus Odhiambo 189 Chapter 14 Two Ways of Understanding the Climate: Economy Link and Designing Climate Change Policies By Firimoni Rweere Banugire 206 Chapter 15 The Analysis of Value Chain for Irrigated Horticultural Crops around Sand Dams and Water Ditches in Dodoma and Bahi District, Dodoma, Tanzania By David Kasian Msola, Elizabeth M. Msoka & Clarence Hugo Nyoni 224 Chapter 16 Trends in Livestock Grazing in the Protected Forests at Mount Kenya Region: Evidence from year 2013 to 2018 using Time Series Analysis By Paul Mwari Maina & Daniel M Nzengya 242 Chapter 17 Strategic Marketing, a Technical Approach for Company Performance in the Telecommunications Industry in Rwanda By Kirabo Joyce, Gregory Namusonge & Mike A Iravo 256 Chapter 18 Voice, Agency and Silences: Traditional African Women’s Tools for Accessing Centers of Power Shaping the Development Agenda By Godard Busingye 270 Chapter 19 Gendered Finance for Peace, Solidarity and Social Injustice in Southern Africa By Tinuade Adekunbi Ojo 281 Chapter 20 Analysis of Mechanisms Used to Handle Conflicts in Public Primary Schools in Geita District, Tanzania By Newton M. Kyando & Sarah M. Ulimboka 299 Chapter 21 Strategic Leadership for Effective Resource Mobilization: A Case of Public Universities in Kenya By Ezekiel Wechuli Wanyama 317 Chapter 22 The Polemics of Policies and Institutions Governing Unreserved Forests: Forest Sustainability Practice in Tanzania By Fadhili Bwagalilo 328 Chapter 23 Influence of Globalization on Pre-school Teacher Pupil Ratio in Relation to Education for Sustainable Development in Uasin Gishu County, Kenya By Everlyne Chebet, Justina Ndaita & Esther Bitok 342 Chapter 24 From Ngaka Cooperative Society to Mlango Mmoja Cooperative: The Case of Coffee Production and Marketing in the Matengo Highlands, Tanzania By Osmund M. Kapinga 351
... The vegetation of the study region is xerophytic starting at the coastal plain with formations resting on sand and thin reddish clays, followed by an area at approximately 50 m above sea level near the foot of the Mahafaly Plateau, dominated by sparse vegetation in close vicinity to the soda lake (Lac Tsimanampesotse), and dry spiny thicket on the limestone Mahafaly Plateau. Trees on limestone are distinctly smaller and occur in much lower densities, resulting in reduced vegetation cover and biomass production compared to the littoral forest (Rasoma et al., 2010;Marquard et al., 2011;Ratovonamana et al., 2011;Ratovonamana et al., 2013;Goodman et al., 2018). ...
Latrine behaviour in lemurs has been interpreted as a means of olfactory communication linked to energy efficient resource defence against neighbouring individuals and/or social bonding within social groups. For social bonding, latrines might best be placed at the core of home ranges, while resource defence could be based on defending the most important part of the home range, i.e., the core area or by establishing olfactory landmarks at the periphery of the home range. Most studies on lemurs describe deposition of urine and faeces in latrines in the core of the home range. In a study at the limit of the distributional range of Lepilemur petteri , at a site with unpredictable weather conditions, we radio-tracked 12 individuals and located latrines within their home ranges. In our study, latrines were located at the periphery of the home ranges. This is interpreted as a means to defend a larger area rather than specific resource rich sites that may or may not provide food in a given year. Regardless of the flexible spatial pattern, and in common with other mammals, lemur latrines are characterized by conspicuous trees, even though urine and faeces are deposited at the base of trees. This indicates some kind of optimal structure of latrines to convey information most effectively, possibly by combining visual and olfactory cues.
... The study by Hosonuma et al. (2012) noted insignificant drivers of forest degradation as mining, urban expansion, and infrastructural development. The study by Ratovonamana et al. (2013) investigated the impact of livestock grazing on forest structure, plant species and composition in Madagascar. A study by Matiku et al. (2013) that was conducted in Arabuko-Sokoke Forest in Kenya noted a strong positive correlation between forest adjacent community's closeness to the forest and exploitation the natural resources and the fact that majority of communities living in forest proximity live in poverty (MEA, 2005;Ruwanza and Shackleton, 2017). ...
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Management of community utilization of protected resources in protected forests is a huge challenge, particularly in the Mount Kenya region because of limited research data on the dynamics and characteristics of households living adjacent to protected forests. This research, conducted in the Mount Kenya West protected forest, sought to examine household perceptions on the different sources of pasture and fodder, to assess the significant household characteristics in driving smallholder farmers dependence on protected forests for pasture and to assess the significance of household characteristics in driving smallholder farmers' dependence on protected forests for grass harvesting for livestock fodder. The research followed a cross-sectional research design with smallholder farmers dwelling adjacent to three forest blocks, namely, Kahurura, Hombe, and Chehe as the target population. The data was collected from May to October 2019. Questionnaires were used to collect data from a sample of 453 participants. Multiple logistic regression was used to assess the significant household characteristics in driving forest dependence cattle grazing and grass harvesting. Results obtained revealed that significant household characteristics driving forest dependence for pasture were the ownership of zero-grazing unit (p=0.03 < 0.05), the proportion of cattle under zero grazing (p=0.04 < 0.05) and proximity to the forest (p=0.08 <0.1). The proportion of cattle in zero-grazing units had the highest marginal effect, followed by ownership of zero-grazing units with proximity to the forest having the lowest marginal effects. Significant household characteristics driving smallholder famers' dependence on protected forests for grass harvesting for cattle included: a household's socioeconomic status (p=0.06<0.1), a household's total size of land owned (p= 0.02 < 0.05), and proportion of cattle kept under a zero-grazing unit (p=0.07<0.1). The proportion of cattle in zero-grazing unit had the highest marginal effects followed by the total size of land owned. These findings contribute to knowledge on the significant micro-level characteristics driving the two forms of forest dependence investigated. Future studies are needed to explore the meso-and-macro-level factors that interact with household characteristics identified to drive forest dependence for livestock grazing and grass harvesting.
Conference Paper
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Overgrazing is an emerging concern in Kenya's indigenous forests. It affects regeneration, species structure and composition and soil. However, information on permissible grazing threshold and effects of overgrazing on forest ecosystem has not been adequately established in Kenya. This study was undertaken in South West Mau; the largest block forming Kenya's biggest water tower, Mau Complex. Grazing is the main driver of degradation in the forest. The objectives of the study were to determine; dependence of forest adjacent communities on forest for grazing, effects of grazing on forest structure and composition, permissible forage off-take levels and ecologically sustainable carrying capacity. Data and information was collected through household surveys, Focus Group Discussions, vegetation assessment under varied grazing intensities (heavy, moderate and light), estimation of primary forage productivity, livestock census and computation of carrying capacity. The study found that 96% of the households grazed their livestock in the forest throughout the year. Although the forest generally showed natural regeneration as exhibited by reversed exponential curve, there was no regeneration in heavily grazed areas. Further, significant variation existed in species diversity, stand density and basal area across the grazing intensity levels. Physical count survey estimated a total 17,263 livestock (14,804 ±396 cattle, 2,365 sheep, 44 goats and 50 donkeys) grazed in the forest daily. The available forage was estimated at 14 million Kg DM/ year. This forage can support 6,104 Tropical Livestock Units (TLUs) throughout the year. Currently, the forest supports 10,629 TLUs, hence grazing threshold has been exceeded by 74%. There is need therefore, to maintain sustainable grazing threshold that would ensure forest regeneration and adequate forage availability. The study will inform grazing policies in Kenya for sustained forest management.
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Societal Impact Statement Madagascar is famous for its unique forests and their fauna. Most of the island is covered by flammable grassy ecosystems long considered to be of human origin and threatening the remaining forests. Yet new studies show that many plants and animals of the grassy systems are unique to Madagascar and restricted to these open habitats. Open grassy ecosystems have markedly different management requirements from forests and bring different contributions to society. We argue that the grassy ecosystems can benefit Madagascar if understood and managed wisely using expanded knowledge bases that also include collaboration with locals. Summary Until recently, nearly all research and interests in Madagascar focused on forested habitats. To help place Madagascar's grassy ecosystems in context, we provide a summary of the origin, development, and evolution of open tropical, C4 grassy ecosystems elsewhere, especially those from Africa; we summarize similarities and differences with the distribution of C3 and C4 grasses in the Malagasy landscape, their plant traits, and inferences on the evolutionary legacy of grasses. We also discuss the animal communities that use and have coevolved in these grassy systems; to help resolve controversies over the pre‐settlement extent of grassy ecosystems, we suggest a variety of complementary geochemical, palaeobotanical, and molecular genetic tools that have been effectively used elsewhere to untangle forest/grassy ecosystem mosaics and the ecological and evolutionary processes that influence them. Many of these tools can and should be employed in Madagascar to fully understand the spatio‐temporal dynamics of open, grassy, and closed forest systems across the island; as regards conservation, we discuss the ecosystem services provided by grassy systems, which are too often ignored in general, not only as a biome, vis‐à‐vis forests, but also for their global importance as a carbon sink and role they play in water management and providing goods to local villagers. We conclude by outlining the necessary research to better manage open ecosystems across Madagascar without threatening endangered forest ecosystems.
Various forest management strategies are in place for the conservation of forest ecosystems across the globe. Nepal is also implementing different forest management and restoration practices and has various impacts on vegetation characteristics. This study aims to compare the richness and diversity of woody plant species, and variability in abundance of woody species assemblages in different forest management stands, viz. restored stands inside Buffer Zone Community Forest (BZCF), natural stands of BZCF and core stands of Parsa National Park. Thirty sampling plots of 30 m × 30 m were laid on each stand, maintaining at least 50 m distance between the plots, where woody plant species having height 1.5 cm was identified and their DBH measured. Species composition was assessed comparing Importance Value Index (IVI) of woody plant species across the forests. Similarly, species diversity and structural diversity across stands were determined using Shannon Diversity index and basal areas of the plant species were calculated. The study showed Shorea robusta and Lagerstroemia parviflora with highest frequency (>80%) in all the sites, and the species diversity was highest in the core stands inside the national park followed by the natural stands of BZCF, and the restored stands of BZCF. Basal area of overall species and density of S. robusta were, however, highest on the restored stands of BZCF, whereas overall density was highest in the natural stands of the BZCF. The study revealed that the forest management practices need improvement in enhancing the plant species diversity of the ecosystems. We recommend to assess the functional attributes of the different forest management stands to evaluate the effectiveness of forest management strategies.
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The Malagasy dry forests are composed of dense dry forests in the western domain and xerophytic thickets in the more arid southern domain. These dry forests are generally less studied than the humid forests. This article provides a brief review of the state of knowledge on how the Malagasy dry forest ecosystems are operating and identifies gaps that future research activities could address. The main gaps on Malagasy dry forest ecosystems concern: (i) their more accurate mapping, (ii) the analysis of the relationships between seed dispersers/pollinators and their natural regeneration, (iii) dry forest regeneration potentials (tree sprouts, seed bank and seed rain), (iv)their resilience to intern (anthropogenic) and extern (climate) disturbances, and (v) more accurate estimation of their biomass production and productivity.
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Madagascar is home to more than 10 000 plant species, 80% of which occur nowhere else in the world. With natural vegetation ranging from rainforest to unique spiny forest, Madagascar’s range of plant diversity makes it one of the world's most important biodiversity hotspots. In common with many other tropical countries, the flora of Madagascar is extremely threatened not only by habitat destruction for agriculture, fuelwood, building materials and so on, but also, in the case of certain species, by over-collection for the horticultural trade. The CEPF Madagascar Vegetation Mapping Project is a three-year project (2003–2006), funded by the Critical Ecosystem Partnership Fund (CEPF) and managed jointly by The Royal Botanic Gardens, Kew, Missouri Botanical Garden, and Conservation International’s Center for Applied Biodiversity Science. The project is innovative in a number of ways. It employs state-of-the art remote sensing technology and methodologies to delimit Madagascar’s vegetation. It represents an all-inclusive collaboration between specialists from a wide range of botanical and conservation institutions, which has ensured the most thoroughly ground-truthed vegetation map ever compiled for Madagascar. Finally, through a series of workshops, it incorporates detailed consultations with the conservation community to ensure that the final products are of maximum relevance and utility to conservation planners and managers. An accurate and updated vegetation map is imperative for conservation planning and natural resource management in Madagascar. It is also essential that the data on which such a map is based be made freely available, so that conservation organisations, government departments, academic institutions and other stakeholders can use them as an up-to-date standard dataset on which to base their activities. The electronic version of this atlas is available on Kew’s website (, and local experts were invited to continually improve and update the map. In order for a vegetation map to fulfil its intended role it must accurately delimit areas with various vegetation types as they currently exist, and assign those areas to objective categories that can be easily recognised in the field and that reliably reflect fundamental biological differences (primarily structural features, for example, physiognomy). Madagascar is becoming increasingly aware of the need to protect its biodiversity. The most immediate use of this vegetation map in conservation is likely to be by protected area managers who wish to understand the flora of their designated areas. It will also provide a valuable baseline for monitoring longer-term changes in vegetation inside and outside protected areas. However, Madagascar also provides an exceptionally high rate of species discovery and description, and this atlas will be used by field biologists attempting to identify potential sampling sites for biodiversity surveys, which will in turn yield data that is critical for biogeographic research and conservation planning. At the 2003 World Parks Congress, Madagascar’s President Marc Ravalomanana emphasised his country’s commitment to conservation by announcing its intent to triple the size of its existing protected area network. This admirable effort to prevent the extinction of many of Madagascar’s endemic species has become known as the ‘Durban Vision’. In order to ensure effective preservation of Madagascar’s biodiversity, the identification of sites for these new protected areas should follow a systematic process. A recent workshop on systematic conservation planning (November 2005, Antananarivo) highlighted the importance of using habitat types and indicators of habitat quality in addition to species distribution data when conducting conservation prioritisation analyses, concluding that this is the best way to produce robust conservation solutions. Because only a small proportion of Madagascar’s species have had their distributions documented, the vegetation types identified by this mapping project are good surrogates for habitat diversity and for the majority of the biota, which is so little known. In addition, conservation practitioners, including NGOs and donors, need information on trends in natural vegetation cover and quality in order to assess the outcomes of their conservation work. The Convention on Biological Diversity includes trends in the extent of habitats among its headline indicators for tracking progress towards the 2010 target (SBSTTA, 2004). The immediate focus of the Durban Vision group will be on establishing new protected areas (map 1) in remaining native vegetation, although subsequent attention could productively turn to managing that vegetation, and the habitat quality categories in the atlas provide valuable information. The atlas also provides important up-to-date information on native vegetation cover and quality, which maximises its potential to aid planning for future habitat restoration activities.
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From June 2007 to March 2009, phenological studies were carried out in Tsimanampetsotsa National Park, a spiny forest ecosystem in southwestern Madagascar. Six phenological plots of 5 x 200 m were installed and monitored biweekly in three vegetation types (dry forest on sandy soil, xerophytic bush on calcareous soil, and dry forest on ferruginous soil). The different phenophases could be linked to ambient conditions. The majority of plant species lost their leaves during the dry season (April to November). In all plots, flowering showed a bimodal distribution: one group of species flowered during the dry season and the other group had their maximum flowering peak during the wet season (December to March). Fruiting started at the end of the dry and beginning of the wet season (December, January), a period when strong winds prevail. This period also coincides with the start of the hot-wet season when possibly seed dispersing animals increase their activity or have come out of hibernation (Microcebus griseorufus). Both phenomena can be interpreted as facilitation for seed dispersal. The presence of leaves was linked to actual rainfall. However, day length rather than the actual rainfall triggered flowering and fruiting. This indicates that plants adapted their reproductive cycles to long-term climatic averages (reflected by day length), which seem to be more reliable in evolutionary terms than using erratic rains as a cue to initiate reproduction.
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The total foliar area or mass of a tree is difficult to measure, as is its bark or cambial area, and various other components of aboveground biomass. A variety of sampling methods is proposed and estimators of these characteristics are presented. Based on probability precepts, all estimators are unbiased. An unbiased estimator of variance for each estimator also is presented. The basis in probability rather than a fitted regression equation provides some important safeguards, and is a useful alternative when fitted regression functions are unavailable for a particular species and physiographic condition.
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We studied the effects of sheep grazing intensity and abandonment on plant species richness and composition, plant life forms and the productivity of North Adriatic Karst pastures. The experimental sites were under controlled grazing regimes (heavy, moderate, light and abandonment) for 10 years. Data were collected during one season; plant species composition, the number of species and above‐ground and below‐ground biomass were evaluated. Species richness was significantly reduced with increasing grazing intensity and abandonment. The greatest differences in species composition were recorded for the heavily grazed site owing to the appearance of a group of grasslands species typical of nutrient‐rich soil. Heavy grazing increased therophytes and decreased the proportion of chamaephytes and geophytes. Above‐ground productivity at the season's peak was typical of subhumid grasslands (up to 500 g m) and was significantly the highest in the abandoned pasture. Below‐ground biomass was significantly the lowest in the heavily grazed sites and the highest in those that were moderately or lightly grazed. We could conclude that grazing intensification and abandonment have significant effects on the structure of these pastures. Low‐ or moderate‐intensity (4–7 sheep ha) grazing seems to be the most appropriate treatment since it can maintain the species richness and typical floristic composition of those pastures.Abbreviations: ANOVA, analysis of variance; DCA, detrended correspondence analysis; HSD, honest significant differenceNomenclature: Martinčič et al. (2007)
Woody and herbaceous species interaction in disturbed and natural environments has attracted a great deal of research attention due to its implications for land cover change, land surface-atmosphere interaction, global carbon budget (House et al. 2003), biodiversity, primary and secondary productivity, and the associated land use management (Archer 1994). Ecosystems of mixed woody and herbaceous plants comprise 15-35% of the terrestrial surface area and are distributed from hot tropical to cold temperate climates across varying topography and soils (House et al. 2003). Mixed woody-herbaceous ecosystems are often heavily impacted by natural and anthropogenic factors such as fire and grazing (House et al. 2003). © 2012 Springer Science+Business Media New York. All rights are reserved.
We evaluated the adequacy of rotational grazing to improve rangeland condition in the Flooding Pampa region, eastern Argentina, comparing the floristic composition dynamic of the 2 main plant communities under rotational and continuous grazing over a study period of 4 years (1993-1996). The experiment was conducted in commercial farms located in 4 sites of the Flooding Pampa region. In each site, a couple of farms, one managed under rotational grazing (implemented in 1989) and an adjacent one managed under continuous grazing at a similar stocking rate (1 AU(.)ha(-1)), constituted the replications of the experiment. Basal cover of species, litter, and bare soil were monitored in midslope and lowland grassland communities on each farm. Total plant basal cover in midslope and in lowland communities remained unchanged over the whole experimental period under both grazing methods. Under rotational grazing, litter cover was higher in both communities while the amount of bare soil showed a significant reduction in lowlands and a tendency to be lower in midslope. Basal cover of legumes, C-3 annual and C-3 perennial grasses was higher, while cover of C-4 prostrate grasses was lower under rotational grazing in the midslope community. In the lowland community, rotational grazing effects were evident only in the drier years, when higher cover of hydrophytic grasses and legumes and lower cover of forbs occurred. Plant species diversity did not change in response to grazing. In conclusion, rotational grazing promoted functional groups composed of high forage value species and reduced bare soil through the accumulation of litter. These changes indicate an improvement in rangeland condition and in carrying capacity. As the stocking rate was approximately 60% higher than the average stocking rate of the Flooding Pampa region, we believe that productivity and sustainability may be compatible by replacing continuous with rotational grazing.
In the Sahel, sheep and goats cannot make full use of browse pastures. The accessibility to this pastures depends on the morphological characters of woody species. For this reason herders intervene by cutting down branches or trees and shrubs. These practices can compromise in long-term the future of small ruminants by degrading the browse pastures. In the Sahel countries, the development of small ruminants has been neglected for the benefit of cattle livestock. The development programs to undertake for improving small ruminants should give priority to impact studies on vegetation and environmental education of herders.