Mopane Research Articles

Mapping key browse resources in a heterogeneous agricultural landscape

We investigated application of MaxEnt, a one-class classifier, in mapping the spatial distribution of Colophospermum mopane, Dichrostachys cinerea and Salvadora persica using drainage, elevation, slope, soil and Normalised Difference Vegetation Index as environmental variables. Model performance was evaluated based on the area under the ROC curve (AUC), Kappa and Total Skills Statistic. The AUC results demonstrated the high predictive power of MaxEnt as test data values of all species, respectively, were 0.694, 0.754 and 0.998 (p < 0.05). Elevation contributed the most in explaining spatial distributions of all species. Results also indicated that several one-class species maps can be integrated into one species distribution map. We showed that C. mopane is likely to co-occur with D. cinerea and S. persica, whereas S. persica is likely to co-occur with D. cinerea. However, there was no habitat suitable for co-occurrence of all species. One-class species mapping can therefore be successful in heterogeneous agricultural landscapes.

Charcoal anatomy and NIR spectra of Spirostachys africana, Terminalia sp. and Colophospermum mopane in different carbonization process

In Mozambique, charcoal processes can result in several disturbances in natural forests. In the present study, we evaluated the effect of four carbonization methodologies on the anatomical characteristics and near infrared spectra of Spirostachys africana, Terminalia sp. and Colophospermum mopane, to contribute with information for an identification database for charcoal control. The carbonization was done in an electric muffle furnace with different final temperature (400/450 °C) and total time (40 min/2 h, 4 h, 6 h). The quantitative changes in anatomy of charcoal samples was not directly related to carbonization programs with respect to particular features of each species. Species are best distinguished for the NIR spectra in the region from 4000 to 5000 cm−1. In the analysis by species, charcoal produced at 450 °C—4 h were more distinct in comparison to other programs that resulted in mixed samples. Final temperature influenced more than total process time in species distinction and the use of NIR is reinforced as a potential tool to discriminate species submitted to different carbonization processes. These traits can be applied in species discrimination based on databases of wood anatomical descriptions and charcoal NIR spectra.

Neotropical jumping plant-lice (Hemiptera, Psylloidea) associated withplants of the tribe Detarieae (Leguminosae, Detarioideae).

The Detarieae, a small tribe of tropical arborescent Leguminosae, has been reported as host of two species of jumping plant-lice: the Neotropical Macrocorsa beeryi (Caldwell) on Hymenaea courbaril and the Afrotropical Retroacizzia mopanei (Pettey) on Colophospermum mopane. Here we add from Brazil 18 new species of Colophorina, Jataiba gen. nov. and Mitrapsylla from Copaifera, as well as nine species of Jataiba gen. nov. and Platycorypha from Hymenaea. In addition to Jataiba, a new genus which is created for five new species on Copaifera and one on Hymenaea, we erect the new genus Apsyllopsis for Psyllopsis mexicana, which is synonymised with Psyllia beeryi Caldwell. Two new combinations are proposed: Apsyllopsis mexicana (Crawford), comb. nov. from Psyllopsis, and Epiacizzia favis (Brown Hodkinson), comb. nov. from Euphalerus. The new taxa are described and illustrated, and keys are provided for the identification of adults and immatures, as far as known. Immatures of Apsyllopsis and Colophorina induce galls on the leaves whereas those of the other taxa are free-living. Colophorina spp. seem to be monophagous whereas members of the other genera tend to be oligophagous. All host species are associated with two or more psyllid species. Copaifera langsdorffii, which hosts 11 species of three genera, constitutes a super-host.

Meeting a diversity of needs through a diversity of species: Urban residents’ favourite and disliked tree species across eleven towns in South Africa and Zimbabwe

Understanding of urban residents’ preferences and dislikes for tree species and attributes is necessary to provide them with the species they most favour. Yet there is relatively little understanding of local species preferences, the reasons underlying them and how they vary with context and scale. We interviewed 1100 urban residents in eleven towns (four in Zimbabwe, four in Limpopo Province and three in the Eastern Cape of South Africa) to determine what were their favourite and least favourite tree species and the reasons for such. Fifty-nine species were listed amongst the preferred species (the four most common being Jacaranda mimosifolia (10% or respondents), Mangifera indica (10%), Adonsonia digitata (7%) and Colophospermum mopane (7%)), and 29 as disliked (the four most common being Vachellia spp, J. mimosifolia, Euphorbia spp. and Melia azedarach), with 16 in common between the two. Across the entire sample, the most common reason for preferring a particular species was that it had tasty fruits (19%), closely followed by the species evoking memories of where the respondent grew up (19%), and that it attained a large size (15%). The main reasons for disliking a species were because it was thorny (26% of responses), messy (16%), allergenic (15%), or poisonous (14%). There were no clear associations between preferences and respondent attributes, other than females being more likely to mention a disliked species than were males. There were clear intra- and inter-regional differences in the species preferred, and some of the reasons provided. There was some indication that preferred species are ones that are most apparent in the local environment but requires further investigation. The regional and inter-town differences emphasise that planting programmes should be informed by local preferences and needs, and that planting a diversity of species is likely to help match the diversity of preferences and needs.

Effects of pruning on Colophospermum mopane leaf phenology and production

Effects of pruning on <i>Colophospermum mopane</i> leaf phenology and production

Clean Cookstove Technology Use for Energy Efficiency in the School System

Globally, clean cookstoves represent the best substitute for open fire biomass stoves in order to reduce greenhouse gas emissions from fuelwood. Prospects to transfer this technology to Botswana are being explored. Our research objectives were to transfer the clean Institutional Cookstove (IC) technology to Okavango Research Institute (ORI), quantify the amount of mopane (Colophospermum mopane) fuelwood it consumes in comparison to the traditional biomass energy system, and analyze its potential to be used as a substitute for the open fire cooking method. The clean IC technology transfer to ORI was successfully completed before testing its energy efficiency and financial viability. It consumed approximately two-thirds less fuelwood than the traditional three stone stove. This presents an opportunity for a reduction in greenhouse gas emissions from fuelwood consumption in Botswana. This is a critical consideration in an environment where there is limited readily available fuelwood. The use of clean cookstoves allows enhanced carbon sequestration by live mopane woodland resources. A financial viability analysis of implementing the clean IC in primary schools showed that it has the potential to save money spent on fuelwood. Our case study provides essential pertinent results on the energy efficiency of the developed prototype, which forms a basis for further research on the use of clean cookstoves for mitigating greenhouse gas emissions from fuelwood consumption in Botswana and the entire Cubango-Okavango River Basin. A comprehensive analysis of cultural barriers to adoption of the technology will be carried out through piloting the construction of the clean cookstove.

Vegetation dynamics in African drylands: an assessment based on the Vegetation Degradation Index in an agro-pastoral region of Botswana

Changes in vegetation conditions are induced both by climatic and human factors. Knowledge about how changes in vegetation conditions relate to its degradation is often lacking, although needed to sustainably manage rangeland resources in drylands. Contributions made to develop land management options require assessing vegetation dynamics and degradation in Palapye, an agro-pastoral region of high economic and biodiversity importance in eastern Botswana. The Vegetation Degradation Index (VDI) was applied to 18-year (1986–2016) time series of annual Normalized Difference Vegetation Index (ANDVI) images to establish vegetation degradation levels, i.e. relatively undegraded, low degradation, medium degradation, and high degradation. Plant species metrics and biophysical variables were then examined at nine sites with the aim of explaining variations in the vegetation degradation levels. Approximately 95% of the study area experienced low degradation and 11% had significant negative trends in ANDVI. Species richness, diversity, and rainfall explained 49% of the variance in degradation levels. Species diversity and richness were highest in Moeng (a relatively undegraded site), whereas they were lowest in Lesenopole (a low degradation site). A probable reason being that Colophospermum mopane contributed 87% of individual trees and shrubs at Lesenopole. Species diversity and richness were also negatively associated with VDI. The non-occurrence of some species such as Sclerocarya birrea and Lonchocarpus capassa on highly degraded sites suggests a link between species composition and the level of degradation. This study combined the use of theremote sensing-based VDI with field-based plant species data for validating vegetation degradation levels in a dryland context.

Ecohydrological threats to Colophospermum mopane in southern Zimbabwe.

Rapid ecohydrological changes in semi-arid landscapes are increasingly threatening humanity’s life-support systems and eroding many of the ecosystem services (ESs) upon which humans occupying such regions depend. Knowing which services and ecohydrological changes to be most concerned about is indispensable to maintaining the general health of such ecosystems and for developing effective ecosystem management practices. In the semi-arid regions of southwestern Zimbabwe where a large population of rural households depend on ESs extracted from the Colophospermum mopane tree, such understanding may be critical in reversing potential ES losses that may have catastrophic effects on the lives of many. We surveyed a total of 127 rural households who occupy the semi-arid landscapes of the Colophospermum mopane belt in southern Zimbabwe. We assessed the ecohydrological conditions characterising ecosystems where they obtain ES provisioning goods using a number of ecohydrological variables commonly cited in the literature on ecohydrology. Building on principal component analysis (PCA), we employed a hierarchical agglomerative clustering method to create unique clusters of households that depicted different levels of risks or threats associated with their ES provisioning harvesting practices. Multiple regression analysis was further performed to identify significant ecohydrological cluster-defining variables. Our results showed that spatial differences in ecohydrological parameters resulted in four distinct ES resource thresholds depicting four categories of risks that households face in extracting such resources in nearby landscapes. We concluded by proposing a number of landscape restoration or management practices targeted at reversing potential ES losses and subsequently safeguarding the livelihoods of many who depend on ESs.

Diversification of African Tree Legumes in Miombo-Mopane Woodlands.

The southern African Miombo and Mopane ecoregions constitute a unique repository of plant diversity whose diversification and evolutionary history is still understudied. In this work, we assessed the diversity, distribution, and conservation status of Miombo and Mopane tree legumes within the Zambezian phytoregion. Data were retrieved from several plant and gene databases and phylogenetic analyses were performed based on genetic barcodes. Seventy-eight species (74 from Miombo and 23 from Mopane, 19 common to both ecoregions) have been scored. Species diversity was high within both ecoregions, but information about the actual conservation status is scarce and available only for ca. 15% of the species. Results of phylogenetic analyses were consistent with current legume classification but did not allow us to draw any conclusion regarding the evolutionary history of Miombo and Mopane tree legumes. Future studies are proposed to dissect the diversity and structure of key species in order to consolidate the network of conservation areas.

Distribution of a habitat specialist: Mopane woodland structure determines occurrence of Near Threatened Lilian’s Lovebird Agapornis lilianae

SummaryThe near-threatened Lilian’s Lovebird Agapornis lilianae is a small parrot endemic to the Zambezi basin in south-east Africa. The species has a fragmented distribution predominantly within mopane woodlands and is widely referred to as a mopane specialist. The harvesting of mopane trees for charcoal production and timber are having widespread impacts on this woodland habitat, raising concerns over its capacity to support biodiversity. This study aimed to understand the key drivers determining the occurrence of Lilian’s Lovebird in the mopane woodlands of Zambia, focusing particularly on aspects of woodland structure, including the size and density of trees. We used a MaxEnt species distribution model based on historical species occurrence data, to inform selection of 116 survey plots in the Luangwa, Luano and Zambezi valleys. Each plot was sampled for Lilian’s Lovebirds and woodland structure described. Occurrence of Lilian’s Lovebird was found to be positively associated with the size of mopane trees (both height and diameter at breast height) suggesting that large ‘cathedral’ mopane trees provide a key resource for the species and that conservation efforts should focus on the protection of sites containing large trees. No Lilian’s Lovebirds were recorded in areas where they previously occurred to the west of Lower Zambezi National Park, and there was an absence of ‘cathedral’ mopane habitat in this area.

Suitability of Wild Host Plants and Firewood as Hosts of Prostephanus truncatus (Coleoptera: Bostrichidae) in Mozambique.

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) populations are maintained in wild host plants such as trees that act as pest reservoirs from where beetle infestation of maize granaries take place. In this study, we assessed the suitability of plant species sold and transported as firewood as well as other plant species in Mozambique as hosts for P. truncatus. Prostephanus truncatus was only recorded from three tree species, which are sold as firewood, i.e., Brachystegia spiciformis, Strychnos spinosa, and Colophospermum mopane. The pest survived and bred in 13 tree and 7 grass species. Dry wood of several tree species and the grasses Acroceras macrum and Hyparrhenia hirta were suitable hosts for pest development. Sale and transport of certain firewood species may be an important driver of the spread of this pest. The importance of dry maize stalks and several grass species in sustaining pest populations is described for the first time. Several grass species are used as thatch or fencing material and, together with maize crop residues close to small-scale granaries, may provide significant sources of beetle infestation.

Effects of pruning on the concentration of macronutrients in Colophospermum mopane leaves

AbstractDespite the nutritional value of Colophospermum mopane leaves to browser's diets, there is limited knowledge on the effect of browsers on the concentration of macronutrients in mopane leaves. A field experiment was conducted in Musina Nature Reserve, Limpopo Province, South Africa to determine the effect of pruning, a proxy for browsing, on the concentration of macronutrients in mopane leaves. Samples were analysed for calcium (Ca), potassium (K), nitrogen (N), phosphorus (P), sulphur (S), chlorine (Cl), magnesium (Mg), nitrate (NO3), sodium (Na), protein and fibre, using inductively coupled plasma atomic emission spectrometry techniques. The effect of pruning on the monthly concentration of macronutrients was tested using a two‐tailed t test: two‐sample assuming equal variance. The seasonal and annual effect of pruning on the concentration of macronutrients was tested using a one‐way ANOVA. Results showed that the amount of Ca, K, N, P, S, Cl, Na, protein and fibre increased during leaf flush in October and then declined as the leaves matured and aged. However, the concentration of Mg and NO3 increased when the leaves reached maturity in June, particularly during senescence stage, and declined thereafter. The concentration of macronutrients between the control and pruned trees was statistically insignificant for most samples.

Effects of pruning on the concentration of secondary metabolites in Colophospermum mopane leaves

Colophospermum mopane, commonly known as mopane, produces secondary metabolites during the growing season. However, there is still insufficient knowledge on the quantity of secondary metabolites and the effect of browsers on the concentration of secondary metabolites. A pruning experiment was conducted in the Musina Nature Reserve, Limpopo province, South Africa, to simulate the effect of browsers on the concentration of secondary metabolites in mopane leaves. The twigs from 40 selected experimental mopane trees were pruned back 50 mm from their tips using a hand shear. The total amount of leaf and shoot biomass removed from branches of selected experimental trees was less than 10%. Three independent samples composed of seven mopane leaves per 40 mopane trees were randomly collected from the canopies of experimental and control trees per sampling event. The dried leaves from each three independent samples were then mixed separately and a pooled sample of 10 g per treatment per sample cycle (55 d) was used for determination of total phenols (TP), condensed tannins (CT) and protein-precipitating tannins (PPT). Results showed that <10% pruning does not have an effect on the amount of secondary metabolites in the mopane leaves. The concentration of TP, CT and PPT increased during leaf flush in October and then declined as the leaves matured and aged. It is concluded that the amount of secondary metabolites in mopane leaves is not dependent on <10% pruning, but appeared to be associated with leaf growth stages. The ability of mopane to produce secondary metabolites has implications on the seasonal diet composition and distribution of browsers in mopane woodland.

Transplant Experiments Point to Fire Regime as Limiting Savanna Tree Distribution

Plant species range shifts are predicted to occur in response to climate change. The predictions are often based on the assumption that climate is the primary factor limiting the distribution of species. However the distribution of grassy biomes in Africa cannot be predicted by climate alone, instead interactions between vegetation, climate and disturbance structure the ecosystems. To test if climatic variables, as predicted by an environmental niche model, determine the distribution limits of two common savanna tree species we established a transplant experiment at a range of latitudes and altitudes much broader than the distribution limits of our study species. We planted seedlings of two common savanna trees, Senegalia nigrescens and Colophospermum mopane, at eight paired high and low elevation sites across an 850 km latitudinal gradient in South African savannas. At each site seedlings were planted in both grassy and cleared plots. After two years of growth, rainfall, temperature and location inside or outside their distribution range did not explain species success. Grass competition was the only variable that significantly affected plant growth rates across all sites, but grass competition alone could not explain the distribution limit. Species distributions were best predicted when maximum tree growth rates were considered in relation to local fire return intervals. The probability of sapling escape from the fire trap was the most likely determinant of distribution limits of these two species. As trees grew and survived 100s of kilometers south of their current range limits we conclude that climate alone does not explain the current distribution of these trees, and that climate change adaptation strategies for savanna environments based only on climatic envelope modelling will be inappropriate.

Effect of shredded Colophospermum mopane wood inclusion as roughage on the performance of fattening Nguni cattle

A study was conducted to determine the effect of shredded Colophospermum (C.) mopane wood inclusion as roughage on the performance of fattening Nguni heifers. The heifers were randomly allocated to four diets with different shredded C. mopane wood inclusion levels (5, 8.5, 10 and 15%) in a completely randomized design. Shredded C. mopane wood inclusion level had effect (P less than 0.05) on intake and feed conversion ratio (FCR). Diet intakes per metabolic weight and FCR of Nguni heifers were optimised at different shredded C. mopane wood inclusion levels. However, shredded C. mopane wood inclusion levels did not affect (P greater than 0.05) diet in vitro digestibility, carcass weight, dressing percentage, meat pH, meat shear force values and meat colour intensities except for red colour intensity of rump steak. It was, thus, concluded that shredded C. mopane wood can be used as roughage without adversely affecting diet intake, FCR, and live weight of Nguni heifers.

Colophospermum Mopane Leaf Production and Phenology in Southern Africa's Savanna Ecosystem - A Review

Colophospermum mopane, commonly known as mopane, is a dominant tree or shrub in the mopane woodland. It is widely distributed in the low-lying areas of southern Africa's savanna. Despite its wide distribution, ability to survive water stress conditions, and value as a source of browse for herbivores, especially during the dry season, there is limited knowledge on mopane leaf production and phenology as well as its implications to browsers.

Performance of ratio‐based, soil‐adjusted and atmospherically corrected multispectral vegetation indices in predicting herbaceous aboveground biomass in a Colophospermum mopane tree–shrub savanna

AbstractAccurate and near‐real‐time estimation of herbaceous aboveground biomass (AGB) at farm level is crucial for monitoring pasture production and proactive management of stock in semiarid rangelands. Despite its importance, remote sensing has been rarely used by range ecologists and managers in Zimbabwe. This study aimed at assessing the performance of classical multispectral vegetation indices (MVIs) when either singly regressed with measured herbaceous AGB or combined with other visible spectral bands in predicting herbaceous AGB in a Colophospermum mopane savannah. Field herbaceous AGB and corresponding Landsat 8 Operational Land Imager visible spectral data were collected during the 2016–2017 rainy season. Relationships between measured AGB and classical MVIs and extended models of MVIs combined with other visible bands were analysed using bootstrapped simple and stepwise multiple linear regression functions. When MVIs were singly regressed with measured AGB, ratio‐based indices yielded the highest r2 value of 0.64, followed by soil‐adjusted indices (r2 = 0.61), while atmospherically corrected MVIs showed the lowest r2 of 0.58 (p = 0.00). A significant improvement in herbaceous AGB estimation was obtained using a combination of MVIs and other visible bands. Soil‐adjusted MVIs showed the greatest increase (44–46%) in r2, while atmospherically corrected and ratio‐based MVIs poorly improved (&lt;5%). The findings demonstrate that combining MVIs with Landsat 8 optical bands, especially green band, provides the best models for estimating AGB in C. mopane savanna rangelands. These findings emphasize the importance of testing band‐MVI combinations when developing models for estimating herbaceous AGB.

Effect of different tree leaf litters on yield and nutrient uptake of clusterbean-oat rotation in arid region of Rajasthan

The study was conducted at ICAR-Central Arid Zone Research Institute, Regional Research Station, Bikaner to study the effect of tree leaf litters on yield and nutrient uptake of clusterbean-oat rotation during 2010-11 and 2011-2012. Leaf litters of seven tree species viz. Mopane: Colophospermum mopane, Gum acacia: (Acacia senegal) , Umbrella tree: (Acacia tortilis) , Indian rosewood: (Dalbergia sissoo), Sour lime: (Citrus aurantifolia), Assyrian plum: (Cordia myxa) and Bengal quince: (Aegle marmeloswere) applied in microplots of 2 x 2 meter @ 2.5 t/ha. Chemical fertilizers were used as per recommendations of individual crop. The result showed that maximum grain yield of clusterbean was obtained with the application of leaf litter treatments of Citrus aurantifolia. The increase in grain yield was in the order of leaf litter treatments of Citrus aurantifolia, Dalbergia sissoo and Aegle marmelos, respectively. The residual effect of leaf litters of Citrus aurantifolia, Dalbergia sissoo and Aegle marmelos increased the grain yield of oat by 13.3-16.0 percentage in 2010-11 and 14.8-16.1 percentage in 2011-12, respectively. There was no significant effect of leaf litters of Cordia myxa and Acacia senegal on grain yield of clusterbean and oat. Litter addition had significant effect on nutrient uptake also. The mean uptake of nutrients was significantly higher in Citrus aurantifolia, Dalbergia sissoo and Aegle marmelos treatments as compared to control. The two years average data showed that the total uptake of N in clusterbean increased from 21.3 kg/ha in control to 32.2, 28.5 and 30.8 kg/ha in Citrus aurantifolia, Dalbergia sissoo and Aegle marmelos treatments, respectively. Nitrogen, phosphorus and potassium uptake was non-significant in the treatments Colophospermum mopane, Cordia myxa, Acacia tortilis and Acacia senegal

Feeding ecology of Lilian’s Lovebird Agapornis lilianae in Liwonde National Park, Malawi

Lilian's Lovebird Agapornis lilianae is a small, near-threatened parrot resident in mopane Colophospermum mopane woodlands. We investigated its diet and foraging behaviour in Liwonde National Park, Malawi. We expected that Lilian's Lovebirds would show little specialisation for a particular food source but generally feed on available seeds, fruits, flowers and other items as observed in other lovebirds. Lilian's Lovebirds fed on 30 different plant species. Lilian's Lovebirds were observed feeding in six habitat types in Liwonde National Park and adjacent areas during the wet season, and four in the dry season. In the wet season lovebirds (23% of observations) foraged in grassy wetland (dambo) areas the most, whilst in the dry season they foraged in grasslands with tree cover (18%) the most. In mopane woodland, foraging flock sizes differed significantly between the wet (mean = 19.8 ± 1.0 lovebirds) and dry season (mean = 33.6 ± 2.3 lovebirds). Grass seeds were lovebirds’ main food source from December to June. The nutritional analysis of preferred foods showed that grass seeds have a relatively high protein and energy content. Grass seed availability is reduced with savanna burning and so early season burning (before May–June) in areas in and outside the park is not recommended.

Insect outbreaks alter nutrient dynamics in a southern African savanna: patchy defoliation of Colophospermum mopane savanna by Imbrasia belina larvae

AbstractInvertebrate herbivore outbreaks have important impacts on system biogeochemical cycling, but these effects have been poorly documented in African savanna ecosystems. In semi‐arid African savannas, outbreaks of the lepidopteran Imbrasia belina (mopane worm) affect discrete patches of the dominant Colophospermum mopane trees; larvae may completely defoliate trees for up to six weeks during each of the early and late growing seasons. We studied the impact of mopane worm outbreaks on the availability of nitrogen (N), phosphorus (P), and potassium (K) within mopane savanna by quantifying major nutrient pools in defoliated and non‐defoliated savanna patches, including leaves, leaf litter, worm frass, and the soil beneath trees. Within an outbreak area, approximately 44 percent of trees were infested, supporting ~29,000 worms/ha, leading to ~640 kg/ha dry weight frass deposition at 1.4 g of frass/day‐individual (fourth or fifth instar), compared with an average 1645 kg/ha dry weight of leaf on trees most of which should be deposited by litterfall at the end of the growing season. Frass had twofold higher P, 10 percent higher K, but equivalent N content than litter. Taking frass and litter deposition together, the N, P, and K contents added due to the outbreak event at our study site were 0.88, 5.8, and 2.8 times those measured in non‐outbreak patches, a pattern which was reflected in the nutrient contents of soil surfaces beneath defoliated trees. Invertebrate herbivory appears to be an important driver for mopane savanna but has been largely neglected.