Herbaceous biomass, species composition and soil properties of keygrazing patches in coastal forest thornveld and two grassland types of theEastern Cape province, South Africa

Seasonal variation in seed bank size and species composition of five selected habitat types within the Tembe Elephant Park. South Africa, was investigated. At three-month intervals, soil samples were randomly collected from five different habitat types: a, Licuati forest; b, Licuati thicket; c, a bare or sparsely vegetated zone surrounding the forest edge, referred to as the forest/grassland ecotone; d, grassland; and e, open woodland. Most species in the seed bank flora were either grasses, sedges, or forbs, with hardly any evidence of woody species. The Licuati forest and thicket soils produced the lowest seed densities in all seasons. Licuati forest and grassland seed banks showed a two-fold seasonal variation in size, those of the Licuati thicket and woodland a three-fold variation in size, whereas the forest/grassland ecotone maintained a relatively large seed bank all year round. The woodland seed bank had the highest species richness, whereas the Licuati forest and thicket soils were poor in species. Generally, it was found that the greatest correspondence in species composition was between the Licuati forest and thicket, as well as the forest/grassland ecotone and grassland seed bank floras.

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Poultry and cattle manure effects on sunflower performance, grain yield and selected soil properties in Limpopo Province, South Africa

South African Journal of Science ◽

10.17159/sajs.2019/6410 ◽

2019 ◽

Vol 115 (11/12) ◽

Author(s):

Matome J. Mokgolo ◽

Jestino Mzezewa ◽

Jude J.O. Odhiambo

Keyword(s):

South Africa ◽

Grain Yield ◽

Soil Properties ◽

Plant Height ◽

Dry Matter ◽

Poultry Manure ◽

Organic Manure ◽

Limpopo Province ◽

Organic Manures ◽

Cropping Season

The application of organic manures as alternatives to reduce the use of mineral fertilisers is considered a good agricultural practice for smallholder farmers. However, the effect of organic manure on soil properties and crop yield depends upon its application rate and its chemical composition. A field experiment was carried out during the 2013/2014 and 2014/2015 seasons at the University of Venda experimental farm (Limpopo Province, South Africa) to determine the effect of three organic manures (cattle, poultry and their 1:1 combination, 20 t/ha) on sunflower (Helianthus annuus L.) performance, grain yield and selected soil properties under rainfed conditions. Poultry manure produced the highest final infiltration rate and cumulative infiltration followed by cattle manure, their combination and the control in that order. Total nitrogen, calcium, and zinc were significantly different between treatments in the first season while potassium, sodium, and zinc were significantly different in the second season. Manure combination and poultry manure produced the highest organic carbon and available phosphorus, respectively, in both seasons compared to other treatments. Organic manure application had a significant (p less than 0.05) effect on dry matter, plant height and stem girth at all growth stages in the second cropping season but only in the flower bud stage for both parameters in the first season. Manure application in the second season resulted in an increase in the grain yield compared to the first season, except after application of poultry manure whereafter the grain yield decreased significantly by 168% from the first cropping season. The application of organic manure had a significant effect on sunflower grain yield, dry matter, head dry matter, plant height and stem girth throughout all growing stages in the second cropping season with poultry manure producing the best values.

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Effects of exotic guava ( Psidium guajava L.) invasion on soil properties in Limpopo, South Africa

African Journal of Ecology ◽

10.1111/aje.12675 ◽

2019 ◽

Vol 58 (2) ◽

pp. 272-280

Author(s):

Sheunesu Ruwanza ◽

Farai Dondofema

Keyword(s):

South Africa ◽

Soil Properties ◽

Psidium Guajava

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Integrating effects of species composition and soil properties to predict shifts in montane forest carbon–water relations

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1718864115 ◽

2018 ◽

Vol 115 (18) ◽

pp. E4219-E4226 ◽

Cited By ~ 19

Author(s):

Toby M. Maxwell ◽

Lucas C. R. Silva ◽

William R. Horwath

Keyword(s):

Species Composition ◽

Soil Properties ◽

Water Use ◽

Sierra Nevada ◽

Water Relations ◽

Montane Forest ◽

Forest Carbon ◽

Landscape Patterns ◽

Stand Productivity ◽

Intrinsic Water Use Efficiency

This study was designed to address a major source of uncertainty pertaining to coupled carbon–water cycles in montane forest ecosystems. The Sierra Nevada of California was used as a model system to investigate connections between the physiological performance of trees and landscape patterns of forest carbon and water use. The intrinsic water-use efficiency (iWUE)—an index of CO2 fixed per unit of potential water lost via transpiration—of nine dominant species was determined in replicated transects along an ∼1,500-m elevation gradient, spanning a broad range of climatic conditions and soils derived from three different parent materials. Stable isotope ratios of carbon and oxygen measured at the leaf level were combined with field-based and remotely sensed metrics of stand productivity, revealing that variation in iWUE depends primarily on leaf traits (∼24% of the variability), followed by stand productivity (∼16% of the variability), climatic regime (∼13% of the variability), and soil development (∼12% of the variability). Significant interactions between species composition and soil properties proved useful to predict changes in forest carbon–water relations. On the basis of observed shifts in tree species composition, ongoing since the 1950s and intensified in recent years, an increase in water loss through transpiration (ranging from 10 to 60% depending on parent material) is now expected in mixed conifer forests throughout the region.

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