scholarly journals Earthworm species occurrence in agroecosystems in the Midlands, KwaZulu-Natal, South Africa

2021 ◽  
Vol 62 (2) ◽  
pp. 411-425
Author(s):  
Thembeka C. Nxele ◽  
Tarombera Mwabvu ◽  
Inam Yekwayo

Little is known about the species composition of earthworms in agroecosystems in South Africa even though earthworms provide soil ecosystem services and are useful biological indicators of changes in the habitats. Given the land use and management impact biodiversity, the aim of this study was to document earthworm species that occur under cultivated land in the KwaZulu-Natal Midlands. A survey of nine farms that practise conservation agriculture was carried out between 2018 and 2020. Twelve earthworm species belonging to four introduced families: Acanthodrilidae (Dichogaster bolaui), Rhinodrilidae (Pontoscolex corenthrurus), Lumbricidae (Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea trapezoides, Lumbricus rubellus, Octolasion cyaneum, Octolasion lacteum), Megascolecidae (Amynthas aeruginosus, Amynthas corticis, Amynthas gracilis, Amynthas rodericensis) and juveniles from an indigenous family Tritogeniidae were recorded from cultivated fields. The type of crop (habitat) affected both species richness and abundance of earthworms significantly. However, post hoc results showed differences in species richness between the soya and the maize only, with greater species richness in the maize. Our results demonstrate that habitat type has a major influence on communities of earthworms in agroecosystems.

Agriculture ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 576
Author(s):  
Sixolise Mcinga ◽  
Lindah Muzangwa ◽  
Kudzayi Janhi ◽  
Pearson Nyari Stephano Mnkeni

Earthworms play a pivotal role in the regulation of soil health. Studies that explore the effects of conservation agriculture (CA) principles on earthworms under the semi-arid climate of the central Eastern Cape (EC) of South Africa (SA) are limited. Therefore, this study investigated the effects of tillage, crop rotations, and residue management on earthworms’ abundance and species richness. The study design followed a split-split plot with three replicates. The main plot was allocated to tillage treatment, which had conventional tillage (CT) and no-tillage (no-till) as factors. Crop rotation treatment was allocated to a subplot, and had maize (Zea mays)–fallow–maize (MFM), maize–fallow–soybean (Glycine max) (MFS), maize–wheat (Triticum aestivum)–maize (MWM), and maize–wheat–soybean (MWS). Residue management was in the sub-subplot with residue retention and residue removal. The study was carried out over four cropping seasons: summer 2015–2016, winter 2016, spring 2016, and summer 2016–2017. The results showed that the genera Amynthas and Lumbricus, both belonging to the anecic group, and Dendrobaena, belonging to the epigeic group, were present. Earthworm species diversity and density were highest under no-till than under CT. Residue retention improved earthworm density regardless of tillage management. Rotations that had fallow periods recorded lower earthworm numbers as compared to continuous cropping systems where wheat was grown in winter. The study concluded that maize–wheat–soybean (MWS) rotation with residue retention results in the highest earthworm abundance and species richness.


Zootaxa ◽  
2018 ◽  
Vol 4496 (1) ◽  
pp. 562 ◽  
Author(s):  
GERUSA PAULI KIST STEFFEN ◽  
RICARDO BEMFICA STEFFEN ◽  
MARIE LUISE CAROLINA BARTZ ◽  
SAMUEL WOOSTER JAMES ◽  
RODRIGO JOSEMAR SEMINOTTI JACQUES ◽  
...  

The knowledge regarding earthworm species richness in subtropical Brazil is limited, particularly in the state of Rio Grande do Sul (RS), where only a few sites have been sampled. In this study we assessed earthworm richness in different ecosystems of RS, prioritizing un-sampled regions. Fifteen ecosystems, including native vegetation and other ecosystems with variable levels of disturbance were sampled in 30 counties in RS, totaling 77 sampling points, mainly in the Pampa biome. Qualitative sampling was performed by handsorting soil monoliths and fixing the earthworms in 4% formalin solution. Species identification was based on morphological characters, and species richness and Shannon (H) and McIntosh (U) diversity indices were calculated for each ecosystem. Twenty-one earthworm species were identified, belonging to seven families: Glossoscolecidae (8), Rhinodrilidae (2), Ocnerodrilidae (4), Megascolecidae (4), Acanthodrilidae (1), Lumbricidae (1) and Criodrilidae (1). From these, ten are new species belonging to the genera: Glossoscolex (6), Fimoscolex (1), Kerriona (1), Eukerria (1), and one aquatic species of the Criodrilidae family, belonging to a new genus. Most of the native species (Urobenus brasiliensis, Fimoscolex n.sp.1 and the Glossoscolex spp.) predominated in ecosystems little altered by human activity, while exotic (Amynthas gracilis, Amynthas rodericensis, Metaphire californica, Aporrectodea trapezoides) and peregrine species (Pontoscolex corethrurus) predominated in areas with more human disturbance. Native ecosystems with lower disturbance, particularly forests and native pastures had higher diversity than disturbed sites. This is the first record of A. rodericencis for Brazil and most sites represent new collection records for the known species in RS.


2017 ◽  
Vol 47 (7) ◽  
pp. 935-945 ◽  
Author(s):  
Amy Choi ◽  
Tara E. Sackett ◽  
Sandy M. Smith ◽  
M. Isabel Bellocq

A growing understanding about the impacts of earthworms (Oligochaeta: Lumbricidae) on ecosystem processes and forest restoration necessitates an examination of their role in Canadian forests where they have become invasive. Little is known about the landscape-scale responses of earthworm populations to different regional characteristics and vegetation types within Canada’s central woodlands. We examined the regional variation of earthworm species richness, biomass, and assemblage composition across a range of four municipal regions (from south to north: Halton, Wellington, York, and Simcoe) and four habitat types (deciduous forest, mixed forest, tree plantation, and meadow) with varying soil characteristics in woodlands of south-central Ontario, Canada. In general, earthworm communities differed by region but not by habitat type. The most southern regions supported the highest earthworm species richness, biomass (i.e., Lumbricus and Octolasion), and density, and this was associated with a south–north gradient in soil characteristics. Assemblage composition differed by region but not by habitat type. The observed south–north gradient suggests an underlying effect of invasion spread associated with human settlement and density. Our results provide baseline information about earthworm communities in south-central Ontario forests and will enable managers to plan for the increasing role of earthworms in Canada’s future forests.


2021 ◽  
Vol 22 (9) ◽  
Author(s):  
Bianca Greyvenstein ◽  
Monique Botha ◽  
Johnnie Van den Berg ◽  
Stefan Siebert

Abstract. Greyvenstein B, Botha M, van den Berg J, Siebert SJ. 2021. Level of urbanization and habitat type, and not patch size, influence predacious arthropod diversity patterns of urban grasslands in South Africa. Biodiversitas 22: 4078-4094. Predacious arthropods provide a valuable ecosystem service within urban environments by suppressing pest numbers. However, urban ecological studies largely ignore this functional group and its diversity and species composition patterns. Some studies have been published regarding these patterns, however they were mostly done in Australia, Europe and America, thus an African perspective is lacking. Our aim was to address the gap in African literature by quantify the differences in predacious arthropod species richness and diversity within urban green space in varying urbanization intensities, habitat types of grassland and patch sizes in South Africa. Various indices were considered to examine the effect of urbanization on the diversity patterns of Chrysopidae (Neuroptera), Mantodea, Araneae and Coccinellidae (Coleoptera). Study sites included three levels of urbanization represented by population density, two types of urban grasslands (i.e., ruderal and fragmented grassland) and a peri-urban rangeland grassland as control, and a wide range of patch sizes. Our results indicated that an increase in urbanization intensities was associated with increased abundance of predacious arthropod taxa. Also, that urban and peri-urban grasslands had similar predacious arthropod species richness and diversity, but differed in species composition. No relationship was found between patch size and arthropod diversity or composition. Thus, predacious arthropod abundances are influenced by the level of urbanization and their species composition is influenced by the type of urban grassland (ruderal or fragmented), which are important considerations for future urban planning/management and conservation strategies. This study gives a South African perspective and indicates that despite the lack of assigned function of urban green spaces, they sustain diverse and distinct predacious arthropod communities, which in turn fulfill various roles in a functioning ecosystem.


2016 ◽  
Vol 60 ◽  
pp. 385-393 ◽  
Author(s):  
T. Ramesh ◽  
Riddhika Kalle ◽  
Colleen T. Downs

2017 ◽  
Vol Volume 113 (Number 1/2) ◽  
Author(s):  
Nondumiso Z. Sosibo ◽  
Pardon Muchaonyerwa ◽  
Lientjie Visser ◽  
Annelie Barnard ◽  
Ernest Dube ◽  
...  

Abstract South Africa currently faces a wheat (Triticum aestivum L.) crisis as production has declined significantly over the past few years. The objective of this study was to explore opportunities for improving yields in intensive irrigated wheat production systems of South Africa through analyses of yield gaps, soil fertility constraints and conservation agriculture practices. The study was conducted in the major irrigation wheat production areas across four geographical regions: KwaZulu-Natal, eastern Highveld, warmer northern and cooler central. Actual yield (Ya) based on long-term yield data ranged from 5.99±0.15 t/ha to 8.32±0.10 t/ha across different geographical regions. The yield potential (Yp) ranged from 7.57 t/ha to 11.45 t/ha. Yield gaps (Yp–Ya) were in the range of 1.58–3.13 t/ha. Yields could be increased by 26–38% through closing yield gaps. On 88.37% and 13.89% of the fields in the KwaZulu-Natal and warmer northern regions, respectively, there was strong evidence of the practise of conservation agriculture, but none in the other regions. On 42.31% of irrigated wheat fields, soil organic carbon was below 1% at a soil depth of 0–20 cm. Fields in which conservation tillage was practised had double the soil organic carbon of conventionally tilled fields (2.15±0.10% versus 1.02±0.05%), but greater acidity and phosphorus deficiency problems. Sustainable approaches for addressing phosphorus deficiency and acidity under conservation tillage practices need to be sought, especially in the KwaZulu-Natal region.


2018 ◽  
Vol 20 (1) ◽  
Author(s):  
Thusile Mabel Gqaleni ◽  
Busisiwe Rosemary Bhengu

Critically ill patients admitted to critical-care units (CCUs) might have life-threatening or potentially life-threatening problems. Adverse events (AEs) occur frequently in CCUs, resulting in compromised quality of patient care. This study explores the experiences of critical-care nurses (CCNs) in relation to how the reported AEs were analysed and handled in CCUs. The study was conducted in the CCUs of five purposively selected hospitals in KwaZulu-Natal, South Africa. A descriptive qualitative design was used to obtain data through in-depth interviews from a purposive sample of five unit managers working in the CCUs to provide a deeper meaning of their experiences. This study was a part of a bigger study using a mixed-methods approach. The recorded qualitative data were analysed using Tesch’s content analysis. The main categories of information that emerged during the data analysis were (i) the existence of an AE reporting system, (ii) the occurrence of AEs, (iii) the promotion of and barriers to AE reporting, and (iv) the handling of AEs. The findings demonstrated that there were major gaps that affected the maximum utilisation of the reporting system. In addition, even though the system existed in other institutions, it was not utilised at all, hence affecting quality patient care. The following are recommended: (1) a non-punitive and non-confrontational system should be promoted, and (2) an organisational culture should be encouraged where support structures are formed within institutions, which consist of a legal framework, patient and family involvement, effective AE feedback, and education and training of staff.


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