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Mushunje LH, Marandure T, Chikwanha OC, Bennett J, Hawkins HJ, Palmer AR, Wu L, M C M, Mapiye C. Supplementation of Acacia dealbata versus Acacia mearnsii leaf-meal has potential to maintain growth performance of lambs grazing low-quality communal rangelands in South Africa. Trop Anim Health Prod 2024; 56:152. [PMID: 38722369 PMCID: PMC11082017 DOI: 10.1007/s11250-024-04004-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 04/23/2024] [Indexed: 05/12/2024]
Abstract
Supplementing livestock grazing communal rangelands with leaf-meals from Acacia trees, which are currently considered as problematic invasive alien plants globally, may be a sustainable way of exploiting their desirable nutritional and anthelmintic properties. The current study evaluated worm burdens and growth performance of lambs grazing low-quality communal rangelands supplemented with leaf-meals prepared from the invasive alien plant species; Acacia mearnsii or A. dealbata. Forty, three-month-old ewe lambs weighing an average of 18.9 ± 0.60 kg were randomly allocated to four supplementary diets: (1) rangeland hay only (control), (2) commercial protein supplement plus rangeland hay, (3) A. mearnsii leaf-meal plus rangeland hay and (4) A. dealbata leaf-meal plus rangeland hay. All the supplementary diets were formulated to meet the lambs' minimum maintenance requirements for protein. All the lambs were grazed on communal rangelands daily from 0800 to 1400 after which they were penned to allow them access to their respective supplementary diets until 08:00 the following morning. The respective supplementary diets were offered at the rate of 400 g ewe- 1 day- 1 for 60 days. Lambs fed the commercial protein supplement had the highest dry matter intake followed by those fed the Acacia leaf-meals and the control diet, respectively (P ≤ 0.05). Relative to the other supplementary diets, lambs fed the commercial protein supplement and A. dealbata leaf-meal had higher (P ≤ 0.05) final body weight and average daily gains. Dietary supplementation did not affect lamb faecal worm egg counts over the study period (P > 0.05). There was no association between supplementary diets and lamb FAMACHA© scores (P > 0.05). It was concluded that supplementation of Acacia dealbata versus Acacia mearnsii has the potential to emulate commercial protein in maintaining growth performance of lambs grazing communal rangelands in the dry season.
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Affiliation(s)
- L H Mushunje
- Department of Animal Sciences, Stellenbosch University, P. Bag X1, Matieland, 7602, South Africa
| | - T Marandure
- Centre for Agroecology, Water and Resilience (CAWR), Coventry University, Wolston Lane, Ryton Gardens, Coventry, CV8 3LG, UK
- Department of Energy and Technology, Swedish University of Agricultural Sciences, Box 7032, Uppsala, SE-75007, Sweden
| | - O C Chikwanha
- Department of Animal Sciences, Stellenbosch University, P. Bag X1, Matieland, 7602, South Africa
| | - J Bennett
- Centre for Agroecology, Water and Resilience (CAWR), Coventry University, Wolston Lane, Ryton Gardens, Coventry, CV8 3LG, UK
| | - H J Hawkins
- Conservation South Africa, Forrest House, Belmont Park, Rondebosch, 7700, South Africa
- Department of Biological Sciences, University of Cape Town, Private Bag X1, Rondebosch, 7701, South Africa
| | - A R Palmer
- Institute for Water Research, Rhodes University, PO Box 94, Makhanda, 6140, South Africa
| | - L Wu
- Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Marufu M C
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, 0110, South Africa
| | - C Mapiye
- Department of Animal Sciences, Stellenbosch University, P. Bag X1, Matieland, 7602, South Africa.
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Adams LD, Giovannoni D, Clark VR, Steenhuisen SL, Martin GD. Reproductive Ecology of the Invasive Alien Shrub Pyracantha angustifolia in the Grassland Biome, South Africa. PLANTS (BASEL, SWITZERLAND) 2023; 12:1308. [PMID: 36986995 PMCID: PMC10058135 DOI: 10.3390/plants12061308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/20/2023] [Accepted: 02/23/2023] [Indexed: 06/19/2023]
Abstract
Knowledge on reproductive traits of problematic invasive alien plants, such as the woody invasive shrub Pyracantha angustifolia of temperate Chinese origin, can help better manage invasive species. To determine factors contributing to its invasion, we investigated floral visitors and pollen loads, self-compatibility, seed set, seed rain, soil seed banks, and seed longevity in the soil. Generalist insects were recorded visiting flowers and all carried pollen loads of high purity (>70%). Floral visitor exclusion experiments showed that P. angustifolia can set seed (66%) without pollen vectors, although natural pollination resulted in higher fruit set (91%). Fruit count surveys and seed set showed an exponentially increased relationship between seed set and plant size with high natural seed yield (±2 million seeds m-2). Soil core samples revealed a high seed density of 46,400 ± (SE) 8934 m-2 under shrubs, decreasing with distance away from the shrub. Bowl traps stationed under trees and fences confirmed that seeds were efficiently dispersed by animals. Buried seeds survived for less than six months in the soil. Due to high seed production, self-compatibility augmented by generalist pollen vectors, and effective seed dispersal by local frugivores, it is difficult to manage the spread manually. Management of this species should focus on the short life span of seeds.
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Affiliation(s)
- Lehlohonolo D. Adams
- South African National Biodiversity Institute, Centre for Functional Biodiversity, School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg 3209, South Africa
- Afromontane Research Unit & Department of Plant Sciences, University of the Free State, Phuthaditjhaba 9866, South Africa
- Centre for Invasion Biology, Department of Plant Sciences, University of the Free State, Phuthaditjhaba 9866, South Africa
| | - Dino Giovannoni
- Department of Physics, Rhodes University, Makhanda (Grahamstown) 6139, South Africa
| | - Vincent R. Clark
- Afromontane Research Unit & Department of Geography, University of the Free State, Phuthaditjhaba 9866, South Africa
| | - Sandy-Lynn Steenhuisen
- Afromontane Research Unit & Department of Plant Sciences, University of the Free State, Phuthaditjhaba 9866, South Africa
| | - Grant D. Martin
- Afromontane Research Unit & Department of Zoology and Entomology, University of the Free State, Phuthaditjhaba 9866, South Africa
- Centre for Biological Control, Department of Entomology and Zoology, Rhodes University, Makhanda (Grahamstown) 6139, South Africa
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Production and meat quality attributes of lambs fed varying levels of Acacia mearnsii leaf-meal as replacement for Triticum aestivum bran. Meat Sci 2022; 196:109042. [DOI: 10.1016/j.meatsci.2022.109042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 10/19/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022]
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Kharivha T, Ruwanza S, Thondhlana G. Effects of Elevated Temperature and High and Low Rainfall on the Germination and Growth of the Invasive Alien Plant Acacia mearnsii. PLANTS (BASEL, SWITZERLAND) 2022; 11:2633. [PMID: 36235501 PMCID: PMC9571736 DOI: 10.3390/plants11192633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 09/29/2022] [Accepted: 10/01/2022] [Indexed: 06/16/2023]
Abstract
The impact of climate change on the germination and growth of invasive alien plants varies depending on the plant species and invasion process. We experimentally assessed the responses of the invasive alien plant Acacia mearnsii to future climate change scenarios-namely, elevated temperature as well as high and low rainfall. Acacia mearnsii was grown at an elevated air temperature (+2 °C), high rainfall (6 mm per day), and low rainfall (1.5 mm per day), and its germination and growth performance were measured over five months. We further examined changes in soil nutrients to assess if the above-mentioned climate change scenarios affected soils. Both elevated temperature and high rainfall did not influence A. mearnsii germination and seedling growth. In contrast, we observed reductions in A. mearnsii germination and growth in the low rainfall treatment, an indication that future drought conditions might negatively affect A. mearnsii invasion. We noted that elevated temperature and rainfall resulted in varied effects on soil properties (particularly soil C, N, Ca, and Mg content). We conclude that both elevated temperature and high rainfall may not enhance A. mearnsii invasion through altering germination and growth, but a decrease in A. mearnsii invasiveness is possible under low rainfall conditions.
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Affiliation(s)
- Tshililo Kharivha
- Department of Environmental Science, Rhodes University, Makhanda 6140, South Africa
- Department of Environmental Science and Centre of Excellence for Invasion Biology, Rhodes University, Makhanda 6140, South Africa
| | - Sheunesu Ruwanza
- Department of Environmental Science, Rhodes University, Makhanda 6140, South Africa
- Department of Environmental Science and Centre of Excellence for Invasion Biology, Rhodes University, Makhanda 6140, South Africa
| | - Gladman Thondhlana
- Department of Environmental Science, Rhodes University, Makhanda 6140, South Africa
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Jansen C, Kumschick S. A global impact assessment of Acacia species introduced to South Africa. Biol Invasions 2021. [DOI: 10.1007/s10530-021-02642-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Chapman RA, Midgley GF, Smart K. Diverse trends in observed pan evaporation in South Africa suggest multiple interacting drivers. S AFR J SCI 2021. [DOI: 10.17159/sajs.2021/7900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Planning for future water resource management in a warming climate is confounded when an expectation of increasing evaporation from open water surfaces with global warming is contradicted by observations of secular declines of pan evaporation. Decreasing pan evaporation has been observed globally – a trend which has been attributed variously to declines in wind run (‘global stilling’), declines in radiation (‘global dimming’) and increases in ambient humidity. This contrast between expectation and observation is known as the ‘evaporation paradox’. We evaluated trends in Symons pan evaporation from 154 pans across South Africa. Whilst 59 pans (38% of the 154) showed a statistically significant decrease in observed evaporation rates (p≤0.05), 30 (20%) showed an increase, and 65 (42%) showed no change. These results do not support simple attributions of trends to a common global cause. There is no spatially coherent pattern to trends across South Africa, suggesting that shifts in local drivers of evaporation confound expectations of secular trends due to global drivers. Changes in fetch conditions of the Symons pan installations may be implicated, whereby increasing tree density (through afforestation, alien plant invasion and woody thickening) increases surface friction, reducing wind run, and/or irrigation nearby, increasing local humidity. Correct attribution of the evaporation paradox to reduced wind run in South Africa must consider changing local conditions. Increased tree cover has been observed near a third of the South African Symons pans. Observed evaporation increases for one fifth of pans may implicate expected global drivers for pans where local fetch conditions have remained relatively constant.
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Affiliation(s)
- R. Arthur Chapman
- Global Change Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Guy F. Midgley
- Global Change Biology, Department of Botany and Zoology, Stellenbosch University, Stellenbosch, South Africa
| | - Kathleen Smart
- Institute for Water Research, and Rhodes Restoration Research Group, Rhodes University, Makhanda, South Africa
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Estimating and Monitoring Land Surface Phenology in Rangelands: A Review of Progress and Challenges. REMOTE SENSING 2021. [DOI: 10.3390/rs13112060] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Land surface phenology (LSP) has been extensively explored from global archives of satellite observations to track and monitor the seasonality of rangeland ecosystems in response to climate change. Long term monitoring of LSP provides large potential for the evaluation of interactions and feedbacks between climate and vegetation. With a special focus on the rangeland ecosystems, the paper reviews the progress, challenges and emerging opportunities in LSP while identifying possible gaps that could be explored in future. Specifically, the paper traces the evolution of satellite sensors and interrogates their properties as well as the associated indices and algorithms in estimating and monitoring LSP in productive rangelands. Findings from the literature revealed that the spectral characteristics of the early satellite sensors such as Landsat, AVHRR and MODIS played a critical role in the development of spectral vegetation indices that have been widely used in LSP applications. The normalized difference vegetation index (NDVI) pioneered LSP investigations, and most other spectral vegetation indices were primarily developed to address the weaknesses and shortcomings of the NDVI. New indices continue to be developed based on recent sensors such as Sentinel-2 that are characterized by unique spectral signatures and fine spatial resolutions, and their successful usage is catalyzed with the development of cutting-edge algorithms for modeling the LSP profiles. In this regard, the paper has documented several LSP algorithms that are designed to provide data smoothing, gap filling and LSP metrics retrieval methods in a single environment. In the future, the development of machine learning algorithms that can effectively model and characterize the phenological cycles of vegetation would help to unlock the value of LSP information in the rangeland monitoring and management process. Precisely, deep learning presents an opportunity to further develop robust software packages such as the decomposition and analysis of time series (DATimeS) with the abundance of data processing tools and techniques that can be used to better characterize the phenological cycles of vegetation in rangeland ecosystems.
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Arasumani M, Bunyan M, Robin VV. Opportunities and challenges in using remote sensing for invasive tree species management, and in the identification of restoration sites in tropical montane grasslands. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 280:111759. [PMID: 33298397 DOI: 10.1016/j.jenvman.2020.111759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
Tropical montane grasslands (TMG) support biodiverse and endemic taxa and provide vital ecosystem services to downstream communities. Nevertheless, invasive alien tree species across the world have threatened tropical grasslands and grassland endemic species. In India, TMG in the Shola Sky Islands of the Western Ghats have been reduced due to exotic tree invasions (Acacias, Pines, and Eucalyptus species). The loss of grassland habitat has, in turn, reduced the range sizes of species endemic to grasslands (plants, birds, amphibians, and mammals), driving some populations to local extinction. Grassland conversion to exotic trees has also impacted ecosystem services in the Western Ghats. Conserving existing grassland and restoring invaded habitat is critical to reverse these losses. This research focused on identifying grassland restoration sites using satellite images with a high spatial resolution (RapidEye). We used an object-oriented Random Forest classification to map the area for grassland restoration. We identified an area of 254 sq. km. as suitable for grassland restoration and an area of 362 sq. km. for grassland conservation and preventing invasion by exotic tree species. For restoration, we recommend careful removal of young and isolated exotic trees at the invasion front and restoring grasslands, instead of removing dense stands of mature exotic trees. Although our limited data indicate that areas with low fire frequency tend to be invaded, and areas invaded by exotic trees tend to burn at higher intensities, we recommend a broader investigation of these patterns to critically examine a potential role for the use of fire in invasive species management. We assume that removing exotic tree species in the identified restoration sites and restoring the grassland will help recover lost habitat and ensure the viability of indigenous and endemic species and increase streamflow.
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Affiliation(s)
- M Arasumani
- Indian Institute of Science Education and Research (IISER) Tirupati, Transit Campus, Karakambadi Road, Andhra Pradesh, 517507, India.
| | - Milind Bunyan
- Ashoka Trust for Research in Ecology and the Environment (ATREE), Royal Enclave, Sriramapura, Bangalore, Karnataka, 560064, India
| | - V V Robin
- Indian Institute of Science Education and Research (IISER) Tirupati, Transit Campus, Karakambadi Road, Andhra Pradesh, 517507, India
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Effects of Lantana camara invasion on vegetation diversity and composition in the Vhembe Biosphere Reserve, Limpopo Province of South Africa. SCIENTIFIC AFRICAN 2020. [DOI: 10.1016/j.sciaf.2020.e00610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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