Regeneration dynamics of Portulacaria afra in restored succulent thicket of South Africa
Introduction Over-grazing by livestock has resulted in the widespread degradation of South Africa’s succulent thicket ecosystems. This is characterised by a significant reduction in the cover of the dominant succulent shrub, Portulacaria afra. Because this species is unable to regenerate naturally i...
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| Format: | Article |
| Language: | English |
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PeerJ Inc.
2023-05-01
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| Series: | PeerJ |
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| Online Access: | https://peerj.com/articles/15081.pdf |
| _version_ | 1797410398170775552 |
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| author | Nicholas C. Galuszynski |
| author_facet | Nicholas C. Galuszynski |
| author_sort | Nicholas C. Galuszynski |
| collection | DOAJ |
| description | Introduction Over-grazing by livestock has resulted in the widespread degradation of South Africa’s succulent thicket ecosystems. This is characterised by a significant reduction in the cover of the dominant succulent shrub, Portulacaria afra. Because this species is unable to regenerate naturally in degraded habitat, active reintroduction is required to restore ecosystem function. However, reintroduction success is relatively low, and the recruitment barriers for this species are poorly understood. Methods By conducting pairwise plot surveys in actively restored and adjacent degraded succulent thicket habitats, the extent of P. afra seedling abundance in these contrasting ecosystem conditions is quantified. Results Seedling abundance was significantly greater in restored ecosystems (W = 23, p = 0.03225). Additionally, seedlings found in restored habitats were strongly associated with open habitat, whereas seedlings in degraded ecosystems were more restricted to nurse sites (X2 = 122.84, df = 2, p-value < 2.2e–16). A weak (R2 = 0,237), but significant (p = 0, 0295) correlation between P. afra cover and seedling abundance was recorded. Conclusion Active restoration of succulent thicket habitat through P. afra reintroduction appears to overcome recruitment barriers. This may suggest that, despite the poor survival of introduced individuals, natural recruitment could contribute to the regeneration of restored succulent thicket ecosystems. |
| first_indexed | 2024-03-09T04:29:23Z |
| format | Article |
| id | doaj.art-06975c4446674b9ab820fb4505ee724e |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T04:29:23Z |
| publishDate | 2023-05-01 |
| publisher | PeerJ Inc. |
| record_format | Article |
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| spelling | doaj.art-06975c4446674b9ab820fb4505ee724e2023-12-03T13:36:39ZengPeerJ Inc.PeerJ2167-83592023-05-0111e1508110.7717/peerj.15081Regeneration dynamics of Portulacaria afra in restored succulent thicket of South AfricaNicholas C. Galuszynski0Spekboom Thicket research group, Botany Department, Nelson Mandela University, Gqeberha, South AfricaIntroduction Over-grazing by livestock has resulted in the widespread degradation of South Africa’s succulent thicket ecosystems. This is characterised by a significant reduction in the cover of the dominant succulent shrub, Portulacaria afra. Because this species is unable to regenerate naturally in degraded habitat, active reintroduction is required to restore ecosystem function. However, reintroduction success is relatively low, and the recruitment barriers for this species are poorly understood. Methods By conducting pairwise plot surveys in actively restored and adjacent degraded succulent thicket habitats, the extent of P. afra seedling abundance in these contrasting ecosystem conditions is quantified. Results Seedling abundance was significantly greater in restored ecosystems (W = 23, p = 0.03225). Additionally, seedlings found in restored habitats were strongly associated with open habitat, whereas seedlings in degraded ecosystems were more restricted to nurse sites (X2 = 122.84, df = 2, p-value < 2.2e–16). A weak (R2 = 0,237), but significant (p = 0, 0295) correlation between P. afra cover and seedling abundance was recorded. Conclusion Active restoration of succulent thicket habitat through P. afra reintroduction appears to overcome recruitment barriers. This may suggest that, despite the poor survival of introduced individuals, natural recruitment could contribute to the regeneration of restored succulent thicket ecosystems.https://peerj.com/articles/15081.pdfSpekboomSeedling recruitmentEcological processesEcosystem functioningAlbany Subtropical ThicketState transitions |
| spellingShingle | Nicholas C. Galuszynski Regeneration dynamics of Portulacaria afra in restored succulent thicket of South Africa PeerJ Spekboom Seedling recruitment Ecological processes Ecosystem functioning Albany Subtropical Thicket State transitions |
| title | Regeneration dynamics of Portulacaria afra in restored succulent thicket of South Africa |
| title_full | Regeneration dynamics of Portulacaria afra in restored succulent thicket of South Africa |
| title_fullStr | Regeneration dynamics of Portulacaria afra in restored succulent thicket of South Africa |
| title_full_unstemmed | Regeneration dynamics of Portulacaria afra in restored succulent thicket of South Africa |
| title_short | Regeneration dynamics of Portulacaria afra in restored succulent thicket of South Africa |
| title_sort | regeneration dynamics of portulacaria afra in restored succulent thicket of south africa |
| topic | Spekboom Seedling recruitment Ecological processes Ecosystem functioning Albany Subtropical Thicket State transitions |
| url | https://peerj.com/articles/15081.pdf |
| work_keys_str_mv | AT nicholascgaluszynski regenerationdynamicsofportulacariaafrainrestoredsucculentthicketofsouthafrica |