Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland
Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the...
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| Format: | Article |
| Language: | English |
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PeerJ Inc.
2017-08-01
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| Series: | PeerJ |
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| Online Access: | https://peerj.com/articles/3591.pdf |
| _version_ | 1827606001277206528 |
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| author | Tineke Kraaij Richard M. Cowling Brian W. van Wilgen Diba R. Rikhotso Mark Difford |
| author_facet | Tineke Kraaij Richard M. Cowling Brian W. van Wilgen Diba R. Rikhotso Mark Difford |
| author_sort | Tineke Kraaij |
| collection | DOAJ |
| description | Season of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid recruitment responses are not related to the season of fire. Germination appeared less rainfall-dependent than in winter-rainfall shrublands, suggesting that summer drought-avoiding dormancy is limited and has less influence on variation in recruitment success among fire seasons. The varied response of proteoid recruitment to fire season (or its simulation) implies that burning does not have to be restricted to particular seasons in eastern coastal fynbos, affording more flexibility for fire management than in shrublands associated with winter rainfall. |
| first_indexed | 2024-03-09T06:31:49Z |
| format | Article |
| id | doaj.art-3677ab64743a4356aeba735d03be4285 |
| institution | Directory Open Access Journal |
| issn | 2167-8359 |
| language | English |
| last_indexed | 2024-03-09T06:31:49Z |
| publishDate | 2017-08-01 |
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| spelling | doaj.art-3677ab64743a4356aeba735d03be42852023-12-03T11:04:39ZengPeerJ Inc.PeerJ2167-83592017-08-015e359110.7717/peerj.3591Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrublandTineke Kraaij0Richard M. Cowling1Brian W. van Wilgen2Diba R. Rikhotso3Mark Difford4School of Natural Resource Management, Nelson Mandela University, George, South AfricaBotany Department, Nelson Mandela University, Port Elizabeth, South AfricaCentre for Invasion Biology, Department of Botany and Zoology, University of Stellenbosch, Stellenbosch, South AfricaGarden Route Scientific Services, South African National Parks, Knysna, South AfricaBotany Department, Nelson Mandela University, Port Elizabeth, South AfricaSeason of fire has marked effects on floristic composition in fire-prone Mediterranean-climate shrublands. In these winter-rainfall systems, summer-autumn fires lead to optimal recruitment of overstorey proteoid shrubs (non-sprouting, slow-maturing, serotinous Proteaceae) which are important to the conservation of floral diversity. We explored whether fire season has similar effects on early establishment of five proteoid species in the eastern coastal part of the Cape Floral Kingdom (South Africa) where rainfall occurs year-round and where weather conducive to fire and the actual incidence of fire are largely aseasonal. We surveyed recruitment success (ratio of post-fire recruits to pre-fire parents) of proteoids after fires in different seasons. We also planted proteoid seeds into exclosures, designed to prevent predation by small mammals and birds, in cleared (intended to simulate fire) fynbos shrublands at different sites in each of four seasons and monitored their germination and survival to one year post-planting (hereafter termed ‘recruitment’). Factors (in decreasing order of importance) affecting recruitment success in the post-fire surveys were species, pre-fire parent density, post-fire age of the vegetation at the time of assessment, and fire season, whereas rainfall (for six months post-fire) and fire return interval (>7 years) had little effect. In the seed-planting experiment, germination occurred during the cooler months and mostly within two months of planting, except for summer-plantings, which took 2–3 months longer to germinate. Although recruitment success differed significantly among planting seasons, sites and species, significant interactions occurred among the experimental factors. In both the post-fire surveys and seed planting experiment, recruitment success in relation to fire- or planting season varied greatly within and among species and sites. Results of these two datasets were furthermore inconsistent, suggesting that proteoid recruitment responses are not related to the season of fire. Germination appeared less rainfall-dependent than in winter-rainfall shrublands, suggesting that summer drought-avoiding dormancy is limited and has less influence on variation in recruitment success among fire seasons. The varied response of proteoid recruitment to fire season (or its simulation) implies that burning does not have to be restricted to particular seasons in eastern coastal fynbos, affording more flexibility for fire management than in shrublands associated with winter rainfall.https://peerj.com/articles/3591.pdfFire seasonPost-fire recruitmentProteaGerminationPrescribed burningCape Floral Kingdom |
| spellingShingle | Tineke Kraaij Richard M. Cowling Brian W. van Wilgen Diba R. Rikhotso Mark Difford Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland PeerJ Fire season Post-fire recruitment Protea Germination Prescribed burning Cape Floral Kingdom |
| title | Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland |
| title_full | Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland |
| title_fullStr | Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland |
| title_full_unstemmed | Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland |
| title_short | Vegetation responses to season of fire in an aseasonal, fire-prone fynbos shrubland |
| title_sort | vegetation responses to season of fire in an aseasonal fire prone fynbos shrubland |
| topic | Fire season Post-fire recruitment Protea Germination Prescribed burning Cape Floral Kingdom |
| url | https://peerj.com/articles/3591.pdf |
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