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Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands
Restoration of subtropical thicket in South Africa using the plant Portulacaria afra (an ecosystem engineer) has been hampered, in part, by selecting sites that are frost prone—this species is intolerant of frost. Identifying parts of the landscape that are exposed to frost is often challenging. Our...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
PeerJ Inc.
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7183751/ https://www.ncbi.nlm.nih.gov/pubmed/32351786 http://dx.doi.org/10.7717/peerj.8980 |
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author | Duker, Robbert Cowling, Richard M. van der Vyver, Marius L. Potts, Alastair J. |
author_facet | Duker, Robbert Cowling, Richard M. van der Vyver, Marius L. Potts, Alastair J. |
author_sort | Duker, Robbert |
collection | PubMed |
description | Restoration of subtropical thicket in South Africa using the plant Portulacaria afra (an ecosystem engineer) has been hampered, in part, by selecting sites that are frost prone—this species is intolerant of frost. Identifying parts of the landscape that are exposed to frost is often challenging. Our aim is to calibrate an existing cold-air pooling (CAP) model to predict where frost is likely to occur in the valleys along the sub-escarpment lowlands (of South Africa) where thicket is dominant. We calibrated this model using two valleys that have been monitored during frost events. To test the calibrated CAP model, model predictions of frost-occurrence for six additional valleys were assessed using a qualitative visual comparison of existing treelines in six valleys—we observe a strong visual match between the predicted frost and frost-free zones with the subtropical thicket (frost-intolerant) and Nama-Karoo shrubland (frost-tolerant) treelines. In addition, we tested the model output using previously established transplant experiments; ∼300 plots planted with P. afra (known as the Thicket-Wide Plots) were established across the landscape—without consideration of frost—to assess the potential factors influencing the survival and growth of P. afra. Here we use a filtered subset of these plots (n = 70), and find that net primary production of P. afra was significantly lower in plots that the model predicted to be within the frost zone. We suggest using this calibrated CAP model as part of the site selection process when restoring subtropical thicket in sites that lie within valleys—avoiding frost zones will greatly increase the likelihood of restoration success. |
format | Online Article Text |
id | pubmed-7183751 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | PeerJ Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-71837512020-04-29 Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands Duker, Robbert Cowling, Richard M. van der Vyver, Marius L. Potts, Alastair J. PeerJ Ecology Restoration of subtropical thicket in South Africa using the plant Portulacaria afra (an ecosystem engineer) has been hampered, in part, by selecting sites that are frost prone—this species is intolerant of frost. Identifying parts of the landscape that are exposed to frost is often challenging. Our aim is to calibrate an existing cold-air pooling (CAP) model to predict where frost is likely to occur in the valleys along the sub-escarpment lowlands (of South Africa) where thicket is dominant. We calibrated this model using two valleys that have been monitored during frost events. To test the calibrated CAP model, model predictions of frost-occurrence for six additional valleys were assessed using a qualitative visual comparison of existing treelines in six valleys—we observe a strong visual match between the predicted frost and frost-free zones with the subtropical thicket (frost-intolerant) and Nama-Karoo shrubland (frost-tolerant) treelines. In addition, we tested the model output using previously established transplant experiments; ∼300 plots planted with P. afra (known as the Thicket-Wide Plots) were established across the landscape—without consideration of frost—to assess the potential factors influencing the survival and growth of P. afra. Here we use a filtered subset of these plots (n = 70), and find that net primary production of P. afra was significantly lower in plots that the model predicted to be within the frost zone. We suggest using this calibrated CAP model as part of the site selection process when restoring subtropical thicket in sites that lie within valleys—avoiding frost zones will greatly increase the likelihood of restoration success. PeerJ Inc. 2020-04-23 /pmc/articles/PMC7183751/ /pubmed/32351786 http://dx.doi.org/10.7717/peerj.8980 Text en © 2020 Duker et al. https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited. |
spellingShingle | Ecology Duker, Robbert Cowling, Richard M. van der Vyver, Marius L. Potts, Alastair J. Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands |
title | Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands |
title_full | Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands |
title_fullStr | Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands |
title_full_unstemmed | Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands |
title_short | Site selection for subtropical thicket restoration: mapping cold-air pooling in the South African sub-escarpment lowlands |
title_sort | site selection for subtropical thicket restoration: mapping cold-air pooling in the south african sub-escarpment lowlands |
topic | Ecology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7183751/ https://www.ncbi.nlm.nih.gov/pubmed/32351786 http://dx.doi.org/10.7717/peerj.8980 |
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