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Modelling the distribution of Aspalathus linearis (Rooibos tea): implications of climate change for livelihoods dependent on both cultivation and harvesting from the wild.

Lötter D, Maitre D - Ecol Evol (2014)

Bottom Line: Climate change predictions for the region indicate a significant warming scenario coupled with a decline in winter rainfall.Most of the areas where range expansion was indicated are located in existing conservation areas or include conservation worthy vegetation.These findings will be critical in directing conservation efforts as well as developing strategies for farmers to cope with and adapt to climate change.

View Article: PubMed Central - PubMed

Affiliation: CSIR, Natural Resources and the Environment P.O Box 320, Stellenbosch, 7602, South Africa.

ABSTRACT
Aspalathus linearis (Burm. f.) R. Dahlgren (rooibos) is endemic to the Fynbos Biome of South Africa, which is an internationally recognized biodiversity hot spot. Rooibos is both an invaluable wild resource and commercially cultivated crop in suitable areas. Climate change predictions for the region indicate a significant warming scenario coupled with a decline in winter rainfall. First estimates of possible consequences for biodiversity point to species extinctions of 23% in the long term in the Fynbos Biome. Bioclimatic modelling using the maximum entropy method was used to develop an estimate of the realized niche of wild rooibos and the current geographic distribution of areas suitable for commercially production. The distribution modelling provided a good match to the known distribution and production area of A. linearis. An ensemble of global climate models that assume the A2 emissions scenario of high energy requirements was applied to develop possible scenarios of range/suitability shift under future climate conditions. When these were extrapolated to a future climate (2041-2070) both wild and cultivated tea exhibited substantial range contraction with some range shifts southeastwards and upslope. Most of the areas where range expansion was indicated are located in existing conservation areas or include conservation worthy vegetation. These findings will be critical in directing conservation efforts as well as developing strategies for farmers to cope with and adapt to climate change.

No MeSH data available.


Related in: MedlinePlus

Suitability of areas for wild Aspalathus linearis under five future climate change scenarios for the period 2041–2070: (A) UKMO, (B) MPI, (C) MIROC, (D), GFDL (E) CSIRO, (F) all models. Map (F) shows the measure of agreement among models on a scale of 1–5 where 5 indicates the strongest overlap.
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fig07: Suitability of areas for wild Aspalathus linearis under five future climate change scenarios for the period 2041–2070: (A) UKMO, (B) MPI, (C) MIROC, (D), GFDL (E) CSIRO, (F) all models. Map (F) shows the measure of agreement among models on a scale of 1–5 where 5 indicates the strongest overlap.

Mentions: The same suite of climate models was used to model the potential distribution of wild A. linearis (Fig. 7A–E) for an intermediate future scenario (2041–2070). Each projection is quite different, and the extent of agreement is less than for the cultivated rooibos (Fig. 7F). The distribution map (Fig. 8A) shows a marked contraction in its bioclimatic range in the northern part of the study area as opposed to the cultivated tea. The Suid-Bokkeveld small-scale farmer community is located in this region and is one of the most important areas where wild rooibos is currently harvested. A further significant range contraction is also visible along the western parts of the study area at lower elevations. These are the areas most vulnerable to species loss. Further south and to the eastern part of the study area, another key harvest locality is found in the region of Wupperthal. Most of this region is not expected to undergo any range shifts (Fig. 8B). Areas that were not predicted to undergo range shifts under future conditions are restricted to elevation ranges of between 800 m and 1050 m above sea level. Range expansion, however, is noticeable toward the south especially along the mountain ranges. This depends on the ability of the species to colonize new sites. Overall, a similar trend of range shift southwards and to higher elevations is observed for both wild and cultivated tea.


Modelling the distribution of Aspalathus linearis (Rooibos tea): implications of climate change for livelihoods dependent on both cultivation and harvesting from the wild.

Lötter D, Maitre D - Ecol Evol (2014)

Suitability of areas for wild Aspalathus linearis under five future climate change scenarios for the period 2041–2070: (A) UKMO, (B) MPI, (C) MIROC, (D), GFDL (E) CSIRO, (F) all models. Map (F) shows the measure of agreement among models on a scale of 1–5 where 5 indicates the strongest overlap.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4020683&req=5

fig07: Suitability of areas for wild Aspalathus linearis under five future climate change scenarios for the period 2041–2070: (A) UKMO, (B) MPI, (C) MIROC, (D), GFDL (E) CSIRO, (F) all models. Map (F) shows the measure of agreement among models on a scale of 1–5 where 5 indicates the strongest overlap.
Mentions: The same suite of climate models was used to model the potential distribution of wild A. linearis (Fig. 7A–E) for an intermediate future scenario (2041–2070). Each projection is quite different, and the extent of agreement is less than for the cultivated rooibos (Fig. 7F). The distribution map (Fig. 8A) shows a marked contraction in its bioclimatic range in the northern part of the study area as opposed to the cultivated tea. The Suid-Bokkeveld small-scale farmer community is located in this region and is one of the most important areas where wild rooibos is currently harvested. A further significant range contraction is also visible along the western parts of the study area at lower elevations. These are the areas most vulnerable to species loss. Further south and to the eastern part of the study area, another key harvest locality is found in the region of Wupperthal. Most of this region is not expected to undergo any range shifts (Fig. 8B). Areas that were not predicted to undergo range shifts under future conditions are restricted to elevation ranges of between 800 m and 1050 m above sea level. Range expansion, however, is noticeable toward the south especially along the mountain ranges. This depends on the ability of the species to colonize new sites. Overall, a similar trend of range shift southwards and to higher elevations is observed for both wild and cultivated tea.

Bottom Line: Climate change predictions for the region indicate a significant warming scenario coupled with a decline in winter rainfall.Most of the areas where range expansion was indicated are located in existing conservation areas or include conservation worthy vegetation.These findings will be critical in directing conservation efforts as well as developing strategies for farmers to cope with and adapt to climate change.

View Article: PubMed Central - PubMed

Affiliation: CSIR, Natural Resources and the Environment P.O Box 320, Stellenbosch, 7602, South Africa.

ABSTRACT
Aspalathus linearis (Burm. f.) R. Dahlgren (rooibos) is endemic to the Fynbos Biome of South Africa, which is an internationally recognized biodiversity hot spot. Rooibos is both an invaluable wild resource and commercially cultivated crop in suitable areas. Climate change predictions for the region indicate a significant warming scenario coupled with a decline in winter rainfall. First estimates of possible consequences for biodiversity point to species extinctions of 23% in the long term in the Fynbos Biome. Bioclimatic modelling using the maximum entropy method was used to develop an estimate of the realized niche of wild rooibos and the current geographic distribution of areas suitable for commercially production. The distribution modelling provided a good match to the known distribution and production area of A. linearis. An ensemble of global climate models that assume the A2 emissions scenario of high energy requirements was applied to develop possible scenarios of range/suitability shift under future climate conditions. When these were extrapolated to a future climate (2041-2070) both wild and cultivated tea exhibited substantial range contraction with some range shifts southeastwards and upslope. Most of the areas where range expansion was indicated are located in existing conservation areas or include conservation worthy vegetation. These findings will be critical in directing conservation efforts as well as developing strategies for farmers to cope with and adapt to climate change.

No MeSH data available.


Related in: MedlinePlus