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Bibliography/Notes

1) PHOTO PATHWAY- In times of drought, Portulaca afra can use the CAM pathway for photosynthesis but when the drought is over, it makes use of the C3 pathway . CAM is favored during the summer months due to the prolonged periods of drought. The switch back to C3 occurs quickly once water is introduced in order to conserve energy.

2) PHOTO PATHWAY- Leaf age also has been shown to impact the photosynthetic pathway used; younger leaves were shown to not make use of the CAM pathway, even when presented with the conditions that induced the change in older leaf tissue. Less mature stomata lack the ability to close completely, thus allowing gas exchange to occur at all points in time.

3) HERBIVORY- Portulacaria afra is a food source for multiple South African herbivores, such as elephants and black rhinoceroses.

4) SOIL CONDITION- Planting portulacaria afra in areas where the soil has been degraded by overharvesting can lead to improved soil condition due to creation of shade and more organic material being added into the soil. This study used woody cuttings planted in specific areas with sandy soil and observed an increase in the amount of native species growing in the areas after some time passed and the portulacaria afra was established. The researchers concluded that this plant could be used in order to restore native species richness to areas that have experienced a drop in the amount of native species growing there.

5) USE AS FODDER- Given the low water use of portulacaria afra, it can be used in order to feed livestock in times of drought. It is already used by some livestock farmers in South Africa but this article mentions the expansion of this practice into other places of similar climates, such as the south western United States. The succulent stems and leaves also act as a supplemental source of water for the livestock and are a reportedly well like by both cattle and goats, although cattle grazing tends to cause significant damage to the plants.

6) MEDICINAL- Many groups have a variety of traditional medicinal remedies that they use as an alternative for modern medicine, one of which is portulacaria afra. This particular plant is used commonly to help treat skin conditions by people who live in rural areas and are unable to reach a hospital for more modern treatments.

Addition to Distribution and habitat
* Addition to the end of section

In these environments, P. afra is a source of food for multiple large herbivores, such as the Black rhinoceros and the African elephant. Although it is not the primary food source for these animals, it still makes up a significant portion of their diet.

Cultivation and uses
Insert growing zones: Portulacaria is a common landscape plant in Phoenix, Arizona and southern California, growing in USDA plant hardiness zones9-11. Cuttings root very easily in most potting media.

Addition to Food source
P. afra is also used to feed livestock during periods of drought due to its succulent nature. Most commonly used for cattle and goats, these plants also act as a supplemental source of water on top of their nutritional benefits.

Medicinal
This is one of the many plants used as a traditional treatment for skin conditions used by people in rural areas that do not have easy access to more modern medicine.

Addition to Carbon sequestration *and ecological impact*
It is capable of either C3 or CAM carbon fixation, depending on factors such as the season and the age of the leaves. In the dry season, it relies on the CAM pathway due to the lack of water, but when water is reintroduced, the plant quickly reverts to the C3 pathway in order to conserve energy. The maturity of the leaf tissue also matters because younger tissue is unable to completely seal the stomata, making CAM impossible. So while the older leaves are able to switch pathways based on the season and conditions, the younger leaves have to rely solely on the C3 pathway. It can sequester a maximum of 15.4 t CO2 ha−1yr−1. The South African government's Working for Ecosystems programme proposes restoring a million hectares (2.5 million acres) of spekboom thicket. The addition of more spekboom into the environment can also help restore native species to areas where they no longer can grow. P. afra has been shown to help create shade and add organic material into sandy soil, which allows for an environment more hospitable to young plants, thus helping restore populations of native species that were reduced by overgrazing and desertification.