Diosma Nature Reserve was formally declared as a provincial nature reserve in 2025. The nature reserve is located in Heiderand, Mossel Bay. Apex Conservation Services was contracted by Mossel Bay Municipality and had the privilege of undertaking field assessments and is in the process of compiling a Protected Area Management Plan for this new nature reserve.
Scope of our project
The project consisted of four core deliverables:
- Compilation of a protected area management plan according to the National Environmental Management: Protected Areas Act (No.57 of 2003)
- Compilation of an Annual Plan of Operations tool that includes responsibilities, timelines, indicators, and outputs for the implementation of the plan
- Undertake a biodiversity survey and baseline data assessment, including a full count of Diosma aristata in the reserve and the identification of all critically endangered and endangered plants and animals in the reserve
- Prepare material to support the public participation process for the management plan
Diosma aristata – Mossel Bay’s local, critically endangered Buchu
Although the nature reserve is home to a number of different vulnerable and endangered species, one of the reserve’s main aims is to conserve Diosma aristata – which this reserve is named after. This plant is commonly known as Mossel Bay buchu or spear-leaf diosma. D. aristata grows only up to 70 cm in height and often occurs in a cluster of individuals in a landscape. The fragrant leaves are less than 2 cm long and have a sharp point at the apex. The flowers are small and creamy white. Seeds of this buchu germinate after fire.
D. aristata is a real Mossel Bay local. Although populations of this plant used to occur from Mossel Bay to Dana Bay, these populations were lost due to coastal developments. This has led to D. aristata becoming critically endangered. Currently D. aristata is located only within the Diosma Nature Reserve and on a number of the surrounding properties. The numbers of surviving plants are so low that the Botanical Society of South Africa has called it “scarcer than rhinos”.
Threats Diosma aristata is facing
Declaring Diosma Nature Reserve is a major step toward protecting D. aristata and other endangered species in the reserve. The indigenous species do, however, still face a number of major threats:
- Invasive alien plants poses a threat of degrading the natural habitat, outcompeting indigenous species, and changing the natural fire regime
- D. aristata requires fire to germinate, and therefore the lack of fire is a major threat to the species survival. However, aseasonal fires or too low or high intensity fires are also threats.
- Continued urbanisation around the reserve continues to threaten plant populations surrounding the reserve
- Illegal dumping and trampling is also a threat to these species in the reserve
A collaborative species count
A species count was done on a cool day in May 2026. This was the fifth species count since 2018. The species count was undertaken to determine how many individual D. aristata plants are present in the reserve. It was undertaken as a collaborative approach between Apex, Mossel Bay Municipality, CapeNature, and Custodians of Rare and Endangered Wildflowers (CREW). During the species count we walked transects through the reserve, and 143 D. aristata plants were identified in the reserve.
Field assessment
A botanical assessment was also undertaken by Apex. Well-renowned botanist Jan Vlok joined our team to undertake the assessment. During the assessment the critically endangered and endangered plants and animals, as well as invasive alien plants, in the reserve were identified. After the field assessment, a list of 210 species was compiled, including 1 critically endangered species, 5 endangered species, and 7 vulnerable species.
Figure: Endangered plant species identified in Diosma Nature Reserve: A) Aspalathus dasyantha (Molbossie); B) Euchaetis albertiniana (Albertinia bearded buchu); C) Lampranthus pauciflorus; D) Muraltia knysnaensis (Knysna butterfly bush); and E) Nanobubon hypogaeum (Sources: SANBI; PictureThis; Magee, 2012)
Protected Area Management Plan
Apex is compiling the protected area management plan for Diosma Nature Reserve. The plan is being compiled in compliance with the National Environmental Management: Protected Areas Act (No.57 of 2003) and all other relevant legislation. The protected area management plan for Diosma Nature Reserve provides a framework for the development and sustainable operation of the reserve. The management plan serves as the primary tool for the reserve’s management and identifies programmes and procedures required to manage the reserve. The plan provides a strategic management framework that lays out the high-level strategic decisions that guide the operational management of the reserve. The plan also provides key guiding principles for the management of the reserve.
Annual Plan of Operations: A practical tool for implementation
Where the protected area management plan provides a high-level framework for management of the reserve, the annual plan of operations tool provides three key functions:
- Facilitate the management of day-to-day tasks of Diosma Nature Reserve
- Provide a platform to compile and submit annual reports
- Provide a platform to compile annual reviews of the management effectiveness of the protected area
The APO tool provides key objectives and management activities to reach each objective. Staff members are also assigned to each objective, and a time period is specified for each task. The intention is that if the management activities are completed under each objective, then the high-level objectives of the protected area will be met and management effectiveness of the protected area will improve.
The APO tool will therefore provide excellent guidance to reach the aims of Diosma Nature Reserve, as well as to identify any areas obstructing the way of reaching these goals.
Apex doing what Apex loves to do
This was the type of project that Apex relishes. We have a passion for the environment, and we are always excited to be a part of projects with high conservation outcomes and which bring value to communities. We believe the management plan will allow the municipality to sustainably manage the reserve and contribute to conserving biodiversity in the area. This nature reserve will be open access, so the Mossel Bay community can enjoy using this area as an escape into nature or for recreational purposes. There are also plans to expand the reserve in the near future.
D. aristata is known to only occur in this area, and nowhere else in the world. It is a major source of pride for Mossel Bay – a real symbol of its extraordinary biodiversity.
So go visit Diosma Nature Reserve. See if you can spot a Diosma aristata. And enjoy Mossel Bay’s newest nature reserve!
Contact us to find out more about the restoration work we do.