The backstage of a nature conservation activity (Part 2)

In Rota Vicentina pilot areas, conservation interventions focus mainly on the two invasive species with the highest prevalence and impact on these natural habitats: the long-leaved wattle (Acacia longifolia) – which we have already talked about here – and the hottentot fig (Carpobrotus edulis).

Continuing to unveil more about the backstage of a nature conservation activity, we will now talk about the planning and intervention strategy for the hottentot fig.

The hottentot fig is a succulent plant, low-growing plant, very common in dune ecosystems, near beach parking or along the way to the beach. It has either yellow or bright pink flower, which leads many people to want to take it home or to their garden. Please don’t do it! This is an invasive plant and by transporting it, you will only be contributing to the increase of its geographic distribution.

Invasive plants are a real threat to biodiversity and ecosystems because they aggressively compete with our native plants and the entire chain that depends on them and also have high negative impacts on natural resources. For this species, the best control technique, in fact the only one advised to execute, is manual pulling, regardless of size, soil type and location.

It is important to know the plant very well and the right way to manage it in its different stages of development and to plan the intervention according to the location and dimension, or other characteristics, of the invasion area:

❌ Avoid stepping on or disturbing threatened or more sensitive flora in the surrounding area
❌ Avoid walking in areas of dense vegetation and, whenever possible, choose existing trails, vegetation-free areas or areas covered with invasive plants (e.g. the hottentot fig itself)
❌ Do not leave the roots of the removed species in contact with the soil
❌ Do not transport invasive plants from the removal site
❌ Do not transport individuals with seeds


The hottentot fig forms dense mats, especially in dune areas, covering the ground and preventing the natural regeneration of native species. The hottentot fig climbs on other species, namely shrubby species similar to the sea-sands juniper, “suffocating” them and blocking the sunlight that feeds them.

The hottentot fig is extremely effective at covering the ground. Its introduction in the coast aimed to control erosion of the coastal sands in critical areas where there are no native vegetation. However, the native flora that naturally inhabits these sensitive ecosystems is equally (or more) effective than the hottentot fig itself in these ecological functions and adds other important ones, such as water retention and soil formation. The predominance of the Hottentot fig creates monospecific areas (with only one species), leading to a decrease in the ecological and aesthetic value of the landscape. This loss of value results in a continuous decline of endangered species and a reduction in endemic or rare species’ biodiversity, which many fauna species depend on to survive.

Taking into account the protection of the most sensitive ecosystems and to avoid sand erosion, the two main forms of intervention in controlling hottentot fig areas are categorized:

In natural ecosystem areas, extensive or punctual clusters of hottentot figs should be controlled when located among native vegetation with greater or lesser density. The greater the number of endemic or threatened species, especially in areas covered with herbaceous vegetation, the higher the priority for conservation efforts.

In situations where there is dense and shrubby vegetation, it is important to avoid indiscriminate trampling or the multiplication of trails. This is because the hottentot fig takes advantage of any “opening” of the path to extend or establish itself. When trying to access certain spots, it is important to try to walk and trample only and exclusively on top of hottentot fig spots and corridors, taking advantage of possible open areas in the dunes to control clusters that try to break through these natural areas.

When many volunteers are present, the efforts should be focused on areas with spaced vegetation and a large dispersion of Hottentot fig clusters. Hottentot fig control should be done as long as native vegetation has a presence of at least 25% in the matrix of these areas, following the methodology and precautions described below:

When well applied, this technique is quite effective in controlling hottentot fig clusters. By freeing up space in the soil, the surrounding native vegetation quickly expands and recolonizes these areas, making it difficult for the hottentot fig to resurge. Nevertheless, the hottentot fig’s ability to spread by seed will continue to be a threat. It is important to recognize it in its post-germination phase and look for it especially near the burrows of small mammals, which inconveniently love to snack on its fruits.

When the hottentot fig patches are too large and the native vegetation is scarce and dispersed, occupying less than 25% of the total intervention area, pulling the plant without applying erosion mitigation measures is not recommended. These extensive areas of hottentot fig appear mainly in degraded dune areas, subjected to soil mobilizations, vehicle crossings on the coast or in abandoned agricultural areas, where the dispersion by fragmentation of the hottentot fig plants occurred and also the elimination of natural vegetation cover.

*Note: The propagation of plants through fragments (stem, root, bulbs, or any other part) is called vegetative propagation and is a form of asexual propagation, that is, there is no seed production and, consequently, no crossing of genetic information from different plants. The new plant will be like a clone of the original one.

In these situations, the intervention strategy must take into account the need to provide for plantations and sowing of dune species (preferably collected or propagated from a nearby dune area), or other measures to mitigate sand erosion. Because these areas are very extensive, it is also preferable to plan these interventions in phases and with large numbers of volunteers (between 15 and 30 people), bringing communities together for the recovery of dune ecosystems. With smaller volunteer groups, especially in the context of interventions in the pilot area of Malhão Ponds (habitat of Mediterranean temporary ponds), it is still possible to intervene in these areas. Intervention in bordering areas that contact with natural vegetation zones should be prioritized, where the seed bank and the present native vegetation helps to recolonize and “advance the line” against the hottentot fig patch.

In general, regardless of the approach, the goal is to provide the necessary support for native vegetation to recolonize invaded areas. Intervention in these areas should always be phased to avoid greater impacts caused by soil erosion.

Ideally, when intervening, we would only have to deal with one of the target species (hottentot fig and long-leaved wattle), but it is most common to find these species cooperating in the invasion, along with many other not metioned in this article. Therefore, it is important to know these techniques well and to plan and define strategies to follow.

This is what has been done and tested for the pilot areas of Rota Vicentina, integrating volunteers into organized missions to recover (our) landscape and enhance the splendor of native vegetation and natural ecosystems in the southwest of Portugal. Stay tuned, when the hiking and volunteering season returns, we will be back for more!