Laurisilva of Madeira

Water channels (called "levadas") might represent a threat through the potential introduction and dissemination of non-native species (for example, the spread of alien plant species for ornamental purposes or through the spread of alien aquatic species), as well as direct disturbance, both for maintenance works and tourists who use the adjacent trails for hiking. Laurisilva is currently sought after by a large number of visitors. In some cases, the passage of these visitors results in the abandonment of organic and inorganic waste inside the property. These may affect the property negatively due to possible interference with ecological processes and making the property less pleasant to visitors. Maintenance works are monitored by the management entity IFCN (IUCN Consultation, 2020), and hiker disturbance is mainly limited to the most touristic water channels.

Despite the use of non-native species as ornamental items in natural habitats having been forbidden since 2023 by law (Decreto Legislativo Regional n.º 17/2023/M), alien plant species are commonly found as ornamental plants along the channels, with the potential of spreading to adjacent areas. Despite some work have been done focussing on this topic (e.g. the replacement of invasive species for native species with ornamental value along the Levada do Norte, in the framework of the Life Fura-bardos project, 2015), further work is needed, carefully managed to prevent a possible outbreeding genetic depression (IUCN Consultation, 2020b).

There is no existing mechanism to prevent the dissemination of alien aquatic species across the channels, from one river course to another, despite some studies already pointing to this potential threat and reporting the presence of aquatic alien species such as the rainbow trout (Oncorhynchus mykiss) (Malmqvist 1988).

The presence of invasive plant species continues to pose a significant threat to the conservation of the Laurisilva of Madeira, particularly at the upper and lower boundaries of the site, where the regeneration and expansion of native forest can be in some cases compromised. Although the core pristine areas generally retain a favourable conservation status, pressure in transitional zones — including former agricultural land at lower elevations and former livestock farming areas or heathlands affected by fires at higher elevations — remains high. Several of these invasive species are also fire-prone species and are favoured by fire disturbance, which increases their capacity for post-fire colonisation and further compromises native ecosystem recovery (Medeiros et al., 2023). The introduction and spread of invasive species near the property is an ongoing issue that continues to present a major challenge for site management and conservation. In response, several measures have been adopted since 1998, most notably the enactment in 2023 of Regional Legislative Decree No. 17/2023/M. This decree regulates the introduction and spread of exotic species within the Autonomous Region of Madeira and ensures the implementation of Regulation (EU) No. 1143/2014 of the European Parliament and of the Council, which focuses on the prevention and management of invasive alien species (IFCN, n.d.-b). Amongst others it could be mentioned two specific projects which are currently underway (IUCN Consultation, 2025). The first, "Early Detection and Rapid Elimination of Invasive Exotic Plants species", aims to establish and equip a specialised team to implement a programme focused on the prompt detection and removal of invasive plant species in natural areas of Madeira. The second project, "Invasive Exotic Plants Species – Awareness and Publicity Actions", seeks to raise awareness among the general public and the school community about the ecological impacts of invasive plants, encouraging their active participation in minimising these negative effects, in Madeira archipelago

Introduction of rainbow trout in the water courses of Madeira Island began in 1960, when the activity of recreational fishing in the inland waters started on the island. Although the restocking was regular for many years and extended to many of the streams, since 2020, restocking has been completely suspended (IUCN Consultation, 2025). The species is now established and its presence has been recorded in several watercourses across the island, including within the World Heritage property and in the levadas (Malmqvist, 1988; Ribeiro et al., 2009; Hughes et al., 1995). Despite being listed among the 100 of the World's Worst Invasive Alien Species (Global Invasive Species Database, 2025), there remains a significant lack of information regarding the distribution and ecological impact of rainbow trout on Madeira's invertebrate fauna. This is of particular concern given the potential for irreversible consequences on native aquatic invertebrates, some of which are endemic to the island (Ribeiro et al., 2009). However possible impacts specifically on the Outstanding Universal Value of the site can be considered low.

Rabbits are invasive species listed among the TOP 100 of the World's Worst Invasive Alien Species, known to cause soil erosion through overgrazing and burrowing, thereby impacting native species that depend on undisturbed ecosystems (Global Invasive Species Database, 2025). On Madeira Island, rabbits are classified as a game species, and a legal framework exists that permits density control actions in areas where damage to vegetation and/or agriculture is observed. Rabbit populations are also subject to reinforcement through restocking initiatives, and recently, new infrastructure has been established for captive breeding to repopulate areas affected by disease outbreaks and deemed suitable for hunting activities (IFCN, n.d.-a). Although these hunting areas are not located within the World Heritage property, they closely border its boundaries (IFCN, n.d.-c). While rabbits are absent in areas where the laurel forest remains in a favourable conservation status (IUCN Consultation, 2025), they still pose a potential threat to forest regeneration, particularly in zones covered by secondary vegetation resulting from recent agricultural abandonment, livestock grazing, or fire events.

There are very few roads crossing the Laurel Forest, and planting of exotic invasive species along roads is nowadays strictly forbidden by law. The above-mentioned law imposes serious restrictions to the use of exotic plants in protected areas and Nature 2000 sites.

Threat from forest fires has been increasing over the recent years, mostly due to climatic changes and the proliferation of woody invasive plant species such as Acacia spp, Eucalyptus globulus, broom Cytisus scoparius and gorse Ulex europaeus at the lower outer limits of the property (IUCN Consultation, 2025). At lower altitudes, these invasive plants mostly occur on abandoned agricultural land, while at the higher outer limits, invasive species thrive in areas affected by past grazing activities and wildfires. Climate change is expected to further increase both the frequency and intensity of wildfires through direct and indirect mechanisms (IUCN Consultation, 2014). However, the capacity to prevent and combat forest fires has been significantly strengthened in recent years. The Plan for the Prevention and Surveillance of Forest Fires (PPVIF), first implemented in 2015, has been updated annually. In 2018, its operational capacity was reinforced with the acquisition of a helicopter by the agency for civil protection and two heavy firefighting vehicles by the IFCN. The Institute now maintains a fleet of 15 vehicles ready for rapid intervention, and drones are widely used for fire surveillance. In addition to a trained corps of forest firefighters, Madeira now benefits from a heli-transported firefighting team that has proven to be highly effective (IUCN Consultation, 2025). It is expected that in the summer of 2025 a second helicopter will be operating in Madeira Regarding the future, IFCN has launched the procedures to hire another 20 specialized firefighters and other 3 technical staff to work in this matters. Expansion of fire-prone invasive species has been of concern, but there are projects underway to reduce the fuel load in transition zones, in line with the Regional Plan for Forestry Management of Madeira (PROF-RAM) approved in 2015, currently under revision. In terms of recent fire events, after a notable reduction in fire-affected areas between 2013 and 2018 (65 ha) compared to the previous five-year period (2008–2012, with 1,248 ha), the Laurisilva forest was again impacted in 2023 and 2024, with 599 ha and 149 ha affected respectively (IUCN Consultation, 2025).

Tourism within the World Heritage site has increased significantly in recent years (IUCN Consultation, 2025). However, although impacts are present, they remain localised. Visitor activity is largely concentrated along designated trails located in rugged and demanding terrain, which naturally restricts hikers from leaving the established paths. Due to concerns about exceeding the carrying capacity on certain trails, several initiatives have been launched to improve existing routes and create new trails in less-visited areas of the property, aiming to disperse visitors and reduce pressure on the local ecosystem.

The most significant of these projects is currently being implemented in the Rabaçal area, involving the improvement of trails, levadas, and tourist pathways. It is expected that this project will enhance the distribution of visitor flows across the site (IUCN Consultation, 2020a). Recently, a novel study assessed the carrying capacity of two of the most frequented trails in Rabaçal: PR6 (25 Fontes), with a Real Carrying Capacity (RCC) of 1,420 visitors/day, and PR6.1 (Risco), with an RCC of 1,220 visitors/day. Field observations showed that actual visitor numbers were well below these thresholds, with peaks of less than 664 visitors/day for both trails (Mota et al., 2021). The university of Madeira is finalizing another study to calculate the RCC for other trails inside the property

A particular concern linked to the intensive use of trails is the inadvertent spread of non-native species by visitors, especially through footwear and equipment. This threat is being addressed through regular monitoring and preventive measures carried out by IFCN staff and nature wardens (IUCN Consultation, 2025).

The recent expansion of forest and other natural areas for "nature sports" could prove to be unsustainable. Major sporting events, which in some cases attract hundreds or even thousands of participants, now traverse previously little-used trails or newly created ones. The ecological effects of such intense and concentrated use require careful study. In particular, the use of sensitive habitats, such as waterfalls covered by specialized plant communities, for activities like canyoning has not been adequately assessed and is likely to result in habitat degradation. Evidence of such impacts is visible in promotional videos, where fragments of bryophyte communities can be seen floating in the water around tourists. Moreover, these activities may facilitate the spread of invasive freshwater species (Dias et al., 2024). The recent expansion and diversification of recreational activities in natural areas has raised significant concerns (IUCN Consultation, 2020b). However, it is important to note that all such activities are currently restricted to designated areas and require licensing (IUCN Consultation, 2025).

Although some landslides are accidental, many can be linked to human activities such as levadas, roads, trails etc. Recent studies have also proven the high risk of landslides in areas covered by invasive species such as Acacia mearnsii and Cytisus scoparius, and therefore a synergic link between distinct threats (Figueiredo, Pupo-Correia & Sequeira 2013, 2016).
Although currently considered a localized threat, proactive measures are being implemented to mitigate the risk. Efforts include the eradication of invasive plant species and the restoration of native vegetation cover, particularly in sensitive and degraded areas, to reduce surface runoff and, thereby, the likelihood of landslides and flash floods (IUCN Consultation, 2025). Additionally, forest fires occurring at the upper limits of the forest can locally exacerbate the risk of landslides by destabilizing soil and vegetation structures (IUCN Consultation, 2025).

Temperature changes (increases) can already be detected (IPCC 2007) and lead not only to long-term ecosystem shifts, loss of ecosystem resilience, loss of quality, or even collapse, but also to increased fire risk. The climate projections for the Madeira Archipelago until the end of the century (CLIMAAT II) suggest an increase in temperature of up to 3.2ºC. The displacement in altitude of mesic ecosystems will lead to the extinction of Mountain ecosystems and consequently also to the extinction of cacuminicolae endemic species (Figueiredo & Sequeira, 2012). Temperature increase and the increase of drought periods can lead to an exponential increase in fire risk during August and September (IUCN Consultation 2025), presenting a high threat to the OUV.

The ferret (Mustela furo) is an introduced mammal species, likely present on Madeira Island since the 16th century, when it was used for rabbit hunting. Escaped individuals may have led to the establishment of feral populations. Its status as an established species has recently been confirmed, with records indicating widespread distribution across the island, including within the boundaries of the World Heritage property (Soto et al., 2024). Documented impacts on endemic and protected fauna outside the property, such as Zino's petrel, have raised growing concerns regarding its ecological effects (Soto et al., 2024).

Ferrets are generalist and opportunistic predators capable of adjusting their diet based on prey availability. Studies from other islands show that while lagomorphs are a primary food source (Bodey et al., 2011), ferrets also prey on a variety of native species, including lizards and passerines, as well as introduced rodents. On Madeira, ferrets could potentially threaten species critical to ecosystem functioning, such as the endemic Madeira laurel pigeon (Columba trocaz), a key seed disperser, and the endemic Madeira wall lizard (Teira dugesii), which plays a dual role as both an arthropod predator and pollinator, while also serving as an essential prey item for native predators like the Macaronesian kestrel (Falco tinnunculus canariensis)(Soto et al., 2024).

Despite these concerns, information regarding ferrets’ distribution and the extent of their ecological impacts within the World Heritage property remains limited.

The domestic cat (Felis catus) is listed among the TOP 100 of the World's Worst Invasive Alien Species (Global Invasive Species Database, 2025) and is considered one of the most harmful and widely distributed mammalian predators globally (Doherty et al., 2016). Island ecosystems are particularly vulnerable to their presence, with cats implicated in 33 (14%) of modern bird, mammal, and reptile extinctions on islands (Loss et al., 2013). On Madeira Island, feral and free-ranging cats have been documented preying on several endangered and endemic taxa, including seabirds, bats, passerines, and lizards (Zino et al., 2001; Rocha, 2015; Galão et al., 2025). Such predation may have cascading effects throughout the ecosystem (Soto et al., 2023). Although there is currently no specific data on the status of this threat within the World Heritage property, recent studies have reported high densities of feral cats across the island and a significant reliance on native wildlife to meet their dietary needs (Soto et al., 2023; Galão et al., 2025). While no major urban settlements are located within the boundaries of the property, several exist in the surrounding areas, posing a potential risk of cats dispersing into the site to hunt. Additionally, various scattered human infrastructures within the property, such as picnic areas, restaurants, accommodations, and waste containers, can provide anthropogenic food sources that sustain feral cat populations and other wild species, such as rodents or ferrets, in otherwise natural environments. Notably, areas such as Parque das Queimadas (Santana), which includes a café located within the boundaries of the Laurisilva forest, are of particular concern due to the maintenance of established cat colonies. These colonies are illegally maintained by animal welfare organizations and nowadays efforts are being carried out by the authorities to sterilise these cats and to displaced them from the area. Despite Felis catus being classified as an invasive species under Regional Decree No. 17/2023/M - which transposes EU Regulation No. 1143/201- applying invasive species control measures to free-ranging cats is not feasible without potentially conflicting with existing national animal welfare legislation (Lei n.º 27/2016). This law promotes the protection and care of stray and feral cats, including the provision of food and veterinary assistance, and explicitly prohibits lethal control measures, replacing culling with fertility control programs. Therefore, it is likely that feral cat populations have increased - and continue to increase - particularly in urban centres surrounding the protected area. Although management options are limited, certain actions remain legally permissible under Lei n.º 27/2016, including the capture and transfer of individuals from ecologically sensitive areas to authorised facilities. Although cats have been removed from certain areas of the island, also in localised areas at the boundaries of the property (e.g. Areeiro) and sterilisation efforts are ongoing in others (IUCN Consultation, 2025), there is currently no specific action plan in place to address this threat within full range of the boundaries of the property.

The New Zealand mud snail (Potamopyrgus antipodarum) is considered one of the most successful and widespread invasive freshwater molluscs globally. It was absent from Madeira Island until relatively recently, with the first confirmed records dating back to 2017. Since then, it has spread rapidly and is now detected in several river basins across the island (Orfão et al., 2024). Its introduction may be linked to the stocking of rainbow trout (Oncorhynchus mykiss) for recreational fishing (Orfão et al., 2024). Their spread may have occurred through unintentional transport between basins, either via natural vectors such as birds or through human activities such as hiking and canyoning (Dias et al., 2024).

Due to its rapid population growth and competitive dominance, P. antipodarum can displace native gastropods and invertebrates, leading to a reduction in biomass, abundance, and taxonomic diversity. In ecosystems where it becomes dominant in the benthic community, its intense grazing pressure - particularly its preference for green algae over diatoms - along with the accumulation of organic matter through increased faecal output, can lead to shifts in primary producer composition. This typically results in decreased carbon availability and increased nitrogen fixation, altering nutrient cycling and ecosystem function (Orfão et al., 2024).

Recent surveys have reported high densities of P. antipodarum in the main watercourse running through the Laurisilva forest within the World Heritage property (Dias et al., 2024). While no severe ecological impacts have yet been detected, the species is in an early expansion phase. Considering the ecological significance and fragility of the Laurisilva ecosystem, this presence is cause for concern, and it is theoretically possible that more pronounced impacts can emerge in the coming years if effective management is not implemented. However impacts have not been identified so far, though intense monitoring is very much needed (IUCN Consultation, 2025).