Adaptation, restoration and creation of habitats for amphibians threatened by climate change in the Montes de Valsaín mountain range, Segovia

Image author: Maria Soledad Redondo Rodriguez/ Fototeca CENEAM

The project "Adaptation, restoration and habitat creation for amphibians threatened by climate change in the Valsaín Forestry, Segovia" was initiated with the aim of counteracting the global decline of amphibians, which are currently the most threatened group of vertebrates in the world. This project was specially designed to respond to the decline of more than a third of amphibian species, which are under some degree of threat due to habitat destruction, adverse climate change, emerging diseases, and the disappearance of critical breeding sites.

Located on the northern slopes of the Sierra de Guadarrama, the Valsaín Forestry encompass an area rich in biodiversity and protected by multiple conservation figures. This natural environment provided a unique setting for the implementation of a project that combines the protection of existing ponds with the creation of new aquatic spaces to facilitate the reproduction of the eleven species of amphibians that reside in the area. The intervention focused on establishing and protecting these vital aquatic environments, essential for the survival and prosperity of the local amphibian populations.

Case Study Description

Challenges:

The Valsaín Forestry are located on the northern slopes of the Sierra de Guadarrama, in the municipality of Real Sitio de San Ildefonso. They cover a forest area of 10,668 ha and are State-owned Public Utility Mountains, managed by the Autonomous National Parks Organisation (OAPN) through the Valsaín Forestry and Sawmill Centre.

It is a well-preserved area with numerous protected statuses, including Natural Site of National Interest (declared in 1930), Special Protection Area for Birds (SPA), Special Conservation Area (SCA), Natural Park and Biosphere Reserve. In addition, since 2013, 3,326 ha of the Valsaín Forestry have been incorporated into the Sierra de Guadarrama National Park and a further 7,011 ha have been included within the Peripheral Protection Zone, as a Special Protection Area of the National Park, acquiring a legal status like that of the National Park.

The area is dominated by sessile pine (Pinus sylvestris) and oak groves (Quercus pyrenaica). At the highest altitudes there are broom woods, creeping junipers, and high mountain pastures.

One of the lines of work of the Conservation and Monitoring Area of the Montes de Valsaín Centre was to contribute to the conservation and recovery of the amphibian communities that inhabit the area, one of the groups most affected by climate change and its consequent changes in habitat and ecosystems. Amphibians are intricately linked to aquatic ecosystems and to the existence of permanent or temporary ponds where they can lay their eggs and complete their metamorphosis until they become adults.

Thus, the survival of amphibian populations depended directly - among other variables - on the existence of water surfaces, whose viability was being compromised - locally, regionally, and globally - by the lower rainfall and higher temperatures brought about by climate change. In addition, habitat loss and fragmentation and the emergence of new diseases (caused by viruses, bacteria, and fungi) were seriously contributing to the decline of amphibian communities worldwide.

The results obtained from the Amphibian Monitoring work carried out at the Montes de Valsaín Centre indicated the need to establish sites that would favour the reproduction and mobility of these species, avoiding as far as possible the mortality of both adults and larvae.

Objectives:

Conservation and improvement of the populations of the eleven species of amphibians that inhabit the Valsaín Forestry (Segovia) through a series of actions to protect the ponds already existing in the area - mainly by fencing them off - and the creation of new spaces suitable for the reproduction of the different species - excavations in the ground to act naturally as new ponds and fencing them off.
Improving the availability of aquatic habitats and the diversity of flora and fauna associated with them.
Favouring other wild species, not linked to these aquatic environments, but which do use them for drinking.

Adaptation measures implemented in the case study:

Structural/physical: Ecosystemic options

Social: Education options

Solutions:

A few years ago it was decided to start an intervention project for the conservation and improvement of the populations of the eleven species of amphibians that inhabit the Montes de Valsaín: salamander (Salamandra salamandra), spanish ribbed newt -gallipato- (Pleurodeles waltl), marbled newt (Triturus marmoratus), common toad (Bufo spinosus), runner toad (Epidalea calamita), midwife toad (Alytes obstetricans), iberian spadefoot toad (Pelobates cultripes), common toad (Discoglossus galganoi), common frog (Pelophylax perezi), long-legged frog (Rana iberica) and the San Antonio frog (Hyla molleri).

The project began with a diagnosis of the initial situation and the specific reproduction requirements of each of the species in order to develop a series of actions to protect the existing ponds in the area - mainly by fencing them off - and to create new spaces suitable for the reproduction of the different species, including excavations in the ground to act naturally as new ponds and fencing them off.

In some cases, the aim was to recover spaces that had been lost due to lack of use, such as some ponds that were used for watering livestock and which became clogged due to lack of maintenance work. In others, sites were adapted which, although good for amphibians, required some intervention, such as fencing to prevent trampling by livestock and the creation of refuge areas. In addition, in places suitable for amphibians, but without habitats for their reproduction, new ponds were created.

Wetland areas of different dimensions were created using wheeled backhoes to avoid damaging the surrounding areas. The depth varied from area to area, with an average depth of 1.5 m, adapted to the terrain to minimise soil movement. The excavated earth was placed on the sides of the excavation to increase the capacity; the slopes were shaped to make the result as natural as possible, allowing the vegetation to settle and fix them. Water evacuation pipes were installed that operate above a certain level, preventing overflows that could damage the structure of the reservoir.

Fences were also installed with treated wooden posts to prevent damage to the amphibians caused by trampling and overgrazing by livestock. The fences are permeable to wildlife.

The interventions did not include the relocation or transfer of animals between ponds; thus, colonisation by the different species (not only amphibians, but also flora and other animals) was entirely natural.

In addition to these in situ conservation measures, the Montes de Valsaín Centre implemented an ex-situ conservation measure. The intervention consisted of removing amphibian larvae that, due to the early drying of the ponds due to the increase in temperature and variations in precipitation, could not complete their metamorphosis, and transferring them to suitable facilities where they could complete the cycle and become adults. Subsequently, they were relocated to their original habitats, thus reinforcing the populations. In no case were specimens removed that could be viable naturally, and so far, no artificial recolonizations were carried out in places other than those from which the larvae were extracted.

Importance and relevance of the adaptation:

Biodiversity conservation: Amphibians are key indicators of environmental health. Protecting them and their habitats not only safeguarded these species, but also benefited a wide range of flora and fauna that depend on these aquatic ecosystems.
Water Resource Management: By creating new ponds and restoring existing ones, the project improved water resource management in the region. This was essential in a context of climate change, where efficient water management is becoming increasingly critical.
Ecological Resilience: By adapting the landscape to withstand changing conditions and improving connectivity between aquatic habitats, the project strengthened the ecological resilience of the region. This enabled ecosystems and their biological communities to better manage the impacts of climate change.
Education and Awareness Raising: The project included a strong educational component, raising awareness of the effects of climate change on local ecosystems and the importance of amphibians as bio-indicators. This fostered greater appreciation and support from the local community and visitors for conservation initiatives.
Innovation in Conservation: The approach of creating and protecting aquatic habitats was considered innovative in amphibian conservation, providing a replicable model for other regions facing similar challenges. In addition, the techniques used in the project can be adapted to improve the management of other ecosystems threatened by climate change.

Additional Details

Stakeholder engagement:

The Valsaín Forestry are located on the northern slopes of the Sierra de Guadarrama and are Public Utility Mountains (Mountains 1 and 2 of the CUP of the province of Segovia) owned by the State, managed by the National Parks Autonomous Body through the Valsaín Forestry and Sawmill Centre, where the Flora and Fauna Conservation and Monitoring Area, responsible for the project, works.

In the area around the works, interpretative signs were installed to explain the project and the problems it seeks to address. These panels provided information related to the object of these works, raising awareness of the consequences that climate change can have, particularly on amphibians and their vulnerability.

As an added component to the work carried out, these actions were provided with an informative component. To this end, various materials were produced and are available on the OAPN website. The materials produced are aimed at a wide variety of target audiences, ranging from more technical information contained in a book with photographic reports of the works, to knowledge and awareness-raising materials aimed at children, as well as other informative elements such as a guide to the amphibians present in the National Parks Network, or a dichotomous key that allows them to be identified without the need to handle the specimens observed.

Project interest:

This type of action is not very demanding in terms of financial and technical resources, so it is easy to replicate in other places. In the case of Valsaín, both the Autonomous National Parks Agency's own resources and funds from the Environmental Promotion Plans (PIMA ADAPTA) were used.

Success and limiting factors:

These were undemanding actions in terms of economic and technical resources, making them easy to replicate elsewhere.

The first data in Valsaín indicated a very considerable success of the interventions carried out to date, with a rapid natural colonisation of the ponds by the amphibian species existing in the area.

One of the most complex aspects of the project was the definition of the intervention sites, which must be suitable for the formation of new ponds, considering both their spatial location and the natural impermeability of the terrain, as no concrete, plastic or artificial material is used. When the soil is not completely impermeable in the initial situation, the progressive accumulation of organic matter contributes to achieving impermeability over time.

A key element of the project has been the monitoring and evaluation of the results - in this case, of the amphibian populations in the different ponds - to which special attention and effort is given. In this sense, it is important to know that there is an extremely high inter-annual variability in amphibian communities, so it is necessary to have long periods of time to know with certain rigour the population trends of the different species in the different places.

Budget, funding and additional benefits:

Budget financed through the PIMA-ADAPTA Plan of the Spanish Office for Climate Change (OECC), ceded to the OAPN for this specific purpose. In general, these were not large-scale actions: the cost included prior knowledge of the species, their requirements and threats; protective fencing; manual or mechanical excavation of a flooding basin (where appropriate); monitoring and control of the evolution of populations and the maintenance of the sheet of water in the constructed ponds, carried out by expert personnel; and on-site signage (where appropriate).

The first data in Valsaín indicated a very considerable success of the interventions carried out to date, with a rapid natural colonisation of the ponds by the amphibian species present in the area. And not only amphibians, but also a wide range of flora and fauna species occupied these spaces, contributing to convert them into valuable habitats. In addition, the ponds were used as drinking troughs by mammals and birds, becoming veritable oases in times of low water availability.

Legal aspects:

The intervention area is a well-preserved area with numerous protected statuses, including Natural Site of National Interest -declared in 1930-, Special Protection Area for Birds (SPA), Special Conservation Area (SCA), Natural Park and Biosphere Reserve. In addition, since 2013, 3,326 ha of the Valsaín Forestry have been incorporated into the Sierra de Guadarrama National Park and a further 7,011 ha have been included within the Peripheral Protection Zone, as a Special Protection Area of the National Park, acquiring a legal status similar to that of the National Park.

These actions are part of the Natural Resources Management Plan (PORN) of the Sierra de Guadarrama National Park.

Implementation time:

2015-2018

Reference Information

Contact:

Marisol Redondo
Valsaín Forestry and Sawmill Centre. OAPN.
C/ Primera, 11. Pradera de Navalhorno. Valsaín. San Ildefonso-La Granja. 40109. Segovia
Email: sredondo@oapn.es

Sources: