Linking nature based solutions & ancestral practices in proglacial Andean landscapes – TierrasNuevas

TierrasNuevas is built around three work packages (WPs), which are described below, along with their interconnections. The project has started in January 2025.

The project focuses initially on four mountain ranges: one in Peru (Cordillera Blanca), two in Bolivia (Cordillera Real and Sajama) and one in Chile (Cajón de Maipo). In these places, the local livelihoods depend on the NCPs produced by high-elevation ecosystems and glaciers, such as camelid herding and wetland management. Human activities and practices differ between mountain ranges, as well as between valleys and communities. Thus, a regional approach, as proposed in TierrasNuevas, is required to provide a representative range of practices on an Andean scale. Based on the previous and current experiences of the consortium and its established collaborations with the local communities for several years we have selected one pilot subwatershed within each mountain range. Each subwatershed includes one flagship valley and several neighbouring glacierized valleys called expansion valleys. The expansion valleys are sites where the NbS tested in the flagship valleys could be replicated in the future by the subwatershed local communities. Efforts will be made to work with partner communities formally recognized as ‘peasant communities’ by the national governments of Peru, Bolivia and Chile. Involving such stable partners is a prerequisite for safe and sound collaborations throughout the project and further facilitates the bridging between local stakeholders and decision makers. First, within each flagship valley, the ancestral NCPs will be co-defined and co-evaluated with the communities (WP1) and in situ testing of selected NCPs will be carried out in the novel, proglacial ecosystems (ecological field data collection; WP3). The functional and taxonomic composition and NCPs of the flagship novel ecosystems will be compared to those of the relative support ecosystems (WP3). As a second step, the outcomes of the experimentation carried out in the flagship valleys will be upscaled, using previously defined physical and socio-economical maps (subwatershed scale;WP2), to both the subwatershed and mountain range levels. Finally, the regional physical and socio-economical cartographies of WP2 will serve to export the outcomes of WP1a and WP3 at the mountain range scale to produce visual tools for decision makers.

During the year 2025, we have organized a three-days’ workshop “opinion paper”, in February 2025, France. The opinion paper has received an invitation for submission in the journal WIRE. In addition, from 16 to 19 May, we have organised a kick-off meeting in Huaraz, Peru. It brought together about twenty participants. Among them, scientists, local actors, and students from the four countries involved in the ANR. From 14 to 18 September, the coordinators of TierrasNuevas participated in the International Mountain Conference (IMC, Innsbruck, Austria), where they have presented the provisional version of the opinion paper. Since September, WP1 co-construction workshops have been underway in Bolivia, Peru and Chile.

Since the Little Ice Age, 8000 km2 of Andean glaciers (from Peru to Tierra del Fuego) have been converted into proglacial landscapes, with heavy consequences over the dynamics of socio-ecosystems at local and regional scales. From Peru to central Chile, this impacts the livelihoods of millions of people who depend upon the NCPs provided by the high mountains, and their water, vegetation and soils. Global warming and land use changes intensify the threat to existing support ecosystems. At higher elevations, emerging proglacial landscapes may host novel ecosystems providing NCPs. The unprecedented pace of glacier retreat currently far exceeds that of the formation of these ecosystems resulting in severe and multiple impacts on several sustainable development goals, namely SDG 3 (good health and well-being), SDG 6 (clean water and sanitation) and SDG 15 (life on land), but also SDG1 (no poverty), SDG 2 (zero hunger) and SDG 8 (decent work and economic growth). TierrasNuevas addresses these concerns explicitly and promotes equal involvement opportunities, and representation of women, thus contributing to reduce gender inequality.

This project is coordinated by Fabien Anthelme and Anaïs Zimmer (IRD, Laboratory AMAP, University of Montpellier).

International Conference :
Zimmer, A; Root Bernstein, M; Recharte, J; Racoviteanu, A; Rabatel, A; Palomo, I; Meneses, RI; Guerrero, M; Condom, T; Charles-Dominique, T and Anthelme, F (Septembre 2025). Knowledge co-production: promoting the future of Andean post-glacial socio-ecosystems. Talk, International Mountain Conference (IMC, Innsbruck Austria). imc2025.info/imc25/sessions-n-workshops/focus-session/fs-3-127-mountain-futures-assessing-challenges-and-co-producing-solutions-to-mountain-social-ecological-futures/

In the high Andes, which have been the cradle of important pre-Hispanic civilizations and are inhabited by millions of people, glacier losses consecutive to warming result in the emergence of large proglacial landscapes (‘tierras nuevas’; + 8000 km2 since 1850), which generate both threats and opportunities for adaptation. Risks include species extinctions, loss of water provision, water contamination from acid rock drainage, slope instability, reduction of biomass for livestock and loss of identity and cultural values. Novel ecosystems, however, are emerging after the retreat of the ice, and can mitigate the risks related to climate change: they are the future providers of key Nature’s Contributions to People (NCPs) for the local populations, which are currently provided by downstream support ecosystems. The speed of glacial retreat far exceeds that of the vegetation primary succession and soil formation. As a result, the novel proglacial ecosystems might not fully supersede the role played by the current support Andean ecosystems, which are fragilized by global changes. Will these novel ecosystems be able to mitigate socio-economic and ecological crises caused by the acceleration of global change? Do they require intervention to enhance NCPs provision? In the high Andes, ancestral practices (Andean camelid herding, terracing, irrigation) have been used for millennia to enhance the sustainability and productivity of high Andean ecosystems, but it has been scarcely used in proglacial landscapes so far. Such practices have the potential to enhance the NCPs provided by novel ecosystems, such as limiting water contamination, increasing biomass production for livestock and slope stability.
The objective of the project TierrasNuevas is to co-construct and evaluate the reasonable implementation of in situ, ancestral Nature-based Solutions (NbS) in proglacial landscapes that can mitigate the negative consequences of glacier retreat on NCPs. For this purpose, we are an inter- and trans-disciplinary consortium that brings together specialists in Human, Earth and Life sciences. The consortium (UMR AMAP, IGE and CESCO; gender ratio = 1) will collaborate with local communities and with long-standing academic and non-academic Andean partners with extensive experience in the focal sites. The project will be carried out in four flagship valleys inhabited by local communities who still use ancestral land-use practices in four mountain ranges in Peru (1), Bolivia (2) and Chile (1). The results collected in the flagships valleys will be exportable to the subwatershed and mountain ranges scales, conferring a regional scope of the project.
TierrasNuevas is built around three work packages (WPs). WP1a, in collaboration with Peasant Communities, co-assesses the local needs for investigations and proposes ancestral NbS to be tested with in situ experiments in WP3. WP2 characterises the landscapes at three spatial scales: the four flagship valleys, their glacierized subwatersheds, and their mountain-range (geo-physical and socio-economic mapping, including the characterization of the support ecosystems). WP3 implements and evaluates the in situ experiments co-constructed in WP1a in proglacial landscapes (vegetation, soil, water quality). Outcomes of WP2 and WP3 are later combined to compare the NCPs delivered by support ecosystems and novel proglacial ecosystems and to upscale results to subwatersheds and mountain ranges. The results are ultimately co-evaluated with stakeholders and decision-makers to propose decision-making tools (WP1b).
In conclusion, TierrasNuevas is a co-constructed project that responds to a strong societal demand on a regional scale and will have a direct impact on management practices and on the socio-economic sustainability and cultural identity of peasant communities in the Andes.