First successful mountain forest restoration in central Argentina 25 years later

Figure 1. Before and after view of the lower portion of the forest restoration area. Note the mountain hostel (“Refugio” in Spanish) in the upper middle of the photo. Yellow arrows indicate areas where active soil erosion was taking place in year 1997. Photo: Daniel Renison
Figure 2. Before and after photo when volunteers were constructing the fences to keep livestock out of the forest restoration area in 1997 and the same fence in 2020 after restoration work. Note that the fence is “taller” in 2020 as compared to 1997 because of soil loss at the fencing area, which is now very much reduced. Photo: Daniel Renison
Figure 3. Before and after view of the upper portion of the forest restoration area in 1996 and 2020. Note the dark vertical soil erosion edges in the 1996 photo which are not present in 2020. Also note the Cedar with a blueish tint that can be seen behind the mountain hostel in 2020 and that represents the only non-native tree in the area, all others are natives. Photo: Carlos Lagger (1996) and Daniel Renison (2020).


The high mountains of central Argentina are losing their soils due to livestock, fires, trampling by vehicles and trekkers, in combination with a reduced forest cover, cold temperatures, a long dry season and heavy rains. With the goal of restoring a portion of forest and reducing soil erosion, in 1997 I selected a 22 ha site devoid of forest and where 30% of the soil surface was lost. The “Quebrada de los Refugios” is near my home town and land owners were in agreement. With volunteer help we built fences to exclude livestock, planted 20000 native trees, and to reduce soil erosion we covered bare soil with native tussocks in 30 erosion gullies. The trees prospered to form a beautiful 25 year old forest stand. Recent studies comparing the restoration area with control and reference areas show important restoration progress in bird, fungi and liken forest communities. More evaluations are needed. We also need to work on 15 remaining active gullies to further reduce soil erosion, on maintenance of fences and trekking trails, and to continue with the control of incipient biological invasions by non-native plants. Twelve similar projects are now being carried out in the region.

Quick Facts

Project Location:
H5MW+Q3 Los Gigantes, Córdoba, Argentina, -31.415539820784, -64.804802280334, 16, GhIJty_70GBqP8ARt4-B4YEzUMA, Los Gigantes, Córdoba, Argentina, AR

Geographic Region:
Latin America

Country or Territory:

Tropical Forest

Montane Grasslands & Shrublands

Area being restored:
22 ha

Project Lead:
Ecosystemas argentinos

Organization Type:
NGO / Nonprofit Organization

Project Partners:
Club Andino Córdoba; National Univesity of Córdoba and CONICET


Project Stage:
Monitoring & Evaluation

Start Date:

End Date:

Primary Causes of Degradation

Agriculture & Livestock, Deforestation, Fire & Weather Events

Degradation Description

The high mountains of central Argentina are losing their soils at an alarming rate and already 20% of the land cover is composed of exposed rock where soils were present in the past. Gullies produced by water erosion are abundant and can reach a depth of over 4 m. The lack of an adequate vegetation cover, trampling by livestock, vehicles and trekkers, in combination with a long dry season, heavy monsoon rains and a cold climate have accelerated soil loss. Due to the high altitude climate and steep slopes, the mountain range is a fragile ecosystem and if current rates of disturbances are not reduced, the area could be converted into a rock desert.

The effects of forest and soil loss on ecosystem function has been poorly studied in the mountains of central Argentina and with mixed evidences, though most consequences are negative there are always some benefits. Native Polylepis trees planted in areas where the topsoil has been partially lost grow about 50% slower than trees planted in well preserved soils suggesting degradation reduces ecosystem recovery. Forests have a unique biodiversity so further reductions in their extension would decrease landscape biodiversity. Older successional forest stages have increasing richness of wood decaying fungi including several species unique to the only known old growth forest found to date. The loss of this unique old growth stand will presumably mean species extinctions. Other ecosystem attributes do not seem to be affected by degradation. For example, soil mycorrhiza biodiversity and inoculation capacity is not lost even with extreme soil degradation, nor is plant richness lost with heavy grazing pressure and the expansion of bare rock due to soil loss.

I have not found studies on socio-economic and political factors contributing to degradation in the mountains of central Argentina. The existence of many abandoned houses and records of an order of magnitude more livestock existing in the mountains of central Argentina a century ago as compared to present day, suggests a net human emigration from the area and lower livestock productivity due in part to soil loss and degradation.

Defining the Reference Ecosystem

The reference ecosystem is based on diverse sources of information (e.g. multiple extant reference sites, field indicators, historical records, predictive data).

Reference Ecosystem Description

Simulations suggest that around 50% of the high mountains of central Argentina could be covered by Polylepis forests if all the area would have been under a history of low livestock pressure, such as in sites far away from human settlements and roads. As forests currently occupy 12% of the mountains, forest expansion is a priority restoration goal. While most remaining forests are highly degraded or in regeneration stage, in our best-preserved forest areas we find regenerating, young, and mature forests in similar proportions. As our project site is only 22 ha, I believe the restored site should be conceptualized as a forest stand which has to be helped into a trajectory leading to the different forest successional stages and that with 25 yrs the restored forest stand should be ending the regeneration stage and entering the young forest stage. No studies exist on reference forest function and biodiversity at the regeneration and young forest stage so these studies should be performed before a good evaluation of restoration success can be done. These evaluations are complicated by the fact that to the best of my knowledge no unaltered reference forests exist in the area but good approximations might be possible.

Project Goals

1. Expand forest area and reduce soil erosion.

2. Determine the best methods to restore high mountain forests.

3. Provide a first successful forest restoration for Argentina to be used as an inspiring model.


The project does not have a monitoring plan.


The three primary stakeholders are the land owners; a family living in the city and two mountaineering clubs. I contacted them to get permission and got much volunteer help from the two mountaineering clubs. Other stakeholders were the neighboring ranchers which used the project site as a pasture for cattle and sheep. I visited all of them and informed them on my intentions, and asked for their advise. I learned that they were very knowledgeable in management of livestock and (of course) no experience in restoration ecology.

I tried involving stakeholders in the planning process but at the time I had no experience in forest restoration myself and was learning from observation, from doing and from the very little literature that I could get hold of in 1997. I did not even know the words “ecological restoration” existed. Stakeholders interests where very different to mine and to the ecological restoration concept. And I soon gave up engaging any stakeholder in the planning process.

I kept stakeholders informed by personal visits, reports, conferences, articles in the newspaper, radio and TV, and in the last decade through the internet – mailing and more resently through the social media. In Argentina people that live in far of mountains with no roads are very well communicated through the internet and social media. In a educational project we gave classes for over 2 years in all 7 schools situated in the high mountains of Córdoba. In my opinion, the most effective educational and outreach strategy was to do much of the restoration work with local volunteers, albeit important aspects of restoration cannot be learned only as a volunteer. In 2017 we colleagues from the ONG Ecosistemas argentinos and the University we created a school for ecological restoration.

How this project eliminated existing threats to the ecosystem:
As livestock was the main threat to the high-mountain forest regeneration, we built and maintained fences to exclude livestock. With the passing years and build up of dry biomass, fires became a new threat, especially during the dry season. For this we put up signposts where we indicate the prohibition of igniting fires (mainly camp-fires) and talked to campers explaining why it was important that no fires were used in the area. To avoid invasions by non-native species we pulled them out or cut them when seen and special rounds are performed to find them and keep their cover at a minimum.

How this project reinstated appropriate physical conditions (e.g. hydrology, substrate)",:
We performed only minor activities to restore physical conditions as lost soils were to expensive (and in my opinion controversial) to reinstate and I gave priority to reducing ongoing soil erosion by building up a good vegetation cover. When time and resources were available, at planting we dealt with compacted soils by digging 40 cm or deeper holes to plant the trees and then filling in the deeper part of the hole with loose soil. When the organic topsoil had been lost we also sometimes added inorganic fertilizer (NPK) which under those conditions triples tree growth.

How this project achieved a desirable species composition:
I used the strategy of planting the dominant native forest species – Polylepis australis – which is a pioneer species of very poor dispersal, and hoped that these plantations in combination with reduction of disturbance would facilitate the re-establishment of most other desired species. Formal studies evaluating what forest plant species have not re-established naturally have to be performed yet, and if necessary missing plants (and eventually other taxa) maybe re-introduced.

How this project reinstated structural diversity (e.g. strata, faunal food webs, spatial habitat diversity):
Within the 22 ha restored forest stand I mimicked a simultaneous post-disturbance forest regeneration by planting most of the area within three years. No tree reposition was performed, thus sites where trees did not prosper remained treeless, creating a mosaic of forests, grasslands and rock. At a landscape scale, structural diversity was reinstated in part because the 22 ha project site is a forest island within a degraded grassland and rock matrix.

How this project recovered ecosystem functionality (e.g. nutrient cycling, plant-animal interactions, normal stressors):
I mainly prescribed a natural recovery of ecosystem functionality. In the most degraded soils where organic topsoil had been lost, we used fertilizers as an input (inorganic NPK – 5 kg in all) to boost tree growth.

How this project reestablished external exchanges with the surrounding landscape (e.g. migration, gene flow, hydrology):
I did not contemplate this aspect so far.

Activities were undertaken to address any socio-economic aspects of the project:
For two years we intensively visited and gave classes in all the high-mountain schools of the region which were seven at that time. Perhaps more influential, during the 25 years of the project I involved over a thousand local volunteers in restoration work, mainly from the nearby cities and towns. In year 2022 there are now 12 other similar restoration projects which are being funded in the high-mountains of central Argentina. To me it is noteworthy that most present day project leaders were at sometime volunteers of the first restoration area in “Quebrada de los Refugios”, and got some or all their funding with my help. Thus, to me it seems that most socio-economic changes produced by the project were mainly through learning as volunteers, in the same way I learned the basics of managing a project as a volunteer during my work at projects based in USA and Peru.

Ecological Outcomes Achieved

Eliminate existing threats to the ecosystem:
So far the threats of livestock and fires have been successfully reduced from the restored site. During the first 5 years livestock continued entering the restoration site due to problems of bad fencing, people who cut the fences, or goats which jumped through. However, we always chased out the livestock within the first few days after they had entered and we attempted to solve each of the problems which caused the livestock to enter. After year 5 we had no more livestock entering the restoration site. Problems in the fencing were mainly due to soil loss under the fences producing passages for livestock – especially young cattle and sheep, due to people cutting fences with the argument that they were unnatural to the area, and due to the extreme climbing abilities of goats which were thankfully sold out by their owner, in contribution to the restoration project. To date only one wildfire affected a small portion of the restored area and was quickly put out by a group of volunteers which had stayed “after hours” during a plantation day, while nowadays illegal use of camp-fires is much reduced. Instead, I consider that the threat of invasions by non-native species is low, but increasing.

Reinstate appropriate physical conditions",:
Some of the originally lost soils are being recovered at the restoration area, mainly due to soil loss in up-slope sites out of the restoration area. Most of this soil “recovery” does not cover surfaces where the original soils were lost, however, a small part does and I believe it is having a good impact on water retention (personal observations). Another physical condition which is being recovered is the soil porosity at the superficial lever (up to 15 cm deep).

Achieve a desirable species composition:
Formal studies were conducted on bird, fungi and liken communities comparing control, restoration and reference sites. The consensus is that the restored forest site is changing in the right trajectory and losing species associated to grasslands and acquiring more forest species. I find it important to mention that augmenting species richness in the restored area was never a restoration goal. The goal is to restore the forest community including its unique species – which can have higher, equal or lower species richness than the control and reference sites. I am not in agreement at how the global scientific community is evaluating “restoration projects” mostly using “species richness” at a local scale as an indicator of success.

Reinstate structural diversity:
No formal studies, but structural diversity and spatial habitat diversity is certainly reinstated as can be seen in the before and after photos, or visually comparing control, restored and reference areas. As formal studies show that the forest bird community is returning to the restored area, it could be hypothesized that faunal food webs have been or are in the process of being restored – this could be an interesting topic for a future evaluation.

Recover ecosystem functionality:
Unknown, this has not been evaluated and of course this could be an interesting topic for a future evaluation.

Reestablish external exchanges with the surrounding landscape:
For the past 12 years I have been evaluating dry season water yield in the restored forest site and in an untreated control site with ongoing degradation. A preliminary analysis suggests there are no costs in terms of water yield due to restored forest cover, with a tendency of a three year improved water yield after a especially rainy season which could be due to improved water retention capacity in the restored forest area (but alternative hypothesis could be true). Given I have no pre-project data on water yield and given the big annual fluctuations in the relative water yields of both studied basins (partially restored and control), many more years of monitoring will be needed. No monitoring of migration or gene flow to date.

Factors limiting recovery of the ecosystem:
Even when disturbances are reduced, natural forest recover is limited due to low seed dispersal of the structuring Polylepis tree species of the area. When planted at the higher elevations and under good livestock exclosures, wind exposure and soil degradation reduces Polylepis growth and presumably forest recovery but does not limit the recovery. When planted at lower elevations leaf cutting ants become a serious limiting factor. The most limiting socio-economic factors in my opinion are two: (1) the scarce amount of qualified restoration leaders. (2) The permanent underestimation of restoration costs as perceived by donors, society and even by restoration leaders themselves. In my experience, the underestimation of restoration costs creates conditions where restoration leathers interested in creating a forest are frustrated because there goals are very hard to meet with the available funding. Instead, increasing funds are going to people which are in good faith excellent managers of massive and popular plantations which are nice food for the livestock industry which does not allow natural forest regeneration in the first place. In the high-mountains of central Argentina, planting without livestock exclusion makes no sense.

Socio-Economic & Community Outcomes Achieved

Economic vitality and local livelihoods:
In the short term (i.e. 10 yrs) the 22 ha forest restoration project mainly benefited the family living at the trail base leading the the project site through increases in sails at their family restaurant. Volunteers, an increasing assistance of trekkers and myself are their best clients. In the longer term (starting from yr 12) a project volunteer got funding to start a new restoration site, and this process has been increasing in number of new project leaders, increasing in funding income for native tree plantation. Funding to the region is presently at around u$a 250000 per year and involves hiring local ranchers for tree plantations. There is an incipient tourist industry where people pay to plant thus helping with work and with funding, a portion of which is reaching local guides.

Provision of basic necessities such as food, water, timber, fiber, fuel, etc.:
Regarding water, reducing soil erosion in the restoration area also involves a reduction in the rate at which the rain water holding capacity of the area was being lost. This said, it is unclear whether the restored forest with hold soils in place at a cost in water yield due to tree evapotranspiration, or whether increased fog capture and water holding capacity due to soil increased infiltration rate will compensate for evapotranspiration. To the best of my knowledge no studies to date report on these aspects of forest restoration at sites similar to ours in climate and using native tree species, even when most mountain restoration programs argue their main benefits are increasing water yield. The restoration does not provide timber, fiber or fuel even when this could be feasible and perhaps desirable. The local government prohibits the use of native plants in the high mountains of Central Argentina – thus legislation would have to be changed before a use of these resources can be made effective.

Cultural dimensions such as recreational, aesthetic and/or spiritual:
The 22 ha restored mountain forest area is part of my culture since we have grown together and I have spent over 800 days working and enjoying the area. Many of those days at the restoration site were shared with my wife, children, colleagues and volunteers. To me it is a very beautiful place. Surely, many more people have a similar opinion.

Regulation of climate, floods, disease, erosion, water quality, etc.:
No formal studies, but surely a restored forest is more desirable than a degraded grassland slowly becoming a rock desert at regulating the climate, floods, soil erosion and water quality. Regarding diseases, here I am not so sure and there might be compromises. On one hand, increases in water quality are evident especially after livestock exclusion and this should reduce stomach diseases in trekkers and campers visiting the area. On the other hand, with increasing habitat structural complexity there have been increases in mice densities, and some people have expressed their concerns that this could augment diseases.

Has the project had any negative consequences for surrounding communities or given rise to new socio-economic or political challenges?:
One neighboring rancher has complained that the Puma or mountain lion (Puma concolor) sometimes hides within the restored forest to predate his sheep. I have also received complaints from mountaineers because of the invasive species control activities which negatively affect their cultural values, especially control of exotic Oak and Pine trees.

Key Lessons Learned

Do not use non-native species. Initially I planted a few non-native trees to provide quick shading and fuel wood, in retrospect this was a big mistake. By year 10 they started to produce seeds and they were time consuming to eradicate as their seedlings kept appearing from the seed bank years after cutting the originally planted trees. Moreover, shading was eventually provided by the native trees, and to reduce wildfires the local government banned the use of camp-fires, so planted non-natives were never (legally) used for burning. Some campers persisted in illegally using camp-fires, and the dry cut logs provided them with easy fuel, and increased wildfire risk. And worst of all, many other people started planting exotic trees “in colaboration” with the project and this was also difficult to stop.

Be a little bit stubborn. While it is good to listen and adapt, being stubborn and continuing with the project activities even under important critique and adverse conditions was the clue to a successful forest restoration. Being out there trying to make a change is a most fantastic feeling, but certainly not free of critique and not easy.

You need a leader. When I started the project many people told me decisions had to be taken horizontally and with all stakeholders involved. I was told that leadership is a bad attribute, instead we should all be equals. And I tended to agree, but no longer do so. In retrospect, to me these ideas are true when the restoration work is being performed by the estate using public funds and when the managers are getting a salary to do their work. When the restoration work is lead by a volunteer like myself, it is asking for to much – and anyhow it worked as judging from before/after photos and the first formal studies. And leadership has to be there, I soon realized that if I did not take the leading role, somebody else did – often the same persons which told me leading was bad!

Long-Term Management

I acknowledge the importance of post-implementation monitoring but so far never have had time nor funding to plan a proper monitoring including control, restored and reference sites. Regarding long-term maintenance, on several occasions I have asked other volunteers including one of the land owners to take charge, they have accepted but I again started taking charge of maintenance myself on a volunteer basis, because I considered the performed maintenance was insufficient. So now my long term plan is to continue being in charge of maintenance until old age, hopefully, until I peg out. No plans for the after death. Because few people know about the “Quebrada de los Refugios” forest restoration, which I believe is the first successful forest restoration for Argentina, and perhaps the second or third for all South America, I am now trying to get more people to know about this project.

Sources and Amounts of Funding

Most funding opportunities for restoration projects were not initially accessible to me because they requested much larger goals in restored forest extension or carbon capture. They requested projects in bio-diverse areas or with the approval of local governmental authorities – which I could never achieve, or projects that worked with indigenous communities which was not the case. I have seen millions of dollars of these funds go to areas where no restoration was ever achieved. Instead, most of the funding I got for paying project expenses were to perform the associated researches and not to perform the restoration “per se”. The only “big” exception, was Rufford Small Grants with UK 35000, and several much smaller contributors like “Fundación Los Algarrobos”, “Club Andino Córdoba”, “Global Forest Generation” and private donations from volunteers.

I estimate that only planting the trees costs about u$a 1000 per hectare, or u$a 1 per tree. To restore this forest into perpetuity (as far as possible), I estimate a cost of u$a 2000 per hectare without taking into account the volunteer workforce. If the labor had to be paid, the cost would be approximately u$a 10000 per hectare, or u$a 10 per tree which eventually forms part of a forest (and not part of a meal for livestock, part of a wildfire or part of a forest invaded or dominated by non-natives).

After winning a price in 2015 many funding opportunities became available to me, given I was the only known person to have restored a forest in Argentina. With the new funding opportunities available I started a new forest restoration site 26 km south of my first restoration in the “Santo Tomás” ranch. With much negotiation, I got approximately u$a 1 per planted tree and a lot of headaches. I do not see any point in accepting more donations to plant, before I can get the missing u$a 9 per tree which I consider necessary to nurture those trees into being a healthy forest – and I am finding it very hard to get funding for looking after the planted trees (fence maintenance, control of invasions, working on reducing soil erosion by planting native tussocks).

Other Resources

More project information in

Relevant publications may be obtained by searching for authors: Ana M. Cingolani; Daniel Renison; Marcelo Cabido; Paula I Marcora

Examples are:

Renison D, Jaacks G, Pollice J, Herrero ML 2022. Forest restoration under leaf-cutting ant pressure: distance from ant nests and plastic tree shelters improve sapling survival. Restoration Ecology.

Renison D, Rodriguez JM, García L, von Wehrden H, Hensen H. 2022. Invertebrate herbivory rather than competition with tussocks will increasingly delay highland forest regeneration in degraded areas under active restoration. Forest Ecology and Management 506:119990

Arriaga J, Torres RC, Renison D. 2021. Evaluación de una técnica de protección física en el éxito de establecimiento de dos especies leñosas nativas de las Sierras de Córdoba (Argentina) en zonas con hormigas cortadoras. Boletín de la Sociedad Argentina de Botánica 56:1-13. DOI: ISSN 1851-2372

Barri FR, Tolelo M, Herzog P, Bellis LM, Renison D. 2021. Avifaunal responses after two decades of Polylepis forest restoration. Neotropical Biodiversity 7:205-211 ISSN 23766808

Cingolani AM, Poca M, Whitworth Hulse JI, Giorgis MA, Vaieretti MV, Herrero L, Navarro Ramos SE, Renison D. 2020. Fire reduces dry season low flows in a subtropical highland of central Argentina. Journal of Hidrology 590:125-538 *

Sparacino J, Renison D, Devegili A, Suarez R. 2020. Wind protection rather than soil water availability contributes to the restriction of high-mountain forest to ravines. New Forests 51:101-117 DOI:10.1007/s11056-019-09722-z

Cáceres Castellanos Y, Schrieber K, Lachmuth S, Auge H, Argibay D, Renison D, Hensen I. 2019. Effects of altitude, land use and microsites on early-life performance of a high mountain tree: insights from an in-situ sowing experiment. Diversity and Distributions. 25:1537–1550 https ://

Renison D, Bergero H, Soteras F, Herrero ML, Rodriguez JM, Torres RC, Cingolani AM, Hensen I. 2019. Progeny performance and pathogen attack relative to elevation in a Neotropical tree. CERNE 25:1-7. ISSN 0104-7760

Becerra AG, Diván A, Renison D. 2019. Bare soil cover and arbuscular mycorrhizal community in the first montane forest restoration in central Argentina. Restoration Ecology 27:804-812. doi:10.1111/rec.12937

Primary Contact

Daniel Renison

Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET



Organizational Contact