Attached I include a paper that could be useful. You can find other works in the section References.

Muchas gracias!

A book I found very useful is "Understanding Soil Change: Soil Sustainability over Millennia, Centuries, and Decades" by Richter et al. They follow the soil property changes before, during, and after farming over hundreds of years with a section on erosion. Not as useful for the vegetative changes, but the vegetation is going to rely heavily on the soil so it is relevant.

Some references:

Prévosto B, Kuiters L, Bernhardt-Römermann M, Dölle M, Schmidt W, Hoffmann M, Van Uytvanck J, Bohner A, Kreier D, Stadler J, Klotz S (2011) Impacts of land abandonment on vegetation: successional pathways in European habitats. Folia Geobotanica 46: 303-325 (DOI: 10.1007/s12224-010-9096-z)

Dölle M, Schmidt W (2009) The relationship between soil seed bank, above-ground vegetation and disturbance intensity on old-field successional permanent plots. Applied Vegetation Science 12: 415-428

Dölle M, Schmidt W (2009) Impact of tree species on nutrient and light availability: evidence from a permanent plot study of old-field succession. Plant Ecology 203: 273-287

Dölle M, Bernhardt-Römermann M, Parth A, Schmidt W (2008) Changes in life history trait composition during undisturbed old-field succession. Flora - Morphology, Distribution, Functional Ecology of Plant 203: 508-522.

Dölle M, Bernhardt-Römermann M, Parth A, Schmidt W (2007) Changes in plant species diversity during thirty-six years of undisturbed old-field succession. Allgemeine Forst- und Jagdzeitung 178: 225-232.

For a slightly different (more dynamic) perspective, you could also take a look at: Volarik D & Hedl R (2013) Expansion to abandoned agricultural lands forms an integral part of silver fir dynamics. Forest Ecology and Management 292: 39-48.

If you still need some more reference, please see below. It is about soil erosion on terraces in the context of land abandonment.

Arnaez, J., Lasanta, T., Errean, M.P., Ortigosa, L., 2010. Land abandonment, landscape evolution, and soil erosion in a Spanish Mediterranean Mountain Region: The case of Camero Viejo. Land Degrad. Dev. 22(6), 537-550.

Aw-Hassan, A., Alsanabani, M., Bamatraf, A.R., 2000. Impact of land tenure and other socioeconomic factors on mountain terrace maintenance in Yemen. CAPRi Working Paper No. 3, CGIAR System-wide Program on Property Rights and Collective Action, International Development Research Center (IDRC), Ottawa, Canada, pp. 42, http://www.capri.cgiar.org/pdf/CAPRIWP03.pdf (08/16/2013).

Bellin, N., van Wesemael, B., Meerkerk, A., Vanacker, V., Barbera, G.G., 2009. Abandonment of soil and water conservation structures in Mediterranean ecosystems – a case study from south east Spain. Catena 76, 114-121.

Esteve, J.F., Imeson, A., Jarman, R., Barberis, R., Rydell, B., Castillo Sánchez, V., Vandekerckhove, L., 2004. Pressures and drivers causing soil erosion. in: Van-Camp, L., Bujarrabal, B., Gentile, A.-R., Jones, R.J.A., Montanarella, L., Olazabal, C., Selvaradjou, S.K. (eds.), Reports of the Technical Working Groups Established Under the Thematic Strategy for Soil Protection. Volume II Erosion. EUR 21319 EN/2, Office for Official Publications of the European Communities, Luxembourg. http://ec.europa.eu/environment/soil/pdf/vol2.pdf (01/27/2013).

Inbar, M., Llerena, C.A., 2000. Erosion processes in high mountain agricultural terraces in Peru. Mt. Res. Dev. 20, 72–79.

Koulouri, M., Giourga, C., 2007. Land abandonment and slope gradient as key factors of soil erosion in Mediterranean terraced lands. Catena 69, 274–278.

Lesschen, J.P., Cammerrat, L.H., Niemann, T., 2008. Erosion and terrace failure due to agricultural abandonment in a semi-arid environment. Earth Surf. Proc. Land. 33, 1574–1584.

Schönbrodt-Stitt, S., Behrens, T., Schmidt, K., Shi, X., Scholten, T., 2013. Degradation of cultivated bench terraces in the Three Gorges Reservoir Area - field mapping and data mining. Ecological Indicators 34, 478–493. doi: 10.1016/j.ecolind.2013.06.010

It would be good to include more information in your question about these abandoned lands--whose is it and who will be managing it?  Is it private lands that the government is going to take over, for example, and then is there a significant annual budget to do something about erosion, and what kind of scale of land does this question cover, like the millions of hectares in the Western USA for example? 

If it is abandoned private lands that the government does not want to do take and spend annual money towards its management, and if they were arid lands like below 10 cm. annual rainfall, then chaos is in charge instead of the humans.  However, if they were converted to carbon sequestration sites using local native perennial grasses, then carbon credit might be created, to be used towards their annual management? 

Dear Craig, Thank you for your further questions. So the lands I'm dealing with are public lands. In this case they have used abandonment as a way of passive restoration, since they are part of a National Park. Therefore, just as you mentioned the budget here is very limited. 

So I was looking for some similar cases to compare my results with. 

Thanks!

Dear Florencia,  

Thanks for your answer, and I think I love your picture with your transect framing you, as the very best of any Research Gate pictures so far.  

Once again, some more information would be helpful, so you can get some good advice from the Research Gate readers.  For example,

1.) a.) How many hectares, b.) what annual rainfall, and c.) what ecological habitat?

2.) What country is this property located?

3.) Have you made a shopping list of native grasses and forbs that could recolonize on their own?

4.) Do you have a list of weeds that are in the area that you do not want to get established

5.) Have you done any soil nutrient tests, like organic matter, pH, N-P-K of the top 4 cm of soil, underneath any duff?

6.) Have you picked the Top-Ten potential local native plant colonizers?

7.) Have you done any soil tests around existing stands of the Top-Ten potential colonizers, to measure the ranges of soil organic matter, pH, N-P-K required for their seedling survival?  Always check for existence of seedlings in the population, and only sample the top 4 cm. of soil minus any duff.

8.) Are you harvesting local seeds of the Top-Ten native colonizers and setting up small scale test plots?  MAXIMUM test plot size per treatment should be one by two meters, like you can see in http://www.ecoseeds.com/greatbasin.html

9.) When you set up test plots with the Top-Ten local native colonizers, are you both sowing seeds and planting out 3-4 month old seedlings as individual species in their own plots?

10.) Are you testing in plots, if the application of fertilizer alone, might get dormant native seeds that are still in the soil, to germinate?  For example on the Shaw property at http://www.ecoseeds.com/shawlist.html that was revegetated by getting the 100+ species of native seeds that had been dormant for over 100 years in the soil, to sprout, and the native clovers did not sprout and appear until we applied calcium and phosphorus.

Look forward to your reply.

P.S. To my reply.  Also, if you could please post at least two pictures of the site: 1.) What you are working with, and 2.) What you want it to look like.  I have attached a picture  of what I want my projects to look like, from the 600 acres done with only 30-40 cm. of rainfall in poor volcanic soils, as an example--solid, weed-free natives to the horizon.

I also want to add Question 11.) Are you able to cut and vale locally any native grass straw to use as mulch on the barren portions of the land you are working on restoring?

There are cheap, quick and easy methods to get the natural revegetation processes started on lands like you are working on, and I feel that readers who have worked on projects like yours, can give you better and more useful answers, the more we can know exactly what you are working on.

Dear Craig, 

Thank you not only for your kind reply, but for your interest on the topic and the compliment on my profile photo :)

So to answer your questions I must say first that I started this discussion for a paper which I already published (see attachment). However since we are at the moment working on a second paper on the same site, I still think is interesting to get references. I will reply your questions using the info also stated in the paper. 

1.) The Park area covers 76,000 ha. The study area corresponds to the lower belt of the Monte Desert (1,900–2,500 m a.s.l.), where mean annual temperature is 13.0 ? 5.7 C with marked daily and seasonal variation. Mean annual precipitation does not exceed 100 mm; up to 75 mm in winter, partly as snow and hail, and less than 10 mm in summer.

2.) The country is Argentina.

3.) We performed vegetation surveyors at all sites. So we do know most species present at the area (as you can see from the photos the cover is very low). 

4.) Weed establishment is not a major problem here. We only have one annual weed in one site. 

5.) Yes, most results are included in the paper. 

6.) As I said, invasives are not problematic specifically at these sites. 

7.) You are right on this point, we did some analysis but not all the ones that you suggested, however I would say that here the major problem is lack of water (or excess during short rain events). Also propagule pressure is an issue, along with the fact the revegetation is not always possible since no one really knows how to reproduce most of the shrub species.  

8.) No we haven't, good idea!

9.) Is just passive restoration, so we are not adding seeds or revegetating.

10.) If we can get good germination of native species this will be a good idea. Also to perform some tests to see if there are some seeds in the soils seedbank. We haven't done anything of this. 

Regarding your last questions, one main problem is that we don't have a reference site since all of them were subjected to agricultural activities. This is the reason why in the paper we compared the sites in terms of their capacity of halting erosion processes. 

Enclose you can find photos of a site with more than 40 years of abandonment and one with only 16. 

Thank you again Craig!

Thank you for your replies.  Looks exactly like most of California where the native vegetation was stripped off by grazing or farming about 100 years ago, but for your areas it looks like the natives were plowed out more than 100 years ago and that the area was originally an arid perennial grassland with over 100 species of annual and perennial wildflowers in the past?  

There are many downside of natural revegetation of your area, based on my California projects:

1.) No native seeds still dormant/viable in the soil.  That is where you have to find relict stands and multiply the seeds commercially to restart the grassland ecosystem that was once lived there.  And you have to start with a minimum of two representatives of the Top-ten major plant families that once grew there.  For example, in California that would be the grass family, sunflower family, bean family, poppy family, etc.

2.) Did arming/grazing drew down the soil nutrient levels below native seedling survival?  Each species of native plant requires a minimum level of soil nutrients for seedling survival from germination to adult plant, and you need to find out what that is for each species that you want to grow back there, and then see at what level your site is starting at.  No matter if you sowed tons of local native seeds per hectare, if the soil nutrients are not there to support seedling survival, they will all sprout and die, like you can see at http://www.ecoseeds.com/good.example.html.

3.) What is the yop 4 cm. of organic matter percentage--below seedling survival?  Once again, each native seedling, in order to survive, needs a minimum top 4 cm. of percentage of organic matter, and without it, seedlings may sprout, and then die like in the web picture mentioned above.  The organic matter also is where the fungi live, and is also the sponge that stored the N-P-K for the plant's future use.

4.) Does the soil still contain the fungi, algae and mosses that the native plants need to survive?  Especially in arid areas, we are always happy to see above-ground vegetation, but usually ignore the soil fungi, algae and mosses (in Colorado called the cryptogamic crust).  

Unfortunately when the native plants that host the fungi have been long gone, you may have to introduce the fungi at the same time you reintroduce the missing plants.  Unlike a farm field, you cannot expect arid native plants to be able to recolonize an arid area that is missing its associated fungi/algae/moss friends.   

And I am making an assumption from your photos, but prior to farming or grazing it a perennial grassland?  And when farmed, it was dryland grain crops and not irrigated?  Because your area looks like the former Southwest grasslands that you can see at http://www.ecoseeds.com/desertgrass.html.

I hope this information is helpful, and am interested in what the subject of your second paper will be?

Somehow my first un-spell-checked draft got posted, please ignore--here is the proper response:

Thank you for your replies and the link to your article.

Your photos look exactly like our Anza-Borrego State Park, that was formerly public grazing lands that were grazed to dust, given to California and is now our largest State park. We are so similar, sharing the same genera of shrubs and grasses for example, what we call the Creosote and Coyote bushes and Alkali saltgrass.

And I completely agree with your conclusion about the weakness of passive succession-based management and I would also add that the area that you studied CANNOT revegetated on its own naturally, but for different reasons in addition to what you pointed out in your research.

Here are some questions to ask:

1.) No native seeds still dormant/viable in the soil? If that is the case, then you have to find relict stands and multiply the seeds commercially to restart the grassland ecosystem that was once lived there. And you have to start with a minimum of two representatives of the Top-ten major plant families that once grew there. For example, in California that would be the grass family, sunflower family, bean family, poppy family, mint family, etc.

2.) Did farming/grazing draw down the soil nutrient levels below native seedling survival? Each species of native plant requires a minimum level of soil nutrients for seedling survival from germination to adult plant, and you need to find out what that is for each species that you want to grow back there, and then see at what level your site’s soil is starting at. No matter if you sowed tons of local native seeds per hectare, if the soil nutrients are not there to support seedling survival, they will all sprout and die, like you can see at http://www.ecoseeds.com/good.example.html.

3.) Is the Top 1-4 cm. of organic matter percentage--below seedling survival? In your study you measured organic matter, but how do those levels relate to native seedling survival? Also your study went too deep, to 30 cm. and for seedling survival it is the top 1-4 cm. that counts.

Once again, each native seedling, in order to survive, needs a minimum top 1-4 cm. of percentage of organic matter, and without it, seedlings may sprout, and then die like in the web picture mentioned above. The organic matter also is where the fungi live, and is also the sponge that stored the N-P-K for the plant's future use, as your paper points out.

4.) Does the soil still contain the fungi, algae and mosses that the native plants need to survive? Especially in arid areas, we are always happy to see above-ground vegetation, but usually ignore the soil fungi, algae and mosses (in Colorado they call them cryptogamic crust). Unfortunately when the native plants that host the fungi have been long gone, you may have to introduce the fungi at the same time you reintroduce the missing plants. Unlike a farm field, you cannot expect arid native plants to be able to recolonize an arid area that is missing its associated fungi/algae/moss friends.

5.) Has anyone checked the soil for perennial native grass phytoliths? I am making an assumption from your photos, prior to farming or grazing it was not a shrubland, but was a 90-95% cover perennial grassland, maybe with dozens of species of perennial grasses and maybe over 100 species of annual and perennial wildflowers, with perhaps a 5-10% shrub cover at most? Any relict examples of that left, like the little tiny examples we have here in California that you can see at http://www.ecoseeds.com/wild.html?

When you find that relict stand-example, and I am not talking about the alkali saltgrass that you found, but something in the genera like Stipa, Poa, Bromus, Muhlenbergia, Oryzopsis, for example. And by checking the soil grass phytoliths, you can reconstruct what grass species grew where.

6.) Going from passive to active ecological restoration, costs? So going from passive to active restoration, is going to need many metric tons of pure gold for the annual Argentina government to spend, and the only reasonable source of that gold will be a worldwide carbon tax, and when we decide to go on a carbon, beef. milk and sheep diet.

Once that area is replanted with its original native grasslands, it could be used as a huge carbon sink to tuck away a lot of CO2. After doing your study, you know that many, many tons of pure gold will be needed to start active restoration of this huge area that takes your breath away, but do any of the managers on the government level know or are thinking about this issue yet, and planning on getting the gold together?

I hope this information is helpful, and am interested in what the subject of your second paper will be?

To add to my answer: I am attaching two Google Earth images of the area you are studying with two more questions:

7.) Has anyone checked the purple-tan color from satellite images for low phosphorus and low potassium caused by grazing and farming?  I put a box around the area that looks both phosphorus and maybe potassium deficient, below the threshold levels that the native perennial grass seedlings need for survival.

8.) Has anyone checked using satellite images, looking for site with both good or pre-grazing and pre-farming or "normal" soil nutrient levels, and also look in those areas for relict stands of the original native grasslands?  

I have enhanced the saturation and contrast of the satellite image, and then marked in green a potential pristine stand on the close-up image, and also marked another potential site as "Good" on the big image.