Mahsa Shahbandeh, a member of the Land-use and biodiversity HES-GEO team reflects on her research focusing on Agricultural Land Abandonment. Follow the article to uncover more.
What exactly is Agricultural Land Abandonment (ALA)?
Basically, before we would start talking about Agricultural Land Abandonment phenomena, we should know something about the terms of land use and land cover.
In general, these are one of the many ways how we could describe the environment around us. As well as talking about climate conditions, geological structure or soil cover of the chosen area, we are also often talking about what’s going on its surface.
So, to explain it briefly – when we want to characterize land cover in a selected region, we are dividing an area into smaller ones with only the same or similar objects (e.g. areas with only forests, rivers, lakes, pastures, grasslands etc.). Describing the land use is just a little bit different, and it’s mainly about assigning a type of human activity to parts of the ground (e.g. agriculture to crop fields, industry to factories, transport to roads etc.).
If we are thinking in categories of land use and land cover about agriculture and supplying food, it is a quick way to ask about where and how big the areas we are using for these purposes. And how are they changing too. Here comes the Agricultural Land Abandonment.
Agricultural Land Abandonment (ALA) is a land use change process. The usage of the land changes from agricultural activities to an abandoned area that is being recolonized by natural (or invasive) species of plants. We can recognize those regions by studying the changes in land cover patterns through time.
Why ALA is essential, and how to recognize it?
ALA affects social-ecological systems and is changing the landscape. In areas where agriculture is shrinking, native species previously displaced by crops could spread and give the field to invasive species. The same is true for animals – the opportunities to live are going better for some species, but in others, one’s situation is getting worse. Also, while the food supply chain is changing, the situation of local people is going different too – when there is no possibility to work and live as previous. Those are the reasons which cause studying the ALA and its potential consequences important.
But how can we recognize the change of a land cover and land use patterns on a wide area without demanding field studies?
The answer is in remote sensing data. There are a lot of satellites in space that are orbiting around the Earth and observing phenomena, and each satellite has one or several missions to do. For instance, the missions include observing Earth’s atmosphere, land, sea, snow and ice, energy budget etc. Also, some of them are concentrating on providing data about land cover and land use.
Comparison of the harvested images from different periods lets us see where objects on the surface have changed and detect (for example) the ALA area. Of course, it requires preparatory activities because raw remote sensed datasets are not ready to direct use. There are specialistic programs to work with that kind of information, called geographical information system (GIS) software. Most known of them are paid ArcGIS and freeware QGIS.
What am I studying at the moment?
Now, for my research, I am using aerial images and satellite products to detect the land-use change and ALA in the last 50 years in a part of central Poland (Szydłowiec powiat – powiat is the polish word for an administrative unit with an area of approximately 500-1000 km2). As a result of my work, I realized that in the study area, vegetation cover (excluding crop fields, pastures and grasslands) increased significantly during selected the period. The extent and density of trees, shrubs and bushes are now much more significant than in the early 1970s when the first aerial and satellite data were collected.
What does it mean?
The answer is one – many people abandoned their agricultural grounds and let them be afforested. It is essential to notice that this change happened in the region, where agriculture areas were landscape dominant. Also, the processes of ALA did not stop. The forest area in Szydłowiec powiat is still expanding. As a result, the character of the whole region is changing.
It causes a lot of consequences, both positive and negative. Maybe many of us would say that abandoning agricultural lands provides nature with the place to reimplement natural, healthy processes. Still, we need to be careful establishing conclusions like this. For instance, some animals use this opportunity to habit and settle there, like wolves, but in another case, the birds or small mammals could not use previously inhabited areas. Also, it is not evident that forests that would appear in the place of abandoned fields would be characterized by higher biodiversity than a patchwork of fields, coppices and balks. The impact of ALA in Szydłowiec powiat on society in the region is also ambiguous. Abandoning the areas was conducted to decrease the population involved in work in the agriculture sector. It forces them to search for employment in other sectors and migrate further, which could improve people’s living standards. Still, it also means that the studied region is now vulnerable to depopulation. There are changes in food production too – now the average farm is getting bigger, which means that the productivity of still used areas is probably higher because of higher specialization. The supply of food is less varied in consequence of removing smaller farms.
As You can see, ALA is a complicated issue – but one thing is for sure – it is interesting to observe it.
This post is written by Mahsa Shahbandeh, a PhD student at Jagiellonian University and a member of the HES-GEO Land-use and biodiversity team. Her main research interests include land-use change, agricultural land abandonment, spatial planning, GIS, and remote sensing. She is also concerned about ecosystems changes and environmental issues.
This research has been supported from the Anthropocene Priority Research Area budget under the program “Excellence Initiative – Research University” at the Jagiellonian University.
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