Kurgans in the Great Hungarian Plain: Our survey continues

This year we continue our large sampling campaign of the kurgans in the Great Hungarian Plain. Kurgans are ancient burial mounds built by nomadic steppic tribes millenia ago, and still harbour dry grasslands in the heavily transformed agricultural landscapes. You can read more about these iconic landmarks in our earlier publications.

Last week we sampled kurgans in the central part of the Great Hungarian Plain, near Szentes and Szarvas, which region is very rich in kurgans. Below we selected some pictures from the fieldwork.

The iconic Gödény-halom (Pelican-mound) near Békésszentandrás: the largest kurgan in Hungary.

Hék-halom mound in the background and a large population of Salvia nemorosa in the foreground.

This is the peak flowering season for Consolida orientalis.

An ancient riverbed and the mounds on the river bank: a nice example how the ancient cultures formed the landscape.

Survey of a mound, where ploughing was recently abandoned.

This mound has been ploughed for a long time, but recently, ploughing has been stopped in at least a part of the kurgan body.

Ecosystem engineering by the Eurasian crane - our new paper in Land Degradation and Development

Our new paper about the impressive ecosystem engineering effect of a large bird has recently been published. 

The citation of the paper:

Valkó, O., Borza, S., Godó, L., Végvári, Z., Deák, B. (2022) Eurasian crane (Grus grus) as ecosystem engineer in grasslands ‒ conservation values, ecosystem services and disservices related to a large iconic bird species. Land Degradation and Development https://doi.org/10.1002/ldr.4314

The paper is open access and can be freely downloaded from the journal homepage by clicking here.

Ecosystem engineer organisms alter the local environment in a way that they create and maintain habitats or microhabitats for other organisms. The engineered patches are characterised by different structure and functioning compared to the surrounding habitats. Well known ecosystem engineers include corals that create reef habitats or beevers that literally engineer whole landscapes. In one of our earlier blogposts we wrote about our study on the ecosystem engineering effects of Steppe Marmots. Among birds, woodpeckers are well known engineers that create nesting places for many other birds. In grasslands, the ecosystem engineering effect of birds has been largely unknown.

We studied here a large, iconic bird species, the Eurasian crane which is a protected species across Europe. The global crane population - thanks to the conservation efforts, wetland restoration projects and to the ability of cranes to coexist with intensive agricultural practices - shows a growing trend. Because of this population increase, we expect that the effects of cranes on natural ecosysetms will also amplify, that is why it is timely and important to evaluate the effects of this large bird on the grassland ecosystems.

Eurasian cranes.

Hungary is an important stopover area during the migration of cranes. During autumn, 100000 - 160000 birds spend a few weeks in the lowland areas of East-Hungary. Cranes are usually foraging on maize stubbles on crop residue, but regularly visit grasslands where they forage on invertebrates. In grasslands they perform a special feeding habit called 'crane-ploughing': they heavily disturb the soil surface by their bill and remove the vegetation. The disturbed surface resembles to a ploughed area and their size range from a few square metres to a few hectares. These are characteristic landmarks in Hungarian alkaline grasslands, but until our study, their ecological function was unknown.

'Crane ploughing' from the birds' eye view.

 

We compared the vegetation of crane-disturbed patches and undisturbed alkaline grasslands in the Hortobágy National Park, at then study sites. We found that the disturbed surfaces were characterised by different structure and function compared to the undisturbed patches. The pioneer vegetation on the disturbed patches sprouted  earlier than in the undisturbed grasslands, and was characterised by short-lived species and forbs. The dominant grass species of alkaline grasslands (Festuca pseudovina) had significantly smaller cover on the disturbed patches. The crane-ploughed patches harboured more species and a different species composition compared to the undisturbed grasslands. The abundance and species richness of insect-pollinated plants increased on the disturbed patches which suggests that these areas offer important nectar sources for pollinators in the otherwise grass-dominated habitat. The early sprouting vegetation on the disturbed patches probably provides important forage source for the livestock early in the season, but in the dry summer period the forage quality value decreases considerably.

Pioneer plants (Erophila verna) and crane feather on the disturbed patches.

Our study showed that foraging cranes have a fundamental effect on the structure and functioning of alkaline grassland ecosystems, by creating patches with altered vegetation composition and ecosystem functioning. 

Vegetation survey in early spring.

The abstract of the paper:

Large bird species, such as cranes are involved in human-wildlife conflicts as they often forage in croplands. The Eurasian crane (Grus grus) is a large iconic bird species, protected across Europe, which, thanks to conservation programs and its ability to utilize croplands for foraging, shows a strongly increasing population trend. This exaggerates the existing conflicts between crop farmers and cranes spilling over to natural habitats, where foraging by large flocks can lead to land degradation. No studies have evaluated the effects of foraging cranes on grasslands, despite these habitats provide important feeding grounds for cranes across their whole range. To fill this knowledge gap, we evaluated the ecosystem engineering effect of foraging Eurasian cranes on the vegetation of dry grasslands in Hungary. We used indicators of vegetation naturalness, forage quality, and floral resource provision to evaluate the ecosystem state from multiple aspects. We sampled 100 quadrats in disturbed patches and 100 in undisturbed grasslands in two seasons and two years (800 observations). Cranes created distinct vegetation patches with different species composition from undisturbed areas. We identified important trade-offs between the positive and negative effects of the foraging activity of cranes on different structural and functional components of the ecosystems. The crane-disturbed earlysuccessional patches increased plant diversity and floral resources but decreased the area of undisturbed grasslands. Although crane-disturbed patches could provide forage for livestock early in the season, the forage quality became poor later in the year. We highlight the importance of monitoring the landscape-level extent of the disturbed areas.

The field season has started - some tricky pictures :)

Now the field season has started and our group spends a lot of time in different parts of Hungary.

Last week, Réka Kiss and Kata Lukács continued one of Réka's favourite projects. In this study, Réka visits the study sites many times per year and the area always shows a different face. From the pictures taken in late April it is not easy to guess what plant is in the focus of this project :)

This picture shows some plastic lids in the grass - but this is not garbage, this is a very important part of our study :)

From a little bit closer, we can observe that the position of the lid marks the position of a very special plant.

Réka is surveying her monitoring plots for this special plant and marks all the vegetative individuals with lids. The different colours are for the different phenological stages: plants with different leaf numbers are marked with different colours.

This very special plant is the spring meadow saffron (Colchicum bulbocodium) which shows its most beautiful and characteristic face in early spring.

Réka is studying the population dynamics of this strictly protected and endangered plant. She has detailed four-year-long dataset on the abundance, phenology, flowering and fruiting success of the individuals and aims to analyse the reproductive success of the plants in the function of climatic parameters.

PhD defense of Laura Godó

Congratulations to Laura Godó for successfully defending her PhD thesis in last Friday!

The title of her dissertation is: The role of animal-plant interactions in preserving grassland biodiversity

Supervisor: Balázs Deák

Huge congratulations to Laura and we are very happy that she is continuing her work in our research group after this very important milestone :)

We wish Laura the best success with these field pictures.

Sometimes life does not show its sunniest and brightest side. Vegetation before mowing...

Our favourite picture by Laura: Salicornia prostrata - a pink miracle :)

Last steps before our public outreach program starts :)

Group photo after kurgan restoration - with Fidó dog :)

The PhD dissertation of Laura is based on the following papers:

Godó, L., Valkó, O., Borza, S., Deák, B. (2022): A global review on the role of small rodents and lagomorphs (clade Glires) in seed dispersal and plant establishment. Global Ecology and Conservation 33: e01982.

Godó, L., Tóthmérész, B., Valkó, O., Tóth, K., Radócz, S., Kiss, R., Kelemen, A., Török, P., Švamberková, E., Deák, B. (2018): Ecosystem engineering by foxes is mediated by isolation in grassland fragments. Ecology and Evolution 8(14): 7044-7054.

Godó, L., Valkó O., Tóthmérész B., Török P., Kelemen A., Deák B. (2017): Scale-dependent effects of grazing on the species richness of alkaline and sand grasslands. Tuexenia 37: 229-246.