Crane migration – A scenic event of the Hortobágy

The Hortobágy, which is one of the most extended coherent nature close open habitats of Europe is an important part of the migration route of the Cranes nesting in Finland, the Baltic states and Russia. The migrating birds – after having a short break in the Hortobágy – fly towards to North Africa. Interestingly many of the Cranes arrived from Siberia: they made a quite long loop on their way to Africa. This year is an exceptional one with an exceptionally high number of cranes, their estimated number is 160 000.

Opposite to their migration in spring (when the Cranes just fly over the grasslands and wetlands of the Hortobágy) they spend a longer time here in this part of the year. The reason is that whilst in springtime the Cranes primarily focus on reaching the nesting areas as soon as possible, in autumn they have more time for migration. They spend their time in the Hortobágy for increasing their (and their youngsters’) fitness by relaxing a bit and feeding. They spend the nights in the wetlands (generally in the numerous shallow fishponds), and during the daytime they are feeding at the neighbouring arable lands and grasslands. The most scenic part of their daily routine is just before sunset, when they compose huge groups and fly back together to the wetlands for having a night rest.

Feeding in the grasslands of Nyírőlapos-puszta

Waiting for the cranes - spider nets in the sunset; Darassa-puszta

The first ones

Just a small group

  

Early arrivals to the fishpond

  

Cranes in the sunset; Darassa-puszta

Grassland restoration by seed sowing: when, what and how much?

Our aim is to answer these important questions to support the successful implementation of grassland restoration projects. Choosing the proper timing of seed sowing and the optimal amount and species composition of the sown seed mixtures are very important for maximising restoration success and saving costs.

The matrix of seed mixtures are generally the grass seeds, which have an important role in weed suppression (Deák et al. 2011). Usually they sow the grass seeds in a density of 20-40 kg/ha in the restoration projects. Choosing the right density is crucial: if we don’t sow enough seeds, it can lead to weed encroachment, but sowing too many grass seeds results in the formation of a dense canopy which act as a barrier for the germination of target species via microsite limitation. In large-scale restoration projects, it is not always possible to compose and use a diverse seed mixture in the entire area; thus, they often use low diversity grass seed mixtures. On the one hand, seed sowing of grasses leads to a rapid and predictable vegetation development, and we can expect a species-poor grass-dominated vegetation two or three years after seed sowing (Török et al. 2010, Valkó et al. 2016a). On the other hand, increasing the diversity of these species-poor sown grasslands requires novel methods and a lot of extra work in the future (Valkó et al. 2016b, 2018).

In our project we sowed grass (Festuca rupicola) seeds in 2014 and a diverse seed mixture (containing 20 forb species) in different combinations (together with the grass seeds, and 1, 2 and 3 years later). We study the species composition and functional diversity of the developed communities and evaluate which solution is the best in terms of weed suppression.

Our preliminary results clearly show that the best solution is sowing the diverse seed mixture together with the grass seeds. This treatment resulted in the most diverse vegetation, the lowest level of weed encroachment and the highest number of established target species. In large restoration sites, which are embedded in an agricultural landscape, the spontaneous establishment of target species is very unlikely, given their impoverished seed banks and the lack of propagule sources. In such areas, active introduction of target species is inevitable for restoring species-rich grasslands. Our results suggest that it is a much more practical and cost-effective solution to sow the diverse seed mixture together with the grass seeds, at the very first stage of grassland restoration.

Here are some pictures about the experiment in October 2018.

In this plot, the diverse seed mixture and the grass seeds were sown in the same year (2014).

Here we sowed the diverse seed mixtures in 2015, i.e. 1 year after the grass seeds (2014).

Here we sowed the diverse seed mixtures in 2016, i.e. 2 years after the grass seeds (2014).

Here we sowed the diverse seed mixtures in 2017, i.e. 3 years after the grass seeds (2014).

Literature Cited

Deák, B., Valkó, O., Kelemen, A., Török, P. Miglécz, T., Ölvedi, T., Lengyel, Sz., Tóthmérész, B. 2011: Litter and graminoid biomass accumulation suppresses weedy forbs in grassland restoration. Plant Biosystems 145: 730-737.

Török, P., Deák, B., Vida, E., Valkó, O., Lengyel, Sz., Tóthmérész, B. 2010: Restoring grassland biodiversity: Sowing low-diversity seed mixtures can lead to rapid favourable changes. Biological Conservation 143: 806-812.

Valkó, O., Tóth, K., Kelemen, A., Miglécz, T., Radócz, S., Sonkoly, J., Tóthmérész, B., Török, P., Deák, B. (2018): Cultural heritage and biodiversity conservation – Plant introduction and practical restoration on ancient burial mounds. Nature Conservation 24:65-80.

Valkó, O., Deák, B., Török, P., Kelemen, A., Miglécz, T., Tóth, K., Tóthmérész, B. 2016a: Abandonment of croplands: problem or chance for grassland restoration? Case studies from Hungary. Ecosystem Health and Sustainability 2(2): e01208.

Valkó O., Deák B., Török P., Kirmer A., Tishew S., Kelemen A., Tóth K., Miglécz T., Radócz Sz., Sonkoly J., Tóth E., Kiss R., Kapocsi I., Tóthmérész B. 2016b: High-diversity sowing in establishment gaps: a promising new tool for enhancing grassland biodiversity. Tuexenia 36: 359-378.

Filming

This week we made a project video about the work in the Department of Ecology, University of Debrecen. The main aim of the film is to provide an overview on the life in the Department, on our research topics and showing the ‘essence of being an ecologist’ to the students. During the filming we had a ‘field action’ scene in the Hortobágy, one in the greenhouse, one in the lab and many others. I think that with the help of the Médiacentrum Debrecen we managed to make an exciting ‘movie’. 

The film will be ready in December. Till then some werk fotos.

PhD defense, Réka Kiss

I am happy to congratulate to my former PhD student, Réka Kiss who successfully (indeed, very succesfully, with summa cum laude) defended her PhD thesis recently.

Réka has been studying the role of seed bank and seed sowing in grassland restoration. She presented the key results of two novel and interesting research topics: 1, her literature review about the links between seed bank, climate change and restoration prospects in the open landscapes in the World and 2, establishment gaps, a novel tool for the restoration of species-rich grasslands.

The most important publications related to her dissertation are as follows

Kiss, R., Deák, B., Török, P., Tóthmérész, B.., Valkó, O. (2018) Grasslands and climate change – How can soil seed bank support community resilience? Restoration Ecology, 26, S141-S150.

Kiss, R., Sonkoly, J., Török, P., Tóthmérész, B., Deák, B., Tóth, K., Lukács, K., Godó, L., Kelemen, A., Miglécz, T., Radócz, Sz., Tóth, E., Balogh, N., Valkó, O. (2018) Germination capacity of 75 herbaceous species of the Pannonian flora and implications for restoration. Acta Botanica Hungarica, 60, 357-368.

Kiss, R., Valkó, O., Tóthmérész, B., Török, P. (2016) Seed bank research in Central-European grasslands - An overview. In: Murphy, J. (ed.) Seed Banks: Types, Roles and Research, Nova Science Publishers, 1-34.

Kiss, R. (2016) The role of soil seed bank in restoration and dynamics of Hungarian plant communities – A review of Hungarian seed bank research . Kitaibelia, 21, 116-135.

Valkó, O., Deák, B., Török, P., Kirmer, A., Tishew, S., Kelemen, A., Tóth, K., Miglécz, T., Radócz, Sz., Sonkoly, J., Tóth, E., Kiss, R., Kapocsi, I., Tóthmérész, B. (2016) High-diversity sowing in establishment windows: a promising new tool for enhancing grassland biodiversity. Tuexenia, 36, 359-378.

Török, P., Kelemen, A., Valkó, O., Miglécz, T., Tóth, K., Tóth, E., Sonkoly, J., Kiss, R., Csecserits, A., Rédei, T., Deák, B., Szűcs, P., Varga, N., Tóthmérész, B. (2017) Succession in soil seed banks and its implications for restoration of calcareous sand grasslands. Restoration Ecology, 26, S134-S140.

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

We would like to congratulate Réka with some nice and memorable photos, taken in our favorite field days. :)

Conservational role of ancient steppic burial mounds - paper freely available

Our paper about the conservational role of ancient steppic burial mounds - published in the journal Biodiversity and Conservation - became freely available: the pdf of the paper can be downloaded freely from the following link: https://rdcu.be/7vg1.

Deák B., Tóthmérész B., Valkó O., Sudnik-Wójcikowska B., Bragina T.M., Moysiyenko I., Apostolova I., Bykov N., Dembicz I., Török P. (2016): Cultural monuments and nature conservation: The role of kurgans in maintaining steppe vegetation. Biodiversity and Conservation 25: 2473–2490.

In our paper (published in 2016, received 29 citations on Google Scholar so far) in cooperation with Bulgarian, Polish, Ukrainian, Russian and Kazakh scientists we revealed the role of burial mounds (so called ’kurgans’) in conserving steppe vegetation in transformed landscapes, we reviewed the factors that are responsible for the extremely high biodiversity maintained by the kurgans, and the factors that threaten their existence.

We pointed out that burial mounds of the steppes have essential role both in preserving our historical and natural heritage, thus their protection highly contributes to the conservation of the ancient steppic cultures, landscapes and biota. Based on our findings we provided recommendations to fine-tune the protection of these important landscape elements.

Isolated steppe vegetation on a kurgan from the Iron Age
Even the kurgan is surrounded by extent arable lands it preserved a species rich fragement of the original vegetation

Kurgans – linkage between biodiversity protection and history

Species-rich dry grassland fragments on ancient burial mounds (kurgans) are my primary and favourite research objects. Kurgans are one of the most iconic landscape elements of the Eurasian steppes. They are ancient burial mounds - dating back even to the Eneolithics - of already disappeared cultures such as the Yamnajas, Schitians, Sarmathians. The first kurgans of the Carpathian Basin were built between 3,300-2,500 BC; thus, even it is not obvious for the first sight kurgans have the same age as pyramids of Egypt (the Great Pyramid of Giza was built under the reign of Khufu between 2,580-2,530).

Most of the kurgans were built from the topsoil of the neighbouring areas, which was piled upon a central pit grave. Their height ranges between 0.5 to 15 metres and their area is generally less than one hectare. First we made a comprehensive review on the distribution, vegetation, land use and threatening factors of the kurgans in Eurasia (Deák et al. 2016 Biodiversity and Conservation). We estimated based on the available literature and existing databases, that there are approximately 600,000 kurgans in the Eurasian steppes and they are widely distributed from Hungary to Mongolia. Even though many kurgans have been raided during the past Millennia, they still hide many interesting archaeological artefacts that can contribute to the understanding of our history. Also the kurgans have important cultural values, they act as sacral places and have an important role in the local folklore (there are many tales and sagas about the kurgans).

The Filagória-kurgan functioning as a demonstration site at the Hortobágy National Park, Hungary.

The reason why kurgans are really interesting objects for ecologists is their special flora and fauna. That is why in the past four years we sampled the vegetation, arthropod assemblages, habitat quality and landscape context of 168 kurgans in Hungary.

Map of the surveyed kurgans

Besides their cultural and historical importance kurgans also have outstanding conservational values. In the intensively used agricultural landscapes kurgans preserving grassland habitats can act as habitat islands for many grassland species (see the papers Deák et al. 2016 Biological Conservation and Deák et al. 2018 Landscape Ecology). The reason for that in many cases even in highly transformed landscapes grassland vegetation of kurgans remained intact due to the respect of historical and cultural values. And well, we have to admit: the steep slopes of the kurgans (which is difficult to plough) also contributed to their undisturbed state in many cases. In some other cases there were some administrative reasons for the conservation of the kurgans. Even during the medieval, city borders were fitted on the location of the kurgans, as they were fix and well visible points in the flat plains. The land use intensity on such kurgans were lower than in the neighbouring areas. The situation is the same with the kurgans located on the borderland of countries. One can find extremely diverse and well preserved loess grassland vegetation in the borderland between Hungary and Romania.

Species rich grassland preserved on the Tatár-kurgan, located in the borderland between Hungary and Romania

In Hungary the kurgans with a natural vegetation predominantly harbour loess, alkali or sand grasslands. These grasslands even being small in their area harbour a lot of protected and regionally rare species. These species were formerly widespread in the landscape but due to the high level of landscape transformation and loss of grassland habitats, they become endangered. Such species are the crested wheatgrass (Agropyron cristatum), Jerusalem sage (Phlomis tuberosa) and the dwarf feather grass (Stipa capillata).

A typical species of the kurgan habitats, the protected Phlomis tuberosa

A good example for the biodiversity potential of the kurgans is the seven metres tall Mondró-kurgan, which is located near the village of Hencida (N 47.222028° / E 21.738456°). Even though the kurgan has been surrounded by arable lands at the time of the Second Military Survey of the Austrian-Hungarian Monarchy (1806-1869), during our visit on the kurgan we found several rare grassland specialist species in its small (40 x 60 metres) isolated grassland (Deák et al. 2015 Kitaibelia). The most interesting species were Inula germanica, Ranunculus illyricus, Aster sedifolius and Rosa gallica. Unfortunately, the encroachment of the woody species threatens the existence of the loess grassland of the kurgan, and thus the existence of the rare species. 

The loess grassland of the Mondró-kurgan with several thousands of Inula germanica.

Literature

Deák, B., Valkó, O., Török, P., Kelemen, A., Bede, Á., Csathó, A.I., Tóthmérész, B. (2018): Landscape and habitat and filters jointly drive richness and abundance of grassland specialist plants in terrestrial habitat islands. Landscape Ecology 33: 1117-1132. doi: 10.1007/s10980-018-0660-x PDF

Deák B., Valkó O., Török P., Tóthmérész B. (2016): Factors threatening grassland specialist plants - A multi-proxy study on the vegetation of isolated grasslands. Biological Conservation 204: 255-262.  PDF

Deák, B., Tóthmérész, B., Valkó, O., Sudnik-Wójcikowska, B., Bragina, T.-M., Moysiyenko, I., Apostolova, I., Bykov, N., Dembicz, I., Török, P. (2016): Cultural monuments and nature conservation: The role of kurgans in maintaining steppe vegetation. Biodiversity & Conservation 25: 2473-2490. PDF

Deák, B., Török, P., Tóthmérész, B., Valkó, O. (2015): Mondró-halom kurgan (Hencida, East Hungary), a refugium of loess grassland vegetation. Kitaibelia 20: 143-149. PDF

GfÖ conference, Vienna

The 48th Annual Meeting of the Ecological Society of Germany, Austria and Switzerland took place in Vienna, Austria, between 10-15 September 2018. The motto of the meeting was 'Ecology - meeting the scientific challenges of a complex world'. Among the approximately 400 talks and posters, our presentation about the dispersal of plant seeds after lavatory washing was featured in a press release.

We presented the following talks and posters in the conference

Deák, B., Tölgyesi, Cs., Kelemen, A., Bátori, Z., Gallé, R., Bragina, T.M., Valkó, O. The role of ancient burial mounds in enhancing the biodiversity of Central-Asian steppes.

Kiss, R., Deák, B., Tóthmérész, B., Török, P., Tóth, K., Körmöczi, Zs., Miglécz, T., Sonkoly, J., Radócz, Sz., Godó, L., Kelemen, A., Tóth, E., Kirmer, A., Tischew, S., Valkó, O.  Establishment gaps – a novel tool in grassland restoration.

Kiss, R., Deák, B., Török, P., Tóthmérész, B., Valkó, O. The role of seed bank in habitat restoration in a changing climate.

Lukács, K., Kuhn, T., Fenesi A., Valkó, O., Ruprecht, E. Seed fire tolerance of herbaceous species from the temperate zone depends on their hydration status.

Valkó, O., Lukács, K., Deák, B., Kiss, R., Miglécz, T., Tóth, K., Godó, L., Sonkoly, J., Radócz, S., Török, P., Kelemen, A., Tóthmérész, B. A new aspect of the dispersal of alien plants - Human-dispersed seeds can survive and disperse after the laundry cycle.

Valkó. O., Török, P., Deák, B., Tóthmérész, B. Prescribed fire as an alternative measure for the conservation of grasslands.