Conservation In Practice |
Corresponding author: Orsolya Valkó ( valkoorsi@gmail.com ) Academic editor: Szabolcs Lengyel
© 2018 Orsolya Valkó, Katalin Tóth, András Kelemen, Tamás Miglécz, Szilvia Radócz, Judit Sonkoly, Béla Tóthmérész, Péter Török, Balázs Deák.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
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. https://doi.org/10.3897/natureconservation.24.20019
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Linking the conservation of cultural heritage and natural values provides a unique opportunity for preserving traditional landscapes and receives an increased awareness from stakeholders and society. Ancient burial mounds are proper objects of such projects as they are iconic landscape elements of the Eurasian steppes and often act as refugia for grassland specialist species. The aim of this project was to reintroduce grassland plant species to burial mounds for representing them as cultural monuments with the associated biodiversity for the public. The effectiveness of seed sowing, transplanting greenhouse-grown plants and individuals from threatened populations on burial mounds in Hortobágy National Park, Hungary was tested. The following questions were answered: (1) which method is the most effective for species introduction? (2) which species can establish most successfully? (3) how does management affect the species establishment rates? It was found advisable to use a combination of seed sowing and transplanting greenhouse-grown plants. Sowing was found as a cost-effective method for introducing large-seeded species, whilst introduction of greenhouse-grown transplants warranted higher establishment rates for a larger set of species. Transplanting adult individuals was more reliable regardless of management regimes, however this method is labour-intensive and expensive. Intensive management, like mowing with heavy machinery and intensive grazing, should be avoided in the first few years after introduction. The authors highlighted the fact that introducing characteristic grassland species on cultural monuments offers a great opportunity to link issues of landscape and biodiversity conservation. This project demonstrated that, by the revitalisation of cultural monuments, cultural ecosystem services can also be restored.
cultural ecosystem services, endangered species, grassland restoration, landscape conservation, landscape element, reintroduction
Open landscapes often harbour surprisingly high biodiversity and they are also an essential part of our cultural heritage (
Integrating cultural ecosystem services into landscape planning and protection can effectively support nature conservation projects which aim to conserve historical landscape elements with a potential of harbouring high biodiversity and providing ecosystem services (
Besides their cultural and aesthetic value, burial mounds often act as biodiversity hotspots in agricultural landscapes. Their particular shape and steep slopes have often prevented ploughing; thus, grassland vegetation has been able to survive on burial mounds (
Spontaneous recovery of target plant populations in degraded landscapes is often hampered by propagule-limitation, i.e. the lack of target species in the seed banks and seed rain, as many grassland plant species have transient seed banks and many are dispersal-limited (
The authors introduced historically widespread species of loess grasslands on burial mounds with species-poor and degraded vegetation in the Hortobágy National Park, Hungary. An approach which was found to be effective in restored grasslands was used, i.e. creating establishment hot-spots for grassland specialist plant species (see also
The study sites are situated in the Great Hungarian Plain, in the Hortobágy National Park (N47.58°, E20.92°). The climate of the area is moderately continental with a mean annual temperature of 9.5 °C and mean annual precipitation of 550 mm (
Target species were reintroduced on to five burial mounds (see Table
Site characteristics of the studied kurgans.
Filagória | Meggyes | Görbeszék | Nyíregyházi | Porosállás | |
---|---|---|---|---|---|
Coordinates | N47.573271°, E20.942839° | N47.585222°, E20.973992° | N47.589589°, E20.872901° | N47.570090°, E20.951617° | N47.550524°, E20.881466° |
Total area (m2) | 7500 | 4500 | 1600 | 10000 | 17000 |
Height (m) | 7 | 2 | 8 | 5.5 | 2.5 |
Total vegetation cover (%) | 78.0±10.4 | 84.0±6.6 | 77.0±5.8 | 78.0±5.7 | 87.0±5.7 |
Vegetation height (cm) | 67.0±20.8 | 83.0±17.5 | 36.0±9.6 | 62.0±17.9 | 72.0±14.8 |
Management type | mown (hand) | mown (hand) | grazed (sheep) | mown (machinery) | mown (machinery) |
The aim of the project was to reintroduce characteristic loess grassland species to the studied burial mounds. Experts of the Hortobágy National Park Directorate selected the list of introduced species and also recommended the set of species to be reintroduced to certain kurgans. They selected a total of 18 species typical of the loess grasslands of the region. Three measures were applied for plant reintroduction: seed sowing, planting of individuals grown in the greenhouse (transplantation) and planting adult plants from threatened natural populations (translocation).
Seed collection
At the first stage of plant introduction, seeds of 16 target species were collected in 2013. Seeds originated from semi-natural loess grasslands of the region. The authors could not collect seeds of two endangered species (Amygdalus nana and Anchusa barrelieri), as from their few existing scattered populations, it was impossible to collect ripened viable seeds. For Rosa rubiginosa, seeds were collected before maturation (in late September) because, in that season, the amount of germination inhibitor compounds is lower in the pericarp (
Seed sowing
The collected seeds of herbaceous species were sown, after soil disturbance by raking in October 2013 (see Table
List of species introduced on the five kurgans. (A) Sown species and the amount of sown seeds (g), (B) Species list and number of greenhouse-grown transplants and (C) Species list and number of individuals translocated from threatened natural populations. Matrix species are marked with an asterisk.
Filagória | Görbeszék | Meggyes | Nyíregyházi | Porosállás | |
---|---|---|---|---|---|
(A) Seed sowing | |||||
Carthamus lanatus | 20 g | 20 g | |||
Centaurea pannonica | 20 g | 20 g | 20 g | 20 g | |
Centaurea sadleriana | 20 g | 20 g | 20 g | ||
Centaurea solstitialis | 20 g | 20 g | |||
Dianthus pontederae | 20 g | 20 g | 20 g | 20 g | |
Filipendula vulgaris* | 500 g | 500 g | 500 g | 500 g | |
Galium verum | 20 g | ||||
Hypericum perforatum | 20 g | ||||
Knautia arvensis | 20 g | ||||
Lotus corniculatus | 20 g | ||||
Lycopsis arvensis | 20 g | ||||
Phlomis tuberosa | 20 g | 20 g | 20 g | 20 g | 20 g |
Salvia austriaca* | 500 g | 500 g | 500 g | 500 g | |
Salvia nemorosa* | 500 g | 500 g | 500 g | 500 g | |
Silene vulgaris | 20 g | 20 g | 20 g | ||
(B) Transplantation | |||||
Carthamus lanatus | 30 | ||||
Centaurea pannonica | 38 | 30 | |||
Centaurea sadleriana | 50 | 45 | 50 | ||
Centaurea solstitialis | |||||
Dianthus pontederae | 20 | 20 | 30 | 50 | |
Filipendula vulgaris | 20 | 20 | 30 | 50 | |
Lotus corniculatus | 34 | ||||
Rosa rubiginosa | 49 | ||||
Salvia austriaca | 10 | 20 | 50 | ||
Salvia nemorosa | 30 | 10 | 20 | 50 | |
Silene vulgaris | 36 | 20 | |||
(C) Translocation | |||||
Amygdalus nana | 35 | 25 | |||
Anchusa barrelieri | 32 | ||||
Phlomis tuberosa | 32 | 124 | 10 | 53 | 20 |
Transplantation
Using the collected seed material, individuals of 11 target species were grown in a greenhouse (see Table
Translocation
In the case of three endangered species, adult plants were translocated to the kurgans from endangered natural populations in the region (Table
Sampling of introduction success
The survival rate of introduced species was tested in September 2015 by counting all individuals. To evaluate reproductive success, the species which flowered or set seeds in September 2015 were listed. For sown species, the establishment rates were calculated as follows. From germination rates in the greenhouse experiment, the predicted numbers of individuals were calculated on the burial mounds using the following equation: Np= SNs × (Ng/100), where Np is the predicted number of individuals per burial mound; SNs is the number of seeds sown on burial mounds and Ng is the number of germinated individuals in the greenhouse experiment. The observed number of individuals were compared with the predicted numbers of individuals. For transplanted and translocated species, the establishment rate was calculated as the ratio of planted individuals/surviving individuals.
The results of the germination experiment showed that the majority of species had good germination rates under greenhouse conditions, regardless of their thousand-seed weights (Supplementary material
Establishment rates in September 2015 (%) of (A) sown species, (B) greenhouse-grown transplants and (C) individuals translocated from threatened natural populations. Species which had flowering individuals are marked with an asterisk.
Filagória | Görbeszék | Meggyes | Nyíregyházi | Porosállás | |
---|---|---|---|---|---|
(A) Seed sowing | |||||
Carthamus lanatus | 0.00 | 12.61* | |||
Centaurea pannonica | 0.00 | 0.00 | 0.00 | 0.00 | |
Centaurea sadleriana | 0.00 | 0.00 | 0.00 | ||
Centaurea solstitialis | 0.11* | 0.75* | |||
Dianthus pontederae | 0.00 | 0.00 | 0.00 | 0.00 | |
Filipendula vulgaris | 0.00 | 0.00 | 0.00 | 0.00 | |
Galium verum | 0.08* | ||||
Hypericum perforatum | 0.02* | ||||
Knautia arvensis | 0.24* | ||||
Lotus corniculatus | 0.00 | ||||
Lycopsis arvensis | 10.68* | ||||
Phlomis tuberosa | 0.00 | 0.00 | 0.00 | 0.00 | 0.00 |
Salvia austriaca | 0.51* | 0.03* | 0.00 | 0.01 | |
Salvia nemorosa | 0.37* | 0.33* | 0.01 | 0.02 | |
Silene vulgaris | 0.03* | 0.00 | 0.00 | ||
(B) Transplantation | |||||
Carthamus lanatus | 0.00 | ||||
Centaurea pannonica | 10.50* | 3.30* | |||
Centaurea sadleriana | 8.00 | 51.10* | 0.00 | ||
Dianthus pontederae | 0.00 | 0.00 | 0.00 | 0.00 | |
Filipendula vulgaris | 10.00 | 0.00 | 0.00 | 0.00 | |
Lotus corniculatus | 0.00 | ||||
Rosa rubiginosa | 75.50 | ||||
Salvia austriaca | 60.00* | 5.00 | 6.00 | ||
Salvia nemorosa | 100.00* | 90.00* | 10.00* | 36.00* | |
Silene vulgaris | 5.60* | 0.00 | |||
(C) Translocation | |||||
Amygdalus nana | 37.10 | 0.00 | |||
Anchusa barrelieri | 56.30* | ||||
Phlomis tuberosa | 66.10* | 75.50* | 75.00* |
The establishment rate of transplanted plants was the highest on the two burial mounds (Filagória and Meggyes) which were managed by hand mowing (Table
Establishment rates of individuals translocated from threatened natural populations were higher than 50% on all sites for Anchusa barrelieri and Phlomis tuberosa (Table
Altogether, 12 species having individuals with flowering shoots were found. The highest proportion of flowering species was found on burial mounds managed by hand mowing (Filagória and Meggyes). Of the established species, Amygdalus nana, Filipendula vulgaris and Rosa rubiginosa failed to flower on any of the kurgans.
The study demonstrated that all three methods (seed sowing, transplanting and translocating) were feasible for plant introduction. Based on these results, several circumstances, such as site conditions, management type, species characteristics, available manpower and financial limitations should be considered when choosing the most feasible method.
Seed sowing
Sowing the seeds of target species is considered to be the least labour- and cost-intensive method for species introductions (
The quality of the collected seed material was assessed by the germination success of all target plant species from which viable seeds could be collected. It was found that the seeds of all collected species germinated under greenhouse conditions, however, species with a hard seed coat (Lotus corniculatus, Lycopsis arvensis, Phlomis tuberosa and Salvia austriaca) and most species of the family Asteraceae (Carthamus lanatus, Centaurea pannonica and C. sadleriana) had moderate germination rates in the greenhouse. On the one hand, as many of these species require some mechanism to break seed dormancy (
It was found that species with high thousand-seed weights (especially Carthamus lanatus and Lycopsis arvensis) could establish most successfully on the burial mounds. It was also found in former studies that species with large seeds can better tolerate the shading effect of litter and can also germinate below thick litter layers (
In many cases, seeds failed to germinate due to the lack of proper establishment microsites (see also Deák et al. 2011). It was found that seed sowing was most effective on burial mounds which were managed by hand mowing. Hand mowing usually creates a higher diversity of microsites favourable for plant germination compared to the homogeneous vegetation structure formed by mowing machinery (
Even though seed sowing is considerably less labour-intensive than the transplanting of individuals, important drawbacks of the method were identified. The success of seed sowing largely depends on the germination rates of the available seed material (see also
Transplanting and translocation
Both transplanting of juvenile and adult plants proved to be a more effective method than seed sowing, as individuals are introduced at a more developed ontogenetic stage which increases the probability of successful establishment (
By translocation, individuals of the threatened donor populations could be saved. All three species which were translocated from threatened natural populations established successfully and two of them (Anchusa barrelieri and Phlomis tuberosa) had flowering and fruiting individuals on the burial mounds and were thus able to establish a new population on the recipient site. This result indicates the importance of this kind of conservation action which aims to translocate individuals from threatened populations to suitable habitats.
Plants are in a sensitive period for a few months after transplantation and translocation; thus, in this early period, intense disturbance, such as trampling, mowing or grazing should be avoided (
Based on these results, in plant introduction projects, it is crucial to collect basic seed material from a local provenance and to test the germination ability of seeds. One part of the seeds can be used for seed sowing on the field and the other part should be germinated in a greenhouse. In the case of larger seeded species, greater success with seed sowing than in the case of smaller-seeded ones can be expected. With transplanting and translocating individuals, the establishment success can be increased, but it is crucial to ensure proper water availability and protect the transplants from severe disturbance.
This study demonstrated that landscape and biodiversity conservation can be linked by species reintroduction projects in historical landscapes. For such projects, burial mounds are ideal objects because they can act as representative spots for society. These results draw attention to the necessity of restoring the landscape and biodiversity values of kurgans which are important parts of the cultural heritage across Eurasia. The need to link conservation and introduction programmes on cultural monuments should be emphasised.
To support future plant reintroduction projects, the following findings should be considered:
Seed material should be collected from regional populations to ensure the use of locally adapted ecotypes. Before large-scale application, indoor germination tests are recommended.
The use of a combination of seed sowing and transplanting greenhouse-grown plants is advisable. Seed sowing is a cost-effective method for introducing large-seeded species, whilst introduction of greenhouse-grown transplants warrants higher establishment rates for a larger set of species.
To create proper microsites for germination and establishment, it is crucial to lightly disturb the soil surface by raking prior to seed sowing.
As post-introduction management, regular watering and mulching is necessary to prevent drought, freezing and weed invasion after transplanting.
Intensive management, such as mowing with heavy machinery and intensive grazing, should be avoided in the first few years after introduction.
This project demonstrated that by the revitalisation of cultural ecosystem services, such as aesthetic values, public relations and educational values, can be restored at the same time (
We are grateful to E. Tóth, L. Gál, K. Süveges and Á. Lovas-Kiss for their help in the seed collection, soil preparation and transplantation. We are grateful to T. Hartel, A. Helm and S. Lengyel for their constructive comments on the manuscript. The restoration project was funded by the Hortobágy National Park and the KEOP-3.1.2/2F/09-11-2011-0009 project. The study was supported by OTKA PD 111807 (OV), NKFI FK 124404 (OV), NKFI KH 126476 (OV), NKFI KH 126477 (BT), OTKA PD 115627 (BD), OTKA K 116639 (BT), NKFI PD 124548 (TM) and NKFIH K 119225 (PT) projects. OV and BD were supported by the Bolyai János Research Scholarship of the Hungarian Academy of Sciences. Authors were funded by the MTA’s Post Doctoral Research Programme. OV and BD were supported by the ÚNKP-17-4-III-DE-151 and ÚNKP-17-4-III-DE-160 New National Excellence Programme of the Ministry of Human Capacities. We are grateful to L. Papp and the Botanical Garden of the University of Debrecen for their support in the greenhouse experiments.