First Survey of the Vascular and Cryptogam Flora on Bulgaria's Ancient Mounds.

Tsvetelina Terziyska,Kiril Vassilev,Magdalena Valcheva,Desislava Sopotlieva,Georgi Nekhrizov,Iva Apostolova,Nikolay Velev,Veselin Shivarov,Anna Ganeva

doi:10.3390/plants11050705

Tsvetelina Terziyska, Kiril Vassilev + Show 7 more

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https://doi.org/10.3390/plants11050705

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Abstract

This work represents the first study of the floristic diversity on Bulgaria’s ancient mounds. The objective of this research was to assess the importance of the mounds for the preservation of the native vascular and cryptogam flora. Our sampling design included 111 ancient mounds distributed throughout the country. We recorded a total of 1059 vascular plants, 58 bryophytes and 61 lichen taxa. Despite their small area, the mounds were shown to preserve nearly a quarter of the Bulgarian flora. The vegetation cover on the mounds included 61% perennials indicating a long-term persistence and stability. The majority (98%) of the established vascular plants were native species. Although the conservation significance of the vascular plant species were not common, we recorded 2 critically endangered, 9 endangered and 14 Balkan endemics during the present study. The lichen Arthopyrenia salicis was recorded for the first time in Bulgaria and a new locality of the rare bryophyte Ceratodon conicus was discovered. The established compositional difference between plots from the northern and southern slopes of the mounds (88.95%) is a testament to the high local habitat diversity. The prevalence of species characteristic for Festuco-Brometea suggests that the mounds preserve fragments of native grasslands and steppes. The variation in cover of agricultural and other human modified areas in the mounds’ immediate surroundings did not substantially affect their species richness. We argue that the ancient mounds should be taken into consideration in future green space planning.

Highlights

Ancient mounds were constructed in temperate Eurasia between 4th millennium BC and 4th century AD and used primarily for burial purposes
Bulgaria is exceptionally rich in ancient mounds with a known number of approximately 50,000 [5]; 11,000 of these mounds have been registered in the Archaeological Map of Bulgaria
We considered species to be generalists if they were diagnostic of synanthropic vegetation or if they had a broad distribution across different habitat types

Summary

Introduction

Ancient mounds ( called tumuli or more commonly kurgans) were constructed in temperate Eurasia between 4th millennium BC and 4th century AD and used primarily for burial purposes. Most of Bulgaria’s ancient mounds are surrounded by vast agricultural lands [4]. Similar to ancient mounds in other European countries, these structures are often standing as sole “islands” of semi-natural vegetation in an otherwise human-modified landscape [3,6,7]. Road verges and buffer strips adjacent to arable land, the ancient mounds preserve small semi-natural fragments and provide an opportunity for the long-term survival of indigenous flora. The long-term persistence of the mounds within agricultural lands, primarily due to sacred and religious respect, naturally makes them a part of the Green and Blue Infrastructure defined at the European level as a “strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services” [10]

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