Balkan Vegetation Database (BVD) – updated information and current status

The Balkan Vegetation Database (BVD; GIVD ID: EU-00-019) is a regional database, which was established in 2014. It comprises phytosociological relevés covering various vegetation types from nine countries of the Balkan Peninsula (Albania – 153 relevés, Bosnia and Herzegovina – 1715, Bulgaria – 12,282, Greece – 465, Croatia – 69, Kosovo – 493, Montenegro – 440, North Macedonia – 13 and Serbia – 2677). Currently, it contains 18,306 relevés (compared to 9.580 in 2016), and most of them (82.8%) are geo-referenced. The database includes both digitized relevés from the literature (65.6%) and unpublished data (34.5%). Plot size is available for 84.7% of all relevés. During the last four years some “header data information” was improved e.g. elevation (now available for 83.4% of all relevés), aspect (67.7%), slope (66%), total cover of vegetation (54.3%), cover of tree, shrub, herb, bryophyte and lichen layers (27.1%, 20.1%, 40.2%, 11.5% and 2.1%), respectively. Data access is either semi-restricted (65.6%) or restricted (34.4%). Most relevés (84.6%) are classified to syntaxa of different levels. The database has been used for numerous studies with various objectives from floristic, vegetation and habitat-related topics, to macroecological studies at the local, regional, national, continental and global levels. During the last four years, BVD data were requested from 111 different projects via the EVA and sPlot databases.

Plant Part Age and Size Affect Sessile Macrobenthic Assemblages Associated with a Foliose Red Algae Phycodrys rubens in the White Sea

Facilitation by foundation species commonly structures terrestrial and marine communities. Intraspecific variation in individual properties of these strong facilitators can affect the whole suite of the dependent taxa. Marine macroalgae often act as ecosystem engineers, providing shelter and substrate for numerous associated organisms. Epibiosis of foliose red algae, however, remains underexplored, especially in the high latitudes. Here we studied sessile macrobenthic assemblages associated with a foliose red algae Phycodrys rubens in the White Sea (66° N) shallow subtidal, and the effect of individual plant properties on their structure. The blades of P. rubens develop annually, and it is possible to tell the young (usually larger) plant parts from the old ones. We hypothesized that epibenthic community structure depends on plant part age and size. We examined epibiosis on 110 plants at two sites, and the results generally supported our hypotheses. Old plant parts were several times smaller, and had higher total cover than young parts. Sponges strongly dominated the epibiosis on old parts, and young parts were dominated by polychaetes and bryozoans. Plant part surface area negatively correlated with total cover on young parts, while on old parts the relatioship was location-specific. On young parts the relative abundance of a polychaete Circeis armoricana increased with surface area, and the proportion of sponges decreased. The patterns indicate that epibenthic community structure is linked to the demography of an ecosystem engineer.

Conservation and pastoral value of former arable lands in the agro-pastoral system of the Alta Murgia National Park (Southern Italy)

Grasslands are an important element of European landscapes and environment. In the last decades, several causes have contributed to their decline among which the intensification of agriculture activities. The National Park of Alta Murgia represents a typical agro-pastoral karst system where the conversion to arable lands caused a drastic decline of semi-natural rocky grasslands of high naturalistic value that traditionally were used for sheep grazing. This change of land use created much concern about the lack of biodiversity and soil degradation. Thus, the Park Authority promotes reconversions of arable lands into grasslands to safeguard biodiversity, increase pastoralism and enhance the multi-functionality of farms. This study evaluates the conservation and pastoral value of plant communities in former arable lands derived from grasslands conversion (by crushing the rocky substrate) and subsequently abandoned. We selected seven sites of these abandoned arable lands, no longer ploughed or sown for three to five or twelve to fifteen years. In order to have a comparison with situations of low anthropic pressures, other five sites were selected in nearby natural rocky grasslands, without evidence of soil disturbance. Further two sites were selected in lands manually cleared from stones and taken out of crop production for more than fifty years. Vegetation samples were carried out according to the standard phytosociological method. Shannon and Richness indexes, ecological and phytogeographical quality and pastoral value were calculated. The ecological quality was calculated through the ratio between cover of diagnostic taxa of the higher syntaxonomic units characterizing the undisturbed pastures and total cover. The phytogeographical value was evaluated considering the cover of endemic, sub-endemic and rare taxa out of the total cover value of each plant sample. For the calculation of pastoral value, we referred to Daget and Poissonet (1969), considering the palatability of taxa on a scale ranging from 0 to 5 according to data found in scientific literature. From a conservation perspective, sites originated from the conversion of rocky pastures by crushing of the rocky surface showed marked differences from undisturbed grasslands, even after 15 years from abandonment. Lands manually cleared and abandoned for more than fifty years, did not show appreciable differences from semi-natural grasslands, conserving many taxa of high conservation value. On the other hand, fields originated from grasslands conversion showed higher pastoral value. This paper emphasizes the need for safeguarding the rocky substrates and their remnant typical grassland communities, even in the so-called quote. Results are useful for the sustainable management of the agro-pastoral system of Alta Murgia, taking into account the ecological and economic role of those lands whose rocky substrate had been crushed.

Estimasi jumlah biomassa lamun di Pulau Pramuka, Karya dan Kotok Besar, Kepulauan Seribu, Jakarta

The research was conducted in Kotok Besar, Karya and Pramuka Islands, Seribu Islands, Jakarta Province from May to July 2013. The aims of the research were to examine the percent cover, composition of vegetation and estimation of seagrass leaves biomass. The squares transect (0.25 m2) was utilized to calculate the seagrass percent cover data. Seagrass data were converted to total cover and biomass formula to estimate the seagrass leaves biomass. The result of our study showed there are 4 species of seagrass occurred in Kotok Besar Island, while 6 species were recorded in Karya and Pramuka Islands. Cymodocea rotundata had the higher value of seagrass cover percentage in Kotok Besar, Karya and Pramuka Islands, while the lower values were Halodule uninervis and Halophila ovalis. In addition, the highest value of seagrass leaves biomass from those islands is Enhalus acoroides and the lower value was Halophila ovalis inKotok Besar and Pramuka Islands, and Halodule uninervis in Karya Island.Keywords: Composition of vegetation, estimated of biomass, seagrass, Seribu Islands Abstrak. Penelitian ini dilakukan di Pulau Kotok Besar, Karya dan Pramuka Kepulauan Seribu-Provinsi Jakarta mulai Mei sampai Juli 2013. Tujuan dari penelitian ini adalah mengetahui komposisi vegetasi lamun dan estimasi jumlah biomassa daun lamun di pulau Kotok Besar, Karya dan Pramuka kepulauan Seribu-Provinsi Jakarta. Penelitian ini dilakukan dengan mengguakan transek kuadrat (0,25 m2) untuk mengetahui persentase penutupan lamun. Data lamun yang diperoleh dikonversikan pada persamaan total penutupan dan estimasi biomasa untuk mengestimasi biomassa daun lamun. Hasil dari penelitian, terdapat 4 jenis lamun yang diperoleh di pulau Kotok Besar dan 6 jenis di pulau Karya dan Pramuka. Persen penutupan tertinggi pada pulau Kotok Besar, Karya dan Pramuka adalah jenis lamun Cymodocea rotundata, sedangkan yang terendah dari masing-masing pulau adalah Halodule uninervis dan Halophila ovalis secara berurutan. Estimasi biomassa daun lamun dengan nilai tertinggi adalah Enhalus acoroides dari ketiga pulau dan terendah adalah Halophila ovalis untuk pulau Kotok Besar dan Pramuka, dan Halodule uninervis untuk pulau Karya.Kata kunci: Komposisi vegetasi, estimasi biomassa, lamun, Kepulauan Seribu

Non-native plants add to the British flora without negative consequences for native diversity

Plants are commonly listed as invasive species, presuming that they cause harm at both global and regional scales. Approximately 40% of all species listed as invasive within Britain are plants. However, invasive plants are rarely linked to the national or global extinction of native plant species. The possible explanation is that competitive exclusion takes place slowly and that invasive plants will eventually eliminate native species (the “time-to-exclusion hypothesis”). Using the extensive British Countryside Survey Data, we find that changes to plant occurrence and cover between 1990 and 2007 at 479 British sites do not differ between native and non-native plant species. More than 80% of the plant species that are widespread enough to be sampled are native species; hence, total cover changes have been dominated by native species (total cover increases by native species are more than nine times greater than those by non-native species). This implies that factors other than plant “invasions” are the key drivers of vegetation change. We also find that the diversity of native species is increasing in locations where the diversity of non-native species is increasing, suggesting that high diversities of native and non-native plant species are compatible with one another. We reject the time-to-exclusion hypothesis as the reason why extinctions have not been observed and suggest that non-native plant species are not a threat to floral diversity in Britain. Further research is needed in island-like environments, but we question whether it is appropriate that more than three-quarters of taxa listed globally as invasive species are plants.

The utility of visual estimation of cover for rapid assessment of graminoid abundance in forest and grassland habitats in studies of animal foraging

QuestionsTo assess the feasibility of using visually-estimated cover in rapid assessment of herbivore food species abundance in the grass layer, we asked the following questions: 1) What is the relationship between total graminoid cover and biomass in forests, and does height improve the prediction of biomass from cover? 2) How does total cover relate to biomass in a grassland habitat? 3) How does elephant food species graminoid cover relate to individual species biomass? 4) How well does species diversity of forest understorey grass layer, calculated from cover data, mirror that calculated from biomass data?LocationNagarahole National Park, India.MethodsWe estimated the abundance of graminoids through visual estimation of cover and weighted harvested biomass in forest and grassland plots. In forests, two estimates of total graminoid abundance, total graminoid cover and sum of species covers, were used. In the grassland, only total graminoid abundance was measured. We examined the relationship between cover estimates and biomass, and the additional utility of height in predicting biomass, using multiple regressions and AIC-based model selection. We also assessed similarity in cover- and biomass-based Simpson’s and Shannon-Wiener diversity indices using regressions.ResultsGraminoid cover explained a large portion of variation in total graminoid biomass in forest and grassland habitats. The sum of species covers was better than total cover in estimating total graminoid biomass in the forest. The benefit of including height to estimate total biomass was moderate in forests but substantial in grassland. Cover estimates were good proxies of food species biomass, and the addition of height did not yield better models for most species. Species diversity indices calculated from cover largely matched those based on biomass.ConclusionsVisual estimation of species cover is a good alternative to biomass harvesting for rapid assessment of abundance of graminoids consumed by generalist herbivores, like elephants.

Level of invasion by alien plants across habitats in the basin of the Ploučnice River

The level of invasion varies depending on the type of the habitat. The aim of this paper is to evaluate the level of floral invasion within the basin of the Ploučnice River in Northern Bohemia. The values of the level of invasion were quantified for vegetation plots from the Czech National Phytosociological Database. Several maps documenting the level of invasion by alien plants were developed based on a quantitative assessment of the level of invasion of particular habitat types. The levels of invasion were measured as a proportion of the species that are aliens and as the total cover by alien species, the same was done for archeophytes and neophytes separately. Mean levels of invasion were used for the habitats.

Experimental removal of the invasive Caulerpa racemosa triggers partial assemblage recovery

The invasive species Caulerpa racemosa var. cylindracea represents a serious threat to the diversity of benthic assemblages in the Mediterranean Sea. In the present study, a removal experiment was carried out to test whether, after 18 months of C. racemosa var. cylindracea exclusion, the macrophyte assemblage resembled a non-invaded assemblage. The results show that in the assemblage invaded by C. racemosa var. cylindracea the number of species, macrophyte cover, Shannon diversity and Pielou's evenness were lower than in the non-invaded assemblage. Erect perennial species were particularly affected and other introduced species were significantly reduced or completely excluded. After 18 months of removal/exclusion of C. racemosa var. cylindracea, only partial recovery of the macrophyte assemblage could be observed. Species numbers, total cover and erect perennial species cover were still significantly lower than in the non-invaded plots. However Shannon diversity and Pielou's evenness had reached comparable levels. In contrast to native macrophytes, the total cover of other introduced species reached a level comparable to the non-invaded plots. In summary, the present study revealed that after 18 months of C. racemosa var. cylindracea exclusion: (i) only partial recovery of the macrophyte assemblage occurred; and (ii) the development of other invasive species was favoured by the absence of C. racemosa var. cylindracea (Sisyphus effect).