Abstract

Background and Aims Studying the relationship between phenotypic and genetic variation in populations distributed across environmental gradients can help us to understand the ecological and evolutionary processes involved in population divergence. We investigated the patterns of genetic and phenotypic diversity in the European crabapple, Malus sylvestris, a wild relative of the cultivated apple (Malus domestica) that occurs naturally across Europe in areas subjected to different climatic conditions, to test for divergence among populations. Methods Growth rates and traits related to carbon uptake in seedlings collected across Europe were measured in controlled conditions and associated with the genetic status of the seedlings, which was assessed using 13 microsatellite loci and the Bayesian clustering method. Isolation-by-distance, isolation-by-climate and isolation-by-adaptation patterns, which can explain genetic and phenotypic differentiation among M. sylvestris populations, were also tested. Key Results A total of 11.6 % of seedlings were introgressed by M. domestica, indicating that crop-wild gene flow is ongoing in Europe. The remaining seedlings (88.4 %) belonged to seven M. sylvestris populations. Significant phenotypic trait variation among M. sylvestris populations was observed. We did not observe significant isolation by adaptation; however, the significant association between genetic variation and the climate during the Last Glacial Maximum suggests that there has been local adaptation of M. sylvestris to past climates. Conclusions This study provides insight into the phenotypic and genetic differentiation among populations of a wild relative of the cultivated apple. This might help us to make better use of its diversity and provide options for mitigating the impact of climate change on the cultivated apple through breeding.

Abstract

Grassland ecosystems are essential for biomass production but are prone to degradation if management practices are inappropriate. Thus, it is necessary to optimize grazing management since the grazing practices and grassland status are interconnected. Herbage mass production and forage quality of the plant species are among the most important factors for grazing livestock performance, grassland carrying capacity, and their sustainable management. We employed optimized methods for the analysis of two historical vegetation datasets (from 1970 and 2008), along with the statistical data on livestock numbers and types from three administrative units within the Vladeasa Mountains area, in the Romanian Carpathians. We looked for trends in grassland quality and productivity and explored their connections to grazing management descriptors and practices. We identified a small but statistically significant decreasing trend between the two periods in both pastoral value (from 63.80 to 61.43) and productivity (from 10.80 t ha(-1) to 9.18 t ha(-1)). The decline in grassland quality and productivity may be associated with the sharp decrease in livestock numbers (from 9,688 LU to 5,085 LU) and the replacement of cattle by sheep as the dominant livestock type. The abandonment of grasslands and traditional practices also increased the deviation from the optimum of the actual stocking rate. This approach can be used as a model for other areas where time-series vegetation data are available from phytosociological literature and/or databases. These insights can be used to design adaptive grazing management plans to optimize grazing management according to the carrying capacity of the grassland ecosystems.

Abstract

Grassland ecosystems are essential for biomass production but are prone to degradation if management practices are inappropriate. Thus, it is necessary to optimize grazing management since the grazing practices and grassland status are interconnected. Herbage mass production and forage quality of the plant species are among the most important factors for grazing livestock performance, grassland carrying capacity, and their sustainable management. We employed optimized methods for the analysis of two historical vegetation datasets (from 1970 and 2008), along with the statistical data on livestock numbers and types from three administrative units within the Vlădeasa Mountains area, in the Romanian Carpathians. We looked for trends in grassland quality and productivity and explored their connections to grazing management descriptors and practices. We identified a small but statistically significant decreasing trend between the two periods in both pastoral value (from 63.80 to 61.43) and productivity (from 10.80 t ha-1 to 9.18 t ha-1). The decline in grassland quality and productivity may be associated with the sharp decrease in livestock numbers (from 9,688 LU to 5,085 LU) and the replacement of cattle by sheep as the dominant livestock type. The abandonment of grasslands and traditional practices also increased the deviation from the optimum of the actual stocking rate. This approach can be used as a model for other areas where time-series vegetation data are available from phytosociological literature and/or databases. These insights can be used to design adaptive grazing management plans to optimize grazing management according to the carrying capacity of the grassland © **. Articles by the authors; UASVM, Cluj-Napoca, Romania. The journal allows the author(s) to hold the copyright/to retain publishing rights without restriction

Abstract

The paper is a synthesis of the palynological studies that have addressed the age of landslides in Transylvania. We discuss the configuration of the paleo-vegetation in the respective areas, but also the probable factors, abiotic or biotic, which promoted the landslides and the relative period when they occurred in Transylvania. The analysis indicates two major periods of onset for landslides, the Pleistocene and Holocene. © 2020, Babes-Bolyai University, "Alexandru Borza" Botanic Garden. All rights reserved.

Abstract

Abstract

The landscape at the Roman Archaeological Site from Moigrad-Porolissum, Romania, is nowadays mostly forested. But how did it look during the Roman period (106-275 AD)? Also, how can multispectral imagery and laser scanning be combined more effectively to detect the signatures of ancient sub-surface archaeological remains? This study employed WorldView2 satellite and LiDAR (Light Detection And Ranging) data to explore current remotely sensed vegetation and terrain proxies. These helped identify past anthropogenic signatures embedded within the landscape for reconstructing the ancient engineered environment. The spectral vegetation and terrain patterns revealed 227 marks (36256.22 m) relevant for the historical landscape, of which 182 correspond to ancient sub-surface features. In open landscapes, the two techniques had equivalent results, while LiDAR provided better detection rates in shrubland patches and forests. Their successive application is an advantageous strategy for optimizing costs. The satellite imagery is employed first, followed by the density analysis of the results, while the more expensive laser-based data collection can be focused on the problematic or promising areas. The vegetation and terrain marks revealed the intricate and extensive ancient defensive system that extended on over 24.5 km(2). Their strategic functions, requiring visibility between and around them, suggest large-scale deforestation (probably over 1 km around the structures). Thus, in contrast to the present forest dominance, it appears that in the 2nd and 3rd centuries AD, at Porolissum there was an anthropogenic open landscape covering over 2158 ha, with urbanization and intense military activity on 198.76 ha.

Abstract

We aimed to detect species distribution patterns at landscape level that have arisen following the colonisation of a mine spoil heap (MSH) by macrolichens. All taxa occurring on various substrates and the degree of occupancy by different vegetation patch types were recorded at a resolution of 50 m x 50 m within a regular square grid of 25 ha, which extended over a 60-year-old abandoned MSH and its adjacent agro-pastoral area. The fraction of MSH was the most important predictor of the lichen composition and richness at grid cell level, followed by the terrain slope and the proportion of heathland. Almost all lichen taxa positively correlated with the MSH fraction were terricolous, fruticose, oligotrophilous, acidophilous species that occurred preferentially on the steep, barren slopes. The few corticolous, nitrophilous species were negatively correlated with the MSH fraction. Except for the corticolous and saprophytic species, the proportion of MSH and the elevation range had each a positive effect on both total and terricolous lichen richness. Conversely, taxonomic distinctness displayed an opposite pattern. Such a contrast was determined by the numerous conspecific (Cladonia) lichens occurring on the steeper MSH slopes, with scarce vegetation. A conspicuous nestedness, but no pattern of species turnover, was detected along the main ecological gradient. This was due to both the corticolous/saprophytic species shared with the adjacent, tailings-free habitats and the terricolous/saxicolous lichens dispersed from proximal source-habitats. The MSH studied can be considered a hotspot for lichen species richness but not for taxonomic diversity.

Abstract

Plant assemblages and successional pathways were studied on large, abandoned ore mining heaps located around the open-cast pits from Rosia Montana., Romania. Four differently aged mining spoils with relatively homogenous substrate and one control plot were investigated using the chronosequence approach. The effects of the waste dump age, slope steepness, position on slope, terrain curvature and potential solar radiation on the plant species composition of different assemblages from spontaneously revegetated primary sites were evaluated. Releves were grouped into floristically similar vegetation types using non-hierarchical cluster analysis (Fuzzy c-Means). The ecological interpretation of the plant assemblages was performed through indicator species values (IndVal) and non-metric multidimensional scaling (NMDS). This study reinforces several important concepts about the deterministic patterns of primary succession. First, the multiple comparisons between plant assemblages reveal that the highest differences are caused by the age of the spoil heap and substrate acidity. Further differences, lower but significant, are determined by terrain curvature and potential solar radiation. Also, environmental factors acting prior to the establishment of the observed plant assemblages (age, substrate pH, slope steepness and position on slope), have subsequently induced a structural differentiation in terms of species richness, vegetation cover and relative cover of the N-fixing species. There are two main possible successional pathways, determined, most likely, by the long term changes in substrate pH under the influence of both abiotic and biotic factors. Two successional series were clearly distinguished: the weakly acidophilous series, comprising communities of Poo compresae-Tussilaginetum farfarae, Festuco rubrae-Agrostietum capillaris and Carpino-Fagetum, and respectively the acidophilous series, comprising plant assemblages of Deschampsietum flexuosae, Pinetum sylvestris sensu lato, Festuco rubrae-Genistetum sagittalis and Vaccinio-Callunetum vulgaris. The spontaneous succession progresses towards woodland and appears to be an ecologically suitable way of restoring the studied disturbed sites, because species typical of natural and semi-natural vegetation have become dominant over time. Within our study area, spontaneous vegetation succession resulted in plant assemblages that resemble the original semi-natural vegetation.

Abstract

Plant assemblages and successional pathways were studied on large, abandoned ore mining heaps located around the open-cast pits from Roşia Montană, Romania. Four differently aged mining spoils with relatively homogenous substrate and one control plot were investigated using the chronosequence approach. The effects of the waste dump age, slope steepness, position on slope, terrain curvature and potential solar radiation on the plant species composition of different assemblages from spontaneously revegetated primary sites were evaluated. Relevés were grouped into floristically similar vegetation types using non-hierarchical cluster analysis (Fuzzy c-Means). The ecological interpretation of the plant assemblages was performed through indicator species values (IndVal) and non-metric multidimensional scaling (NMDS). This study reinforces several important concepts about the deterministic patterns of primary succession. First, the multiple comparisons between plant assemblages reveal that the highest differences are caused by the age of the spoil heap and substrate acidity. Further differences, lower but significant, are determined by terrain curvature and potential solar radiation. Also, environmental factors acting prior to the establishment of the observed plant assemblages (age, substrate pH, slope steepness and position on slope), have subsequently induced a structural differentiation in terms of species richness, vegetation cover and relative cover of the N-fixing species. There are two main possible successional pathways, determined, most likely, by the long term changes in substrate pH under the influence of both abiotic and biotic factors. Two successional series were clearly distinguished: the weakly acidophilous series, comprising communities of Poo compresae-Tussilaginetum farfarae, Festuco rubrae-Agrostietum capillaris and Carpino-Fagetum, and respectively the acidophilous series, comprising plant assemblages of Deschampsietum flexuosae, Pinetum sylvestris sensu lato, Festuco rubrae-Genistetum sagittalis and Vaccinio-Callunetum vulgaris. The spontaneous succession progresses towards woodland and appears to be an ecologically suitable way of restoring the studied disturbed sites, because species typical of natural and semi-natural vegetation have become dominant over time. Within our study area, spontaneous vegetation succession resulted in plant assemblages that resemble the original semi-natural vegetation. © 2018, Springer International Publishing AG, part of Springer Nature.

Abstract

The paper contributes to the knowledge of forest history during the Dacian Civilization, focusing on the mountainous region where the Dacian fortresses of the Orăştie Mountains were located. Some historical and archaeological evidence has been reviewed regarding the use of trees by the Dacians. Emphasis was laid on the analysis of the papers that present indirect evidence in this respect, namely the palynological sequences from the region, belonging to the period of interest, the Subatlantic. On the basis of these, it was possible to reconstruct the natural environment and especially the forest dynamics in the studied region. The palynological analyses performed demonstrate the millennial age of the forests in the area, and aim at further comparisons with the current situation of forests in the region. © 2018, Babes-Bolyai University, "Alexandru Borza" Botanic Garden. All rights reserved.