sub-Mediterranean Regions Research Articles

Socio-Economic Viability of the High Nature Value Farmland under the CAP 2023–2027: The Case of a Sub-Mediterranean Region in Slovenia

Socio-Economic Viability of the High Nature Value Farmland under the CAP 2023–2027: The Case of a Sub-Mediterranean Region in Slovenia

Podnebne projekcije temperature zraka in padavin za porečja Ledave, Pesnice in Vipave do konca 21. stoletja

As part of the project ‚CeVoTak‘, Integrated Management of Small Water Retention and Soil Erosion Prevention Measures in Agricultural Catchments, we studied changing temperature and precipitation conditions up to the year 2100. The study was conducted on agricultural lands in the catchments of the Ledava and Pesnica rivers in the sub-Pannonian region and the Vipava river in the sub-Mediterranean region. A common climate database was used to create the climate projections - RCM (Regional Climate Model) simulations from the project EURO-CORDEX and scenarios RCP (Representative Concentration Pathway), RCP2.6, 4.5 and 8.5. The projections were prepared for three time periods 2011-2040; 2041-2070 and 2071-2100 for 6 different regional climate models for average, minimum and maximum air temperatures and precipitation. Analysis of the ensemble of model simulations for all scenarios shows similar results for the basin of all rivers, an increase in temperature (maximum in winter, minimum in spring), with high confidence for all scenarios and periods. Projections of precipitation are less reliable, but show an increase in annual precipitation due to the winter increase. The use of climate change projections with expert interpretation is essential for determining the vulnerability of individual areas and building resilience through the implementation of climate change adaptation.

New floristic data of vascular plants from Bosnia and Herzegovina

Based on the field, herbarium and bibliographic research, I report distributional data for four rare plant taxa native for the sub-Mediterranean region of Bosnia and Herzegovina. It includes new records and confirmations for taxa in the genera Campanula, Cardamine, Pisum and Teucrium. New localities for Campanula portenschlagiana and Cardamine fialae are listed and the presence of two taxa Pisum sativum subsp. elatius and Teucrium flavum are confirmed for the country. In addition, a brief morphological description and photographs of these taxa are presented. The special attention was paid to the conservation categories of these taxa. C. portenschlagiana and C. fialae should be placed in the endangered category (VU) in Bosnia and Herzegovina, while P. sativum subsp. elatius and T. flavum should be classified under the Data Deficient category (DD).

Sown diversity effects on yield and resistance to weed invasion: Clues to improve mixture design under climatic change in the Mediterranean

With the aim to improve mixture design, particularly in regions vulnerable to climate change, we tested several forage communities following the biodiversity–ecosystem function (BEF) framework. We sowed monocultures and 4-species mixtures from a pool of 7 forage species in a sub-Mediterranean region (Eastern Pyrenees) and assessed the diversity effects on yield and resistance to weed invasion. The tested species included two grasses and five legumes with contrasting temporal patterns and different climatic amplitudes. The communities differed in their specific composition (mixture types) and the relative abundance of the components, following a simplex design, which allowed us to estimate separately the two components of the diversity effect: the individual species effects and that due to species interactions. Whereas monocultures performed in a highly variable way within and across harvests, both in relation to yield and weed suppression, mixture variability was narrower. Both functions increased in mixtures (with significant interaction effects between 24% and 57% for yield and 13% and 96% for weed suppression), especially in those mixtures including Mediterranean species, which showed the highest diversity effects that persisted over the three experimental years. Extreme climatic events during the experimental period might have affected not only the species’ individual performances but also the strength of species interactions. Both components of diversity, identities and interactions, were key in maintaining high performances. We conclude that, under the current climate change scenario, it is important to include species in mixtures that increase resistance or resilience not only at the species level but also at the community level, through enhanced interaction effects.

RHYSOGENESIS OF LAVANDULA ANGUSTIFOLIA AND PECULIARITIES OF ROOTED PLANT DEVELOPMENT

Lavandula angustifolia has a great economic importance in perfumery, cosmetics, food manufacturing, aromatherapy, and pharmaceutical industry. This species finds its phytosociological optimum in the sub-Mediterranean region. Latitudinal and altitudinal gradients are expected to affect species diversification in peripheral alpine populations. In this study, phenotypic traits including morphometric parameters, volatile organic compounds and essential oils were analyzed in lavender peripheral populations selected in order to explore different ecological conditions. Plants were cultivated under uniform conditions to observe variations due to the genetic adaptation to native environments and to exclude the short-term response to environmental factors. According to the research, the peculiarities of the regenerative ability of Lavandula angustifolia lavender, which was propagated vegetatively by grafting, were established. Also, the influence of stimulating drugs for rooting, namely, treatment of cuttings with their solutions (Charcor, Heteroauxin, Emistim C, Epin-extra) was determined. The percentage of rooting cuttings of lavender narrow-leaved depending on the type of growth regulator. The influence of growth of regulating preparations for plants on specificity of formation of such morphometric indicators of rooted cuttings, as the linear sizes of an above-ground part, number and the linear sizes of the formed roots is carried out. These morphometric indicators are the basis for improving the efficiency of the vegetative method of propagation of lavender. This creates a prerequisite for the widespread use of ornamental plants, including lavender, for the needs of landscaping by simplifying the receipt of a sufficient amount of high quality planting material. After all, vegetative reproduction involves the preservation of all decorative features and properties of the mother plant. The issue of meeting the needs of the domestic market with the required amount of planting material of plants adapted to the soil and climatic conditions of the area remains extremely relevant. Improving the existing technological parameters of vegetative propagation of narrow-leaved lavender through the use of growth-regulating preparations for plants makes it possible to obtain high-quality and viable planting material. And this is a very important practical issue of ornamental nurseries, which requires careful study and analysis from a scientific point of view.

The effect of bedrock and species mixture on wood density and radial wood increment in pubescent oak and black pine

Wood density and radial wood increment were examined in trees of pubescent oak (Quercus pubescens Willd.) and black pine (Pinus nigra Arnold., subsp. nigra) in relation to stand mixture and underlying bedrock. Trees of both species from pure and mixed stands were sampled across two types of bedrock, limestone and flysch. Trees from each species were similar in age. Wood density was estimated in standing trees using resistance drilling and increment cores were taken from a smaller subsample of trees of both species. Tree-ring, earlywood and latewood widths were measured and compared to radial profiles of wood density. The influence of stand mixture, diameter at breast height and bedrock on wood density was examined using a Bayesian general linear model. Wood density was significantly higher in pubescent oak than in black pine. Stand mixture was found to affect wood density positively, although the magnitude of the effect was relatively small when compared to other influencing factors also included in the current study. The effect of diameter on wood density was positive on both bedrocks in pubescent oak and negative or neutral in black pine. The size of the effect varied by bedrock and species. On flysch bedrock, the influence of diameter on wood density was stronger than it was on limestone. These indirect bedrock effects on wood density are probably a result of different soil fertility rather than the bedrock itself. There was a notable difference in radial wood increment in both species across the two bedrocks, whereas the differences in densities were smaller. Higher wood densities found on flysch in the subsample of pubescent oaks are likely an effect of higher proportions of latewood, while the opposite trend was observed in black pine. Higher wood density was found on limestone in black pine despite higher latewood percentages on flysch. In the context of forest management, the species composition of the naturally occurring mixtures in the sub-Mediterranean region should be adjusted slightly to favor pubescent oak, since it is a climax species and will bind more carbon for longer than black pine due to higher wood densities. Future forest management should also promote the overall development of pubescent oak trees in sub-Mediterranean stands. The results are especially important in the European context, because the share of sub-Mediterranean stands is expected to rise with global warming.

Timeline of Leaf and Cambial Phenology in Relation to Development of Initial Conduits in Xylem and Phloem in Three Coexisting Sub-Mediterranean Deciduous Tree Species

It is unclear how the anticipated climate change will affect the timing of phenology of different tree organs/tissues and thus the whole-tree functioning. We examined the timing of leaf phenology and secondary growth in three coexisting deciduous tree species (Quercus pubescens Willd., Fraxinus ornus L. and Ostrya carpinifolia Scop) from a sub-Mediterranean region in 2019. In addition, we investigated the relationship between leaf and cambial phenology and the onset of the potential functioning of initial conduits, as determined by the completed differentiation process (vessels) or final size (sieve tubes). For this purpose, leaf development was monitored and the microcores of cambium and the youngest phloem and xylem increments were repeatedly collected at 7–10-day intervals during the growing season. The results revealed differences in the timing of leaf development and seasonal radial growth patterns in spring among the studied tree species, depending on wood porosity. We found that cambial cell production started in all cases in the first half of March. However, in ring-porous Q. pubescens and F. ornus, radial growth in the stem occurred more than a month before buds were swollen, whereas in diffuse-porous O. carpinifolia, these two events were detected at almost the same time. The end of cambial cell production occurred earliest in F. ornus (mid-July) and two weeks later also in the other two species. The widest initial earlywood vessels and early phloem sieve tubes were found in Q. pubescens, the narrowest initial earlywood vessels in O. carpinifolia and the narrowest early phloem sieve tubes in F. ornus. This indicates differences in the efficiency of conducting systems among the studied species. This novel approach of studying phloem phenology and anatomy in relation to leaf and xylem development contributes to a better understanding of how different tree species adapt their structure of secondary vascular tissues in response to environmental change.

Screening of leaf metabolites in historical mulberry trees (Morus alba L.) from different eco-geographical regions of Slovenia

The article presents the existing genetic resources of historical mulberry trees in Slovenia and reveals that pruning management and geographical distribution exhibit significant effect on certain biochemical traits. Former sericultural regions in Europe retained a number of centuries-old white mulberry (Morus alba L.) trees, which represent both, a valuable natural heritage and outstanding monuments of the very early attempts to establish a European sericulture, since their leaves were traditionally used to feed the silkworm larvae (Bombyx mori L.). The aim of the presented research was to collect data regarding eco-geographical locations of historical mulberry trees in Slovenia and to screen the content of the main metabolites in leaves to determine genotypes of local origin which are superior in individual compounds defined as feed markers. During field excursions, the highest number of mulberry trees was recorded in the Submediterranean region, followed by the Subpannonean, South-Eastern region and Central Slovenia. Pruning recordings revealed that pollarding is traditionally used in the Submediterranean region. The main phenolic compounds identified in leaves were caffeoylquinic acid derivatives, quercetin malonylhexoside, rutin, kaempferol acetylhexoside and isoquercetin. Pruning significantly affected the levels of total protein and quercetin dirhamnosylhexoside, which were higher in the annually pruned trees. Geographical distribution has a significant effect on total proteins as well as on total phenolics, caffeoylquinic acid derivatives and flavonols. Linear discriminant analysis enabled a comprehensive assessment of leaf metabolites and confirmed that mulberries of different Slovenian regions have distinctive biochemical traits. We were able to recognize caffeoylquinic acid, quercetin malonylhexoside, rutin, kaempferol acetylhexoside and isoquercetin as valuable feed markers with respect to their known beneficial effect on silkworm larvae growth and cocoon quality. By reviewing the existing mulberry genetic resources and their leaf metabolites, we highlighted the natural, cultural and scientific value of the white mulberry.

Geographic variation of Pinus heldreichii Christ from the Western Balkans based on cone and seed morphology

Pinus heldreichii (Bosnian pine) is a Balkan-Apennine endemic and relict pine species that inhabits high mountains in the Mediterranean and sub-Mediterranean regions. Nineteen populations of P. heldreichii from the Western Balkans encompassing 187 individual trees were examined to evaluate morphological variation, a rarely studied aspect of the species. Univariate and multivariate statistics were applied in order to assess the variation of morphological traits of cones and seeds, evaluate the relationships among the sampled populations and verify geographic differentiation in the Dinaric Alps versus Scardo-Pindic mountains. The observations of P. heldreichii covering the populations from the western margins and the centre of the species distribution range indicated a morphological variation among populations and their geographic structure. In general, the southern populations (Scardo-Pindic group) had lower values for the most of morphological traits than the northern ones (Dinaric group). The observed geographic differences between these populations exhibit a north-western to south-eastern gradient, with a few inconsistencies. The southernmost sampled population, Tomorr in Albania, showed remarkable morphological divergence from the other studied populations and appeared to be a distinct morphological group. The pattern of morphological variation in Bosnian pine most likely resulted from multiple effects of long-term isolation and fragmentation in high mountain systems, adaptation to extreme environments and human disturbances.

Site Index and Volume Growth Percentage Determination for Privately Owned Uneven-aged Stands of Quercus pubescens and Quercus ilex along the Croatian Adriatic Coast

Background and Purpose: Although organized forestry has existed in Croatia for more than 250 years, this mostly entailed state forests. During the last decade, Extension Services have started to support the development of forest management plans for privately owned forests. Lately, FMPs have been developed for nearly 3/4 of privately owned forests in Croatia. During the creation of those plans, yield tables and normal models for state-owned forests, primarily even-aged stands with long-time management, were used because similar data was not developed for uneven-aged and poorly managed forests. This research encompasses privately owned forests in the Croatian Mediterranean and sub-Mediterranean regions where holm oak ( Quercus ilex L.) and downy oak ( Quercus pubescens Willd.) are the prevailing species in forest stands. The main goal was to determine site indices revealed in the analysis of yearly radial increments and to create relevant yield tables. Materials and Methods: In this study, 1286 oak trees were cored to the centre on 377 locations spread in privately owned forests in Croatian Mediterranean and sub-Mediterranean regions. The ratio of trees and locations was approximately 3:1 for Q. pubescens. Some cored trees were more than two centuries old. After the standard sample preparation for dendrochronological analysis, cores were scanned, and tree-ring widths were determined. In total, ring width for over 67,000 rings was determined and measured. Results: Based on the data dispersion of cumulative tree increments at 40 years of age, 2 site index classes for Q. ilex and 3 for Q. pubescens were created based on k-means clustering. Prodan’s growth function was fitted to the created clusters to determine the site’s “model” tree. For the model trees, the percentage of volume growth was calculated. For easier field site index determination, height curves based on field data for each site index were calculated. Conclusions: For the first time in Croatia, systematic and controlled data on the growth (and age) of uneven-aged privately owned forests in the Croatian Mediterranean and sub-Mediterranean area were collected. Based on the data collected in the field, three different site indices for downy oak and two site indices for holm oak were determined. These results could find their application during operational forest management and forest exploitation because they allow for more accurate determination of the site production strength in the explored stands.

Effect of soil water availability on intra-annual xylem and phloem formation and non-structural carbohydrate pools in stem of Quercus pubescens.

Non-structural carbohydrates (NSCs, i.e., starch and soluble sugars) are frequently quantified in the context of tree response to stressful events (e.g., drought), because they serve as a carbon reservoir for growth and respiration, as well as providing a critical osmotic function to maintain turgor and vascular transport under different environmental conditions. We investigated the impact of soil water availability on intra-annual leaf phenology, radial growth dynamics and variation in NSC amounts in the stem of pubescent oak (Quercus pubescens Willd.). from a sub-Mediterranean region. For this purpose, trees growing at two nearby plots differing in bedrock and, consequently, soil characteristics (F-eutric cambisol on eocene flysch bedrock and L-rendzic leptosol on paleogenic limestone bedrock) were sampled. Non-structural carbohydrates were analysed in outer xylem and living phloem (separately for non-collapsed and collapsed parts). Results showed that xylem and phloem increments were 41.6% and 21.2%, respectively, wider in trees from F plot due to a higher rate of cell production. In contrast, the amount of NSCs and of soluble sugars significantly differed among the tissue parts and sampling dates but not between the two plots. Starch amounts were the highest in xylem, which could be explained by the abundance of xylem parenchyma cells. Two clear seasonal peaks of the starch amount were detected in all tissues, the first in September-November, in the period of leaf colouring and falling, and the second in March-April, i.e., at the onset of cambial cell production followed by bud development. The amounts of free sugars were highest in inner phloem + cambium, at the sites of active growth. Soil water availability substantially influenced secondary growth in the stem of Q. pubescens, whereas NSC amounts seemed to be less affected. The results show how the intricate relationships between soil properties, such as water availability, and tree performance should be considered when studying the impact of stressful events on the growth and functioning of trees.

Latitude and Altitude Influence Secondary Metabolite Production in Peripheral Alpine Populations of the Mediterranean Species Lavandula angustifolia Mill.

Lavandula angustifolia Mill. has a great economic importance in perfumery, cosmetics, food manufacturing, aromatherapy, and pharmaceutical industry. This species finds its phytosociological optimum in the sub-Mediterranean region. Latitudinal and altitudinal gradients are expected to affect species diversification in peripheral alpine populations. In this study, phenotypic traits including morphometric parameters, volatile organic compounds (VOCs) and essential oils (EOs) were analyzed in lavender peripheral populations selected in order to explore different ecological conditions. Plants were cultivated under uniform conditions to observe variations due to the genetic adaptation to native environments and to exclude the short-term response to environmental factors. Results showed qualitatively and quantitatively intra-specific variations in secondary metabolites, mainly along the latitudinal gradient, while minor effect was attributable to the altitude. This latter affected more the morphometric parameters. As the latitude augmented, VOCs showed lower content of monoterpene hydrocarbon (mh) and higher content of oxygenated monoterpenes (om); whereas EOs showed higher content of mh and non-terpene derivatives (nt) and lower content of sesquiterpene hydrocarbons (sh). Lavender aroma and EO composition varied in every population, for a total of 88 and 104 compounds identified, respectively. Eleven and 13 compounds were responsible for 95% of the dissimilarity, with linalool, linalyl acetate and 1,8-cineole as major contributors. As the latitude augmented, linalool decreased and 1,8-cineole increased while linalyl acetate content was unaffected. These results are discussed with regards to the potential adoption of the lavender peripheral alpine populations for the improvement of quality and productivity of lavender cultivations, especially in mountainous areas.

New belemnites (Megateuthididae, Cylindroteuthididae) from the Bajocian and Bathonian of the Yuryung-Tumus Peninsula, northern Siberia, Russia and their palaeobiogeographic implications

New species of Paramegateuthis (Megateuthididae) and Cylindroteuthis (Cylindroteuthididae) are described from the Bajocian–Bathonian boundary interval of the Yuryung-Tumus Peninsula, northern Siberia, Russia. Additionally, Paramegateuthis subishmensis Stoyanova-Vergilova, 1983, first documented from the Sub-Mediterranean region, is described herein from the Arctic. We propose the presence of a temporary passage between the Boreal and Tethyan seas in the European part of Russia during the Early Bajocian Humphriesianum Chronozone as an explanation of the migration of P. subishmensis. New belemnite records from the Yuryung-Tumus section contribute to the palaeontological characteristics of the Arctic domain.

Annual reproductive activity of ewes from Jezersko-Solchava, Bovec and Istrian breeds under variable field conditions

The aim of this study was to establish the time course of the annual reproductive cycle in ewes of the Jezersko-Solchava, Bovec and Istrian breeds (n=24, 8 of each breed) with various production features in the sub-Mediterranean region under field conditions. The ewes were followed over a period of 2.5 years, starting at the age of 3 months. Serum progesterone concentrations used for the evaluation of ovarian activity were measured twice monthly with a 10-day interval. The studied ewes displayed a general pattern of annual reproductive activity known for sheep breeds of moderate latitudes, correlating negatively with photoperiod (P<0.0001), but some differences were observed between them regarding puberty onset and the resumption of ovarian activity after lambing. In the Jezersko-Solchava and Bovec breeds, puberty started in the first autumn after their birth, at the average ages of 7.7±1.4 and 8.5±1.5months, respectively. The majority of the Istrian ewes entered puberty in the following autumn, at the age of 18 months, confirming the late sexual maturity of this breed. Ovarian activity continued until the early spring, lasting on average 3.9±0.6 moths in Jezersko-Solchava, 4.0±0.6months in Bovec and 3.7±0.6months in Istrian ewes.Breeding season in mature Jezersko-Solchava and Bovec ewes started in early autumn and ended rapidly with pregnancies in all studied ewes of these breeds. Spring lambing in mature Jezersko-Solchava ewes was followed by the resumption of ovarian activity in June 2011, indicating an early timing of the breeding season in this sheep breed. Pregnancies in Jezersko-Solchava ewes were confirmed from August 2011 on with a 100% pregnancy rate in October 2011. Ovarian activity was detected in August 2011 in 75% of the Bovec ewes and 100% of the Istrian ewes. In November 2011, all of the Bovec ewes were pregnant, while in Istrian ewes, pregnancy rate only reached 75%. Our results indicate important differences in the patterns of annual reproductive activity in various native sheep breeds that are bred under identical environmental and geographical conditions.

Growth dynamic of three different white willow clones used in a zero-discharge wastewater treatment system in the sub-Mediterranean region – an early evaluation

Growth dynamic of three different white willow clones used in a zero-discharge wastewater treatment system in the sub-Mediterranean region – an early evaluation

First records of six ant species (Hymenoptera: Formicidae) for Slovenia

Six ant species recorded for the first time in Slovenia are presented: Camponotus gestroi, Hypoponera eduardi, Lasius lasioides, Tapinoma cf. nigerrimum, Temnothorax jailensis and Temnothorax turcicus. They were found in the period of the last 9 years, five of them in southwestern Slovenia in the Submediterranean region, while T. turcicus was recorded in northeastern Slovenia. Findings of C. gestroi and T. jailensis considerably extend their previously known ranges in Europe.

Assessing escapes from short rotation plantations of the invasive tree species Robinia pseudoacacia L. in Mediterranean ecosystems: a study in central Italy

Abstract: Black locust (Robinia pseudoacacia L.) is a fast growing tree species native to temperate North America, and widely diffused and naturalized in Europe. It is one of the candidate species for establishing bioenergy plantations on marginal lands in temperate and sub-Mediterranean regions. This potential is in contrast to its well-known invasive habit, leading to a potential damage to plant biodiversity in many European countries. Advise against black locust plantation in regions where it is already invasive has been issued by several international reports, as well as the adoption of mitigation measures (e.g., “containment” buffer zones) to prevent the spread of the species into natural and semi-natural habitats. In the Mediterranean basin, however, no studies have been carried out aimed at quantifying the escape rate of black locust saplings from plantation stands and its recruitment into natural habitats, together with the effectiveness of a buffer zone in reducing the spread. In this study we investigated the spread of black locust along 35 transects surrounding three 20-year- old plantations and including three different land cover types: abandoned arable land, semi-natural woodland and a buffer zone (orchards) with a low degree of farming input. In addition, the effect of soil disturbance on seed propagation was investigated. Our results demonstrate that the density of black locust regeneration is strongly affected by the land cover, abandoned agricultural land being the most prone to black locust colonization. Contrastingly, the spread was minimal in the buffer zone and negligible in semi-natural woodland. During the investigated year, seed generative propagation was also negligible. The semi-natural woodland seems to resist well to black locust invasion, though further observations are needed to assess the consequences of stand harvesting disturbance as well, according to local standard forest management. Buffer zones seem to be very effective in controlling black locust invasion. Best management practices, with active farming inputs, are also discussed.

SENSITIVITY OF LAND TO CLIMATE CHANGE AND SUSTAINABLE DEVELOPMENT IN THE SUBMEDITERRANEAN KARST AREA OF BOSNIA AND HERZEGOVINA

UDK 631.4:551.583(497.6)&#x0D; The value of the landscape in the karst region of Bosnia and Herzegovina (B&amp;H) is the foundation of its existence and the key role in its appearance and formation is played by geomorphology and the soil. Through history the man has created a „cultural landscape” which is completely adapted to the natural conditions. He further enriches the space and makes it more appealing. Soils in B&amp;H karst are extremely heterogeneous and form a real pedological mosaic. Found on the Mesozoic sediments of limestone and dolomite of the Middle and Upper Jurassic and Early and Late Cretaceous are Bare rocks (barren land), Rocky grounds (Lithosol), Limestone-dolomite Black soil (Calcomelanosol) and Brown soil on limestone and dolomite (Calcocambisol). A specificity of these rocks are the screes that are transported down the hillside. A series may occur on them in which, if shale materials are contained, Rendzina appears as a calcareous soil. In addition to the above mentioned limestone and dolomite, there are marly limestones of Jurassic and Cretaceous age and Quaternary sediments on which Alluvial soils (Fluvisol) developed as well as the soils of karst fields which are sometimes very porous and skeletal and sometimes heavy and clayey on impermeable substrate (hydromorphic soils).&#x0D; The paper will provide an overview of characteristic soil types in the Sub-Mediterranean upper and lower karst region of B&amp;H taking into account a range of properties that make them sensitive and vulnerable within the ecosystem. These should include a lack of water on the surface and large fluctuations in the amount of water during the rainy and dry seasons and whimsicality of climate in general, which has a huge impact on the state of biodiversity and human lives in this region.

Short communication: Effects of summer rainfall variations on sheep body state and farming sustainability in sub-Mediterranean pastoral systems

In sub-Mediterranean climate the grassland aboveground phytomass production peaks in late spring and drops in summer, when the decrease of the pasture feed value may lead to the worsening of the animal welfare. Our goal was to define the summer rainfall values leading to a decrease of semi-extensive farming system sustainability in sub-Mediterranean regions. Summer rainfall variations reflect in the aboveground phytomass production and on the sheep body state. Differences of body condition score (BCS) among years were significant in late summer, which is the mating period for sheep. In the driest year the BCS of end August drops down to 2.1, largely below the value considered sufficient to ensure the animal breeding/milking performances (2.5). Reduction of summer rainfall greater than 15–20% compared to the normal average value (thus less than expected by the scenario of climate change) might be detrimental for semi-extensive rearing sustainability in sub-Mediterranean climate.

Carbon and water flux patterns of a drought-prone mid-succession ecosystem developed on abandoned karst grassland

Successional ecosystems developed spontaneously on agricultural lands cover a substantial area worldwide, particularly in Europe and North America. The functioning of these ecosystems in terms of carbon and water fluxes remains fairly under-investigated. Here, carbon and water exchanges of a spatially heterogeneous tree-shrub-grassland mosaic developed on former semi-dry calcareous grassland in the sub-Mediterranean region of Slovenia were studied. Using eddy covariance, the annual, seasonal and daily dynamics of net ecosystem exchange (NEE) and water vapor exchange were examined, together with their environmental controls during the period August 2008–December 2012. Over this period, the ecosystem appeared to be a carbon sink but the annual carbon fixation had a span of more than four-fold, from 82 to 351gCm−2yr−1. This variability was largely explained by different durations of drought events that occurred during the summer despite the high and relatively evenly distributed rainfall. This is related to the poor ecosystem rain use efficiency, only 0.10–0.35gCm−2yr−1 was taken up per mm of rain and the estimated deep water drainage ranged between 44 and 72% of the incoming rain. Drought periods were identified by deriving the critical soil water content (SWC) (here 0.145m3m−3) at which evapotranspiration and carbon fluxes started to be limited by water availability. The estimated annual gross primary productivity was shown to be linearly dependent on the duration of the longest annual drought period and not on the drought intensity. Despite a severe drought in the summer of 2012, the ecosystem proved quite resilient to drought stress and restored its carbon uptake after several rain events. As shown by the light response curves, the light dependency of carbon exchange was affected by seasonality and environmental factors, particularly SWC, vapor pressure deficit (VPD) and air temperature (Ta). Interaction between the factors was also observed; negative effect of low SWC was significantly enhanced in the conditions of higher Ta or higher VPD.