Nutritional Quality of Herbaceous Vegetation in a Phryganic Mediterranean Ecosystem During the Grazing Period

Grazing is an economically and environmentally valuable activity in phryganic Mediterranean ecosystems. The herbaceous vegetation of these ecosystems provides an essential feed source for grazing ruminants. Despite the extension and economic importance of phryganic ecosystems in Mediterranean Basin there has been relatively little scientific focus on nutritional quality of their herbaceous vegetation. The nutritional quality of herbaceous vegetation in a phryganic ecosystem was assessed for two consecutive years during the grazing period (March to July). Herbage samples were analysed for chemical composition, metabolizable energy, in vitro dry matter digestibility, in vitro neutral detergent fiber digestibility and mineral content (Ca, P, K, Mg) at monthly basis. According to the results time of harvest significantly affected crude protein, neutral detergent fiber, acid detergent fiber, lignin and the content of minerals (i.e. Ca, P, Mg, K). Mean monthly temperature found to have a great negative impact on nutritional quality. During the grazing period, the nutritional quality of herbage vegetation was strongly correlated with growing degree days. Over a threshold of about 700 growing degree days the nutritional quality of herbage dramatically decreased. Overall the current study provides crucial information for the nutritional dynamics of the herbage vegetation of the phryganic Mediterranean ecosystems that can be towards developing an efficient grazing strategy

Synergistic Effect of Selenium Addition and Water Stress on Melilotus officinalis L. Mineral Content

The objective of this study was to examine the combined effects of selenium (Se) enrichment and water stress on the accumulation of available macro- and micronutrients in Melilotus officinalis L. aerial parts. Plants of M. officinalis were subjected to three levels of Se addition (0, 1 and 3 mg Se L-1 water) and to two water treatments: a) full irrigation and b) limited irrigation (water stress). The above ground biomass (stems and leaves) was analyzed for Se, potassium (K), sodium (Na), magnesium (Mg), iron (Fe), copper (Cu), calcium (Ca), manganese (Mn) and zinc (Zn). Se addition differentially affected the K, Mg and Ca content of M. officinalis aerial parts, while it led to the reduction of the micronutrients Cu, Fe and Mn. Water stress resulted in the increase of K, Na, Mg, Ca and Cu, and to the decrease of the Fe, Zn and Mn content. An interaction between selenium addition and water treatment was more notable for Ca and Mg, which decreased under water stress at low Se level and for Zn and Cu, which increased under water stress at high Se level. According to our findings, Se-induced increased accumulation of some inorganic ions in the aerial parts of this species under water stress conditions could serve as a means to alleviate the adverse impact of water deficit on important metabolic processes, enhancing M. officinalis tolerance to water stress

Ecological restoration across the Mediterranean Basin as viewed by practitioners

Restoration efforts in the Mediterranean Basin have been changing from a silvicultural to an ecological restoration approach. Yet, to what extent the projects are guided by ecological restoration principles remains largely unknown. To analyse this issue, we built an on-line survey addressed to restoration practitioners. We analysed 36 restoration projects, mostly from drylands (86%). The projects used mainly soil from local sources. The need to comply with legislation was more important as a restoration motive for European Union (EU) than for non-EU countries, while public opinion and health had a greater importance in the latter. Non-EU countries relied more on non-native plant species than EU countries, thus deviating from ecological restoration guidelines. Nursery-grown plants used were mostly of local or regional provenance, whilst seeds were mostly of national provenance. Unexpected restoration results (e.g. inadequate biodiversity) were reported for 50% of the projects and restoration success was never evaluated in 22%. Long term evaluation (> 6 years) was only performed in 31% of cases, and based primarily on plant diversity and cover. The use of non-native species and species of exogenous provenances may: i) entail the loss of local genetic and functional trait diversity, critical to cope with drought, particularly under the predicted climate change scenarios, and ii) lead to unexpected competition with native species and/or negatively impact local biotic interactions. Absent or inappropriate monitoring may prevent the understanding of restoration trajectories, precluding adaptive management strategies, often crucial to create functional ecosystems able to provide ecosystem services. The overview of ecological restoration projects in the Mediterranean Basin revealed high variability among practices and highlighted the need for improved scientific assistance and information exchange, greater use of native species of local provenance, and more long-term monitoring and evaluation, including functional and ecosystem services' indicators, to improve and spread the practice of ecological restoration

Post-planting treatments and shading effects in a Fraxinus angustifolia Vahl. silvopastoral system

<span>Silvopastoral systems present difficulties in their management due to their complexity. When trees are planted into grasslands, they need protection from livestock to prevent damage from trampling or browsing, especially during early years of establishment. One of the common post-planting protective treatments is the protection of individual trees with shelters. Trees also need protection from competition from herbaceous vegetation. The aim of present study was to evaluate the effects of using different types of tree shelters and of controlling competing herbaceous vegetation on the growth of planted young trees and, to assess the effects of heavy shading on the herbage production and composition. The study was conducted in a </span><em>Fraxinus angustifolia</em><span> silvopastoral system of a 2 x 2.5 m spacing plantation in northern Greece. The effects of solid-walled (tubex and handmade by greenhouse nylon) and wire mesh tree shelters as well as of herbicide application and mechanical removal of the competing herbaceous vegetation on tree height, height increment and the crown surface area of the trees were tested. The effects of artificial shading (80%) on the production of the natural herbaceous vegetation were also investigated. All measurements were recorded three years after plantation. The use of solid wall tubex shelters resulted in higher tree height and higher crown surface area in comparison to the other tested shelters. The solid wall Nylon shelters were more beneficial to the above growth parameters than the wire mesh ones. Both vegetation control treatments proved beneficial to all the growth parameters of </span><em>Fraxinus angustifolia</em><span>. The artificially applied heavy shading reduced herbage production by 54% compared to the control. The results indicated that post planting treatments in the Mediterranean droughty conditions are essential for the success of this tree species establishment. Furthermore, the later thinning of the dense spacing is important to maintain high herbage production. </span

Soil Properties and Plant Community Changes along a Goat Grazing Intensity Gradient in an Open Canopy Oak Forest

Understanding how the management practices of silvopastoral systems affect the long-term sustainability of oak ecosystems and what their influence is on nutrient cycling and plant community, is of great interest. The aim of this study was to examine the effects of relative grazing intensity on soil properties and on vegetation characteristics in an open canopy oak forest dominated by Quercus frainetto. The research was conducted in the area of Pentalofos, which is located in Evros region, north-eastern Greece and is grazed by goats. The distance from a goat corral was used to represent relative grazing intensity. In June 2011, soil and vegetation samples were collected along transects placed at 50, 150, 300, 600 and 1200 m from the goat corral, running perpendicular to three replicates. Soil measurements included pH, phosphorous (P) and nitrogen (N) concentrations while vegetation measurements included plant cover, species composition and diversity. Plant cover was not significantly different among grazing intensities. Species diversity, especially of the woody vegetation layer, was significantly higher in the light grazing intensity in comparison to both the heavy and the very light grazing. Heavy grazing reduced soil organic matter while it increased total nitrogen. Grazing intensity did not affect available P and soil pH. Light to moderate goat grazing could ameliorate floristic diversity and increase sustainability of oak forests in the Mediterranean region

Soil Properties and Plant Community Changes along a Goat Grazing Intensity Gradient in an Open Canopy Oak Forest

Understanding how the management practices of silvopastoral systems affect the long-term sustainability of oak ecosystems and what their influence is on nutrient cycling and plant community, is of great interest. The aim of this study was to examine the effects of relative grazing intensity on soil properties and on vegetation characteristics in an open canopy oak forest dominated by Quercus frainetto. The research was conducted in the area of Pentalofos, which is located in Evros region, north-eastern Greece and is grazed by goats. The distance from a goat corral was used to represent relative grazing intensity. In June 2011, soil and vegetation samples were collected along transects placed at 50, 150, 300, 600 and 1200 m from the goat corral, running perpendicular to three replicates. Soil measurements included pH, phosphorous (P) and nitrogen (N) concentrations while vegetation measurements included plant cover, species composition and diversity. Plant cover was not significantly different among grazing intensities. Species diversity, especially of the woody vegetation layer, was significantly higher in the light grazing intensity in comparison to both the heavy and the very light grazing. Heavy grazing reduced soil organic matter while it increased total nitrogen. Grazing intensity did not affect available P and soil pH. Light to moderate goat grazing could ameliorate floristic diversity and increase sustainability of oak forests in the Mediterranean region

Predicting Tree Species Diversity Using Geodiversity and Sentinel-2 Multi-Seasonal Spectral Information

Measuring and monitoring tree diversity is a prerequisite for altering biodiversity loss and the sustainable management of forest ecosystems. High temporal satellite remote sensing, recording difference in species phenology, can facilitate the extraction of timely, standardized and reliable information on tree diversity, complementing or replacing traditional field measurements. In this study, we used multispectral and multi-seasonal remotely sensed data from the Sentinel-2 satellite sensor along with geodiversity data for estimating local tree diversity in a Mediterranean forest area. One hundred plots were selected for in situ inventory of tree species and measurement of tree diversity using the Simpson&rsquo;s (D1) and Shannon (H&prime;) diversity indices. Four Sentinel-2 scenes and geodiversity variables, including elevation, aspect, moisture, and basement rock type, were exploited through a random forest regression algorithm for predicting the two diversity indices. The multi-seasonal models presented the highest accuracy for both indices with an R2 up to 0.37. In regard to the single season, spectral-only models, mid-summer and mid-autumn model also demonstrated satisfactory accuracy (max R2 = 0.28). On the other hand, the accuracy of the spectral-only early-spring and early-autumn models was significant lower (max R2 = 0.16), although it was improved with the use of geodiversity information (max R2 = 0.25)

Retrieval of Leaf Area Index Using Sentinel-2 Imagery in a Mixed Mediterranean Forest Area

Leaf area index (LAI) is a crucial biophysical indicator for assessing and monitoring the structure and functions of forest ecosystems. Improvements in remote sensing instrumental characteristics and the availability of more efficient statistical algorithms, elevate the potential for more accurate models of vegetation biophysical properties including LAI. The aim of this study was to assess the spectral information of Sentinel-2 MSI satellite imagery for the retrieval of LAI over a mixed forest ecosystem located in northwest Greece. Forty-eight field plots were visited for the collection of ground LAI measurements using an ACCUPAR LP-80: PAR &amp; LAI Ceptometer. Spectral bands and spectral indices were used for LAI model development using the Gaussian processes regression (GPR) algorithm. A variable selection procedure was applied to improve the model&rsquo;s prediction accuracy, and variable importance was investigated for identifying the most informative variables. The model resulting from spectral indices&rsquo; variables selection produced the most precise predictions of LAI with a coefficient of determination of 0.854. Shortwave infrared bands and the normalized canopy index (NCI) were identified as the most important features for LAI prediction

Phenotypic variation of Lotus corniculatus L. natural populations in relation to habitat type and management regimes

Lotus corniculatus is a highly diverse legume with good adaptability to different soil and climatic conditions. The objective of this research was to estimate the phenotypic diversity of individual L. corniculatus plants growing under two different habitat types with different grazing management. The collection of plant material was conducted in four forested and four open grassland sites in northern Greece. Plants from open grassland had significantly lower leaf area, leaf perimeter, leaf length, leaf width and internode length compared to those from the forest. This morphological differentiation could be contributed to by differences in grazing intensity. Plants from open grasslands had significantly higher total phenols and condensed tannins, but lower crude protein content compared to those from the forest. Environmental factors in association with grazing management are the main contributors to the highly divergent concentrations of phenols, tannins and condensed tannins

Effects of Ski-Resort Activities and Transhumance Livestock Grazing on Rangeland Ecosystems of Mountain Zireia, Southern Greece

The objective of the present study was to assess the impacts in time of the ski-resort infrastructure and transhumance livestock grazing on floristic composition, diversity, and rangeland health indices related to ecosystem stability and function. The study was carried out at a site under the pressure of ski resorts and livestock grazing (Ano Trikala) and a site only under the pressure of livestock grazing (Sarantapicho), both located at Mt Zireia, Southern Greece. The plant cover was measured at each site, and the floristic composition was calculated and classified into four functional groups: grasses, legumes, forbs, and woody species. Species richness, ecosystem function and stability landscape indices, diversity indices, and forage value were calculated. According to the results, the development of the ski resort in Ano Trikala had a neglectable negative impact on plant cover (reduced by 5%), while it had a minor impact on species richness and floristic diversity. Livestock grazing had a positive impact on maintaining plant cover in high values. These results suggest that livestock grazing can counterbalance the effects of ski resorts and related activities on plant cover and floristic diversity. Besides the relatively limited effects on the vegetation community, the ski resort significantly negatively impacted landscape composition, function, and stability. Forage value was 25% lower close to the ski resort, mainly due to the significantly lower percentage of legumes. Transhumance livestock grazing should be used as a management tool in ski-resort areas, as it benefits floristic diversity