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Authors = Michael Vrahnakis ORCID = 0000-0001-9079-3697

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25 pages, 1223 KiB  
Review
The Impact of Cattle Grazing on Shrub Biomass: A Review on Temperate Ecosystems
by Dimitrios Oikonomou, Maria Yiakoulaki, Yannis Kazoglou, Michael Vrahnakis and Gavriil Xanthopoulos
Land 2025, 14(6), 1277; https://doi.org/10.3390/land14061277 - 14 Jun 2025
Viewed by 735
Abstract
Cattle grazing is particularly important to natural and semi-natural ecosystems, having often replaced grazing by smaller domestic ruminants such as goats and sheep. While cattle are mainly considered grazers rather than browsers, the pressures, direct or indirect, they exert on shrub encroachment are [...] Read more.
Cattle grazing is particularly important to natural and semi-natural ecosystems, having often replaced grazing by smaller domestic ruminants such as goats and sheep. While cattle are mainly considered grazers rather than browsers, the pressures, direct or indirect, they exert on shrub encroachment are significant. Thus, their grazing and browsing activities can often be considered complementary to ecosystem management, especially in landscapes characterized by shrub presence and frequent wildfires. Several factors may influence the impact of cattle browsing, including the stocking rate, the specific breed of cattle, and their adaptation to the respective ecosystem, as well as the particular type of ecosystem. This review examines the impact of cattle browsing on shrubs across various temperate ecosystems. Findings indicate that cattle usually consume only 5–10% of woody forage, but exceptional browsers like Highland cattle can consume up to 45%, making them promising for controlling shrub encroachment. Nevertheless, grazing often negatively impacts shrub richness, especially when combined with management interventions or wildfires, thereby raising concerns about plant regeneration. Future research should prioritize the ecological value of indigenous browsing cattle breeds over productivity-focused goals; however, several studies fail to specify the breeds examined, thereby limiting the ability to draw breed-specific conclusions. Full article
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21 pages, 1789 KiB  
Review
Agroforestry and the Climate Crisis: Prioritizing Biodiversity Restoration for Resilient and Productive Mediterranean Landscapes
by Rigas Tsiakiris, Kalliopi Stara, Yannis Kazoglou, Petros Kakouros, Dimitris Bousbouras, Anastasios Dimalexis, Panayotis Dimopoulos, Georgios Fotiadis, Ilias Gianniris, Ioannis P. Kokkoris, Konstantinos Mantzanas, Maria Panagiotopoulou, Olga Tzortzakaki, Vassiliki Vlami and Michael Vrahnakis
Forests 2024, 15(9), 1648; https://doi.org/10.3390/f15091648 - 18 Sep 2024
Cited by 6 | Viewed by 3210
Abstract
This study deals with the future of the traditional agroforestry systems (TAFSs) in the northern Mediterranean Basin. Important productive systems, such as ancient non-irrigated olive groves and extensive silvopastoral systems, from subalpine grasslands to coastal landscapes, are being irreversibly degraded, threatening the bio-cultural [...] Read more.
This study deals with the future of the traditional agroforestry systems (TAFSs) in the northern Mediterranean Basin. Important productive systems, such as ancient non-irrigated olive groves and extensive silvopastoral systems, from subalpine grasslands to coastal landscapes, are being irreversibly degraded, threatening the bio-cultural heritage of the Mediterranean region, an area recognized as a global biodiversity hotspot. In the midst of the global biodiversity and climate crisis, immediate actions are proposed for the protection and conservation management of TAFSs, within a new EU policy framework. Having the TAFSs of Greece in the spotlight of this analysis, a four-step approach was used in order to review the value of agroforestry in terms of (a) biodiversity (birds, mammals, invertebrates and soil biota), (b) agroforestry landscapes, such as traditional olive groves on terraces and valonia silvopastoral systems, (c) ecosystem services, especially concerning cultural values, and (d) the modern threats to traditional agroforestry. Through this research, problems are highlighted and European policy priorities are defined. Our conclusion is that there is an immediate need to revise the European Union rural, forestry, and environmental policies in the Mediterranean region, following the provisions of the new EU Nature Restoration Law, in order to revive agroforestry landscapes and make them productive and sustainable again for the benefit of rural economies, local communities, and biodiversity, especially in marginal Mediterranean mountainous and island areas, where depopulation and susceptibility to wildfires are major threats. Full article
(This article belongs to the Section Forest Economics, Policy, and Social Science)
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18 pages, 2053 KiB  
Article
Envisaging Participatory Management in Protected Areas: Local Response to Proposed Conservation Actions in Relation to Environmental Orientation
by Vassiliki Kleftoyanni and Michael Vrahnakis
Land 2024, 13(7), 976; https://doi.org/10.3390/land13070976 - 2 Jul 2024
Cited by 3 | Viewed by 1326
Abstract
Involving local people in natural area management is very important to address the complexity of environmental management issues for the sustainable use of local resources. Participatory methods require the contribution of local stakeholders in decision-making. Mapping the environmental views of local communities allows [...] Read more.
Involving local people in natural area management is very important to address the complexity of environmental management issues for the sustainable use of local resources. Participatory methods require the contribution of local stakeholders in decision-making. Mapping the environmental views of local communities allows for the detection of aspects that could facilitate management efforts. This research—in the frame of the Skyros LIFE project and the PAMNATURA project—measures the local acceptability of the conservation actions proposed by the LIFE project in Skyros island (Greece), in relation to recording local people’s environmental orientation using the 15-item revised New Ecological Paradigm (NEP) scale. The research was carried out by means of questionnaires. The LIFE project proposed actions were grouped into three categories according to their theme, i.e., promoting (a) nature protection, (b) agro-pastoralism and (c) ecotourism. The sample seems to largely agree with the LIFE project proposals, while the results showed high scores for most of the NEP scale items, implying pro-environmental beliefs, though there appears to be disagreement or neutrality regarding a few items. The local acceptability of the proposed actions was found to correlate to local people’s environmental concern measured through the NEP scale. Drawing on the results, the implementation of actions related directly or indirectly to economic activities and the preservation of traditional activities, as well as environmental education and interactive informing and consultation, could enhance local participation. Skyros island seems to offer an appropriate social background for applying participatory and adaptive management and implementing conservation programs. Full article
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22 pages, 13147 KiB  
Article
Changes in Surface Runoff and Temporal Dispersion in a Restored Montane Watershed on the Qinghai–Tibetan Plateau
by Xiaofeng Ren, Erwen Xu, C. Ken Smith, Michael Vrahnakis, Wenmao Jing, Weijun Zhao, Rongxin Wang, Xin Jia, Chunming Yan and Ruiming Liu
Land 2024, 13(5), 583; https://doi.org/10.3390/land13050583 - 28 Apr 2024
Cited by 3 | Viewed by 1736
Abstract
Surface runoff is a major component of the hydrological cycle, and it is essential for supporting the ecosystem services provided by grassland and forest ecosystems. It is of practical importance to understand the mechanisms and the dynamic processes of runoff in a river’s [...] Read more.
Surface runoff is a major component of the hydrological cycle, and it is essential for supporting the ecosystem services provided by grassland and forest ecosystems. It is of practical importance to understand the mechanisms and the dynamic processes of runoff in a river’s basin, and in this study, we focused on the restored montane Pailugou Basin in the Qilian Mountains, Gansu Province, China, since its water status is extremely important for the large arid area and local economies therein. Our purpose was to determine the annual variation in the surface runoff in the Pailugou Basin because it is important to understand the influence of climate fluctuations on surface water resources and the economy of the basin. In addition, little is known about the annual variations in precipitation and runoff in this region of the world. Daily atmospheric precipitation, air temperature and runoff data from 2000 to 2019 were analyzed by the calculation of the uneven annual distribution of surface runoff, the calculation of the complete adjustment coefficient, and the vector accumulation expressed by the concentration degree. We also used the cumulative anomaly approach to determine the interannual variation trend of runoff, while the change trend was quantified by the sliding average method. Finally, we used the Mann–Kendall mutation test method and regression analysis to establish the time-series trend for precipitation and runoff and to determine the period of abrupt runoff changes. The results indicated concentrated and positive distributions of surface runoff on an annual basis, with a small degree of dispersion, and an explicit concentration of extreme flows. The relative variation ranges exhibited a decreasing trend, and the distribution of the surface runoff gradually was uniform over the year. The runoff was highest from July to September (85% of the annual total). We also determined that annual surface runoff in the basin fluctuated over the 20-year period but showed an overall increasing trend, increasing by 3.94 × 105 m3, with an average increase rate of 0.42 × 105 m3 every ten years. From 2005 to 2014, the annual runoff and the proportion of runoff in the flood season (July to September) to the annual runoff fluctuated greatly. The correlation between the runoff and precipitation was significant (r = 0.839, p < 0.05), whereas the correlation between air temperature and surface runoff was low (r = 0.421, p < 0.05). Full article
(This article belongs to the Section Land Systems and Global Change)
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19 pages, 1721 KiB  
Review
Grazing as a Management Tool in Mediterranean Pastures: A Meta-Analysis Based on A Literature Review
by Dimitrios Oikonomou, Michael Vrahnakis, Maria Yiakoulaki, Gavriil Xanthopoulos and Yannis Kazoglou
Land 2023, 12(7), 1290; https://doi.org/10.3390/land12071290 - 26 Jun 2023
Cited by 12 | Viewed by 3115
Abstract
The present study reviews the impact of mechanical interventions, and controlled burning combined with grazing in the Mediterranean-climate regions (MCRs) of the world. Relevant studies were searched for in the Web of Science database. Additional studies were located in the citations of these [...] Read more.
The present study reviews the impact of mechanical interventions, and controlled burning combined with grazing in the Mediterranean-climate regions (MCRs) of the world. Relevant studies were searched for in the Web of Science database. Additional studies were located in the citations of these publications, and in a local database. Finally, 26 studies were included in this review. Since 1978, several other relevant studies have emerged at a rate of 24% in a 5-year time step. The studies have focused on the effects of combined grazing with other management tools on vegetation structure (18 publications), biomass productivity (16 publications), and floristic diversity (12 publications). The results were analyzed for (a) sites and treatments and (b) effects on plant structure, productivity and floristic diversity. Herbaceous forage increased after a reduction in shrub cover. Shrubs tended to recover in the grazed pastures. Vegetation height was reduced in almost in all cases according to available data. Despite its potential recovery, shrub biomass was affected by grazing in most cases. The impact of subsequent grazing was mixed regarding floristic diversity. Grazing is a useful tool for landscape management in MCRs, but the proper way to combine it with other interventions depends on the management goals. Full article
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23 pages, 3966 KiB  
Article
Land Use Changes for Investments in Silvoarable Agriculture Projected by the CLUE-S Spatio-Temporal Model
by Stamatia Nasiakou, Michael Vrahnakis, Dimitrios Chouvardas, Georgios Mamanis and Vassiliki Kleftoyanni
Land 2022, 11(5), 598; https://doi.org/10.3390/land11050598 - 19 Apr 2022
Cited by 18 | Viewed by 4214
Abstract
Investment in biology-based technological innovations is a key requirement for the development of modern agriculture/forestry. The expansion of innovative biological technologies includes changes in crops/cultivations, such as the transition from intensive monocultures to multiple crops of lower agrochemical inputs with the integration of [...] Read more.
Investment in biology-based technological innovations is a key requirement for the development of modern agriculture/forestry. The expansion of innovative biological technologies includes changes in crops/cultivations, such as the transition from intensive monocultures to multiple crops of lower agrochemical inputs with the integration of woody trees/shrubs or animals, represented by Agroforestry. This innovative biological technology is further promoted at the European Union (EU) level by powerful institutions such as the Green Deal and the new CAP, mainly by tools such as ecoschemes and agri-environmental and climate measures (AECMs). The use of integrated regional spatiotemporal models, such as CLUE-S, to predict land use changes in the framework of Agroforestry is rather restricted. This paper examines Agroforestry as a vehicle that can contribute to achieving the rural development of the region of Thessaly, Greece. It sets a time horizon for reviewing the changes that are expected in the most important units of land uses of the rural landscape of the municipality of Mouzaki, western Thessaly plain, in the year 2040, which serves as model land for the region of Thessaly. It examines these changes with the effect of three (3) socio-economic scenarios: (a) a linear operating scenario (business as usual, BAU), (b) an ecological land protection (ELP) scenario, and (c) a rapid economic development (RED) scenario. These scenarios were introduced in the non-spatial module of the CLUE-S spatiotemporal model, while in the spatial module sixteen (16) characteristic landscape parameters were introduced as independent variables. The most important land use units, including traditional silvoarable and silvopastoral woodland systems, were the dependent variables. The simulations of the changes of the land use units showed that under the RED scenario, in the year 2040 the extent of the silvoarable systems is expected to increase significantly (57%) compared to the reference year of 2020, while the rest of the land use units under the other scenarios are mainly regulated by depopulation/abandonment of the rural areas and the processes of natural succession. The fact that the extent of silvoarable systems is increasing, in combination with the favorable institutional environment created by European rural policies, gives impetus to regional rural development through investments in the agricultural sector and mainly in Agroforestry systems. Full article
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16 pages, 1423 KiB  
Article
Land Use Demands for the CLUE-S Spatiotemporal Model in an Agroforestry Perspective
by Georgios Mamanis, Michael Vrahnakis, Dimitrios Chouvardas, Stamatia Nasiakou and Vassiliki Kleftoyanni
Land 2021, 10(10), 1097; https://doi.org/10.3390/land10101097 - 16 Oct 2021
Cited by 24 | Viewed by 4035
Abstract
Rural landscape evolution models are used as tools for the analysis of the causes and impact of land use changes on landscapes. The CLUE-S (the Conversion of Land Use and its Effects at Small regional extent) model was developed to simulate the changes [...] Read more.
Rural landscape evolution models are used as tools for the analysis of the causes and impact of land use changes on landscapes. The CLUE-S (the Conversion of Land Use and its Effects at Small regional extent) model was developed to simulate the changes in current land use, by using quantitative relationships between land uses and driving factors combined with a dynamic modeling of land use competition. One of the modules that build the “CLUE-S” is the non-spatial subset of the model that calculates the temporal evolution of the land use/cover under several socio-economic scenarios. The purpose of this research was to estimate the demands of land use in the area of Mouzaki, Thessaly plain, Greece with the ultimate goal of using them in the non-spatial module of the CLUE-S to predict the evolution of land uses in year 2040. These estimations are the quantitative prediction of the spatial change for all land use types at the aggregate level. Three models of forecasting the future land cover in the area were simulated, in order to obtain a clear view of the different land uses in the future. We distinguished three model-scenarios for calculating the demand-forecasts: (a) business as usual (BAU) scenario, that deals with a linear projection of the current land use demands, (b) rapid economic development (RED) scenario, and (c) ecological land protection (ELP) scenario. In the BAU scenario the land use demands for the year 2040 were calculated using linear interpolation utilizing historical data from 1960 to 2020. In the RED scenario, the demands were calculated by maximizing the economic benefit of land uses, and in the ELP scenario the demands were calculated by maximizing the environmental benefit of land uses. Furthermore, a multi-criteria analysis was performed to find the trade-offs between economic benefit maximization and environmental benefit optimization. It was found that the agricultural lands reach their maximum area under the RED scenario, while reaching their lower bound for the ELP scenario. The same goes for agroforestry systems. The grasslands reach their lower bound under the ELP scenario, while they achieve a higher value under the RED scenario. Concerning the silvopastoral woodlands, although an increase is foreseen under the BAU scenario, it appears that they reach their lower bound in the other two scenarios, RED and ELP. Forests receive intermediate values and cover a larger area under the ELP scenario compared with the RED scenario. The expected forest cover under the BAU scenario is higher. Moreover, sparse and dense shrublands receive their lower bound for both optimization scenarios, while the settlements reach the upper bound for the RED scenario and the lower one under the ELP scenario. Full article
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11 pages, 1984 KiB  
Article
Changes in Water Quality of the River das Antas as It Passes through Rural and Urban Areas
by Valdemir Antoneli, Manuel Pulido-Fernández, João Anésio Bednarz, Leonardo Brandes, Michael Vrahnakis, Yannis Kazoglou, Javier Lozano-Parra and Ramón García-Marín
Urban Sci. 2021, 5(1), 22; https://doi.org/10.3390/urbansci5010022 - 12 Feb 2021
Cited by 3 | Viewed by 3404
Abstract
The catchment area of River das Antas (Irati, Paraná, Brazil) is of high importance both for human consumption and irrigation. Within Irati, this river passes through a rural area and through the city of Irati, crossing both poor and rich neighbourhoods. We selected [...] Read more.
The catchment area of River das Antas (Irati, Paraná, Brazil) is of high importance both for human consumption and irrigation. Within Irati, this river passes through a rural area and through the city of Irati, crossing both poor and rich neighbourhoods. We selected three study areas downstream (a rural area, poor community, and rich neighbourhood) in which we measured turbidity, the concentration of sediments and pH during rainy days. Our results showed downstream trends of increasing turbidity and concentrations of sediments with decreasing pH. The values of turbidity and of concentration of sediments were significantly different in the rural area, while the pH values were significantly different between the three study areas. These findings highlight the effect of agricultural activities in the generation of sediments and turbidity. The—presumably expected—effects of organic urban waste from the poor neighbourhood were also detected in the pH values. We conclude that efforts should be made to ensure that land planning and training/education programmes on sustainable farming practices are undertaken by the authorities to reduce water pollution and its effects on water bodies during rainfall events, since paving streets is not a feasible option in the short term due to the high costs associated with this measure. Full article
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13 pages, 17887 KiB  
Article
Partial Grazing Exclusion as Strategy to Reduce Land Degradation in the Traditional Brazilian Faxinal System: Field Data and Farmers’ Perceptions
by Valdemir Antoneli, Manuel Pulido Fernández, Taís de Oliveira, Javier Lozano-Parra, João Anésio Bednarz, Michael Vrahnakis and Ramón García-Marín
Sustainability 2020, 12(18), 7456; https://doi.org/10.3390/su12187456 - 10 Sep 2020
Cited by 4 | Viewed by 3209
Abstract
Land degradation is becoming a serious concern for the sustainability of traditional agrosilvopastoral systems such as the Brazilian faxinal. The IAP (Environmental Institute of the Federal State of Paraná) is favoring the partial exclusion to grazing for 10 years as strategy both to [...] Read more.
Land degradation is becoming a serious concern for the sustainability of traditional agrosilvopastoral systems such as the Brazilian faxinal. The IAP (Environmental Institute of the Federal State of Paraná) is favoring the partial exclusion to grazing for 10 years as strategy both to recover degraded lands and to reduce negative effects. Nevertheless, this strategy is being followed by a reduced number of owners (faxinalenses) and little is known about the effectiveness of these measures due to either lack of field data and knowledge on faxinalenses’ perceptions. We have identified one out of few farms that have followed this official strategy and, within the same farm, we have compared values of some soil properties (bulk density, porosity, water holding capacity, penetration resistance, soil organic matter and root density) from an excluded area to grazing for 10 years, with some areas that represent a gradient of grazing intensity (natural forest, secondary forest, degraded forest, grassland and a degraded area by pigs). In addition, we have interviewed some faxinalenses (one faxinal farm is owned by several farmers) in order to better understand how the risk of land degradation is perceived by them and their opinions about the usefulness of partial grazing exclusion as a strategy to improve the management of their farms. The results have shown that soil quality increases considerably as a consequence of grazing exclusion, in spite of land has been used for cropping yerba mate during the exclusion time, but faxinalenses are not mindful of these benefits and they are no longer interested in excluding other areas of their farms. They think this strategy is simply an obligation imposed by the environmental authority. Full article
(This article belongs to the Special Issue Natural Risk Perception and Geography Education)
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