Habitat loss is a key driver of biodiversity loss. However, hardly any long-term time series analyses of habitat loss are available above the local scale for finer-level habitat categories. We ...analysed, from a long-term perspective, the habitat specificity of habitat-area loss, the change in trends in habitat loss since 1989 (dissolution of the communist state), and the impact of protected areas on habitat loss in Hungary. We studied 20 seminatural habitat types in 5000 randomly selected localities over 7 periods from 1783 to 2013 based on historical maps, archival and recent aerial photos and satellite imagery, botanical descriptions, and field data. We developed a method for estimating habitat types based on information transfer between historical sources (i.e., information from a source was used to interpret or enrich information from another source). Trends in habitat loss over time were habitat specific. We identified 7 types of habitat loss over time regarding functional form: linear, exponential, linear and exponential, delayed, minimum, maximum, and disappearance. Most habitats had continuous loss from period to period. After 1986 the average annual rates of habitat loss increased, but the trend reversed after 2002. Nature conservation measures significantly affected habitat loss; net loss was halted, albeit only inside protected areas. When calculating the degree of endangerment based on short-term data (52 years), we classified only 1 habitat as critically endangered, but based on long-term data (230 years), this increased to 7 (including habitat that no longer existed). Hungary will probably reach the global Convention on Biological Diversity Target 5 but will probably not achieve the EU Biodiversity Strategy target of halting habitat loss by 2020. Long-term trend data were highly useful when we examined recent habitat-loss data in a wider context. Our method could be applied effectively in other countries to augment shorter-term data sets on trends in habitat area. La pérdida de hábitats es un conductor importante de la pérdida de la biodiversidad. Sin embargo, difícilmente está disponible una serie de análisis a largo plazo por encima de la escala local para categorías de hábitat de un nivel más fino. Analizamos, desde una perspectiva de largo plazo, la especificidad del hábitat en la pérdida del área de hábitats, el cambio en las tendencias de pérdida de hábitats desde 1989 (disolución del estado comunista), y el impacto de las áreas protegidas sobre la pérdida de hábitat en Hungría. Estudiamos 20 tipos de hábitats seminaturales en 5000 localidades seleccionadas al azar a lo largo de siete periodos desde 1783 hasta 2013 con base en mapas históricos, fotografías aéreas recientes y de archivos e imágenes de satélites, descripciones botánicas, y datos de campo. Desarrollamos un método para estimar los tipos de hábitats basado en la transferencia de información entre las fuentes históricas (es decir, se usó información a partir de una fuente para interpretar o enriquecer la información proveniente de otra fuente). Las tendencias en la pérdida de hábitats fueron específicas por hábitat. Identificamos siete tipos de pérdida de hábitats a través del tiempo con respecto a la forma funcional: lineal, exponencial, lineal y exponencial, retrasada, mínima, máxima, y desaparición. La mayoría de los hábitats tuvieron una pérdida continua de un periodo o a otro. Después de 1986, las tasas anuales promedio de la pérdida de hábitats incrementaron, pero la tendencia se revirtió después del 2002. Las medidas de conservación de la naturaleza afectaron considerablemente a la pérdida de hábitats; se detuvo la pérdida neta, no obstante sólo fue dentro de las áreas protegidas. Cuando calculamos el grado de peligro basado en información de corto plazo (52 años), solamente clasificamos a un hábitat como en peligro crítico, pero con base en la información de largo plazo (230 años), esta clasificación incrementó a siete hábitats (incluyendo a un hábitat que ya no existía). Hungría probablemente alcanzará el Objetivo 5 global de la Convención sobre la Diversidad Biológica pero probablemente no sea el caso para el objetivo de detener la pérdida de hábitats para el 2020 impuesto por la Estrategia de Biodiversidad de la UE. La información de largo plazo sobre las tendencias fue muy útil cuando se examinaron datos recientes de pérdida de hábitats en un contexto más amplio. Nuestro método podría aplicarse efectivamente en otros países para aumentar los conjuntos de datos de corto plazo sobre las tendencias en áreas de hábitat. 生境丧失是生物多样性丧失的ー个关键驱动力。然而，目前几乎没有对局部尺度、高精度生境分类下的 生境丧失的长期时序分析。我们从长期的视角分析了匈牙利生境面积减少的生境特异性、自 1989年以来生境 丧失的变化趋势以及保护地对生境丧失的作用。我们利用历史地图、档案ヽ近期的航片及卫星影像、植物记录 和野外数据，在 5000 个随机选择的地区,研究了 20 个半自然生境类型从 1783 年到 2013 年的 7 个时间段内 的变化。我们建立了一个基于历史来源之间信息传递(即ー个来源的信息用于解释或完善另ー个来源的信息) 的方法来估计生境类型。生境丧失随时间发展的变化趋势有生境特异性。我们根据函数类型分出7 类随时间 发生的生境丧失: 线性、指数型、线性及指数型、延迟型、最小型、最大型以及生境消失。大部分生境都随着 时间流转持续地丧失。在 1986 年之后, 生境丧失的平均年变化率増加, 而这个趋势在 2002 年后有所逆转。自 然保护措施有效遏制了生境丧失，使净减少停止’ 尽管这一影响仅在保护地之内。当根据短期数据(52 年)计算 瀕危程度时, 只有一个生境被评为极度瀕危, 但根据长期数据(230 年) 评估’极度瀕危的生境増加到了 7 个（包 括已经不存在的生境) 。匈牙利很可能完成全球《生物多祥性公约》的第五个目标, 但可能难以达到〈〈欧盟生物 多样性战略》在 2020 年前遏止生境丧失的目标。长期变化趋势可用于在更大的背景下检验近期生境丧失的数 据。我们的方法可以有效应用于其它国家, 来补充生境面积变化的短期数据。
Large herbivores have a keystone role in many forest ecosystems. There is widespread recognition that undesirable changes may be caused by the complete removal of grazing-related disturbances, ...whereas there can be benefits from properly managed, targeted livestock grazing, both from a forest management and biodiversity perspectives. However, there are also many contradictory statements and results about forest grazing. We summarize the main scientific evidence and knowledge gaps on forest livestock grazing through a global review of the literature for the temperate region. We analysed 71 publications discussing the impact of livestock grazing on vegetation in forests. Grazing reduces vegetation biomass, but less obvious effects relevant to conservation include increased habitat diversity and increased regeneration of selected canopy tree species. Moreover, detailed guidance on how grazing should be carried out for conservation purposes is limited because the results are strongly context dependent. The direction and amplitude of effects can be influenced not only by forest type and stocking levels, but by foraging preferences of livestock, availability of alternative forage, grazing season and herder activity. We stress the need for well-planned real-world experiments and observations, and for more quantitative studies to foster evidence-based conservation management. Grazing differences between wild ungulates and livestock should be better studied, because the effects are often overlapping. We suggest widening the temporal and spatial scales of case studies and stress the need to create space and openness for interdisciplinary and participatory research and conservation approaches, initiating knowledge co-production on the benefits and dis-benefits of grazing in forests.
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•Targeted livestock grazing can benefit both forest management and biodiversity.•We reviewed 71 papers on the vegetation impact in temperate forests.•Grazing can increase habitat diversity and regeneration of canopy tree species.•Impacts are highly contextual but local factors are often not properly documented.•Approaches and attitudes towards livestock forest grazing should be reconsidered.
•Old-growth oak forest studies were underrepresented in Europe and Asia.•Large tree density and volume of deadwood increased with humidity gradient.•Oak proportion, tree density, and sapling density ...decreased with humidity.•Diameter of trees followed negative exponential or rotated sigmoid distribution.•Relative density and basal area of oaks decreased in the last decades.
The structure and composition of temperate old-growth oak forests are reviewed based on 108 case studies about 175 stands. The stands were classified as dry, dry-mesic and mesic forest types and the variables (density, basal area, size distribution, dead wood volume) were compared among them.
Compared to the global range of this forest type, the United States was overrepresented, while West and Central Asia, Europe and Central America were underrepresented. In mesic oak forests the basal area and density of large trees were higher than in dry stands, while tree density and sapling density were lower. The proportion of oaks in tree and sapling layers were the highest in dry and lowest in mesic forests. The size distribution of trees followed negative exponential or rotated sigmoid types. In dry habitats all size categories are dominated by oaks, while in mesic type, only large ones followed the same trend. The volume of dead wood and the proportion of downed dead wood increased along the humidity gradient. In stands with repeated measurements, basal area and relative density of oaks decreased in the last decades.
The understanding of the structure and composition of temperate old-growth oak forests is necessary for their restoration and application of close to nature forestry principles.
•Plantations and spontaneous forest regrowth may obscure semi-natural forest loss.•Forest trajectories since the 1780 s were synthetized in 1,728 sites at national level.•In Hungary 36% of forests ...are semi-natural and 33% are semi-natural continuous forest.•Nearly half of the semi-natural forest loss was due to conversion to arable land.•Landscape planning and sustainable management require assessment of forest continuity.
Despite deforestation taking place globally, forest cover is increasing in many European landscapes. This increase, however, resulting from plantations and spontaneous forest regrowth, may obscure the generally declining trend of semi-natural forests, though the latter are essential for local and landscape-level conservation strategies and sustainable forest management. We assessed changes in semi-natural and secondary forest cover since the 18th century in Hungary, focusing on the continuity of semi-natural forests. The main trajectories of regional and country-scale forest transformations were reconstructed from the fine-scale site histories of 1,728 randomly selected sample localities. Historical and recent datasets were complemented with field data to estimate forest cover change for seven time periods between the 1780s and the 2010s. Total forest cover changes over these 230 years showed a U-shape curve (from 25% to 24%), leading to a forest minimum in the first half of the 20th century. Semi-natural and secondary forests exhibited strikingly different trends. The proportion of semi-natural forests decreased to 36% of the total forest area by the 2010s, driven mainly by conversion to arable land, while 88% of the actual semi-natural forests have remained continuous forest since the 18th century. Our results showed that when reconstructing landscape-scale historical forest cover change and continuity, the loss of semi-natural forests remains hidden if the calculations are limited to ‘total forest cover change’. It would therefore be immensely important to distinguish between semi-natural and secondary forests, and between types of continuity in the assessments used for conservation-oriented landscape planning and sustainable forest management.
Increasing human activity is altering the structure of forests, which affects the composition of communities, including birds. However, little is known about the key forest structure variables that ...determine the richness of bird communities in European temperate oak forests. We, therefore, aimed to identify key variables in these habitats that could contribute to the design of management strategies for forest conservation by surveying 11 oak-dominated forest sites throughout the mid-mountain range of Hungary at 86 survey points to reveal the role of different compositional and structural variables for forest stands that influence the breeding bird assemblages in the forests at the functional group and individual species levels. Based on decision tree modelling, our results showed that the density of trees larger than 30 cm DBH was an overall important variable, indicating that large-diameter trees were essential to provide diverse bird communities. The total abundance of birds, the foliage-gleaners, primary and secondary cavity nesters, residents, and five specific bird species were related to the density of high trunk diameter trees. The abundance of shrub nesters was negatively influenced by a high density of trees over 10 cm DBH. The density of the shrub layer positively affected total bird abundance and the abundance of foliage gleaners, secondary cavity nesters and residents. Analysis of the co-dominant tree species showed that the presence of linden, beech, and hornbeam was important in influencing the abundance of various bird species, e.g., Eurasian Treecreeper (
Certhia familiaris
), Marsh Tit (
Poecile palustris
) and Wood Warbler (
Phylloscopus sibilatrix
). Our results indicated that large trees, high tree diversity, and dense shrub layer were essential for forest bird communities and are critical targets for protection to maintain diverse and abundant bird communities in oak-dominated forest habitats.
•In stands 40–99years old we found less than 15m3/ha dead wood regardless of age.•Stands above 100years old contain relatively high volume of dead wood (37–45m3/ha).•Large-diameter logs (DBH>30cm) ...are absent from the stands younger than 100years.•Very low rate of decayed dead wood indicates intensive forest management.
Dead wood (DW) has great importance for many wildlife species and ecological processes. The volume of DW is considered a useful indicator of the sustainability and maintenance of biodiversity in forests. Though dry-mesic oak forests cover large areas in Hungary, little is known about DW quantities or dynamics in these forests. We investigated DW conditions in five age classes of dry-mesic Quercus petraea and Q. cerris dominated forests in the Hungarian Carpathians. Stands of the first four age classes (age class 1: 40–59, age class 2: 60–79, age class 3: 80–99, age class 4: 100–119years old) were managed and stands at least 120years old were unmanaged at least for 30years (age class 5). We measured the volume, density, dominance and size distribution of standing DW and volume of downed DW. We also evaluated the decay stages of DW on an ordinal scale (I-V, intact to well-decayed). The effect of age class on the derived variables such as density, dominance, volume or proportion of DW was analysed with general linear mixed models using age class as a fixed and region as a random effect. Mean total DW volume did not reach 15m3/ha in age class 1, 2 and 3. A much larger volume of DW was found in age class 4 and 5, where the mean total volume of DW was 36.9 and 45.1m3/ha, respectively. Volume and proportion of total DW over 30cm in diameter were markedly lower in age classes 1, 2 and 3 than in age classes 4 and 5, moreover standing and downed DW over 30cm in diameter were totally absent in stands under 100years old. The proportion of well-decomposed (decay stage IV and V) DW was much lower (3–18% of the volume) in all five age classes than in old-growth stands of dry-mesic oak forests. After three decades of non-intervention (age class 5), the volume of DW can approach that of old-growth forests. The 40–99-year old stands contained a similarly low percentage of DW as other managed dry-mesic oak forests in Europe. Based on the results, it is likely that stands greater than 100years old will support much higher biodiversity of saproxylic organisms compared to younger stands.
Aichi Target 15 aims to enhance the resilience of ecosystems through the restoration of 15% of degraded land by 2020. Compliance with the target is still insufficient, partly due to the lack of ...appropriate baselines and knowledge of restoration efforts. The four-level model of ecosystem condition was suggested to set the baseline and support the estimation of progress. This study is the first to assess the condition of MAES ecosystem types at a country scale, using the suggested approach. Altogether 613,000 ha of land is in close to natural condition (Level 1), 893,000 ha in a slightly degraded state (Level 2), 1,907,000 ha in moderately degraded condition (Level 3), and 5,890,000 ha of land is in highly modified category (Level 4). An inventory of ecological restoration interventions was created based on the reports of the national park directorates and EU LIFE projects. The findings of the restoration database of 634 interventions were compared to the need for restoration of nine habitat types. Restoration efforts were focused at habitat types with the most extended degraded area, except for dry forest restoration and the fight against invasive species in all three forest types. This study provides a more reliable estimate of habitats in natural state than Habitat Directive reporting can achieve, and is therefore better suited for estimating compliance with the 15% target. Only 1% of degraded land was the target for restoration in the period of 2002–2016. The details of the survey regarding habitat and degradation types can support further restoration planning.
Characteristic features of European woodland include both a reduction in natural forest areas and an increase in former agricultural areas occupied by secondary woodland. The management of these ...areas is challenging in terms of nature conservation, agricultural and forestry management and policy. The aim of our study was to reconstruct the history and to document the current tree stand structure for a secondary oak-beech woodland in Hungary. Towards the end of the 1800s, this area which was once almost completely occupied by a continuous forest, had been transformed into a wood-pasture. As a result of its gradual abandonment, the closed forest stand of the pasture increased from 10 to 52% between 1963 and 2005. The most characteristic feature of this woodland is the abundance of large trees. Globally, the number of large and ancient trees is rapidly diminishing. Therefore preserving and maintaining such areas, where large trees could live, is an essential management task.
Aim: This paper introduces a new method for vegetation-based landscape classification. As a case study, we present the landscape classification of Hungary with a total area of 9.3 million ha. ...Location: Hungary. Methods: Data from the MÉTA (Magyarországi Élőhelyek Térképi Adatbázisa: GIS Database of the Hungarian Habitats) vegetation survey were used in our analyses. The basal units of the survey were hexagons with an area of 35 ha, in which surveyors estimated the cover of the various types of the (semi)-natural vegetation. The sample unit in our analyses was a rosette consisting of seven hexagons. The distance between sample units was calculated based on the relative cover of (semi-)natural habitats by Rao's beta diversity, a new distance measure that includes the similarities between habitats. A hierarchical classification was then performed using the UPGMA (unweighted pair group method with arithmetic mean) algorithm. Results: The optimal number of groups was 41 on the basis of average silhouette. Landscape types dominated by forests or grasslands were separated at the highest dissimilarity level. At lower levels, the division of groups could be attributed to differences in site conditions (dry, mesic, wet, saline). The most common landscape types (more than 400 occurrences) in Hungary are those dominated by zonal forests, degraded treeless habitats, xeric and mesic saline and alkaline habitats, and reedbeds and wet meadows. The rarest types (less than 50 occurrences) are mosaics of edaphic habitats, and coniferous forests. Conclusions: Landscape classification based on (semi-)natural vegetation may be used for estimating landscape diversity, landscape modeling, selection of study sites, regionalization of local scientific results, and for landscape development planning and nature conservation management. The new distance measure has met our expectations and resulted in a classification with clearly interpretable groups. It is likely that this distance measure may also prove to be appropriate for numerical syntaxonomy, in which the stability of the resulting groups may be increased by taking into consideration the similarities/differences in phytosociological preference of species.
Questions: Multiple potential natural vegetation (MPNV) is a framework for the probabilistic and multilayer representation of potential vegetation in an area. How can an MPNV model be implemented and ...synthesized for the full range of vegetation types across a large spatial domain such as a country? What additional ecological and practical information can be gained compared to traditional potential natural vegetation (PNV) estimates? Location: Hungary. Methods: MPNV was estimated by modelling the occurrence probabilities of individual vegetation types using gradient boosting models (GBM). Vegetation data from the Hungarian Actual Habitat Database (MÉTA) and information on the abiotic background (climatic data, soil characteristics, hydrology) were used as inputs to the models. To facilitate MPNV interpretation a new technique for model synthesis (re-scaling) enabling comprehensive visual presentation (synthetic maps) was developed which allows for a comparative view of the potential distribution of individual vegetation types. Results: The main result of MPNV modelling is a series of raw and re-scaled probability maps of individual vegetation types for Hungary. Raw probabilities best suit within-type analyses, while re-scaled estimations can also be compared across vegetation types. The latter create a synthetic overview of a location's PNV as a ranked list of vegetation types, and make the comparison of actual and potential landscape composition possible. For example, a representation of forest vs grasslands in MPNV revealed a high level of overlap of the potential range of the two formations in Hungary. Conclusion: The MPNV approach allows viewing the potential vegetation composition of locations in far more detail than the PNV approach. Re-scaling the probabilities estimated by the models allows easy access to the results by making potential presence of vegetation types with different data structure comparable for queries and synthetic maps. The wide range of applications identified for MPNV (conservation and restoration prioritization, landscape evaluation) suggests that the PNV concept with the extension towards vegetation distributions is useful both for research and application.
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