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Sacred oak woods increase bird diversity and specialization: Links with the European Biodiversity Strategy for 2030
Abstract
Sacred groves in Greece are usually forest remnants with large trees around chapels, protected through centuries by Orthodox religion. We examined the comparative ecological value of 20 oak-dominated sacred groves vs managed oakwoods, in terms of their habitat characteristics and avian communities (passerines and wood-peckers). Sacred groves have maintained a more pronounced old-growth character than managed oakwoods in terms of average Diameter at Breast Height (DBH) and tree height. Besides holding significantly greater bird species richness and abundance, they supported greater functional richness, phylogenetic diversity, and phylo-genetic bird species variability. Bird communities in sacred groves were more heterogeneous and showed greater avian specialization levels than in managed woods. Generalized Linear Models showed that the main factor positively affecting all aspects of bird diversity was DBH, while the abundance of dead trees increased bird abundance. Our results underline the importance of maintaining large-sized trees in forest management practices to support bird diversity and decrease biotic homogenization. Since the new European Biodiversity Strategy explicitly requires all remaining European primary and old-growth forests to be strictly protected by 2030, we argue that sacred groves, despite their small size, meet the criteria to be considered in the strict protection and restoration targets of the strategy, as primary old growth woods of high biodiversity value.
... Nos résultats montrent aussi que la présence de vieux arbres dans les haies entraîne une augmentation dans l'abondance en espèces protégées. Les vieux arbres offrent en effet une multitude de niches écologiques, favorisant l'avifaune (Benedetti et al., 2021 ;Kebrle et al., 2021). En plus d'abriter des cavités, ces arbres se distinguent généralement par leur hauteur et leur largeur, assurant ainsi des zones propices à la nidification, au repos et à la recherche de nourriture pour les oiseaux comme discuté précédemment. ...
Les haies revêtent une importance écologique primordiale car elles jouent un rôle essentiel dans la protection des sols, de celle des eaux de surfaces et souterraines, dans le maintien de microclimats favorables à de nombreuses espèces, dans la dispersion de la faune et de la flore mais aussi en abritant de nombreuses espèces protégées. Dans le cadre de la crise climatique, elles participent au stockage du carbone et présentent un intérêt microclimatique sur les territoires. Vécues parfois comme une contrainte par le monde agricole, les haies constituent cependant des habitats privilégiés pour de nombreuses espèces d’oiseaux protégées, rendant leur préservation indispensable pour le maintien de la biodiversité. Nous avons, par cette étude, voulu évaluer empiriquement dans quelle mesure les haies accueillent des espèces d’oiseaux protégés et cela selon les types de haies et de paysages dans lesquelles elles s’insèrent au sein de la Région Grand Est. Pour répondre à cet objectif, 1219 points d'écoute et 1840 haies ont été échantillonnés en 2021 et 2022 dans les dix départements de la région de manière aléatoire et stratifiée selon la densité de haie présente dans le paysage. La position de tous les oiseaux détectés a été relevée. L’étude se déroulant en période de reproduction pour les oiseaux, les individus détectés sur ou à l’intérieur des haies échantillonnées étaient considérés comme utilisant la haie comme habitat de nidification ou de repos. Les caractéristiques des haies ont aussi été inventoriées. La composition paysagère entourant les haies a été extraite à posteriori à partir de bases de données spatiales nationales. Des analyses statistiques ont été réalisées pour étudier les cortèges d'oiseaux et caractériser les types de haies et de paysages. Ces analyses ont montré que les cortèges d'oiseaux présents dans les haies étaient relativement homogènes, car l'étude portait uniquement sur des oiseaux utilisant spécifiquement les haies comme habitat de reproduction, donc ayant des exigences écologiques proches. Des modèles linéaires à effets mixtes ont été utilisés afin d’étudier l’effet des variables des haies et du paysage sur trois indices liés aux espèces protégées : la probabilité de présence d'au moins une espèce protégée, l'abondance en espèces protégées et leur richesse spécifique. Des modèles d’occupation de site uni-saison ont aussi été utilisés afin d’estimer le pourcentage d’occupation des haies par au moins une espèce protégée en prenant en compte le fait que la détection des espèces n’est pas exhaustive sur le terrain. Ces modèles ont montré que quasiment toutes les haies étaient occupées par au moins une espèce protégée, à l’exception de quelques haies basses, abimées et entretenues trop intensément et cela dans les paysages de grandes cultures, démontrant ainsi l'importance écologique des haies pour les oiseaux protégés. La présence des espèces protégées dans les haies était davantage liée aux caractéristiques des haies qu’à celles du paysage, ce qui indique que les haies ont une importance écologique majeure quel que soit le contexte paysager. L'abondance en espèces protégées et la richesse spécifique étaient les plus élevées dans les haies hautes, larges, anciennes et présentant une bonne hétérogénéité d'habitats (présence d'arbres anciens, de cavités, de bois morts etc.). La continuité des haies était également un facteur engendrant une abondance et une richesse plus élevée en espèces d’oiseaux protégés. Les trois indices étudiés étaient fortement influencés négativement par les mesures d'entretien des haies et présentaient des valeurs plus faibles dans les haies de petite taille, endommagées et très entretenues. De plus, la richesse et l'abondance étaient négativement affectées par l'homogénéité du paysage. Au-delà de la question de l’utilisation des haies comme habitat par les oiseaux protégés, les résultats semblent plaider en faveur de la préservation et restauration de paysages ruraux hétérogènes ainsi que pour la préservation des ripisylves et des haies au sens large. Des propositions ont été faites pour améliorer le protocole d’échantillonnage des haies et réduire les biais de détection identifiés dans cette étude. Des perspectives pour généraliser davantage l’étude de l’utilisation des haies par les espèces protégées à d’autres taxons sont aussi présentées.
... He wondered 'how long does a stump take to disappear, how many years does a dead tree take to fall and how many years does a fallen dead tree take to disappear?', and 'how effective are sacred forests as protection against falling rocks and other upslope hazard?'. Thanks to the THALIS project, many of the questions raised by Oliver have been successfully investigated (see Kyparissis et al. 2015;Stara et al. , 2016Tsiakiris et al. 2017;Avtzis et al. 2018;Muggia et al. 2018;Marini Govigli et al. 2020, 2021Benedetti et al. 2021;Diamandis et al. 2021;Stara 2021Stara , 2022Zannini et al. 2021; Moudopoulos-Athanasiou 2022; Roux et al. 2022); yet others remain to be further explored. ...
Like one of the ancient trees he wrote about so elegantly and perceptively, Oliver Rackham’s roots run deep while his influence branches far. He was undoubtedly the leading scholar in landscape history and historical ecology, and his work continues to resonate not just with his peers but with a much wider public audience too. His combination of extensive archival research, meticulous fieldwork and place-name analysis were truly ground-breaking. He not only changed the way we think about the landscape; he in fact altered that landscape in turn – enriching, clarifying, bringing it to life. This book, which honours Rackham’s memory, is a unique collection of contributions from leading global authorities on countryside and landscape history. A number of chapters come from individuals who were his friends and collaborators, and they each share a debt to his scholarship and methods. Ranging all over Europe from Białowieża Forest in Poland to the Mediterranean, and across the world from New England to northern Japan, the wealth of perspectives gathered here makes for a diverse and weighty discussion. Collectively, the contributions represent an acknowledgment of Rackham’s huge impact and influence at the same time as offering a benchmark for current thinking in countryside history worldwide. This volume will appeal to researchers, postgraduate students, final-year undergraduates, lecturers and scholars on the one hand, but also to anyone who loves the countryside and is fascinated by its complex history. As we lose irreplaceable heritage landscapes to climate change and development, an understanding of what they are and what they mean only becomes more vital.
... Some species, characterized by a relatively high evolutionary uniqueness (e.g., European robin Erithacus rubecula and Eurasian hoopoe Upupa epops), were found to be linked to the presence of large urban trees or bushes. 24,39,40 Then, the configuration of the different urban areas of the city can shape the avian composition in terms of evolutionary uniqueness. 7 This information is important for correctly developing strategies to protect more unique bird species. ...
Urbanization alters avian communities, generally lowering the number of species and contemporaneously increasing their functional relatedness, leading to biotic homogenization. Urbanization can also negatively affect the phylogenetic diversity of species assemblages, potentially decreasing their evolutionary distinctiveness. We compare species assemblages in a gradient of building density in seventeen European cities to test whether the evolutionary distinctiveness of communities is shaped by the degree of urbanization. We found a significant decline in the evolutionary uniqueness of avian communities in highly dense urban areas, compared to low and medium-dense areas. Overall, communities from dense city centres supported one million years of evolutionary history less than communities from low-dense urban areas. Such evolutionary homogenization was due to a filtering process of the most evolutionarily unique birds. Metrics related to evolutionary uniqueness have to play a role when assessing the effects of urbanization and can be used to identify local conservation priorities.
... They also host rarer fauna, containing a greater variety of fungi than their managed counterparts (Diamantis et al. 2021). Likewise, vakoúfika possess greater bird species richness and reduce biotic homogenization, while ancient individual trees support all aspects of bird diversity; it is suggested that all these aspects make them distinct targets for conservation and restoration in European policy, in line with the European Biodiversity Strategy for 2030 (see Benedetti et al. 2021). ...
In recent years there is a growing interest in the “Sacred Forests” (vakoúfika) of Zagori in Northwest Greece. These are either groves or individual trees, dedicated to patron saints, protected through customary laws, communal regulations, religious excommunications, and supernatural narratives. For ca. 300 years they have represented the tangible reminders of rituals, beliefs, and pre-modern ways of managing the commons to an extent that they survive in the present. This article introduces archaeology into the interdisciplinary discourse revolving around vakoúfika. Through the concepts of dwelling, walking, and archaeological ethnography, I evaluate the concept of static “traditional” mountainous communities and focus on the changes that might have occurred to the rituals and beliefs associated with vakoúfika over the past centuries. The case study is the Sacred Forest of Băeasă (Vovousa), dedicated to St. Viniri and the associated rituals. In situ observations and especially the exploration of the role of two stones in the celebration reveal an archaeological layer to the pilgrim, in which the center of the ritual was the forest not its associated chapel.
... Livelihood support from ecosystem products in southern Malawi (Pullanikkatil et al., 2020), southwestern Ethiopian mountains (Nischalke et al., 2017), Southern China (Min et al., 2017), Himalayan mountains (Nepal et al., 2018) and South Africa (Ngwenya et al., 2019) has been reported. Additionally, the sacredness of mountains in different religions and cultures is widely acknowledged (Ceruti, 2019;Benedetti et al., 2021). ...
Mountains are highly significant regions in the context of climate change and sustainable development, at the intersection of accelerated warming and a large population depending directly or indirectly on them. They are regions of high biological and cultural diversity and provide vital goods and services to people living in and around mountain regions and in downstream areas. Building on the IPCC’s Fifth Assessment Report (AR5), Chapter 2 “High Mountain Areas” of the Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC), and the IPCC Working Group I contribution to AR6, this Cross-Chapter Paper (CCP) assesses new evidence on observed and projected climate change impacts in mountain regions, their associated key risks and adaptation measures.
Additional contributing authors:
Irasema Alcántara-Ayala (Mexico), Simon K. Allen (Switzerland/New Zealand), Maaike Bader (Germany), Sophie Bigler (Switzerland), James Camac (Australia), Ritodhi Chakraborty (New Zealand/India), Aida Cuni Sanchez (Norway/Spain), Nicolás Cuvi (Ecuador), Fabian Drenkhan (Peru/Germany), Abid Hussain (Nepal/Pakistan), Amina Maharjan (Nepal), Robert Marchant (United Kingdom), Graham McDowell (Canada/USA), Samuel Morin (France), Laura Niggli (Switzerland), Ana Ochoa (Ecuador), Avash Pandey (Nepal), Julio Postigo (USA/Peru), Estelle Razanatsoa (South Africa/Madagascar), Valeria M. Rudloff (Chile), Christopher Scott (USA), Madison Stevens (Canada), Daithi Stone (New Zealand), Jessica Thorn (United Kingdom/Namibia), James Thornton (Switzerland/United Kingdom), Daniel Viviroli (Switzerland), Saskia Werners (The Netherlands)
Environmental sustainability and resilience of cities is based on the biological diversity of green urban areas. Biodiversity of green infrastructure in dynamic urbanized environments is changing very fast. Understanding these ecological processes (and using them to environmental management of urban ecosystems) supports the application of birds as bioindicators. Although there is a consensus that long-term bird studies are extraordinarily valuable for better understanding of real temporal trends in avian urban diversity changes, these are still very rare. The main aim of this study is the assessment of long-term changes (during 30 years) in avian communities in historic manor parks in Central-European urbanized landscapes. Statistical testing of hypotheses as well as using calculation of faunistic indexes based on guild approach revealed high stability in bird diversity of large historic manor parks for a period 1994–2023. Results revealed the role of historic manor parks not only as historical sites but also as important urban biodiversity hotspots, which need specific management practice to maintain biodiversity in environmentally sustainable cities. Results also supported our better understanding of the joining of natural and historical heritage in cities worldwide in the frame of new scientific concept of Biocultural Diversity.
The development of societies, including spiritual development, is closely connected to forests. The larger interrelations among changing societies, transforming forest landscapes, and evolving spiritual values related to forests have yet to be extensively considered. Addressing this research gap is important to avoid the neglect of spiritual values in forest policy and management. Our exploratory study investigates spiritual values of forests from European and Asian perspectives, assessing 13 countries. Based on expert knowledge from 18 interdisciplinary experts, we first define forest spiritual values (forest spirituality). We then elaborate on the idea that forest spirituality evolves as societies and landscapes change, and propose a transition hypothesis for forest spirituality. We identify indicators and drivers and portray four stages of such a transition using country-specific examples. We find that during a first stage ("nature is powerful"), forest spirituality is omnipresent through the abundance of sacred natural sites and practices of people who often directly depend on forests for their livelihoods. An alternative form of spirituality is observed in the second stage ("taming of nature"). Connected to increasing transformation of forest landscapes and intensifying land-use practices, "modern" religions guide human-nature interrelations. In a third stage ("rational management of nature"), forest spirituality is overshadowed by planned rational forest management transforming forests into commodities for the economy, often focusing on provisioning ecosystem services. During a fourth stage ("reconnecting with nature"), a revival of forest spirituality (re-spiritualization) can be observed due to factors such as urbanization and individualizing spirituality. Our core contribution is in showing the connections among changing forest perceptions, changing land-use governance and practices, and changing forest spirituality. Increasing the understanding of this relationship holds promise for supporting forest policy-making and management in addressing trade-offs between spiritual values and other aspects of forests.
Aim: We assessed the spatial distribution of four different types of avian specialization throughout Europe, identifying landscape features associated with specialization, and quantifying where the Natura 2000 network intersects with areas of high avian specialization.
Location: Europe
Time period: Present day
Taxa studied: European breeding birds
Methods: We used the European Atlas of breeding birds and four avian specialization measures (diet, foraging behavior, foraging substrate, and habitat). We calculated specialization richness and identified geographic hotspots for each of these ecological traits. We tested whether altitudinal gradient, landscape heterogeneity, or dominant land-use predicted each type of specialization richness. We determined which types of European protected areas are most associated with higher specialization richness.
Results: Diet and foraging substrate specialists increased with altitude while richness of foraging behavioral specialists decreased. There was a greater richness of diet and habitat specialists in forests than in other environments. The Natura 2000 areas declared under Bird and both directives (Birds and Habitats) intersected with a high diet, foraging substrate, and habitat specialist richness. The richness of foraging behaviour specialists was high in Birds directive areas. Single and multiple hotspots of specialization were greater in protected than non-protected areas. However, almost 30% of specialization hotspots did not intersect with protected areas.
Main conclusions: Our findings suggest that higher levels of avian specialization in Europe are positively associated with altitude and forested land cover. Importantly, we found that the Natura 2000 network supports all types of avian ecological specialization, albeit mainly in areas declared under both directives.
Primary forests are critical for forest biodiversity and provide key ecosystem services. In Europe, these forests are particularly scarce and it is unclear whether they are sufficiently protected. Here we aim to: (a) understand whether extant primary forests are representative of the range of naturally occurring forest types, (b) identify forest types which host enough primary forest under strict protection to meet conservation targets and (c) highlight areas where restoration is needed and feasible.
We combined a unique geodatabase of primary forests with maps of forest cover, potential natural vegetation, biogeographic regions and protected areas to quantify the proportion of extant primary forest across Europe's forest types and to identify gaps in protection. Using spatial predictions of primary forest locations to account for underreporting of primary forests, we then highlighted areas where restoration could complement protection.
We found a substantial bias in primary forest distribution across forest types. Of the 54 forest types we assessed, six had no primary forest at all, and in two‐thirds of forest types, less than 1% of forest was primary. Even if generally protected, only ten forest types had more than half of their primary forests strictly protected. Protecting all documented primary forests requires expanding the protected area networks by 1,132 km2 (19,194 km2 when including also predicted primary forests). Encouragingly, large areas of non‐primary forest existed inside protected areas for most types, thus presenting restoration opportunities.
Europe's primary forests are in a perilous state, as also acknowledged by EU's “Biodiversity Strategy for 2030.” Yet, there are considerable opportunities for ensuring better protection and restoring primary forest structure, composition and functioning, at least partially. We advocate integrated policy reforms that explicitly account for the irreplaceable nature of primary forests and ramp up protection and restoration efforts alike.
Natural spruce forests are restricted to the highest mountain ranges in the Czech Republic. Spruce is also the commonest tree species in managed forests. Owing to a massive decline of spruce forests in Central Europe, caused by recent climatic fluctuations and disturbances, the lichen diversity and species composition was compared between ten representative natural mountain old-growth forests in the Czech Republic and their counterparts in mature managed forests. The old-growth forests are characterized by a higher species richness, abundance, number of Red-listed species, functional, taxonomic and phylogenetic diversities. Plots with the highest species richness are situated in the Šumava Mountains, an area with a relatively low sulphur deposition in the past. Bioindication analysis searching for lichen indicators supported several species (e.g. Xylographa vitiligo, Chaenotheca sphaerocephala) and genera (e.g. Calicium, Xylographa) with a strong preference for old-growth forests. Analysis of lichen functional traits revealed a higher abundance of species with a vegetative reproduction in managed forests that may be explained by a higher efficiency in colonization by young successional stages. Lichens with stalked apothecia, pigmented ascospores and large ascospores are more frequent in old-growth forests. Our results are briefly discussed in terms of nature conservation, focusing on national refugees of old-growth forest species, biodiversity hot-spots, practical use of indicator species and representative measures for an evaluation of forest quality.
Measuring the extent to which a species is specialized is a major challenge in ecology, with important repercussions for fundamental research as well as for applied ecol‐ogy and conservation. Here, we develop a multidimensional index of specialization based on five sets of ecological characteristics of breeding bird species. We used two recent databases of species traits of European birds based on foraging ecology, habitat, and breeding characteristics. The indices of specialization were calculated by applying the Gini coefficient, an index of inequality. The Gini coefficient is a measure of statistical dispersion on a scale between 0 and 1, reflecting a gradient from low to high specialization, respectively. Finally, we tested the strength of the phylogenetic signal of each specialization index to understand how the variance of such indices is shared throughout the phylogeny. The methods for constructing and evaluating a multidimensional index of bird specialization could also be applied to other taxa and regions, offering a simple but useful tool, particularly suited for global or biogeo‐graphic studies, as a contribution to comparative estimates of the degree of speciali‐zation of species.
The retention forestry approach is considered as one of the potentially effective tools for sustainable forest management for conservation of biodiversity in managed temperate and boreal forests. Retention of old-growth forest structures (e.g., very large old living trees) in forest stands during clear-cutting provides maintenance of key habitats for many old-growth forest interior-species. Most of ecological studies on green tree retention (GTR) consequences for biodiversity have been focused on birds. However, the long-term studies of GTR impacts on forest birds are very poor. In this paper, we focused on assessment of the long-term consequences of leaving legacy oak trees on the cut areas for bird diversity 18–22 years after clear-cutting in managed temperate European hardwood floodplain forests. Results based on bird counting using mapping of bird nesting territories revealed a key importance of legacy oak trees for maintaining bird diversity in the study area. These results are widely applicable for managed temperate hardwood forests with serious dominance of oak (Quercus sp.) in forest stands. Legacy oak trees in this habitat type are keystone structures for bird diversity. Retention approach focused on these trees is potentially an important conservation tool for preserving forest bird diversity and other associated species in temperate hardwood forests managed by clear-cutting.
Forest structural complexity could be a good predictor of overall species
diversity. Since tree harvesting has a negative effect on forest structure,
it is important to analyse the effects of this disturbance on sensitive
groups, as forest birds. In this study, we aimed to shed light on this
aspect by analysing a set of univariate metrics in bird communities
breeding in three coppiced forest habitats (coppiced of chestnut, coppiced
of Turkey oak and high forest of beech) along a gradient in age classes. We
hypothesised that, with increasing forest age, (i) breeding bird communities will
progressively increase in diversity and, (ii) due to higher habitat
heterogeneity due to coppicing, a higher species turnover in the first age
classes could appear. In each forest habitat, all the metrics significantly
increased, from recently coppiced to more mature forests, due to
progressively higher availability of resources and niches along the gradient.
When comparing paired forest habitats, abundance and richness were
significantly different only in the two oldest age classes, highlighting that
responses to different tree composition were more marked in the mature
phase. In all forest habitats, species turnover (βw diversity)
decreased progressively along the age gradient and was highest in the
youngest age classes where many vegetation layers were present. Due to
different coppice management practices, growth regime and consequent habitat
heterogeneity, chestnuts showed a different pattern when compared to other
forest habitats, with an increase in species turnover (βw diversity)
at intermediate level. With increasing age of the forests, all the diversity
metrics increased and species turnover decreased, highlighting the role of
older forests as strategic habitats for highly structured bird communities.
We assessed the assemblages of birds inhabiting pine-dominated managed forest, aged between 1–5 years and above 140 years. Birds were counted on study plots representing eight different phases to the forest's development, with nesting, foraging and migratory guild categories recognised. Numbers of bird species and population densities, both increased markedly with stand age (respectively r = 0.988 and r = 0.936, P < 0.001). While numbers of ground-nesting bird species failed to correlate with stand age, successively older stands did support ever-greater proportions of species in the assemblage that nested in tree crowns (r = 0.976, P < 0.005) or tree holes (r = 0.833, P < 0.005). Raptors were most abundant in forest at the oldest stages of growth, and there was an age-gradient-related increase in the shares of both plant-eating species (r = 0.952, P < 0.005) and raptors (r = 0.764, P < 0.005). Resident birds were most numerous in the oldest forest. PCA for ten selected variables (relating to guild type) showed that the two principal components explained almost 98% of the variation among groups of bird guilds in relation to forest age. On the basis of their suitability for birds it was possible to distinguish three categories of stand by age group, of which the first encompasses the initial stage, the second a broad interval involving middle-aged stands of between 16 and 140 years, and the third forest more than 140 years old. The presence of the oldest stands of all can thus be seen to play a very important role in maintaining high-diversity populations of birds in managed forest.
Many studies have dealt with the habitat requirements of cavity‐nesting birds, but there is no meta‐analysis on the subject and individual study results remain vague or contradictory. We conducted a meta‐analysis to increase the available evidence for nest‐site selection of cavity‐nesting birds. Literature was searched in Web of Science and Google Scholar and included studies that provide data on the habitat requirements of cavity‐nesting birds in temperate and boreal forests of varying naturalness. To compare nest and non‐nest‐tree characteristics, the following data were collected from the literature: diameter at breast height (DBH) and its standard deviation (SD), sample size of trees with and without active nest, amount of nest and available trees described as dead or with a broken crown, and amount of nest and available trees that were lacking these characteristics. Further collected data included bird species nesting in the cavities and nest‐building type (nonexcavator/excavator), forest type (coniferous/deciduous/mixed), biome (temperate/boreal), and naturalness (managed/natural). From these data, three effect sizes were calculated that describe potential nest trees in terms of DBH, vital status (dead/alive), and crown status (broken/intact). These tree characteristics can be easily recognized by foresters. The results show that on average large‐diameter trees, dead trees, and trees with broken crowns were selected for nesting. The magnitude of this effect varied depending primarily on bird species and the explanatory variables forest type and naturalness. Biome had lowest influence (indicated by ΔAIC). We conclude that diameter at breast height, vitality, and crown status can be used as tree characteristics for the selection of trees that should be retained in selectively harvested forests.
Intensive management implies harvesting large, old trees, which reduces the old-growth attributes. This negatively affects biodiversity, especially saproxylic beetles. In managed temperate oak forests, rotation extension induced by increasing the diameter threshold of final harvest by about 10 cm compared to conventional practices (i.e. DBH around 70 cm) might mitigate this negative effect. Here, we used a gradient of the proportion of overmature trees (DBH ≥ 80 cm) among mature trees (DBH ≥ 70 cm) across plots of high oak French forests to test the potential effect of increasing diameter threshold on (1) structural features and (2) species composition and diversity of saproxylic beetles communities. We assessed deadwood and microhabitats availability (i.e. volume/density and diversity) and canopy openness in 81 1-ha plots across eleven French forests. Results highlighted that a larger proportion of overmature trees, for a given density of mature trees, had limited effects on structural features: only cavities density showed a significant positive response, with no cascading effect on cavicolous beetles. Moreover, the proportion of overmature trees had no significant effect on the composition of saproxylic beetles communities (and ecological variables altogether explained only 17% of the composition inertia). By contrast, mature tree density enhanced microhabitat density and indirectly increased the abundance of rare species. Thus, shifting DBH from 70 to 80 cm in high oak forest could have no or limited effect on saproxylic beetles conservation. Improved strategies might rather stem from combining (1) longer rotation extension and (2) less intensive management practices in extended rotation stands.
Old-growth forests have become rare in North America but provide habitat for unique assemblages of species that often are rare in younger forests. Insects and related arthropods reach their highest diversity in old-growth forests because of their stable moderate temperature and relative humidity and the rich variety of resources represented by high plant species richness and structural complexity. Old-growth arthropod assemblages typically are distinct from those in younger, managed forests. Major subcommunities include the arboreal community that is composed of a rich assemblage of herbivores, fungivores, and their associated predators and parasitoids that function to regulate primary production and nutrient fluxes, the stem zone community that includes bark- and wood-boring species and their associated predators and parasitoids that initiate the decomposition of coarse woody debris, and the forest floor community composed of a variety of detritivores, fungivores, burrowers, and their associated predators and parasitoids that are instrumental in litter decomposition. Insect outbreaks are relatively rare in old-growth forests, where the diversity of resources and predators limit population growth. In turn, insects contribute to plant diversity and limit primary production of host plant species, thereby promoting development of old-growth forest characteristics. Arthropods also provide important functions in decomposition and nutrient cycling that may be lost in younger, managed forests with limited provision of coarse woody debris and accumulated litter. Protection of remnant old-growth forests within the forest matrix may be particularly valuable for maintaining the diversity of plant and arthropod predators that can minimize outbreaks, thereby contributing to resilience to changing environmental conditions.
Conventional managed forests and sacred groves are seldom assessed to determine their effectiveness in biodiversity conservation strategies. This study investigated tree and insect diversity in Jachie sacred grove (JSG) and Nkrabea forest reserve (NFR) in Ashanti region, Ghana. The study area constituted eight plots of 50 × 50 m along two 300 m long transects. Insects were sampled in eight pitfall traps, diagonally between the transects. Out of 150 individuals, 13 species in NFR and 15 species from JSG were registered. Celtis mildbraedii was the most dominant species in NFR = 43.18% and JSG = 23.58%. Mean DBH showed a significant relationship with basal area in NFR and JSG. Tree diversity and richness were higher in JSG (í µí°» í® í° = 1.43–2.3 ± 0.10; í µí°· = 1.8–3.69 ± 0.30) compared to NFR (í µí°» í® í° = 0.86–1.56 ± 0.09; í µí°· = 1.1–2.3 ± 0.57). However, insect diversity was higher in NFR (í µí°» í® í° = 1.34 ± 0.10) than in JSG (í µí°» í® í° = 0.5 ± 0.005). Camponotus furvus and Pachycondyla tarsata were most abundant in JSG and NFR, respectively. These findings will help conservationists work closely with traditional authorities in protecting sacred groves as key biodiversity hotspots.
Disturbance regimes are changing worldwide, and the consequences for ecosystem function and resilience are largely unknown. Functional diversity (FD) provides a surrogate measure of ecosystem function by capturing the range, abundance and distribution of trait values in a community. Enhanced understanding of the responses of FD to measures of vegetation structure at landscape scales is needed to guide conservation management. To address this knowledge gap, we used a whole-of-landscape sampling approach to examine relationships between bird FD, vegetation diversity and time since fire. We surveyed birds and measured vegetation at 36 landscape sampling units in dry and wet forest in southeast Australia during 2010 and 2011. Four uncorrelated indices of bird FD (richness, evenness, divergence and dispersion) were derived from six bird traits, and we investigated responses of these indices and species richness to both vertical and horizontal vegetation diversity using linear mixed models. We also considered the extent to which the mean and diversity of time since fire were related to vegetation diversity. Results showed opposing responses of FD to vegetation diversity in dry and wet forest. In dry forest, where fire is frequent, species richness and two FD indices (richness and dispersion) were positively related to vertical vegetation diversity, consistent with theory relating to environmental variation and coexistence. However, in wet forest subject to infrequent fire, the same three response variables were negatively associated with vertical diversity. We suggest that competitive dominance by species results in lower FD as vegetation diversity increases in wet forest. The responses of functional evenness were opposite to those of species richness, functional richness and dispersion in both forest types, highlighting the value of examining multiple FD metrics at management-relevant scales. The mean and diversity of time since fire were uncorrelated with vegetation diversity in wet forest, but positively correlated with vegetation diversity in dry forest. We therefore suggest that protection of older vegetation is important, but controlled application of low-severity fire in dry forest may sustain ecosystem function by enhancing different elements of FD.
This study explored the hole-nesting bird community for two years, in three beech forest stands of central Italy. Our experimental design involved 12 replicated sampling points in each study area for a total of 36 sampling points. Stand characteristics were measured through selected environmental variables (tree diameter, tree density, volume of dead wood, diversity of dead wood and canopy closure), to develop habitat models for describing the factors affecting the abundance of hole-nesting birds. We performed generalized linear models to determine which environmental variables better explained the presence and abundance of hole-nesting birds in the three study areas. The species that showed the highest values of abundance are the Nuthatch, the Blue Tit and the Great Tit. Within the guild of hole-nesting birds there are differences in the selection of suitable trees for nesting, roosting or foraging. Primary cavity nesters (woodpeckers) are mostly related to the presence of large trees, the volume of dead wood and tree height. The presence and abundance of secondary cavity nesters (tits, nuthatches and treecreepers) seem to be mostly influenced by diversity of dead wood. The diversity of dead wood is an important variable that influences the presence and abundance of hole-nesting birds. Maintenance of both living and standing dead wood in forest ecosystems is recommended to increase the effectiveness of conservation actions affecting the hole-nesting birds.
Sacred natural sites (SNS) are instances of biocultural landscapes protected for spiritual motives. These sites frequently host important biological values in areas of Asia and Africa, where traditional resource management is still upheld by local communities. In contrast, the biodiversity value of SNS has hardly been quantitatively tested in Western contexts, where customs and traditions have relatively lost importance due to modernization and secularization. To assess whether SNS in Western contexts retain value for biodiversity, we studied plant species composition at 30 SNS in Central Italy and compared them with a paired set of similar but not sacred reference sites. We demonstrate that SNS are important for conserving stands of large trees and habitat heterogeneity across different land-cover types. Further, SNS harbor higher plant species richness and a more valuable plant species pool, and significantly contribute to diversity at the landscape scale. We suggest that these patterns are related not only to pre-existent features, but also to traditional management. Conservation of SNS should take into account these specificities, and their cultural as well as biological values, by supporting the continuation of traditional management practices.
Birds are conspicuous in many habitats, occur worldwide, are ecologically diverse, and are better known than other vertebrate groups. Birds devour pests, pollinate flowers, disperse seeds, scavenge carrion, cycle nutrients, and modify the environment in ways that benefit other species. Investigation of these ecosystem functions directly as ecosystem services has grown immensely over the last two decades and the ecological relevance of birds is well established. Birds are also observed, fed, and used as artistic and spiritual inspiration by millions of people around the globe. Yet the economic relevance of birds is not widely appreciated and the economic relevance to human society of birds' ecological roles is even less understood. Quantifying the services provided by birds is crucial to understand their importance for ecosystems and for the people that benefit from them. In this paper, we briefly review the rise and fall of economic ornithology and call for a new economic ornithology with heightened standards and a holistic focus within the ecosystem services approach. Birds' ecological roles, and therefore, ecosystem services, are critical to the health of many ecosystems and to human well-being. By understanding and valuing bird services and disservices through careful natural history research, we can better assess the environmental consequences of bird declines and extinctions and communicate these findings to the public and policy makers, thereby increasing public support for the conservation of birds and their habitats.
The response of woody species to anthropogenic disturbances was studied in three forest stands viz., Swer, Nonglang and Nongkrem representing subtropical humid forests of the area. These forest stands were preserved till recently as sacred groves on the basis of religious beliefs. However, during the past decade, some portions of these sacred groves have been disturbed due to product extraction following erosion in religious beliefs. The diversity and regeneration of woody species present in these forests has been studied to assess the response of the species to human disturbance. A total of 114 woody species (³5cm dbh) were identified in the three forests. The species richness in disturbed stands was significantly lower in the disturbed stand (24-26) than the undisturbed stands (60-32). The density also followed a similar trend in Swer and Nonglang forest stands whereas, it increased from 898 stems ha in the undisturbed standto 954 stems ha in the disturbed stand at Swer. The basal area of woody species-1-1 was significantly higher in the undisturbed stands (27-62 m ha) than the disturbed stands (3.14 to 58.25 m ha). The distribution of density in different dbh classes resulted in a reverse J-shaped curve in all the undisturbed stands, while in the disturbed stands, there was a reduction in density in the higher dbh classes. The densities of seedlings and saplings were significantly higher in the undisturbed stands than the disturbed stands, although seedling density far exceeded the sapling density in all the stands. The proportion of species showing no regeneration was high in the undisturbed stand as compared to the disturbed stand. Results revealed that species richness significantly got reduced, tree population structure showed a decrease in higher girth class individuals and the regeneration status of the species was also altered due to disturbance.
We investigate patterns of phylogenetic diversity in relation to species diversity for European birds, mammals and amphibians, to evaluate their congruence and highlight areas of particular evolutionary history. We estimate the extent to which the European network of protected areas (PAs) network retains interesting evolutionary history areas for the three groups separately and simultaneously.
Europe.
Phylogenetic (QEPD) and species diversity (SD) were estimated using the Rao's quadratic entropy at 10' resolution. We determined the regional relationship between QEPD and SD for each taxa with a spatial regression model and used the tails of the residuals (QERES) distribution to identify areas of higher and lower QEPD than predicted. Spatial congruence of biodiversity between groups was assessed with Pearson's correlation. A simple classification scheme allowed building a convergence map where a convergent pixel equalled to a QERES value of the same sign for the 3 groups. This convergence map was overlaid to the current PAs network to estimate the level of protection in convergent pixels and compared it to a null expectation built on 1000 randomization of PAs over the landscape.
QERES patterns across vertebrates show a strong spatial mismatch highlighting different evolutionary histories. Convergent areas represent only 2.7% of the Western Palearctic, with only 8.4% of these areas being covered by the current PAs network while a random distribution would retain 10.4% of them. QERES are unequally represented within PAs: areas with higher QEPD than predicted are better covered than expected, while low QEPD areas are undersampled.
Patterns of diversity strongly diverge between groups of vertebrates in Europe. Although Europe has the world's most extensive PAs network, evolutionary history of terrestrial vertebrates is unequally protected. The challenge is now to reconcile effective conservation planning with a contemporary view of biodiversity integrating multiple facets.
The origins of ecological diversity in continental species assemblages have long intrigued biogeographers. We apply phylogenetic comparative analyses to disentangle the evolutionary patterns of ecological niches in an assemblage of European birds. We compare phylogenetic patterns in trophic, habitat and climatic niche components.
Europe.
From polygon range maps and handbook data we inferred the realized climatic, habitat and trophic niches of 405 species of breeding birds in Europe. We fitted Pagel's lambda and kappa statistics, and conducted analyses of disparity through time to compare temporal patterns of ecological diversification on all niche axes together. All observed patterns were compared with expectations based on neutral (Brownian) models of niche divergence.
In this assemblage, patterns of phylogenetic signal (lambda) suggest that related species resemble each other less in regard to their climatic and habitat niches than they do in their trophic niche. Kappa estimates show that ecological divergence does not gradually increase with divergence time, and that this punctualism is stronger in climatic niches than in habitat and trophic niches. Observed niche disparity markedly exceeds levels expected from a Brownian model of ecological diversification, thus providing no evidence for past phylogenetic niche conservatism in these multivariate niches. Levels of multivariate disparity are greatest for the climatic niche, followed by disparity of the habitat and the trophic niches.
Phylogenetic patterns in the three niche components differ within this avian assemblage. Variation in evolutionary rates (degree of gradualism, constancy through the tree) and/or non-random macroecological sampling probably lead here to differences in the phylogenetic structure of niche components. Testing hypotheses on the origin of these patterns requires more complete phylogenetic trees of the birds, and extended ecological data on different niche components for all bird species.
This manual can be downloaded for free from URL
http://www.worldagroforestry.org/output/tree-diversity-analysis
Effective data analysis requires familiarity with basic concepts and an
ability to use a set of standard tools, as well as creativity and imagination.
Tree diversity analysis provides a solid practical foundation for training in
statistical methods for ecological and biodiversity studies.
This manual arose from training researchers to analyse tree diversity data
collected on African farms, yet the statistical methods can be used for a
wider range of organisms, for different hierarchical levels of biodiversity and
for a variety of environments — making it an invaluable tool for scientists and
students alike.
Focusing on the analysis of species survey data, Tree diversity analysis
provides a comprehensive review of the methods that are most often used in
recent diversity and community ecology literature including:
• Species accumulation curves for site-based and individual-based species
accumulation, including a new technique for exact calculation of sitebased
species accumulation.
• Description of appropriate methods for investigating differences in
diversity and evenness such as Rényi diversity profiles, including methods
of rarefaction to the same sample size for different subsets of the data.
• Modern regression methods of generalized linear models and generalized
additive models that are often appropriate for investigating patterns of
species occurrence and species counts.
• Methods of ordination for investigating community structure and the
influence of environmental characteristics, including recent methods
such as distance-based redundancy analysis and constrained analysis of
principal coordinates.
The manual also introduces a powerful new software programme,
BiodiversityR, that is capable of performing all the statistical analyses
described in the book. The software is built using the free R language and
environment for statistical computing, and several of its libraries such as
the vegan community ecology package and the R-commander graphical
user interface. The software is provided on CD.
After publishing this manual, the BiodiversityR software was modified into
a package that can be downloaded and installed from URL
https://cran.r-project.org/package=BiodiversityR
The vegan community ecology package can be downloaded from URL https://cran.r-project.org/package=vegan.
Installation guidelines for windows users are available from URL
http://dx.doi.org/10.13140/RG.2.1.4706.0082.
A tutorial for ensemble suitability modelling is available from URL
http://dx.doi.org/10.13140/RG.2.1.1993.7684.
As forests undergo natural succession following artificial afforestation, their bird assemblages also change. However, interspecific avian social organization associated with forest succession has not been fully understood, particularly for mixed-species bird flocks. To disentangle how mixed-species flocks change as a function of local forest structure, we analyzed flock characteristics (particularly species richness, flocking frequency and propensity) and vegetation physiognomies along a presumed successional series (early, middle, and advanced) simultaneously in subtropical forests in southern China. As hypothesized, monthly point counts demonstrated that complexity of flocks increases with the progression of natural forest succession at a local scale. Advanced forests differed significantly from pioneering plantations with respect to vegetation structure, flock characteristics and constituents (especially for understory specialists). Importantly, forest succession affected flock patterns particularly in relation to the flocking propensity of regular species, and the frequency of nuclear species (Huet’s fulvetta Alcippe hueti), which in turn determined flocking occurrence at different successional stands. Canonical correspondence analysis indicated that understory flocking species (mainly Timaliidae babblers) were significantly associated with intact native canopy cover, complex DBH diversity, as well as high densities of dead trees and large trees, representing a maturity level of successional stands. Our study reveals that the effect of natural forest succession on mixed-species bird flocks is species-specific and guild-dependent. From a conservation perspective, despite a high proliferation of pine plantation in southern China, priority should be placed on protecting the advanced forest with a rich collection of understory flocking specialists.
Existing global protected area networks have two shortcomings: (1) they do not cover certain habitats, and (2) local people often resent their formal management. Here, we show that communities around the world traditionally protect natural sites that are dedicated to ancestral spirits or deities. Such sites cover a wide variety of habitats and are often located in biodiversity rich regions. Case studies on sacred groves show that these small forest patches play an important role in biodiversity conservation. Furthermore, natural sacred sites are maintained through traditional methods of community based conservation that do not require governmental involvement. Incorporating these sites into conservation networks could enhance the effectiveness of protected areas by covering a wider variety of habitats and by harnessing the support of local people. In this article, we discuss current threats to sacred groves that need to be addressed through management approaches. More research on the ecology and underlying socioeconomic mechanisms of natural sacred sites is required to fully reveal their potential for biodiversity conservation.
Sacred natural sites are frequently better protected than many officially protected areas, but an overall understanding of their role in conservation strategies is lacking. Over the last few years, scientists have assembled quantitative data from sacred natural sites, comparing their biodiversity values with those of the surroundings, officially protected areas and other management approaches such as forest reserves. This chapter draws on information from over a hundred studies throughout Africa and Asia, which provides concrete evidence that many sacred natural sites have great importance to biodiversity conservation, in addition to their spiritual value to one or more faith groups. Sacred natural sites appear to be extremely common in some countries, although much remains to be learned about their global extent, as research reported in the scientific literature tends to be focused on a few countries. Sacred natural sites are often the only remaining patches of natural or semi-natural habitat in cultural landscapes (see Figure 2.1) and can contain rich biodiversity, sometimes exceeding nearby protected areas and forest reserves. However, a number of problems have been identified threatening the role of sacred natural sites in long term conservation strategies. They are often too small to support a full complement of expected species and many sites are suffering from increased anthropogenic pressure, in some cases exceeding the capacity of the ecosystem to maintain its integrity. Sacred natural sites are sometimes heavily modified or even planted; a proportion of these may nonetheless retain a rich complement of biodiversity at local level. Sacred natural sites are often recognized and used by local communities for their secular values, including medicinal plants, non timber forest products and other ecosystem services such as tourism or watershed protection. Unfortunately, many sacred natural sites are now under threat or have already disappeared in recent years. The pattern of loss has not been quantified but it is recognized to be increasing. Integration of sacred natural sites into conservation strategies can be complex but provides an important way of preserving these unique places and the biological and cultural values they represent. Where appropriate from social and conservation perspectives, the conservation of sacred natural sites should be included in national conservation plans.
Functional diversity is a component of biodiversity that generally concerns the range of things that organisms do in communities and ecosystems. Here, we review how functional diversity can explain and predict the impact of organisms on ecosystems and thereby provide a mechanistic link between the two. Critical points in developing predictive measures of functional diversity are the choice of functional traits with which organisms are distinguished, how the diversity of that trait information is summarized into a measure of functional diversity, and that the measures of functional diversity are validated through quantitative analyses and experimental tests. There is a vast amount of trait information available for plant species and a substantial amount for animals. Choosing which traits to include in a particular measure of functional diversity will depend on the specific aims of a particular study. Quantitative methods for choosing traits and for assigning weighting to traits are being developed, but need much more work before we can be confident about trait choice. The number of ways of measuring functional diversity is growing rapidly. We divide them into four main groups. The first, the number of functional groups or types, has significant problems and researchers are more frequently using measures that do not require species to be grouped. Of these, some measure diversity by summarizing distances between species in trait space, some by estimating the size of the dendrogram required to describe the difference, and some include information about species abundances. We show some new and important differences between these, as well as what they indicate about the responses of assemblages to loss of individuals. There is good experimental and analytical evidence that functional diversity can provide a link between organisms and ecosystems but greater validation of measures is required. We suggest that non-significant results have a range of alternate explanations that do not necessarily contradict positive effects of functional diversity. Finally, we suggest areas for development of techniques used to measure functional diversity, highlight some exciting questions that are being addressed using ideas about functional diversity, and suggest some directions for novel research.
There is growing awareness that protected areas (PA) may not suffice to deliver all the targets set by international conventions and guarantee the conservation of biodiversity and ecosystem services in anthropogenic landscapes. However, landscapes such as sacred natural sites (SNS), which are managed with clear benefits for people and nature although not having conservation as their primary purpose, can help deliver those goals. While a number of studies have demonstrated SNS’ values for biodiversity and ecosystem services, the fundamental question of whether and how SNS may complement PA at a national scale has never been addressed. Here, we assembled a nationwide inventory of 2332 SNS in Italy and compared their spatial distribution and landscape features with those of PA. We showed that there is scarce overlap between SNS and PA and that different factors drive the density of the two networks. SNS are more frequently associated with cultural landscapes at low and medium elevations and in extensively agricultural and peri-urban settings. PA, in contrast, are mainly found in more natural environments, at higher elevations, and farther from human settlements. These results indicate that the two networks largely complement each other and have different benefits for people and biodiversity. Land planning approaches should aim to valorize this complementarity. Instead of simply including SNS into PA, SNS could obtain a legal status through other emerging policy frameworks, such as the recognition of “other effective area-based conservation measures”.
Riparian forests, an integral part of savanna ecosystems, are threatened across West Africa by agricultural expansion. However, some patches of original riparian vegetation are protected by traditional beliefs as ‘Sacred Groves’. We assessed the role of Sacred Groves in maintaining landscape-scale bird assemblages by conducting 144 1-h point counts, distributed over 24 plots in eastern Guinea-Bissau. The plots were situated in three riparian habitat types with different levels of human modification (Sacred Grove, Young Secondary Forest, Annual Cultures) and the adjacent Wooded Savanna. We accumulated 4572 records of 174 species and compared total species richness, composition, and functional traits among the four habitat types. At the plot level, species richness was higher in Wooded Savannas and Annual Cultures compared to Secondary Forests and Sacred Groves. Bird communities in Wooded Savannas were similar to those in Annual Cultures and differed the most from those of Sacred Groves. Bird community composition in Young Secondary Forests was similar to that in Annual Cultures but showed a shift towards the community composition found in Sacred Groves. Certain traits were strongly specific to habitat type. For example, Sacred Groves were characterized by a high number of forest specialists and insectivorous birds. Our results suggest that the rapid successional dynamics in riparian habitats enable disturbance tolerant forest species to recolonize fallow areas after a relatively short period of time. However, Sacred Groves hold a distinct avifauna and their conservation may therefore be crucial for forest specialist species and the re-establishment of bird assemblages in fallow riparian areas. Our findings also stress the importance of respecting and strengthening traditional forms of nature protection.
Biodiversity encompasses multiple attributes such as the richness and abundance of species (taxonomic diversity), the presence of different evolutionary lineages (phylogenetic diversity), and the variety of growth forms and resource use strategies (functional diversity). These biodiversity attributes do not necessarily relate to each other and may have contrasting effects on ecosystem functioning. However, how they simultaneously influence the provision of multiple ecosystem functions related to carbon, nitrogen, and phosphorus cycling (multifunctionality) remains unknown. We evaluated the effects of the taxonomic, phylogenetic, and functional attributes of dominant (mass ratio effects) and subordinate (richness effect) plant species on the multifunctionality of 123 drylands from six continents. Our results highlight the importance of the phylogenetic and functional attributes of subordinate species as key drivers of multifunctionality. In addition to a higher taxonomic richness, we found that simultaneously increasing the richness of early diverging lineages and the functional redundancy between species increased multifunctionality. In contrast, the richness of most recent evolutionary lineages and the functional and phylogenetic attributes of dominant plant species (mass ratio effects) were weakly correlated with multifunctionality. However, they were important drivers of individual nutrient cycles. By identifying which biodiversity attributes contribute the most to multifunctionality, our results can guide restoration efforts aiming to maximize either multifunctionality or particular nutrient cycles, a critical step to combat dryland desertification worldwide.
Central European temperate oak woodlands are highly valued for their rich biodiversity. They are also of great economic importance and forest management aims to produce high quality timber, which demands high investments. The aim of this literature review is to identify management options for forestry and nature conservation that sustain both the ecological value of oak forests and the economic viability of oak silviculture. We addressed three main questions: a) Oaks and close-to-nature forestry-what are the key silvicultural challenges and options?, b) What is the particular significance of ecological continuity and which structural features are of importance for biodiversity conservation in oak forests?, c) What are the key elements and possible strategies of forest management that sustain the ecological values in oak forests in combination with viable forestry? Light availability appeared to be a conspicuous link connecting the conservation and the silvicultural aspects of multifunctional oak forest management: Both young oak trees and multiple oak woodland specialist species are characterized by their need for increased sunlight exposure. This common denominator provides a sound basis for integrative management practices for forestry and nature conservation. The concept of retention forestry offers purposeful approaches. So the harvest of valuable timber oaks or the creation of canopy gaps for oak regeneration can be used to release the crowns and trunks of habitat oaks from shading and competition. When looking at the management of oak woodland biodiversity hotspots, the re-establishment of (modified) historical forest management techniques, which increase stand openness and create transitional habitats that provide suitable oak regeneration niches, seems to be necessary. Not only the continuity of oak woodland cover and natural site conditions, but also the uninterrupted temporal continuity and availability of wood-related structural features turned out to be of particular importance for oak woodland specialist species. We identified an urgent need for systematic forest planning approaches that secure the long-term availability of these structural features within areas or "sustainability units" that are large enough to maintain viable populations of oak woodland specialist species. In particular, conservation-oriented forestry measures should mainly be implemented in those areas, where the greatest effectiveness is to be expected. In the sustainability units, oak regeneration measures ought to take place either in close vicinity to old oak stands or directly in these stands. The choice of one of these options should be based on a careful consideration of the needs and possibilities of both silvicultural and nature conservation management.
Integrative management strategies that simultaneously aim for wood production and biodiversity conservation are considered crucial to protect biodiversity of forest species outside protected areas. In this study, we evaluated whether deadwood enrichment as an integrative strategy at a scale of 17,000 ha resulted in enhanced biodiversity of saproxylic and non-saproxylic taxa eight years after the implementation of the strategy. The strategy included active deadwood enrichment with harvest remnants, retention of deadwood, and nature forest reserves areas. The analysis was based on data on the occurrence of plants, fungi, beetles, true bugs and birds from directly before and after the implementation of the strategy. The implementation of the strategy resulted in an increase in the deadwood amount by an average of 90 ± 40 m³ ha⁻¹ (mean ± SE) over this period. While deadwood amounts doubled in production forests (+90%), they increased even more in nature forest reserves (+160%). Multidiversity (species density of all taxa) increased with an increase in deadwood amount; this was a result of an increase in the multidiversity of saproxylic species as the non-saproxylic multidiversity did not respond. Among single taxon groups, fungal and beetle species density responded positively to the increase in deadwood amount, especially when only saproxylic species were analysed. Importantly, this effect was not only found in the nature forest reserves, but also in the production forests. We thus conclude that active deadwood enrichment in production forests and nature forest reserves is a promising tool to rapidly promote the protection of forest biodiversity.
The continued provision of old-growth elements in forest landscapes is a critical factor for biodiversity conservation in Central Europe. A well-established method for predicting the potential of forests to maintain biodiversity is to quantify tree-related microhabitat structures (TreMs). Our aim was to predict the TreM abundance and diversity for collectives of TreM-bearing trees; here 15 large trees per plot that were preselected by the largest crown sizes using remote sensing information. TreMs were inventoried on 2085 living trees across 139 plots (each 1 ha) in montane forests of the Black Forest, southwest Germany according to a detailed catalogue comprising 64 different TreM structures. We tested the influence of forest management, forest cover in the surrounding landscape (25 km radius), forest type, the number of standing dead trees, altitude and mean diameter at breast height (DBH) on the abundance and diversity of TreMs on living trees. All plots are managed or have been recently (20-40 yrs) abandoned from management. Generalized linear models (GLM) were used to identify the drivers of abundance and diversity of TreMs. The abundance of TreMs borne by the 15 large trees per plot is greater on plots located at higher altitudes. Increasing mean DBH leads to significantly higher abundance and diversity of TreMs. Groups of TreM-bearing trees in monospecific coniferous forests have the highest abundance but those in mixed-coniferous-broadleaved forests have the greatest diversity of TreMs. The occurrences of 11 out of 64 specific TreM structures were related to forest management, forest type, altitude or mean DBH. Large branch holes and buttress cavities increased with mean DBH and were found more frequently in mixed-coniferous-broadleaved forests than in the other forest types. The abundance of epiphytes on TreM bearing trees increased with altitude. This study demonstrates that the average abundance and diversity of TreMs can be predicted with readily available forest attributes. Additionally, the occurrence of specific TreMs could be described with the variation in these selected forest attributes.
The exploitation of natural resources by people generally has detrimental effects on nature but in some cases anthropogenic activities can result in changes to the natural environment that produce new habitats and increase biodiversity. Understanding and supporting such cultural aspects of land use is an important part of effective conservation strategies. The UK has a range of cultural landscapes that contribute to the landscape matrix and are often important for biodiversity. However, little research has been conducted on the relationship between various types of cultural landscapes or their effects on biodiversity. We examined the interaction between semi-natural sacred sites and lowland heathland in Cornwall, and the contribution these sites make to the overall biodiversity within the habitat. We found that semi-natural sacred sites had significantly higher levels of biodiversity compared to surrounding heathland; the existence and use of the sites created new and important habitats for rare and threatened heathland species; and the spiritual and cultural use of the sites aids the management of heathland. Promoting the use of semi-natural sacred sites could therefore contribute to biodiversity conservation. Furthermore, the cultural and spiritual importance of such sites potentially increases the availability of volunteer resources for their management. We highlight the importance of an integrated management approach for achieving effective biodiversity conservation in areas containing multiple types of cultural landscapes.
Integrative forest management attempts to simultaneously fulfill both wood production and biodiversity conservation in a given forest region, and presumably supplants the need for unmanaged forest reserves. This is the dominant management paradigm in the temperate zone of Europe, yet few studies have examined the validity of this approach. We used Slovenia as a test bed to examine how the long-term practice of integrative forest management has influenced two structural components of mature forest conditions, namely coarse woody debris (CWD) and large living trees, as well as the distribution of the White-backed Woodpecker, a species dependent on such conditions. Data were compiled from national inventory plots, coupled with separate surveys in 51 forest reserves. The mean volume of CWD and density of large beech trees across managed forests in Slovenia was 15 m3 ha−1 and 6 ha−1, respectively; these mean values were significantly higher (165 m3 ha−1 and 55 ha−1) in old-growth reserves. CWD was primarily comprised of small diameter pieces in managed forest, whereas large diameter pieces in multiple stages of decay represented most of the volume in reserves. These results, coupled with the limited distribution of the woodpecker across the country, suggest that integrative management practiced over a large scale may be insufficient for maintaining biodiversity dependent on mature forest conditions at current levels of wood extraction.
Tree related Microhabitats (hereafter TreMs) have been widely recognized as important substrates and structures for biodiversity in both commercial and protected forests and are receiving increasing attention in management , conservation and research. How to record TreMs in forest inventories is a question of recent interest since TreMs represent potential indirect indicators for the specialized species that use them as substrates or habitat at least for a part of their life-cycle. However, there is a wide range of differing interpretations as to what exactly constitutes a TreM and what specific features should be surveyed in the field. In an attempt to harmonize future TreM inventories, we propose a definition and a typology of TreM types borne by living and dead standing trees in temperate and Mediterranean forests in Europe. Our aim is to provide users with definitions which make unequivocal TreM determination possible. Our typology is structured around seven basic forms according to morphological characteristics and biodiversity relevance: i) cavities lato sensu, ii) tree injuries and exposed wood, iii) crown deadwood, iv) excrescences, v) fruiting bodies of saproxylic fungi and fungi-like organisms, vi) epiphytic and epixylic structures, and vii) exudates. The typology is then further detailed into 15 groups and 47 types with a hierarchical structure allowing the typology to be used for different purposes. The typology, along with guidelines for standardized recording we propose, is an unprecedented reference tool to make data on TreMs comparable across different regions, forest types and tree species, and should greatly improve the reliability of TreM monitoring. It provides the basis for compiling these data and may help to improve the reliability of reporting and evaluation of the conservation value of forests. Finally, our work emphasizes the need for further research on TreMs to better understand their dynamics and their link with biodiversity in order to more fully integrate TreM monitoring into forest management.
The importance of biodiversity conservation is well recognized, and the loss of biodiversity is particularly evident in highly urbanized areas. On the other hand, green spaces inside cities, as parks, can provide a resource for maintaining and increasing biodiversity, especially for bird species. However, only a few studies have addressed the effects of vegetation structure and land use composition on different components of biodiversity.
Here, we explored the response of bird community composition to environmental differences related to land use composition and vegetation structure in green spaces in the city of Beijing, China. We compared the values of taxonomic diversity, functional diversity and community evolutionary distinctiveness in breeding bird communities, among ten urban parks of the world's third most populous city. Variation partitioning analysis and generalized linear mixed models were used to explore the unique and shared effects of land use composition and vegetation structure on each biodiversity metric.
Park size was not associated with the diversity of bird communities in Beijing. Land use composition was the best predictor of change in bird community composition, followed by vegetation structure at ground level and the intersection between land use and vegetation structure at tree level. Water coverage increased bird species richness, while the presence of large trees increased both taxonomic diversity and bird functional richness in urban parks. Finally, the presence of patches of deciduous trees showed a positive effect on the average score of evolutionary distinctiveness of bird communities. In conclusion, we highlight that different elements of the environment are supporting different components of bird community diversity.
Species diversity is a major determinant of ecosystem productivity stability invasibility, and nutrient dynamics. Hundreds of studies spanning terrestrial, aquatic, and marine ecosystems show that high-diversity mixtures are approximately twice as productive as monocultures of the same species and that this difference increases through time. These impacts of higher diversity have multiple causes, including interspecific complementarity, greater use of limiting resources, decreased herbivory and disease, and nutrient-cycling feedbacks that increase nutrient stores and supply rates over the long term. These experimentally observed effects of diversity are consistent with predictions based on a variety of theories that share a common feature: All have trade-off-based mechanisms that allow long-term coexistence of many different competing species. Diversity loss has an effect as great as, or greater than, the effects of herbivory, fire, drought, nitrogen addition, elevated CO2, and other drivers of environmental change. The preservation, conservation, and restoration of biodiversity should be a high global priority.
This paper explores the changing relationship between society and the environment, taking as a proxy the local valuation of trees in Zagori, NW Greece. We used voucher specimens and asked informants to score perceived value for selected tree species and list associations with the trees. The 4,511 responses were sorted into broad categories. Utilitarian values dominated responses although intangible values were a constant feature. In species that were culturally dominant in the past the change in utilitarian values has been dramatic. Younger informants failed to identify common tree species and were generally unaware of values attached to trees by previous generations. Some species remain highly valued but now more for their intangible significance. We argue that simple tools to record the valuation of trees are useful in exploring the relationship between people and the landscape they inhabit.
Himalayan forests are undergoing rapid changes due to population growth and economic development and their associated bird communities are among the most threatened and least-studied on earth. In the Chinese Himalaya, traditionally managed Tibetan sacred forests are keystone structures for forest bird conservation. Yet, it remains unclear which fine-scale habitat characteristics of the sacred forests are best associated with Himalayan forest bird species. Our goal here was to quantify the relationship between forest habitat characteristics and bird communities in Tibetan sacred forests to understand habitat associations of common forest birds in the Chinese Himalaya. In 2010 and 2011, we conducted bird point counts and habitat surveys at 62, 50-m radius, sample points distributed within and adjacent to six Tibetan sacred forests in northwest Yunnan, China. From this data, we constructed habitat–occupancy relationship models for 35 bird species and documented tree-use patterns of 14 common arboreal foraging bird species. Our modeling results revealed that large diameter trees and heterogeneity in vertical vegetation structure were the most important habitat characteristics, and were positively associated with occupancy of 63 % of the study bird species. Furthermore, we found that occupancy of eight bird species of conservation concern was related to specific thresholds of forest integrity characteristics. For example, predicted occupancy of three of eight species was high in forested habitats with >15 % bamboo cover and was greatly reduced when bare ground cover exceeded 5 %. We found that bird species foraged on pine (Pinus
densata, 58 % more than it was available) and poplar (Populus davidiana, 41 %) in higher proportion to their availability, but that foraging success was highest on fir (Abies spp.), oak (Quercus spp.), willow (Salix spp.) and Chinese Larch (Larix potaninii). Our findings suggest that, although conservation is not a primary management goal of Tibetan sacred forests, these lands harbor critical habitat features for forest breeding birds of the Chinese Himalaya.
Large trees are considered keystone structures in agricultural and forestry production landscapes, but research demonstrating this in urban landscapes is urgently needed. If large trees are keystone structures in urban parks, it is imperative that this is recognized in policy to ensure their ongoing existence. We studied the role of large native trees for birds in urban parks in Canberra, Australia. We found that (1) large trees had a consistent, strong, and positive relationship with five measures of bird diversity, and (2) as trees became larger in size, their positive effect on bird diversity increased. Large urban trees are therefore keystone structures that provide crucial habitat resources for wildlife. Hence, it is vital that they are managed appropriately. With evidence-based tree preservation policies that recognize biodiversity values, and proactive planning for future large trees, the protection and perpetuation of these important keystone structures can be achieved.
Identifying and protecting "keystone structures" is essential to maintain biodiversity in an increasingly human-dominated world. Sacred forests, i.e. natural areas protected by local people for cultural or religious regions, may be keystone structures for forest birds in the Greater Himalayas, but there is limited understanding of their use by bird communities. We surveyed birds and their habitat in and adjacent to six Tibetan sacred forests in northwest Yunnan China, a biodiversity hotspot Our goal was to understand the ecological and conservation role of these remnant forest patches for forest birds. We found that sacred forests supported a different bird community than the surrounding matrix, and had higher bird species richness at plot, patch, and landscape scales. While we encountered a homogeneous matrix bird community outside the scared forests, the sacred forests themselves exhibited high heterogeneity, and supported at least two distinct bird communities. While bird community composition was primarily driven by the vegetation vertical structure, plots with the largest-diameter trees and native bamboo groves had the highest bird diversity, indicating that protecting forest ecosystems with old-growth characteristics is important for Himalayan forest birds. Finally, we found an increased bird use of the sacred forests and their edges during 2010, a severe drought year in Yunnan, indicating that sacred forests may serve as refuges during extreme weather years. Our results strongly indicate that sacred forests represent an important opportunity for Himalayan bird conservation because they protect a variety of habitat niches and increase bird diversity at multiple spatial scales.
With the rise of new powerful statistical techniques and GIS tools, the development of predictive habitat distribution models has rapidly increased in ecology. Such models are static and probabilistic in nature, since they statistically relate the geographical distribution of species or communities to their present environment. A wide array of models has been developed to cover aspects as diverse as biogeography, conservation biology, climate change research, and habitat or species management. In this paper, we present a review of predictive habitat distribution modeling. The variety of statistical techniques used is growing. Ordinary multiple regression and its generalized form (GLM) are very popular and are often used for modeling species distributions. Other methods include neural networks, ordination and classification methods, Bayesian models, locally weighted approaches (e.g. GAM), environmental envelopes or even combinations of these models. The selection of an appropriate method should not depend solely on statistical considerations. Some models are better suited to reflect theoretical findings on the shape and nature of the species’ response (or realized niche). Conceptual considerations include e.g. the trade-off between optimizing accuracy versus optimizing generality. In the field of static distribution modeling, the latter is mostly related to selecting appropriate predictor variables and to designing an appropriate procedure for model selection. New methods, including threshold-independent measures (e.g. receiver operating characteristic (ROC)-plots) and resampling techniques (e.g. bootstrap, cross-validation) have been introduced in ecology for testing the accuracy of predictive models. The choice of an evaluation measure should be driven primarily by the goals of the study. This may possibly lead to the attribution of different weights to the various types of prediction errors (e.g. omission, commission or confusion). Testing the model in a wider range of situations (in space and time) will permit one to define the range of applications for which the model predictions are suitable. In turn, the qualification of the model depends primarily on the goals of the study that define the qualification criteria and on the usability of the model, rather than on statistics alone.
Hole-nesting birds include species highly dependent on old trees or dead wood for nesting, roosting, breeding and feeding. In this study we characterize the assemblages of these species occurring in five different habitat types located in a heterogeneous Mediterranean landscape. We used the point count method. In all habitat types, tits (Parus major and Cyanistes caeruleus) were the most abundant species, except in beech forests, where Sitta europaea showed the highest mean abundance. Hole nesting bird
assemblages increase in abundance, richness and diversity, with significant changes from termophilic and sclerophyllous forests (Holm-oak and Cork-oak) to temperate and mesophilic forests (chestnut, Turkey oak and Beech). This pattern reflects the progressive change in vegetation type both due to structure and species composition, ultimately due to progressive change in altitude and local climate. In particular, data at singles species level corroborate that the presence of mature and dead trees (i.e., with high mean diameter) may explain the abundance of Sitta europaea, Picus viridis and Certhia brachydactyla. Our dataset highlights that, for the hole-nesting birds, mesophilous beech and oak Mediterranean forests of biogeographic and conservation concern, represent suitable habitat types for these specialized species.