Presence and abundance of the Eurasian nuthatch <Emphasis Type="Italic">Sitta europaea</Emphasis> in relation to the size,isolation and the intensity of management of chestnut woodlands in the NW Iberian Peninsula

Throughout most of the north-west Iberian Peninsula, chestnut (Castanea sativa) woods are the principal deciduous woodland, reflecting historical and ongoing exploitation of indigenous forests. These are traditionally managed woodlands with a patchy distribution. Eurasian nuthatches (Sitta europaea) inhabit mature deciduous woods, show high site fidelity, and are almost exclusively found in chestnut woods in the study area. We studied the presence and abundance of nuthatch breeding pairs over two consecutive years, in relation to the size, degree of isolation and intensity of management of 25 chestnut woods in NW Spain. Degree of isolation was assessed in view of the presence of other woodland within a 1-km band surrounding the study wood. Wood size was the only variable that significantly predicted the presence of breeding pairs (in at least one year, R ² = 0.69; in both years, R ² = 0.50). The number of pairs was strongly predicted by wood size, isolation and management (R ² = 0.70 in 2004; R ² = 0.84 in 2005); interestingly, more isolated woods had more breeding pairs. Breeding density was likewise significantly or near-significantly (P ≤ 0.1) higher in small isolated woods, which is possibly attributable to lower juvenile dispersal in lightly forested areas and/or to lower predator density in smaller and more isolated patches. Breeding density was higher (though not significantly so) in more heavily managed woods, possibly due to the presence of larger chestnut crops and larger trees (with higher nuthatch prey abundance). Our findings highlight the complexity of the relationships between the patch properties and the three studied levels (presence, number and density of pairs), and also the importance of traditionally managed woodlands for the conservation of forest birds.     

Native oak retention as a key factor for the conservation of winter bird diversity in managed deciduous forests in northern Italy

Birds can serve as useful model organisms to investigate community level consequences of forestry practices. In this study we investigated the relationships between wintering bird communities and habitat and landscape characteristics of lowland managed forests in Northern Italy. This area is characterized by the spread of the black locust, an alien species that has been favored by forestry practices at the expense of natural oak forests. Birds were censused in winter by point counts in randomly selected plots of 50 m radius. We first addressed bird community–habitat relationships by means of habitat structure measurements, then we investigated bird community–landscape relationships by using GIS techniques. We used generalized linear models (GLM) to test for the effects of habitat and landscape variables on bird community parameters (namely bird species richness, diversity and abundance). Bird community parameters were influenced by oak biomass and tree age, and by oak area and core area, while the other forest habitat types showed less influence. In forest management terms, the main conclusion is that the retention of native oaks is the keyfactor for the conservation of winter bird diversity in local deciduous woods. At the habitat level black locust harvesting may be tolerated, provided that old, large, native oaks are retained in all local woodlots to preserve landscape connectivity and foraging resources. At the landscape meso-scale, large native oak patches, should be preserved or, where necessary, restored. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

China's contribution to urban forestry

This commentary reviews the remarkable contributions made in China to the development of urban forests and to research on urban forests. It points out the significance of the Forest Law of the People's Republic of China (adopted in 1984) to the establishment of urban forests in China. Unique Chinese concepts such as Sponge Cities and Forest Cities are reviewed. Examples of the contributions of Chinese scholars to our knowledgeof urban forestry are presented.     

Fragmentation and recreational use affect tree regeneration in urban forests

The aim of this study was to test whether fragmentation or recreational use affect tree regeneration in urban forests, and to quantify these effects. We sampled tree saplings at different distances from edges in spruce (Picea abies) dominated forests, and at different distances from paths that represented different levels of wear. Generalized linear mixed models were used to test our hypotheses. We found that fragmentation favours the regeneration of deciduous trees in urban spruce dominated forests: distance from the edge had a pronounced effect on regeneration, at least up to 80 m into the forests. Saplings of Betula pendula, Populus tremula, other deciduous species and Pinus sylvestris benefited from edge conditions. Betula pubescens saplings, however, were most abundant in the interior and small Sorbus aucuparia saplings at 25–30 m from the edge. All species suffered from the direct effects of trampling, while varying responses of species to distance from the paths were observed up to 6 m, and possibly further. As trees essentially define the living conditions for other forest species, we suggest that the spatial extent of edge and trampling effects should be studied for different types of forests. This knowledge should then be used in urban forestry and planning to define the threshold value that will allow for at least some “intact” interior. We suggest a diameter larger than 160 m to support indigenous species in boreal spruce dominated forests.     

Urban woodland management – The case of 13 major Nordic cities

A postal questionnaire survey about the forest situation and management in urban woodland was carried out around the three largest urban agglomerations in each of the five Nordic countries, Denmark, Finland, Iceland, Norway and Sweden. Twenty estate managements responded, giving a respondent rate of 54%. Our material from 13 cities includes 108,888 ha productive forests, representing approximately 13% of all urban woodland areas in the Nordic region. The tree species composition in the urban woodland areas largely reflected the typical tree species distribution in the respective vegetation zones. It is expected that the percentage of Fagus sylvatica and Quercus spp. in the nemoral zone, and boreal hardwoods will increase in the future. The proportion of young and middle-aged forests is high in all urban woodlands, despite the focus on old forests in urban woodland management policy and research since the 1970s. Current silvicultural systems belonging to even-aged forestry prevail in most cities. However, the use of clear-cutting has decreased over the last 30 years. A conservative felling policy makes it likely that the proportion of old stands will increase. Various restrictions on forest management are briefly discussed. Reasons for changes in silvicultural practices differ from city to city, but recreation and conservation are most commonly reported.     

Layout and composition of house-embracing trees in an island Feng Shui village in Okinawa,Japan

A Feng Shui village landscape, which embodies the symbiosis of nature and man, might be re-evaluated as an ideal landscape model in East Asia. Ho:go is one essential word for a Feng Shui village in Ryukyu Islands. The literal meaning of Ho:go is to embrace and protect by forest planting in order to retain the living energy. Ho:go also refers to a forest belt that encircles a house, a village, several neighbouring villages, or the coastline, and is called House Ho:go (habitat-embracing forest), Village Ho:go, District Ho:go, and Coastline Ho:go, respectively. However, such Feng Shui village landscapes have disappeared rapidly since Word War II because of the changing life styles. In order to preserve the traditional Feng Shui village landscape, our primary research focus concerns the actual structure, management, and regeneration of house-embracing Garcinia subelliptica Merr. trees. We chose to survey the two best preserved villages of Tonaki Island and Bise village in northern Okinawa Island. We reproduced the actual distribution and sizes of house-embracing G. subelliptica trees by HO CAD software. We found tree lines were much thicker in the borderline of the village, in particular, those either facing the coast or standing in the north. In contrast, there was usually one tree line inside the village. The surveyed G. subelliptica trees on Tonaki Island were much smaller than those in Bise Village. More demand of G. subelliptica trees for timber use in this small isolated island and better maintenance might be assumed to be the reasons for the difference in tree height between the two surveyed villages. Thus, proper maintenance in terms of cutting and cleaning are necessary to preserve house-embracing G. subelliptica tree lines in a traditional Feng Shui village. A traditional village landscape might also serve purposes for forest tourism and environmental education.     

Urbanization increases the range,but not the depth,of forest edge influences on Pinus sylvestris bark pH

The influence of forest edge on Pinus sylvestris bark pH was evaluated in urban and suburban pine forests in Yekaterinburg (South Taiga subzone, Central Urals, Russia). The measurements was conducted in 18 transects (rows of 6–10 sample plots arranged in pairs along a 100–260 m line perpendicular to the forest boundary); 12 transects (110 plots) were located in the urban forest and 6 transects (58 plots) in the suburban forest. All the characteristics studied (degree of urbanization, distance from forest boundary, and type and age of boundary), were found to have a significant effect on the pH of P. sylvestris bark. Bark alkalinization increased on average by 0.2 to 0.5 pH units above background along a gradient from the forest interior to the forest edge. In urban forests, the edge influence was about twice greater (0.6–0.8 pH units) than in suburban forests (0.2–0.3 pH units), while the depth ranged between 70 and 160 m. Little variation in the depth of the edge influence observed due to transect characteristics, and no differences were noted due to degree of urbanization. The range of the edge influence was cumulative over the time that had elapsed since forest fragmentation and highway construction. The results show that urban airborne dust pollution affects southern taiga pine forests to a depth of about 100 to 150 meters from forest boundary. This circumstance is important to take into account when planning the locations of the borders of forests, roads, residential and social areas.     

Open woodland and savanna decline in a mixed-disturbance landscape (1938 to 1998) in the Northwest Wisconsin (USA) Sand Plain

Our research illustrates how a landscape mosaic changes in association with a mixed natural-anthropogenic disturbance history. Our study area is the Northwest Wisconsin (USA) Sand Plain (NWSP), a region with a rich disturbance history including fire, insects and clearcut forestry. We integrated historic airphotos from 1938, 1960, 1980 and 1998 within a GIS to describe change among four landcover classes describing a canopy-closure gradient: closed forests, woodlands, savannas and “open barrens”. Our work addresses two literature needs: empirical studies of mixed-disturbance landscapes, and nonforest habitats within a forest matrix. Our analysis shows that: the area of open barrens fluctuated, woodlands and savannas declined severely and closed forests increased through time. Falling median patch sizes and other landscape metrics suggest that the woodlands are becoming more fragmented. The landcover transitions driving this change vary according to time and place. The dominant transitions are toward closed forests from all classes, and transitions toward open barrens are also consistently important. The woodlands, savannas and open barrens habitats are mostly comprised of transient patches, persisting for less than 20 years. This contrasts with closed forests that often persist for 40 plus years. These changes are consistent with the disturbance regime that is shifting from fire- to forestry-dominance. Our results show a trend towards landscape simplification, manifest as losses of intermediate-density habitats (woodland and savanna) and shrinking patch sizes. The transient nature of the nonforest habitats shows that disturbance resulting in total or partial canopy removal will be vital for their conservation at a landscape scale.     

Three decades of urban forestry in China

Urban forestry has been formally recognized as a codified academic discipline in China’s higher education since 1992. This short communication attempts to revisit the emergence and development of urban forestry in China over the last three decades. Despite the traditional disciplinary division existing between forestry (which focuses on forested landscapes in non-urbanized regions) and landscape architecture (which concerns about individual and collective plants in urbanized environments), urban forestry offers an interdisciplinary convergence point, drawing upon disciplinarily-specific understanding and expertise of both forestry and landscape architecture, that supersedes the urban-rural distinction and could be translated into flexible, integrative, and transdisciplinary approaches for the effective governance of urban and peri-urban forests. With the enrichment of empirical evidence from China’s unique socioeconomic context and the theoretical advancement of urban forestry, innovative practical initiatives like “National Forest City” successfully transform urban forestry knowledge into on-the-ground practices. While China’s unprecedented urbanization has been accompanied by social and environmental problems calling for solutions wherein urban forestry can contribute, it offers a fertile ground for further advancing the development of urban forestry.     

A study on village forest landscape in small island topography in Okinawa,Japan

Forest landscape based on Feng Shui concepts in East Asia deserves research focus for its cultural and ecological contexts. How to contain the wind is the primary principle of Feng Shui practice in small island villages. To protect from strong wind, house-embracing Fukugi (Garcinia subelliptica Merr.) tree lines have been planted around the hamlets and along the coastline in small islands. After Tonaki and Bise villages, we continued to study the actual forest structure, e.g., the forest layout, composition, and density, and further discussed the regeneration and management of Feng Shui trees on small islands. Another objective of this study was to compare the features of the house-embracing Fukugi trees in Aguni Island to those in the two former survey sites of Tonaki Island and Bise village.House-embracing Fukugi trees along the village borderlines and in the north were thicker in Tonaki and Bise villages. In contrast, Fukugi trees on Aguni Island are laid out almost single file. Differences in village topography might contribute to the difference of layout. Hamlets in Aguni are located on the southern part of the island, backed by the high land, and somewhat far from the seashore, while Tonaki and Bise villages are located close to the sea.Fukugi tree density in Aguni was much lower, while, the mean DBH was higher than those in Tonaki and Bise. A large number of small trees were found in the lower storey in the previous survey sites in Tonaki and Bise, where the villages were built on sandy soil. In contrast, small trees were few due to the regular cutting in Aguni Island. Routine chopping and cutting of extended branches were still conducted once a year on Aguni Island. The Shimajiri Mahji soil might also contribute to the few lower storey trees.The biggest tree on Aguni island is estimated to be about 296 years old. The old trees might have been planted prior to the building of Goban villages. Different to Tonaki and Bise, hamlets on Aguni might not be Goban villages. It also suggests that Fukugi trees might have been planted prior to 1737, though central government started to recommend to plant a Fukugi tree belt around every house, every village, and along the coastline in 1737.     

Ecosystem functioning in cities: Combined effects of urbanisation and forest size on early-stage leaf litter decomposition of European beech (Fagus sylvatica L.)

Environmental changes associated with urbanisation can affect the functioning of ecosystem processes. In cities, forests are among the most frequent types of green areas and provide a wide range of ecosystem services including air cleaning, decomposition of leaf litter and recreation. The European beech (Fagus sylvatica) is a frequent and widespread deciduous tree in temperate forests in Central Europe. In this study, we examined the effects of urbanisation on decomposition processes of F. sylvatica leaves in different-sized forests in the urban region of Basel, Switzerland. We used standardised litterbags (mesh size: 2 mm) with F. sylvatica leaves to assess the impact of degree of urbanisation (indicated by the percentage cover of sealed area in the surroundings) and forest size on the early stage of leaf litter decomposition and seasonal microbial activity. We found combined effects of degree of urbanisation and forest size on the decomposition rate of leaf litter (k_litter). Large forests showed the highest k_litter in areas with sparse settlements and the lowest k_litter in densely settled areas, whereas the opposite pattern was recorded for small and medium-sized forests. This indicates that abiotic and biotic forest characteristics of forests of similar size differently influenced k_litter depending on the degree of urbanisation. Moisture content of litter was the best predictor of microbial activity, followed by forest size. We assume that factors acting at the landscape scale such as the degree of urbanisation might be too coarse to detect any differences in microbial activity. Our results revealed that even small urban forests contribute to this important ecosystem function. As decomposers are at the bottom of the food chain, management actions that support the biological activity in soil might be also beneficial for species at higher trophic ranks.     

The association between plant diversity and perceived emotions for visitors in urban forests: A pilot study across 49 parks in China

Urbanization introduces uncertainties to the biodiversity of plant communities. The perception of biodiversity can be associated with positive mental health and well-being, but direct evidence is still insufficient. In this study, we collected data about plant biodiversity assessments from studies on urban forests in the literature of China’s national knowledge infrastructure. Records of the species amount, Shannon index, and Simpson index were extracted from 49 urban forest parks in 13 cities across mainland China from 2018 to 2021. A total of 1938 facial photos were obtained from microblogs with check-in locations at these parks in the Sina Microblog in 2020. Happy, sad, and neutral emotions and positive response index (PRI; happy minus sad) were rated and mapped for spatial distributions. The amount of species was distributed as a heterogeneous pattern for all plant types, and biodiversity was higher in the northern regions (e.g., ~55% in Qingdao and over 50% in Taiyuan) than in southern cities along the Yangtze River (e.g., ~35% in Huaihua and Changsha). Trees did not account for the association of biodiversity with emotional expressions. Smiles were elicited mostly in parks with more diverse shrubs (Shannon index: R=0.4335; P = 0.0029) and herbs (R=0.6162; P = 0.0008). Females showed more smiles than males (47% vs. 32%, respectively; F=39.15, P < 0.0001), and happy emotions tended to be higher in older visitors (senior vs. younger: 58% vs. 43%, respectively; F=2.72, P = 0.0280). Overall, we recommend visiting parks in northern cities of China for the benefit of evoking positive emotions through experiencing abundant undergrowth species. Female visitors would benefit more than males in the promotion of mental well-being by perceiving diverse shrubs and herbs in urban forest parks.     

Comparing climate-growth responses of urban and non-urban forests using L. tulipifera tree-rings in southern Indiana,USA

Urban forests have many positive effects on human health and recreation. However, urban areas can create stressful environments for native trees, leading to increased mortality and an altered ecosystem. Here, we compare growth variability and the climate response from old (>200 years) L. tulipifera growing in an urban forest in Bloomington, IN to surrounding non-urban sites in southern Indiana using dendrochronological techniques. We found that L. tulipifera growing in the urban forest responded similarly with small differences to climate compared to the non-urban sites. Radial growth from urban L. tulipifera had statistically similar correlation values with temperature, soil moisture, and precipitation compared to the trees in non-urban forests. Growth variability between the urban and non-urban L. tulipifera trees showed good agreement through time with the exception of the 20th century, where the urban forest experienced a stand-wide release from competition. Our results indicate that some urban forests may function similarly to non-urban forests from an ecological perspective. These findings suggest management practices from non-urban old-growth forest could be useful for management of rare urban old-growth forests.     

Urban forest management and governance in Latin America and the Caribbean: A baseline study of stakeholder views

Cities in the Latin America and Caribbean (LAC) region and around the world are setting long-term greening goals that include planting more trees and increasing green cover. Research in LAC cities has mainly focused on biodiversity and vegetation, with little understanding of the mechanisms underlying the decisions through which stakeholders achieve urban greening. Exploring stakeholders’ views about urban forest management and governance can provide us with an opportunity to identify needs and research gaps for urban greening and urban forestry in LAC. To our knowledge, there has never been a region-wide empirical study to capture these stakeholder views. Here we explore how stakeholders working in urban forestry in LAC, including governmental, and non-governmental professionals, define urban forests, and view management and governance issues as well as educational opportunities. We used an online survey based on a combination of open- and closed-ended questions. The survey was delivered to participants at the first two regional conferences on urban forests in LAC organized by the United Nations. We collected 91 responses from stakeholders working in 50 different cities of varying population sizes across 6 LAC bioregions. Most respondents considered parks, planted green corridors, street trees, and remnant forests in urban and peri-urban areas as components of urban forests. Stakeholder views on management and governance were divided in two distinct perspectives, one dominated by public participation issues, and another one related to operational issues. Most respondents considered operational and management tools for urban forests to exist in LAC cities, but they disagreed on the existence of inventories, long-term strategies, and ways for the public to engage in urban forestry. Responses also revealed that some educational opportunities, such as arboricultural certification, are still relatively scarce and in high demand in the region. This study provides a regional baseline and first insights into a more diverse view of urban forestry which could be enriched with more empirical studies in the future.     

Participatory urban forestry in Nepal: Gaps and ways forward

Managing urban population and environment has been one of the most important challenges recently. This paper attempts to assess the existing practices, people's perception, gaps and ways forward for participatory urban forestry and aims to help promote UF through identifying the current status, future prospects for and peoples’ perception about UF in two cities of Nepal. The study was conducted in Pokhara sub-metropolitan city and Bharatpur municipality of Nepal. Total numbers of plants in the effective green spaces are estimated as 285,500 in Pokhara and 213,250 in Bharatpur, and the number of tree species was 62 and 52 respectively. The religious tree species – Ficus bengalensis and Ficus religiosa are the most common and hazardous in both cities. The urban people have preferred small, less branchy and attractive tree species. However, the choice of existing species is inappropriate and not according to the people's interest. Therefore, urban people are unsatisfied with the existing species and their frequencies. The municipal authorities and other related organizations do not have any specific plan, programs and activities nor is there any public involvement to promote urban forestry. Regular coordination, cooperation and monitoring are required for the involvement of various stakeholders such as municipality, government office, community organizations and urban people. Analysis further shows that people's perception on urban forestry is encouraging as most of them agreed that the urban forests are useful for addressing the challenging urban environment. Adequate institutions and financial resources coupled with effective cooperation and coordination among concerned organizations could ameliorate the urban environment as urban community forestry.     

Carbon sequestration estimates of indigenous street trees in the City of Tshwane,South Africa

Amelioration of global warming presents opportunities for urban forests to act as carbon sinks, and thereby could possibly be included in the potential future carbon trade industry. The City of Tshwane Metropolitan Municipality provided a strategy in 2002 to plant 115,200 indigenous street trees in the period 2002–2008. These trees hold a monetary carbon value in their potential future growth. In order to calculate the carbon sequestration potential, the growth rates of Combretum erythrophyllum, Searsia lancea and Searsia pendulina were determined. Combined species growth regressions of C. erythrophyllum–S. lancea and S. lancea–S. pendulina are also presented. Combretum erythrophyllum has the fastest growth rate while those of S. lancea and S. pendulina are slower. The results from growth regression relationships were used in a generic allometric biomass regression to calculate the carbon sequestration rate of each species, which was extrapolated to determine the total quantity of carbon to be sequestrated by the street trees over a 30-year period (2002–2032). It is estimated that the tree planting will result in 200,492 tonnes CO₂ equivalent reduction and that 54,630 tonnes carbon will be sequestrated. The carbon dioxide reductions could be valued at more than US$ 3,000,000. But this estimate should also be viewed in the context of the limitations presented in this study. This illustrates that when future carbon trade becomes operational for urban forests these forests could become a valuable source of revenue for the urban forestry industry, especially in developing countries.     

Roads limit of seed dispersal and seedling recruitment of Quercus chenii in an urban hillside forest

Paved roads in urban forests cause forest fragmentation and thus reduce animal populations, threaten dispersal and recruitment of animal-dispersed plants. Here, we tracked animal-mediated seed dispersal of Quercus chenii in the urban forest centre and near roadsides to test the effect of paved roads on seed dispersal and recruitment. We conducted experiments in a forest patch in urban areas of Wuhan, China. The forest was dominated by the focal tree species and separated by paved roads. Only two potential seed dispersal animals, one rodent (Niviventer confucianus) and one jay (Garrulus glandarius) were observed in this stand. Seeds were removed farther but not as fast in the forest centre compared to roadsides, while no differences of seed fate, dispersal direction, and seedling establishment were detected between the forest centre and roadsides, indicating the thick vegetation along roadsides provided feeding shelters for small animals. However, when compared with primary forests containing more seed dispersers, seed removal rate in this urban forest fragment was much slower in both forest centre and roadside. Furthermore, due to road barriers, seeds were seldom moved across the paved road and remained in the fragmented stand, reflecting a limited function of seed dispersers. These results suggested paved roads isolated forests into small “islands” and weakened the ecological function of seed dispersers by impeding long distance seed dispersal. Reintroducing dispersers and building wildlife corridors would be impactful ways to restore urban forest patches.     

Woody species composition of chestnut stands in the Northern Apennines: the result of 200 years of changes in land use

Chestnut stands (orchards and coppices) are among the most typical elements of the southern European mountain landscape and a protected habitat (9260 Castanea sativa woods) according to the European Union (Directive 92/43/EEC). As an anthropogenic landscape, they require specific measures to address preservation or to guide their evolutionary trend. In the Northern Apennines, a landscape multiscalar-multitemporal approach was adopted to highlight factors that have acted on the evolution of this habitat and which still might affect either its preservation or its evolutionary dynamics. Using a diachronic GIS-approach, we analyzed old cadastral maps (drawn up 200 years ago), and aerial photographs. Both the present distribution pattern of the woody species and the incidence of important chestnut diseases were also surveyed. The factors explaining the current extent and species composition of the local chestnut forests confirm their status as an anthropogenic habitat. The present landscape distribution of chestnut woods is heavily linked to past human settlements. Chestnut blight and ink disease are more an indirect reason for past felling activities than an actual direct cause of damage to trees, because of the hypovirulence spread and the limited incidence of the ink disease. Vegetation dynamics of abandoned chestnut forests evolved only partly towards deciduous Beech and Hop Hornbeam stands, thus suggesting both the possibility of a recovery of this cultivation and the need for new criteria for its management.     

Spatial distribution of saplings in heavily worn urban forests: Implications for regeneration and management

We studied the spatial distribution of saplings in the vicinity of other saplings and mature trees in heavily worn urban forests. Our aim was to identify favorable microsites for saplings to regenerate under different levels of wear. We hypothesized that these safe microsites were situated close to tree trunks that might offer shelter from trampling caused by humans and their pet dogs. The distribution of saplings was explored at 0.1–0.6 m to the nearest sapling and 0.1–2 m to the nearest mature tree. Sorbus aucuparia was the most abundant sapling species, followed by Populus tremula, Betula pubescens and Picea abies. These species all tended to cluster with their conspecific saplings and were generally randomly distributed with respect to mature trees. Saplings of S. aucuparia and P. tremula favored growing close to mature P. abies (already at 0.4–0.8 up to 2 m from the trunk base, respectively) and S. aucuparia trees (at 0.2–0.4 m up to 2 m). Betula sp. and Acer platanoides grew close to Pinus sylvestris trees. Furthermore, with increased levels of wear, saplings clustered more likely together and close to tree trunks. The results are contrary to the gap regeneration hypothesis known from rural unworn forests where saplings often grow in canopy gaps. We suggest the idea of a ‘sheltering group’, i.e. tree groups and thickets of densely growing conspecific saplings, for the maintenance of regeneration of saplings and other vegetation in heavily worn recreational forests. Since urban forestry may strongly affect the existence and spatial location of a high variety of microhabitats, small-scale spatial exploration is needed to identify microsites that offer opportunities for natural regeneration under heavy recreational use. To maintain natural regeneration and the survival of saplings in worn urban forests, we recommend microhabitat-level species-specific forest management.     

Observations on the occurrence and phenology of the invasive elm defoliator Aproceros leucopoda (Hymenoptera: Argidae) in the Czech Republic

Aproceros leucopoda has been found at nine locations in urban areas and in forests in the Czech Republic. Aproceros leucopoda was first reported at a location 700 m a.s.l. in the northern part of the country in 2011. The other locations range in elevation from 150 to 460 m a.s.l. In the current study, A. leucopoda was studied in four plots, where larvae and their zigzag feeding tracks were observed on 10 Ulmus trees located south of Lanžhot (southeastern Czech Republic) in 2014 and 2015. In 2014, feeding tracks and larvae were detected in late May, from 22 June to 13 July, and from 9 August to 6 September, suggesting the occurrence of three generations per year in the southeastern Czech Republic. The southern Czech Republic has been colonized much earlier than other parts of the country because of its proximity to localities with A. leucopoda in Slovakia and Austria. The presence of larvae or evidence of larval feeding was detected on only 2.84% of monitored leaves. We suggest that A. leucopoda endangers solitary elms in urban greening areas more than elms in forests.