ABSTRACT Gymnosperms, which are seed-producing plants without a protective covering and sometimes described as lacking true flowers, include a relatively limited number of species, most of them being located in the northern hemisphere, of which a significant portion are conifers. Among gymnosperms, the Pinaceae family stands out as one of the most widespread and diverse. This family includes several genera and a few hundred species, primarily distributed across temperate to subarctic regions in the northern hemisphere, with some reaching into parts of the southern hemisphere, including certain areas of Southeast Asia. Pinaceae is, from the forestry point of view, one of the most important families, as it comprises many timber species with great ecological value. Within this family, the genus Pinus is one of the best represented. It is mainly distributed in the northern hemisphere, including North America and Eurasia. The group is made up of around ninety species, seven of which grow naturally in Spain. Of these, only two are native to the region of Galicia, while the rest are primarily located in other parts of the country. In Galicia, although the natural presence is limited, other species are commonly found in managed forest plantations and ornamental settings, often alongside various non-native pine species. During 2006–2009, work was carried out to create the Galician Catalogue of Singular Trees and, during 2017–2019, a review was undertaken. All the trees and tree formations included in the original list were inspected in the field, as well as other specimens and tree formations, with the aim of drawing up a list of possible candidates to add to the catalogue. This is a brief description of the species belonging to the Pinaceae family with singular trees in Galicia, highlighting the specimens recorded in the 2006–2009 list and those candidate specimens pending inclusion.

ABSTRACT There is widespread international recognition that trees make places nicer and more comfortable to live in and having more of them contributes to climate adaptation and nature recovery initiatives. However, planting and retaining enough trees to deliver meaningful benefits at the local level is proving challenging due to the demand for high-density housing, and pressures to make development profitable. Static-to-decreasing trends in urban tree canopy cover in the UK are common, often due to poorly informed development decisions that result in tree loss without replacement and new trees failing to compensate for the removals. Urban planning is an effective mechanism for optimising tree canopy cover and its associated benefits, but there is currently no standardised approach to help planners make the most of trees for their communities. Modelling canopy cover into the future is feasible, but complex considerations and a lack of research data hamper it. This paper reviews essential elements for modelling those projections, but further refinement will be necessary as more detailed data on the growth characteristics of local species become available. Despite these limitations, canopy cover analysis remains a valuable tool for organisations seeking to enhance their responses to climate and nature emergencies.

ABSTRACT Urban tree research has become a significant research topic in Indian megacities, which face difficulties from growing urbanisation, climate change, and biodiversity loss. This study undertakes a bibliometric review of 76 articles (2000–2024) from 6 Indian megacities, representing 240 unique authors with an annual publication growth rate of 3.9%. The maximum number of papers (9) was published in 2021 and Nagendra, H. emerged as the most productive author (12 publications, 854 citations). Prominent journals included the Indian Journal of Agricultural Sciences (6 papers) and Urban Forestry & Urban Greening (464 citations). Key institutions were the University of Delhi and the Ashoka Trust for Research in Ecology and the Environment (eight papers), sponsored by funding from the University Grants Commission (UGC) and the Department of Science and Technology (DST). Based on centrality and relevance, four key research themes were identified, with most terms categorised under emerging or declining themes. Geographically, Delhi accounted for the highest number of studies. Most research studies (36 papers) were observational, employing surveys and city-wide assessments centred on whole-tree evaluations. The most frequently investigated areas were diversity and pollution (major themes), species diversity, land-use change, and carbon sequestration (minor themes). Urban tree management in India is administered by national schemes, state governments, and municipal entities, but it suffers from fragmented planning and inadequate monitoring. Cities exhibit opposing trends: Delhi and Hyderabad pursue large-scale plantings, whereas Mumbai and Chennai struggle with space and ecological constraints, and Kolkata remains low in tree cover. Despite significant funding from the Compensatory Afforestation Fund (CAMPA) and allied initiatives, uneven execution limits results. Adapting global ideas like climate-adaptive planting, community-driven monitoring, and nature-based urban design can help Indian megacities improve resilience, biodiversity, and ecosystem services.

ABSTRACT This study introduced the potentials of two new genotypes of pistachio named URΙ (University of Rafsanjan Ι) and URΠ (University of Rafsanjan Π) resulting from a breeding programme in Iran. These genotypes were selected from Banehbaghi seedlings (P. vera × P. mutica) in 2009 and compared in terms of appearance and growth characteristics with 12 genotypes of P. khinjuk and P. mutica in 2022–2023. Based on the results, growth habit in P. khinjuk and P. mutica were erect, semi-erect or semi-spreading but this characteristic was erect with rounded crown in URΙ and URΠ. Leaf colour in most of the genotypes was green or light green, while dark green in URΙ and grey green in URΠ. Trunk colour was greying brownish in P. mutica, while grey in P. khinjuk, URΙ and URΠ. The highest chlorophyll index, Fv/Fm and Ch a were observed in URΙ. The appearance and growth characteristics of URΙ and URΠ such as rounded crown, grey trunk colour, dark green and grey green leaf colour and also high Fv/Fm and thick leaves with leathery texture, create a valuable potential for using URΙ and URΠ in urban forestry in urban and suburban landscapes as xerophytic genotypes.

ABSTRACT Mature trees are crucial in urban landscapes, delivering substantial ecological, aesthetic, and microclimatic benefits. Balled and burlapped (B&B) trees are widely used to accelerate canopy establishment, yet their small root balls and limited structural roots often result in poor anchorage, particularly under wind loading. This study evaluated four support methods through mechanical pulling tests and finite element wind force simulations: timber pole support, cable anchoring, steel support, and underground steel anchoring. The results showed statistically significant differences in performance across systems. Steel supports exhibited the highest pulling force resistance (12.53 kN), while underground steel anchors generated the greatest bending moment (16.16 kNm). Wind simulations confirmed that steel supports withstood the highest threshold wind speeds up to 77.52 km hr−1, while unsupported trees failed at just 27.72 km hr−1. These findings underscore the importance of support selection tailored to environmental exposure. Steel-based systems are recommended for storm-prone or exposed urban sites due to the significantly longer service life of steel supports compared to timber; they are more suitable for long-term maintenance in exposed areas where they face environmental corrosion. Conversely, lighter support systems may suffice in sheltered zones. The short service life of timber supports, especially in tropical climates, necessitates frequent maintenance or replacement, which can be costly in the long run. This research provides a biomechanical framework for selecting context-appropriate support systems, enhancing transplanted trees’ long-term stability and survival in tropical urban forestry.

ABSTRACT Trees and forests are widely acknowledged for enhancing the integrity and quality of life for nature and society. But is this appeal supported by scientific evidence? The Catholic University of Malawi, Nguludi campus was used to (1) explore on-campus tree species diversity, (2) examine community perceptions on the role of on-campus trees and forests driven by the interrelations and interactions of environmental factors, and (3) analyse the outcomes driven by the on-campus trees and forests. To achieve this, an Explanatory Sequential Mixed Methods Approach was employed to explore on-campus resource differentiation. The specific constellations of interconnectedness of environmental resources were teased apart and then linked to community livelihoods. The findings show that (1) The Catholic University of Malawi has low tree species diversity with the highest Rẻnyi diversity profile of H-alpha (α = 1.8) followed by 1.4 and 0.7, respectively, (2) Most respondents to the survey confirmed that trees and forests on campus contribute positively to their mental health, with an index of 0.117, followed by positive responses to improving air quality (0.105) and promoting aesthetic values (0.102). In contrast, only a few respondents consider the role of on-campus trees and forests in enhancing soil fertility (0.07), promoting water security (0.09), and providing opportunities for studying nature (0.09). (3) The findings show a positive correlation between tree species diversity and the nexus of biota, climate and material. As the diversity of tree species decreased, the Normalised Difference Vegetation Index (NDVI) and carbon sink also decreased. Such changes weaken the Resource Nexus and subject the university’s infrastructure and its people to the extremes of climate change.

ABSTRACT Urban trees are essential for sustaining biodiversity and delivering key ecosystem services within rapidly urbanising cities. Nevertheless, the maintenance and protection of healthy trees that can accommodate high habitat diversity must be ensured. The present study explored the relationship between tree characteristics such as size, health, nativity, location, and microhabitat richness in urban greenspaces and nearby highway roads in the fast-growing Nagpur city, India. Data from 203 trees (both native and non-native species) across parks and roads, revealed distinct patterns in Tree-Related Microhabitats (TreMs). Tree size and health were identified as the most influential predictors of microhabitat richness, with larger and healthier trees supporting a greater diversity of microhabitats. Contrary to traditional assumptions, non-native trees exhibited slightly higher microhabitat richness than native ones, suggesting their adaptability and potential contributions to ecology in urban environments. Spatial placement of trees in parks or along motorable roads did not significantly influence microhabitat richness, indicating that tree-level factors have a more substantial role. The present study on TreMs in India sheds light on the significance of conserving urban greenspaces and trees, with an emphasis on ensuring the conservation and restoration of urban greenspaces.

ABSTRACT University campuses represent human-managed and relatively protected ecosystems. However, anthropogenic activities such as gardening and landscaping contribute to the introduction and proliferation of alien tree and shrub species. The present study assesses the diversity and distribution of invasive and non-invasive alien trees and shrubs across undisturbed areas and human-impacted areas of Mahatma Gandhi University (MGU) campus, Kerala, India, and compares the findings with other Indian university campuses. Twenty-three alien trees belonging to 22 genera and 12 families were recorded along with 40 alien shrubs representing 30 genera and 22 families. These included two invasive trees, six invasive shrubs, 21 non-invasive trees, and 34 non-invasive shrubs. The human-impacted zone exhibited the highest alien species richness and taxonomic diversity, particularly among non-invasive trees and shrubs. These results suggest that anthropogenic disturbance significantly promotes the richness and proliferation of both invasive and non-invasive alien trees and shrubs, with invasive shrubs demonstrating the ability to establish even in relatively undisturbed habitats. A comparative analysis with other Indian university campuses revealed that alien trees and shrubs constitute a significant proportion (40–55%) of the recorded woody flora, with invasives (comprising 10–35% of the alien pool) consistently posing a greater ecological risk. The findings highlight the necessity of systematic monitoring and management strategies to mitigate the spread of invasive alien trees and shrubs and safeguard campus biodiversity.

ABSTRACT The environment and human health are both influenced by air quality and air pollution, which is a growing environmental problem in the metropolises of developing countries. Urban forests are considered critical in improving urban ecosystem services, especially air quality improvement and air pollution mitigation. Urban forests have developed in Ahmedabad since 2019. This research investigates the effects of urban forests on air pollutants (NO2, SO2, PM2.5, and PM10) and air quality in Ahmedabad city in India. The annual and zonal variation in air pollutants and air quality before and after the development of urban forests was also examined. Primary data on tree species’ diversity, spatial distribution, size, and tree density were collected and analysed to examine their influence on air pollution. Additionally, data on air pollutants were collected to establish their relationship with various urban forest features using descriptive statistics, Pearson correlation, and bivariate regression analysis techniques. The results show that the extent of urban forests contributes to decreasing air pollutants. The distribution and size of urban forests, and number and diversity of trees are all significantly correlated with air pollutants and air quality. The findings of this research suggest important planning implications for the growth of urban forest cover to planners and policy makers.