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Ecological Analyses of Street Trees of Indian Cities to Achieve United Nations Sustainable Development Goals
... Additionally, there is a growing interest to use Adenanthera pavonina L. in sustainable cultivation practices and in the regeneration of degraded soils, due to its nitrogen-fixing capacity and improvement of soil structure (Luo et al., 2023;Jadhavar & Deshpande, 2022). Recent researches are also exploring the potential of this species in regenerative agriculture systems, where its use can help to reduce the dependence on chemical fertilizers and enhance the resilience of the agricultural ecosystem (Webb et al., 2021;Ekka et al., 2024). ...
Substrates made from organic materials originated from composting agricultural organic wastes, constitutes available and profitable alternatives for farmers. However, plant's responsiveness to organic enrichment depends on the plant species, on the proportion and on the quality of such organic composts. The objective was to determine the best substrate formulated with different proportions of soil and organic compost on the emergence and initial growth of Adenanthera pavonina L. The experiment was performed in greenhouse where treatments were arranged in a completely randomized design, comprised by organic compost and Latosol in the proportions of: 0:100; 20:80; 40:60; 60:40; 80:20(v:v). The emergence speed and speed index of emergence were evaluated in seedlings until 30 days after planted. Seedling height, diameter, number of leaves, dry mass of the aerial portion and roots, and their relationships in the seedlings, were evaluated 90 days after sowing. The addition of organic compost from tree pruning added with cattle and goat manure to the soil, to compose the substrates, increased the percentage and emergence speed of seedlings. Seedlings showed higher Dickson Quality Index when cultivated on substrates composed of 53:47(v/v) of organic compost:Latosol, therefore, being this one the recommended substrate formulation to produce this species’ seedlings.
The current study evaluated the effects of air pollution on selected street trees in the National Capital Territory during the pre- and post-monsoon seasons to identify the optimally suitable tree for green belt development in Delhi. The identification was performed by measuring the air pollution tolerance index (APTI), anticipated performance index (API), dust-capturing capacity (DCC) and proline content on the trees. The APTI of street trees of Delhi varied significantly among different tree species (F11,88.91 = 47.18, p < 0.05), experimental sites (F3,12.52 = 6.65, p < 0.001) and between seasons (F1,31.12 = 16.51, p < 0.001), emphasizing the relationships between trees and other types of variables such as the climate and level of pollution, among other factors. This variability emphasizes the need to choose trees to use for urban greening in the improvement of air quality in different environments within cities. Ascorbic acid (AA) concentration and relative water content (RWC) had a strong influence on APTI with an extremely significant moderate positive correlation between AA concentration and APTI (r = 0.65, p < 0.001) along with RWC and APTI (r = 0.52, p < 0.001), indicating that higher levels of AA concentration and RWC are linked to increased air pollution tolerance. The PCA bi-plot indicates AA has poor positive loading coefficients with PC1 explaining 29.49% of the total variance in the dataset. The highest APTI was recorded in Azadirachta indica (22.01), Leucaena leucocephala (20.65), Morus alba (20.62), Ficus religiosa (20.61) and Ficus benghalensis (19.61), irrespective of sites and seasons. Similarly, based on API grading, F. religiosa and F. benghalensis were identified as excellent API grade 6 (81–90%), A. indica and Alstonia scholaris as very good API grade 5 (71–80%), M. alba, Pongamia pinnata and Monoon longifolium as good API grade 4 (61–70%) and Plumeria alba as moderate API grade 3 (51–60%) in different streets of Delhi. As these plants are indigenous to the region and hold significant socio-economic and aesthetic significance in Indian societies, they are advisable for avenue plantations as part of various government initiatives to support environmental sustainability.
The composition of species, as well as their population and regeneration status of tree species, provide an important ecological foundation for assessing the current state and rate of ecosystem degradation. Therefore, the present study aimed to determine the plant species composition with population and regeneration status of the 40 different tree species in peri-urban vegetation of Ranchi, eastern India using 52 belt transects each of 0.10 ha. A total of 58 different plant species of 49 genera and 26 families were recorded with the majority (86%) of native Indian origin species. The 14% of exotic origin species included dominant invasives in herb, shrub, and tree layers viz., Mesosphaerum suaveolens (L.) Kuntze. (2949 ind. ha−1), Lantana camara L. (1667 ind. ha−1), and Acacia mangium Willd. (33 ind. ha−1), respectively. On the other hand, 59% of the total plant species were IUCN Red-listed including Endangered (Tectona grandis L.f.), Near Threatened (Aegle maremlos (L.) Corrêa), Data Deficient (Mangifera indica L.), and Least Concern (Dalbergia sissoo Roxb. ex DC). Total adult tree density and basal cover were 541 ind. ha−1 and 24.93 m2 ha−1, respectively and Shorea robusta C.F.Gaertn. was the most dominant tree (295 ind. ha−1) recorded in the majority of the studied patches (87%) where adult tree density (ind. ha− 1) ranged from 10 to 1520 with a mean of 363 ± 49 (SE) signifying that the majority of the studied urban vegetation was Sal dominated forest patches. The total density of tree seedlings (22,627 ind. ha−1) was highest in the studied peri-urban vegetation of Ranchi followed by total tree saplings density (2677 ind. ha−1) and adult tree (GBH ≥ 10 cm) density (541 ind. ha−1) signifying good regeneration status (density of seedlings > saplings > adults) of the peri-urban vegetation of Ranchi. was the most common human disturbance observed in 31% of the total studied patches. No regeneration of 56% of the total tree species, the prevalence of human disturbances in the 48% studied patches, and the occurrence of invasives in all three layers of vegetation in the studied peri-urban vegetation signify the ongoing biotic and abiotic pressure on the survival of different plant species at various growth stages. Besides, the predominance of plant species of rare and very rare occurrences (56.9%), IUCN Red-listed (59%) with a total of 84% native Indian origin species demonstrated the importance of the studied peri-urban vegetation and warrants for immediate conservation measures to protect it from further depletion.
This study explores the crucial role of sustainable urbanization in addressing the climate crisis and fostering socio-economic development. Rapid urban population growth presents cities with unprecedented challenges, including ecological degradation, public health issues, and escalating greenhouse gas emissions. Sustainable urbanization emerges as a pivotal strategy to tackle these challenges by advocating for environmentally responsible practices, enhancing urban resilience, and fostering inclusive economic growth. The article conducts a comparative analysis of sustainable urbanization initiatives in diverse cities, with a focus on their approaches to reducing carbon footprints, enhancing disaster resilience, and improving overall quality of life. Examining case studies from Copenhagen, Curitiba, Singapore, Stockholm, and Melbourne, the research highlights innovative strategies in sustainable transport, renewable energy adoption, waste management, and green space integration. These cities serve as exemplars, showcasing successful solutions such as efficient public transportation systems, robust waste recycling programs, promotion of renewable energy, and prioritization of green spaces. The overarching message of this research underscores the critical need for coordinated, cross-sectoral efforts to unlock the full potential of sustainable urbanization. A holistic approach that integrates environmental, social, and economic dimensions is essential for creating urban environments that are resilient, inclusive, and sustainable. This comprehensive strategy not only addresses the climate crisis but also contributes significantly to achieving global sustainability goals.
The present study was carried out to assess the floristic diversity and community characteristics in the forest and alpine zone of Gulmarg Wildlife Sanctuary (GWLS), Kashmir Himalaya. A total of 123 sites were selected along an elevational gradient (2300–4200 m a.m.s.l) in each and every accessible aspect and habitats from July 2018 to June 2022. The present study recorded 364 species of vascular plants belonging to 227 genera and 74 families. Of the total species, 22 were trees, 34 shrubs, 290 herbs and 14 ferns. A total of 18 communities (10 within forest and 8 within alpine zone) were identified. Within the identified forest communities, species richness ranged from 44 to 198; tree density and total basal area ranged from 185–810 Ind ha−1 and 20.28–159.8 m2 ha−1, respectively. Density of shrubs and herbs in forest zone ranges from 886–2040 Ind ha−1 and 27.79–87.75 Ind m−2, respectively. Within the alpine communities, species richness ranged from 26–93; total density of shrubs and herbs ranged from 1410.0–5540 Ind ha−1 and 31.73–102.2 Ind m−2, respectively. Within the forest zone, diversity of trees, shrubs and herbs ranged from 0.88–1.67, 0.27–1.82 and 3.29–4.81, respectively. Within the alpine communities, species diversity of shrubs and herbs ranged from 0.73–1.33 and 2.21–3.69, respectively. Present study presents a first comprehensive floristic and community assessment of GWLS, and provides a template, which can be replicated in other protected as well as unprotected areas of the Kashmir Himalaya.
Temperate broadleaf forests in the Western Himalaya support a large number of local agro-pastoral communities and provide numerous ecosystem services. Several authors have raised serious concerns about the sustainability of current extractive pressures in these forests. We conducted a detailed ecological study on different forests in Askot Wildlife Sanctuary area to assess their current status in terms of species composition and regeneration of dominant tree species. We quantified structure and composition, population structure and regeneration pattern in six major forest types and compared the findings of a previous study conducted by other authors in the same area about 20 years ago. A total of 180 plots in 18 sites were sampled following the standard phytosociological methods. Canonical component analysis was used to predict the impact of environmental factors on forest communities, and land use land cover changes detected influence of ongoing anthropogenic pressures in the area. The study revealed that extractive pressures in the study area have increased since then, which resulted in the decline of the forested area. However, there has been an expansion of Macaranga pustulata, Quercus leucotrichophora and Quercus lanuginosa since the year 2000 and there is a decline in the regeneration of Quercus semecarpifolia. Considering the significance of high-altitude forests and the ecological sensitivity of Q. semecarpifolia, it is recommended to initiate urgent conservation measures in the region.
Questions
Do forest structural parameters related to stand heterogeneity enhance functional diversity (FD) of understorey plant communities? Do FD and functional composition of understorey plant communities vary between high‐forest (HF) and old coppices‐with‐standard (oldCWS) management types? Are HF stands characterized by a higher FD than oldCWS?
Location
Submediterranean beech forests of Montagne della Duchessa Reserve (central Italy).
Methods
We sampled 57 (20 m × 20 m) forest plots, 29 oldCWS and 28 HF stands, where we recorded plant species cover abundance. We used Leaf–Height–Seed and clonal traits, and run multiple separate linear models to quantify the effect of forest structural parameters and management types on FD and functional composition of understorey plant communities.
Results
We found that increasing lying deadwood enhanced FD of specific leaf area (SLA) through micro‐environmental heterogeneity of soil fertility regardless of management type. We also found that increased horizontal stratification filtered the range of plant sizes, probably through light reduction. HF management enhanced FD of SLA and clonal traits through micro‐environmental heterogeneity, while reducing the FD of plant size and seed mass. HF tended to select plant communities characterized by high resource acquisition strategies but lower persistence between ramets, possibly as an effect of more mature forest conditions.
Conclusion
Our study suggests that understorey plant community diversity and composition change in response to forest structure and management. Combining Leaf–Height–Seed with clonal traits offers a promising framework for understanding and predicting plant response to management practices.
This study aimed to examine the effects of spatial and temporal variability in edaphic, and climatic attributes on soil net nitrogen mineralization rate, and to understand the pattern of fine root decomposition of dominant and co-dominant tree species, and its influence on the nutrient cycling in forest ecosystems. Study was carried out at four different sites in sub-tropical forest ecosystems of Shorea robusta, in foothills of Central Himalayan region, India. Co-dominant tree species at four sites were Mallotus philippensis (site A), Glochidion velutinum (site B), Holarrhena pubescens (site C), and Tectona grandis (site D). Buried bag technique was used for nitrogen mineralization, while fine root decomposition was determined using fine root mesh bags. Seasonal variation, soil depth, soil characteristics, and site variability, all significantly (p < 0.05) affected nitrogen mineralization rates. Fine root decomposition was significantly affected by nutrient concentration of fine roots. Total mineral nitrogen was maximum at site D (16.24 ± 0.96 μg g−1 soil), while minimum at site C (10.10 ± 0.84 μg g−1 soil). Maximum nitrogen mineralization (13.18 ± 0.18 μg g−1 month−1) was recorded during summer season at site D, while the minimum nitrogen mineralization (3.20 ± 0.46 μg g−1 month−1) was recorded during rainy season at site C. Inorganic-N and net nitrogen mineralization was relatively higher in 0–20 cm soil layer than 20–40 cm and 40–60 cm soil layer. The fine roots showed 70.61–74.82 % weight loss on completion of 365 days of decomposition
process. Maximum fine root decomposition was observed in the G. velutinum, and minimum in T. grandis. A significant positive correlation (p < 0.05) was observed between root nitrogen and carbon content, and decomposition rates per month. This study concluded that the spatial and temporal variability in soil nitrogen mineralization rates and fine root decomposition optimises nutrient cycling in forest ecosystems, which can contribute to the development of sustainable forest management practices.
Cities offer a phenological preview of natural forest response to global change. • How much do urban tree planting preferences (e.g., species) influence phenology? • We employ >400 PlanetScope images to estimate individual tree phenology in a city. • Species and plant functional type mixtures governed phenology more than heat. The elevated heat of urban areas compared to their surroundings makes humid temperate cities a useful preview of future climate effects on natural forest phenology. The utility of this proxy rests on the expectation that trees in urban areas alter their phenology in response to warmer site conditions in spring and fall. However, it is possible that apparent lengthening of the growing season is instead governed by human-driven tree species selection and plant functional type (PFT; trees, shrubs, turfgrass) heterogeneity typical of managed landscapes. Without the use of highly spatially and temporally resolved remote sensing data, the roles of tree taxonomy and local site characteristics (e.g., impervious cover) in controlling phenology remain confounded. To understand the drivers of earlier start of season (SOS) and later end of season (EOS) among urban trees, we estimated individual tree phenology using >130 high-resolution satellite images per year (2018-2020) for~10,000 species-labeled trees in Washington, DC. We found that species identity alone accounted for 4× more variability in the timing of SOS and EOS compared with a tree's planting location characteristics. Additionally, the urban mix of PFTs may be more responsible for apparent advances in SOS (by between 1.8 ± 1.3 and 3.5 ± 1.3 days) than heat per se. The results of this study caution against associating longer growing seasons in cities-observed in moderate to coarse resolution remote sensing imagery-to within-species phe-nological plasticity and demonstrate the power of high-resolution satellite data for tracking tree phenology in biodi-verse environments.
