scholarly journals Species Diversity and Distribution Pattern of Heritage Trees in the Rapidly-Urbanizing Province of Jiangsu, China

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1543
Author(s):  
Kaidi Li ◽  
Guangfu Zhang
Keyword(s):  
Species Diversity ◽  
Distribution Pattern ◽  
Spatial Differentiation ◽  
Tree Density ◽  
Range Shift ◽  
Tree Age ◽  
Cultural Tradition ◽  
Rapid Urbanization ◽  
Heritage Trees ◽  
Tree Habitat

Heritage trees have important ecological, historical, and landscape values in cities. Rapid urbanization may cause dramatic change of ecosystem functions of cities, thereby inevitably affecting the growth performance of ancient trees. However, few studies have explored their species diversity and spatial differentiation on the medium scale in the scenario of urbanization in China. Here, we took Jiangsu Province in China, with developed economy in recent decades, as a typical case. Based on the provincial forest inventory data, we addressed the abundance, species richness, tree density, and species diversity of ancient trees in 13 cities, and their tree habitat, growth status, and tree age, as well. Then, we compared the spatial differentiation of tree attributes by 13 districts and nine tree habitats. We also applied detrended correspondence analysis (DCA) and redundancy analysis (RDA) to determine the leading factor influencing their distribution pattern. The 7678 heritage trees in Jiangsu belonged to 215 species. More than half of the trees were native with domination by Ginkgo biloba. Villages and farmlands accommodated the most heritage trees while parks and gardens harbored the most species. This indicates that sparsely-populated rural community and scenic areas with open space are conducive to accommodating more urban heritage trees. The tier 3 heritage trees (100–299 years) accounted for about 80% of the total. Overall, most ancient trees in Jiangsu grew well. The species diversity index (H) of 13 cities was between 1.98 and 3.39. The H value among the 13 cities was largely affected by elevation range shift, while the tree density by GDP per capita. DCA showed that the ratio of unique species was >40%, and that dominant species presented little habitat preference. Therefore, species diversity among different cities are affected by climate and topography, as well as human factors. With the accelerating urbanization process, tree habitat, cultural tradition, and urban history should be taken into consideration for management and conservation of heritage trees in the future.

Tree density, basal area and species diversity in a disturbed dry tropical forest of northern India: implications for conservation

2006 ◽  
Vol 33 (3) ◽  
pp. 256-262 ◽  
Author(s):  
R. SAGAR ◽  
J.S. SINGH
Keyword(s):  
Species Diversity ◽  
Tropical Forest ◽  
Basal Area ◽  
Tree Density ◽  
Dry Forest ◽  
Conservation Strategies ◽  
Stem Density ◽  
Dry Tropical Forest ◽  
Number Of Species ◽  
Northern India

Dry tropical forest communities are among the world's most threatened systems and urgent measures are required to protect and restore them in degraded landscapes. For planning conservation strategies, there is a need to determine the few essential measurable properties, such as number of species and basal area, that best describe the dry forest vegetation and its environment, and to document quantitative relationships among them. This paper examines the relationships between forest basal area and diversity components (number of species and evenness) for a disturbed dry tropical forest of northern India. Data were collected from five sites located in the Vindhyan dry tropical forest of India, selected on the basis of satellite images and field observations to represent the entire range of conditions in terms of canopy cover and disturbance regimes. These sites represented different communities in terms of species composition. The forest was poorer in species richness, and lower in stem density and basal area than wet forests of the tropics. Across sites (communities), the diversity components and tree density were positively related with total tree basal area. Considering basal area as a surrogate of biomass and net production, diversity is found to be positively associated with productivity. A positive relationship between basal area, tree density and species diversity may be an important characteristic of the dry forest, where recurring disturbance does not permit concentration of biomass or stems in only a few strong competitors. However, the relationships of basal area with density, alpha diversity and evenness remain statistically significant only when data from all sites, including the extremely disturbed one, are used in the analysis. In some sites there was a greater coefficient of variation (CV) of basal area than in others, attributed to patchy distribution of stems and resultant blanks. Therefore, to enhance the tree diversity of these forests, the variability in tree basal area must be reduced by regulating local disturbances. Conservation activities, particularly fuelwood plantations near human settlements, deferred grazing and canopy enrichment through multi-species plantations of nursery-raised or wild-collected seedlings of desirable species within the forest patches of low basal area, will be needed to attain restoration goals, but reforestation programmes will have to be made attractive to the forest-dwelling communities.

scholarly journals Decoupling forest characteristics and background conditions to explain urban-rural variations of multiple microclimate regulation from urban trees

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5450 ◽  
Author(s):  
Wenjie Wang ◽  
Bo Zhang ◽  
Lu Xiao ◽  
Wei Zhou ◽  
Huimei Wang ◽  
...  
Keyword(s):  
Light Intensity ◽  
Explanatory Power ◽  
Weather Conditions ◽  
Tree Density ◽  
Urban Trees ◽  
Lower Percentage ◽  
Air Cooling ◽  
Rapid Urbanization ◽  
Unit Distance ◽  
Urban Rural

Background Rapid urbanization in semi-arid regions necessitates greater cooling, humidifying, and shading services from urban trees, but maximizing these services requires an exact understanding of their association with forest characteristics and background street and weather conditions. Methods Here, horizontal and vertical air cooling, soil cooling, shading, and humidifying effects were measured for 605 trees from 152 plots in Changchun. Additionally, weather conditions (Tair, relative humidity, and light intensity), forest characteristics (tree height, diameter at breast height (DBH), under-branch height, canopy size, tree density, and taxonomic family of trees) and background conditions (percentage of building, road, green space, water, and building height, building distance to measured trees) were determined for three urban-rural gradients for ring road development, urban settlement history, and forest types. Multiple analysis of variance and regression analysis were used to find the urban-rural changes, while redundancy ordination and variation partitioning were used for decoupling the complex associations among microclimate regulations, forest characteristics, background street and weather conditions. Results Our results show that horizontal cooling and humidifying differences between canopy shade and full sunshine were <4.5 °C and <9.4%, respectively; while vertical canopy cooling was 1.4 °C, and soil cooling was observed in most cases (peak at 1.4 °C). Pooled urban-rural data analysis showed non-monological changes in all microclimate-regulating parameters, except for a linear increase in light interception by the canopy (r2 = 0.45) from urban center to rural regions. Together with the microclimate regulating trends, linear increases were observed in tree density, Salicaceae percentage, Tair, light intensity outside forests, tree distance to surrounding buildings, and greenspace percentage. Redundancy ordination demonstrated that weather differences were mainly responsible for the microclimate regulation variation we observed (unique explanatory power, 65.4%), as well as background conditions (12.1%), and forest characteristics (7.7%). Discussion In general, horizontal cooling, shading, and humidifying effects were stronger in dry, hot, and sunny weather. The effects were stronger in areas with more buildings of relatively lower height, a higher abundance of Ulmaceae, and a lower percentage of Leguminosae and Betulaceae. Larger trees were usually associated with a larger cooling area (a smaller difference per one unit distance from the measured tree). Given uncontrollable weather conditions, our findings highlighted street canyon and forest characteristics that are important in urban microclimate regulation. This paper provides a management strategy for maximizing microclimate regulation using trees, and methodologically supports the uncoupling of the complex association of microclimate regulations in fast urbanization regions.

scholarly journals Spatial Assessment of Heat Exposure in Bay Cities: A Case of Xiamen in China

2018 ◽  
Vol 53 ◽  
pp. 03065
Author(s):  
Haifeng Yang ◽  
Ya'nan Wang ◽  
Wei Shui
Keyword(s):  
High Temperature ◽  
Index System ◽  
Heat Exposure ◽  
Spatial Differentiation ◽  
Evaluation Index System ◽  
Theoretical Development ◽  
Evaluation Index ◽  
Rapid Urbanization ◽  
Extreme High Temperature ◽  
Exposure Evaluation

With the global warming, the rapid urbanization process and the increasing intensity and scope of human activities, extreme high temperature and cooresponding high temperature events were frequent, meanwhile, the degree of urban exposure to high temperatures was growing. The research constructed the heat exposure evaluation index system by taking the heat exposure evaluation index system in Xiamen, a gulf-based city with high-temperature. This study evaluated the influence factors, spatial differentiation features and hotspots of the heat exposure based on the methods of geo-spatial analysis, emergy accounting theory, expert consultation and analytic hierarchy process in Xiamen. The research results were expected to promote the theoretical development of urban heat exposure researches, and to provide decision-making reference for heat exposure assessment, regulation and adaptation in Xiamen and similar high temperature cities.

scholarly journals Distribution pattern of Tugai forests species diversity and their relationship to environmental factors in an arid area of China

PLoS ONE ◽  
2020 ◽  
Vol 15 (5) ◽  
pp. e0232907
Author(s):  
Yong Zeng ◽  
Chengyi Zhao ◽  
Zbigniew W. Kundzewicz ◽  
Guanghui Lv
Keyword(s):  
Species Diversity ◽  
Environmental Factors ◽  
Distribution Pattern ◽  
Arid Area

Dynamics of ruderal species diversity under the rapid urbanization over the past half century in Harbin, Northeast China

2013 ◽  
Vol 17 (2) ◽  
pp. 455-472 ◽  
Author(s):  
Xiaoshuang Chen ◽  
Weibo Wang ◽  
Hong Liang ◽  
Xiaoli Liu ◽  
Liangjun Da
Keyword(s):  
Species Diversity ◽  
Northeast China ◽  
Rapid Urbanization ◽  
Half Century ◽  
The Past ◽  
Past Half Century ◽  
Past Half

Heterogeneity in ponderosa pine/Douglas-fir forests: age and size structure in unlogged and logged landscapes of central Colorado

2000 ◽  
Vol 30 (5) ◽  
pp. 698-711 ◽  
Author(s):  
Merrill R Kaufmann ◽  
Claudia M Regan ◽  
Peter M Brown
Keyword(s):  
Ponderosa Pine ◽  
Size Structure ◽  
Fire Regime ◽  
Age Distribution ◽  
Landscape Scale ◽  
Tree Density ◽  
Tree Age ◽  
Riparian Areas ◽  
Forest Patches ◽  
Tree Removal

Tree age and size structures were compared within and among topographic categories in portions of a 35-km2 unlogged landscape and a comparable adjacent logged landscape. Tree density was generally higher in the logged landscape. One fifth of plots in the unlogged landscape had trees older than 400 years, but no trees older than 400 years remained in the logged landscape plots. Ten recruitment pulses were identified for the unlogged study area, accounting for 49% of all trees measured during 26% of the 421-year survival record. Recruitment pulses in the logged area accounted for fewer trees during a larger amount of time. Most recruitment periods in the unlogged landscape coincided with known past major fires. The mixed-severity historical fire regime created openings that persisted for as long as 148 years. The following components exist in the unlogged landscape: (i) forest patches having a distinct age cap reflecting regeneration following an earlier stand-replacing fire, (ii) uneven-aged forest patches having no evidence of an age cap, (ii) openings created by fire, and (iv) riparian areas. Results suggest that the logged landscape is poised to regain an old-growth age distribution, and tree removal in the logged landscape could restore the size distribution found in the unlogged landscape. However, the unlogged landscape has openings not found in the logged landscape that should be considered in restoration efforts at a landscape scale.

Assessment of tree species diversity and its distribution pattern in Pachamalai Reserve Forest, Tamil Nadu

2016 ◽  
Vol 36 (1) ◽  
pp. 32-46 ◽  
Author(s):  
Suganthi Kanagaraj ◽  
Muthu Selvaraj ◽  
Rajiv Das Kangabam ◽  
Govindaraju Munisamy
Keyword(s):  
Species Diversity ◽  
Distribution Pattern ◽  
Tree Species ◽  
Tamil Nadu ◽  
Tree Species Diversity ◽  
Reserve Forest

scholarly journals Complex landscape topography can facilitate local adaptation during a range shift

2019 ◽  
Author(s):  
Robert N. Fitt ◽  
Lesley T. Lancaster
Keyword(s):  
Gene Flow ◽  
Local Adaptation ◽  
Spatial Differentiation ◽  
Niche Differentiation ◽  
High Elevation ◽  
Climatic Conditions ◽  
Range Shift ◽  
Landscape Complexity ◽  
Topographic Complexity ◽  
Complex Landscape

Warming climates provide many species the opportunity to colonise newly-suitable regions at higher latitudes and elevations. Despite becoming warmer, higher latitudes and elevations nevertheless offer novel climatic challenges, such as greater thermal variability and altered frequency of weather events, and these challenges exert selection on expanding populations. However, high gene flow and genetic drift during the expansion phase may limit the degree to which species can adapt to novel climatic conditions at the range front. Here we examine how landscape topographic complexity influences the opportunity for local adaptation to novel conditions during a range shift. Using RAD-seq data, we investigated whether elevation, latitude, climatic niche differentiation, and gene flow across a complex landscape were associated with signatures of adaptation during recent range expansion of the damselfly Ischnura elegans in Northeast Scotland. Our data revealed two distinct routes of colonisation, with admixture between these routes resulting in increased heterozygosity and population density. Expansion rates, assessed as directional rates of gene flow, were greater between more climatically similar sites than between climatically divergent sites. Significant genetic structure and allelic turnover was found to emerge near the range front at sites characterised by high elevation, low directional gene flow, and high spatial differentiation in climate regimes. This predictive combination of factors suggests that landscape complexity may be a prerequisite for promoting differentiation of populations, and providing opportunities for local adaptation, during rapid or contemporary range shifts.

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