Island biogeography theory and the urban landscape: stopover site selection by the silver-haired bat (Lasionycteris noctivagans)

2022 ◽  
Author(s):  
Hannah Adams ◽  
Liam McGuire
Keyword(s):  
Island Biogeography ◽  
Urban Forest ◽  
Natural Habitat ◽  
Negative Relationship ◽  
Urban Forests ◽  
Forest Patches ◽  
Stopover Site ◽  
Island Biogeography Theory ◽  
The Impact ◽  
Lasionycteris Noctivagans

Many migratory bats require forested sites for roosting and foraging along their migration path, but increased urbanization and intensive agricultural practices may reduce the availability of stopover sites. Urban forests may provide important stopover habitat, maintaining landscape connectivity in regions where the majority of natural habitat has been cleared for development. Island biogeography theory can be applied to urbanized temperate forest biomes where small urban forests represent islands separated from the larger “mainland” forest. We used acoustic monitoring during the fall migration period to investigate the use of urban forest habitat by the migratory species Lasionycteris noctivagans Le Conte, 1831. We predicted that recorded activity would have a positive relationship with forest patch area and shape and a negative relationship with isolation from other forest patches, as suggested by island biogeography theory. We observed greater activity at larger forest patches, and although relationships for shape and isolation were not statistically supported the observed patterns were consistent with predictions. Our results demonstrate the need for more in-depth research on the habitat requirements for both migratory and resident bat species and the impact that ongoing urbanization has on local bat populations.

scholarly journals Traces of urban forest in temperature and CO<sub>2</sub> signals in monsoon East Asia

2021 ◽  
Author(s):  
Keunmin Lee ◽  
Je-Woo Hong ◽  
Jeongwon Kim ◽  
Jinkyu Hong
Keyword(s):  
Co2 Emissions ◽  
Urban Areas ◽  
Urban Forest ◽  
Urban Forests ◽  
Forest Canopies ◽  
Area Index ◽  
Drought Period ◽  
Vegetation Activity ◽  
Urban Heat ◽  
The Impact

Abstract. Cities represent a key space for our sustainable trajectory in a changing environment, and our society is steadily embracing urban green space for its role in mitigating heatwaves and anthropogenic CO2 emissions. This study reports two-year surface fluxes of energy and CO2 measured via the eddy covariance method in an artificially constructed urban forest to examine the impact of urban forests on air temperature and net CO2 exchange. The urban forest site shows typical seasonal patterns of forest canopies with the seasonal march of the East Asian summer monsoon. Our analysis indicates that the urban forest reduces both the warming trend and urban heat island intensity compared to the adjacent high-rise urban areas and that photosynthetic carbon uptake is large despite relatively small tree density and leaf area index. During the significant drought period in the second year, gross primary production and evapotranspiration decreased, but their reduction was not as significant as those in natural forest canopies. We speculate that forest management practices, such as artificial irrigation and fertilization, enhance vegetation activity. We also stipulate that ecosystem respiration in urban forests is more pronounced than typical natural forests in a similar climate zone. This can be attributed to the substantial amount of soil organic carbon available due to intensive historical soil use and soil transplantation during forest construction, as well as relatively warmer temperatures in urban heat domes. Our observational study also indicates the need for caution in soil management for less CO2 emissions in urban areas.

scholarly journals Study of the Spatiotemporal Variation Characteristics of Forest Landscape Patterns in Shanghai from 2004 to 2014 Based on Multisource Remote Sensing Data

2018 ◽  
Vol 10 (12) ◽  
pp. 4397 ◽  
Author(s):  
Yang Li ◽  
Chunyan Xue ◽  
Hua Shao ◽  
Ge Shi ◽  
Nan Jiang
Keyword(s):  
Spatial Distribution ◽  
Landscape Pattern ◽  
Urban Forest ◽  
Urban Forests ◽  
Urban Ecosystem ◽  
Landscape Patterns ◽  
Forest Landscape ◽  
Forest Patches ◽  
Forest Coverage ◽  
High Degree

The landscape patterns of urban forests not only reflect the influence of urbanization on urban forests, but also determines its function in urban ecosystem services. In the case of mastering the overall forest landscape pattern of a city, a study of the structure of urban forest landscapes at different scales and in urbanized regions is beneficial to a comprehensive understanding of the forest characteristics of a city. In the present study, an attempt was made to map and monitor the spatio-temporal dynamics of an urban forest in Shanghai from 2004 to 2014 using remote sensing techniques. Methods of landscape ecology analysis are followed to quantify the spatiotemporal patterns of an urban forest landscape by urban and rural gradient regionalization. The results show that the spatial structure of an urban forest landscape is essentially consistent with an urban landscape pattern. Due to strong interference from human activities, the ecological quality of forest landscapes is low. At the landscape level, the urban forest coverage rate increased from 11.43% in 2004 to 16.02% in 2014, however, the number of large patches decreased, there was a high degree of urban forest landscape fragmentation, landscape connectivity was poor, landscape patch boundaries were uniform, and weak links were present between ecological processes. Different urban and rural gradient division methods exhibit obvious gradient characteristics along the urban–rural gradient in Shanghai. The regional differences in the urban forest landscape ecological characteristics have further increased as a result of urban planning and zoning. The total amount of urban forest is located closer to the urban center, which has the smallest total amount of forest; however, in terms of urban forest coverage, the suburbs have more coverage than do the outer suburbs and the central urban areas. The urban forest landscape’s spatial distribution area is evidently different. Urbanization affects the areas closest to urban residential areas, which are markedly disturbed by humans, and the urban forest landscape has a high degree of fragmentation. The forest patches have become divided and unconnected, and the degree of natural connectivity has gradually decreased over the past 10 years. At the landscape class level, broadleaf forests are dominant in Shanghai, and their area exhibits an increasing trend; shrublands and needleleaf forests, however, show a decreasing trend. Compared with other forest types, the spatial distribution of broadleaf forest is concentrated in the suburbs, and the aggregation effect is relatively apparent. From the perspective of urban forest landscape pattern aggregation characteristics in Shanghai, the spatial distribution of urban forest landscape point patterns in the study area exhibit extremely uneven characteristics. The point density of urban forest patches larger than 1 ha in Shanghai increased from 2004 to 2014. However, the total number of patches with areas larger than 5 ha decreased, and this decrease plays an important role in the ecological environment. In the past 10 years, the concentration characteristics of urban forests with large patches has gradually decreased. In 2014, the urban forest landscapes decreased by 5 km compared to the intensity of aggregates in 2004, which also indicates that urban forests in Shanghai tend to be fragmented. The results of this study can be useful to help improve urban residents’ living environments and the sustainable development of the urban ecosystem, and they will also be vital to future management.

scholarly journals Breeding density of the Tawny Owl Strix aluco in urban forests of Ljubljana City (Central Slovenia)

Acrocephalus ◽  
2017 ◽  
Vol 38 (172-173) ◽  
pp. 31-35
Author(s):  
Tjaša Pršin ◽  
Darja Kušar ◽  
Tanja Obermajer ◽  
Al Vrezec
Keyword(s):  
Urban Areas ◽  
Urban Forest ◽  
Urban Forests ◽  
Forest Patches ◽  
Tawny Owl ◽  
Point Count ◽  
Strix Aluco ◽  
Nature Park ◽  
Territory Density ◽  
Point Count Method

SummaryResults of the survey carried out in the territories of Tawny Owl Strix aluco in Ljubljana urban forests (Tivoli, Rožnik and Šišenski hrib Nature Park and Golovec Hill) were compared with the species territory density in non-urban forest of Mt. Krim. Surveys were performed with the point count method using playback in the springs of 2002 and 2016. The density established at Golovec Hill was 9.3 territories / 10 km2, while in Tivoli, Rožnik and Šišenski hrib Nature Park it reached 10.4 territories / 10 km2, which was higher than at Mt. Krim (4.1-5.8 territories / 10 km2), although densities between sites were not statistically different. Based on our surveys, the estimated population size of the urban Tawny Owl in Ljubljana would consist of 57 to 65 pairs. Our results suggest that the Tawny Owl can adapt well to the living conditions in the city urban forests and indicate the importance of the forest patches in urban areas.

scholarly journals Traces of urban forest in temperature and CO<sub>2</sub> signals in monsoon East Asia

2021 ◽  
Vol 21 (23) ◽  
pp. 17833-17853
Author(s):  
Keunmin Lee ◽  
Je-Woo Hong ◽  
Jeongwon Kim ◽  
Sungsoo Jo ◽  
Jinkyu Hong
Keyword(s):  
Co2 Emissions ◽  
Urban Areas ◽  
Urban Forest ◽  
Urban Forests ◽  
Forest Canopies ◽  
Area Index ◽  
Drought Period ◽  
Vegetation Activity ◽  
Urban Heat ◽  
The Impact

Abstract. Cities represent a key space for a sustainable society in a changing environment, and our society is steadily embracing urban green space for its role in mitigating heat waves and anthropogenic CO2 emissions. This study reports 2 years of surface fluxes of energy and CO2 in an artificially constructed urban forest measured by the eddy covariance method to examine the impact of urban forests on air temperature and net CO2 exchange. The urban forest site shows typical seasonal patterns of forest canopies with the seasonal march of the East Asian summer monsoon. This study shows that the urban forest reduces both the warming trend and urban heat island intensity compared to the adjacent high-rise urban areas and that photosynthetic carbon uptake is large despite relatively small tree density and leaf area index. During the significant drought period in the second year, gross primary production and evapotranspiration decreased, but their reduction was not as significant as those in natural forest canopies. We speculate that forest management practices, such as artificial irrigation and fertilization, enhance vegetation activity. Further analysis reveals that ecosystem respiration in urban forests is more pronounced than for typical natural forests in a similar climate zone. This can be attributed to the substantial amount of soil organic carbon due to intensive historical soil use and soil transplantation during forest construction, as well as relatively warmer temperatures in urban heat domes. Our findings suggest the need for caution in soil management when aiming to reduce CO2 emissions in urban areas.

scholarly journals Evaluation of Forest Edge Structure and Stability in Peri-Urban Forests

Forests ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 338
Author(s):  
David Hladnik ◽  
Andrej Kobler ◽  
Janez Pirnat
Keyword(s):  
Urban Forest ◽  
Residential Buildings ◽  
Canopy Structure ◽  
Urban Forests ◽  
Forest Edge ◽  
Canopy Height ◽  
Forest Edges ◽  
Forest Patches ◽  
Forest Patch ◽  
Edge Structure

In the presented research, we studied the forest edge structure of urban and peri-urban forests on the outskirts of Ljubljana (Slovenia) consisting of a number of patches covering the collective surface of 1884 ha. They differ from each other according to the degree of fragmentation and by the share of the interior forest area. On the basis of LiDAR data, we conducted an analysis of the edges of the persistent forest patches and estimated them with regard to the land use they bordered on. The horizontal estimation of forest edges and the changes of forest edges, in the last decades, were estimated using digital orthophoto images of cyclic aerial surveys of Slovenia, from 1975 to 2018. The data, provided by LiDAR, were used to obtain an accurate estimate of forest edges and the metrics of their vertical canopy structure. On the basis of the canopy height model (CHM), we determined the height classes, the heights of the tallest trees, and indices of canopy height diversity (CHD) as variables subjected to a k-means cluster analysis. To determine the forest edge and trees stability, their heights and diameters at breast height (DBH) were measured and their canopy length and h/d (height/diameter) dimension ratios were estimated. In the study area of the Golovec forest patch, more than half of the forest edge segments (56%) border on residential buildings. After the construction of buildings, 54% of the newly formed forest edges developed a high and steep structure. Unfavorable h/d dimension ratio was estimated for 16% of trees, more among the coniferous than among the deciduous trees. Similar characteristics of newly formed forest edges bordering on built-up areas were determined in other sub-urban forest patches, despite the smaller share of such forest edges (19% and 10%, respectively). Tools and methods presented in the research enable the implementation of concrete silvicultural practices in a realistic time period and extend to ensure that adequate forestry measures are taken to minimize possible disturbances.

scholarly journals Measuring Multi-Scale Urban Forest Carbon Flux Dynamics Using an Integrated Eddy Covariance Technique

2019 ◽  
Vol 11 (16) ◽  
pp. 4335 ◽  
Author(s):  
Kaidi Zhang ◽  
Yuan Gong ◽  
Francisco J. Escobedo ◽  
Rosvel Bracho ◽  
Xinzhong Zhang ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Green Infrastructure ◽  
Urban Forest ◽  
Scale Effects ◽  
Atmospheric Stability ◽  
Urban Forests ◽  
Co2 Flux ◽  
Forest Patches ◽  
Multi Scale ◽  
Co2 Dynamics

The multi-scale carbon-carbon dioxide (C-CO2) dynamics of subtropical urban forests and other green and grey infrastructure types were explored in an urbanized campus near Shanghai, China. We integrated eddy covariance (EC) C-CO2 flux measurements and the Agroscope Reckenholz-Tänikon footprint tool to analyze C-CO2 dynamics at the landscape-scale as well as in local-scale urban forest patches during one year. The approach measured the C-CO2 flux from different contributing areas depending on wind directions and atmospheric stability. Although the study landscape was a net carbon source (2.98 Mg C ha−1 yr−1), we found the mean CO2 flux in urban forest patches was −1.32 μmol m−2s−1, indicating that these patches function as a carbon sink with an annual carbon balance of −5.00 Mg C ha−1. These results indicate that urban forest patches and vegetation (i.e., green infrastructure) composition can be designed to maximize the sequestration of CO2. This novel integrated modeling approach can be used to facilitate the study of the multi-scale effects of urban forests and green infrastructure on CO2 and to establish low-carbon emitting planning and planting designs in the subtropics.

scholarly journals Demand for Urban Forests and Economic Welfare: Evidence from the Southeastern U.S. Cities

2006 ◽  
Vol 38 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Pengyu Zhu ◽  
Yaoqi Zhang
Keyword(s):  
Population Density ◽  
Household Income ◽  
Environmental Kuznets Curve ◽  
Urban Forest ◽  
Urban Forests ◽  
Economic Welfare ◽  
Kuznets Curve ◽  
Forest Coverage ◽  
The Impact ◽  
The Relationship

This study examines the relationship between urban forests and household income and population density in the 149 cities with populations over 40,000 in nine southeastern states. Our empirical results show that urban forest percentage across the cities has characteristics of the environmental Kuznets curve. We find that household income around $39,000 is a threshold that changes the relationship between income and urban forest coverage from negative to positive, whereas the impact of population density on urban forests is just the opposite, from positive to negative when population density is around 180 persons per square kilometer.

scholarly journals Effects of Adjacent Land Use Types on the Composition of Vascular Flora in Urban Forest Ecotones in the Southern Poland

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1440
Author(s):  
Beata Fornal-Pieniak ◽  
Barbara Żarska ◽  
Marcin Ollik
Keyword(s):  
Plant Species ◽  
Nature Reserve ◽  
Urban Forest ◽  
Urban Forests ◽  
Native Forest ◽  
Anthropogenic Pressure ◽  
Vascular Flora ◽  
Forest Plants ◽  
The Impact ◽  
The City

The purpose of the research was the recognition of edge effects regarding similarities and differences of vascular flora in undergrowth layers in the urban forest ecotones. Four types of urban forest neighborhoods were analyzed: ecotones adjacent to the manor park, the agriculture field, housing estates and the road. The plant compositions in the forest ecotones were compared with the plant compositions in the urban forest interior and the forest nature reserve. The phytosociological type of studied forests was a subcontinental oak-hornbeam one (Tilio-Carpinetum). Diagnostic plant species (e.g., characteristic) for forests from the non-diagnostic ones were identified. Forest consistent plant species dominated in the ecotone adjacent to the manor park and in the interior of urban forests too, but the best conditions for these plants were inside the forest nature reserve, where native consistent forest plants showed the highest dominance when comparing all studied areas. A higher anthropogenic pressure from the adjacent areas results in supporting the growth of inconsistent plant species in the forests, and these plants are mostly represented by plants belonging to grass and synanthropic communities. Another conclusion drawn from our research is that the protected forest, represented by a nature reserve in the city, provides better “shelter” for native forest plants than the urban forest without any protection. Ultimately, a permanent challenge is to achieve and maintain the balance between nature and the impact of anthropogenic activities on urban forests in the city. The high quality of green areas, biodiversity, including forests, implicates possibilities of sustainable development in cities. The research results will be useful for local urban planners and ecologists during their work on strategies of city development, including shaping of green infrastructure.

scholarly journals Carbon absorption capability of single-leaf and compound-leaf plants in the BNI Urban Forest, Banda Aceh

2021 ◽  
Vol 918 (1) ◽  
pp. 012027
Author(s):  
M Daud ◽  
BM Bustam ◽  
E Harnelly ◽  
W Dharma
Keyword(s):  
Carbon Dioxide ◽  
Water Content ◽  
Leaf Area ◽  
Urban Forest ◽  
Chlorophyll Concentration ◽  
Urban Forests ◽  
Species Selection ◽  
Compound Leaf ◽  
Single Leaf ◽  
The Impact

Abstract The creation of Open Green Spaces is one of the options for mitigating the impact of global warming. In order to maximize the function of urban forests as carbon dioxide absorbers, plant species selection for urban forests must be considered. The goal of this study was to compare the ability of single-leaf and compound-leaved plants growing in urban forests to absorb carbon dioxide. Exploratory survey methods with purposive sampling were used. The single-leaf plant, B. asiatica (520 cm2), had the maximum leaf area, whereas the single-leaf species, M. elengi had the lowest leaf area (47.50 cm2). The plant with the highest water content in leaves was found in single-leaf plants, B. asiatica (ranging from 74.67 percent to 77.32 percent), while plant F.decipiens from the compound-leaf plant had the lowest water content (ranging from 44.34 percent to 46.14 percent). The plant with the highest percentage of carbohydrate mass at 06.00 am was M. elengi (531.63 percent), and the plant with the lowest percentage of carbohydrate mass was P.indicus (211.15 percent). At 11 am, the compound-leaf plant S.mahogani (496.76 percent) had the largest percentage of carbohydrate mass, B.asiatica had the lowest (289.29 percent). B.asiatica had the most carbon dioxide absorption per leaf area per hour (g/leaf/hour), whereas S. mahogany had the lowest. S.mahogani (32.514 Å) had the highest chlorophyll concentration in the 06.00 am sample, while P.indicus had the highest chlorophyll concentration in the 11.00 am sample (42.440 Å).

scholarly journals Forest Structure and Anthropogenic Disturbances Regulate Plant Invasion in Urban Forests

2021 ◽  
Author(s):  
Prakash Chandra Aryal ◽  
Chandramani Aryal ◽  
Kiran Bhusal ◽  
Devendra Chapagain ◽  
Man Kumar Dhamala ◽  
...  
Keyword(s):  
Invasive Species ◽  
Forest Structure ◽  
Urban Forest ◽  
Urban Forests ◽  
Principal Component ◽  
Anthropogenic Disturbances ◽  
Invasion Success ◽  
Anthropogenic Factors ◽  
Forest Patches ◽  
Factors Affecting

Abstract Urban forest ecosystems, the structure and functions therein, are subjected to anthropogenic disturbances. Native and sensitive species from those forests might be lost due to such disturbances. At the same time, supplemented anthropogenic resources might create opportunities for exotic and invasive species. Although, invasive species are considered as one of the major threats to the urban biodiversity and ecosystems, the researches on invasion dynamics in the Himalayas have mostly focused on the impacts of invasion on forest structure and productivity. This study aims to understand the influence of forest structure and anthropogenic factors in invasion success that are poorly covered in the existing literature. We selected 11 urban forest patches for the study considering the presence-absence of selected invasive species and structural attributes. We used Principal Component Analysis (PCA) to reduce co-linearity in the covariates and generalized linear mixed effects model (GLMM) to identify the factors affecting the invasion success. We found that the structural attributes of the forests and anthropogenic disturbances regulated invasion success in urban forests. This implies that maintaining urban forest structural attributes, especially maintaining the stands with large-sized trees, are essential to regulate and control invasion in the context of urbanization.

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