scholarly journals Tree Growth and Resilience to Extreme Drought Across an Urban Land-use Gradient

2013 ◽  
Vol 39 (6) ◽  
Author(s):  
Robert Fahey ◽  
Margaret Bialecki ◽  
David Carter

Understanding the response of urban forests to extreme climatic events, such as drought, will be essential to predicting impacts of climate change on the urban tree canopy and related ecosystem services. This study evaluated variation in tree growth and drought resistance (growth during drought) and resilience (growth in period following drought) across four land-use categories (built, transportation, park, and semi-natural forest) and four species (Acer saccharum, Gymnocladus dioicus, Liriodendron tulipifera, and Pinus strobus) at The Morton Arboretum in suburban Lisle, Illinois, U.S. Tree growth and resistance to drought both varied as an interaction between landuse and species (F15, 100 = 5.25, p < 0.001; F15, 100 = 2.42, p = 0.005). Resilience of tree growth to extreme drought was generally high and did not vary across species and land-uses. In this study, individual tree species responses to drought varied across land-uses, illustrating the difficulty of predicting the reaction of urban forests to projected increases in the frequency of extreme climatic events. Tree growth response to drought varied even across the relatively narrow range of growing conditions studied here. Investigation of a broader range of sites, encompassing the full urban forest continuum, would likely demonstrate even greater variation in tree response to extreme climatic events.

2020 ◽  
Vol 12 (23) ◽  
pp. 3928 ◽  
Author(s):  
Shaobai He ◽  
Huaqiang Du ◽  
Guomo Zhou ◽  
Xuejian Li ◽  
Fangjie Mao ◽  
...  

The application of deep learning techniques, especially deep convolutional neural networks (DCNNs), in the intelligent mapping of very high spatial resolution (VHSR) remote sensing images has drawn much attention in the remote sensing community. However, the fragmented distribution of urban land use types and the complex structure of urban forests bring about a variety of challenges for urban land use mapping and the extraction of urban forests. Based on the DCNN algorithm, this study proposes a novel object-based U-net-DenseNet-coupled network (OUDN) method to realize urban land use mapping and the accurate extraction of urban forests. The proposed OUDN has three parts: the first part involves the coupling of the improved U-net and DenseNet architectures; then, the network is trained according to the labeled data sets, and the land use information in the study area is classified; the final part fuses the object boundary information obtained by object-based multiresolution segmentation into the classification layer, and a voting method is applied to optimize the classification results. The results show that (1) the classification results of the OUDN algorithm are better than those of U-net and DenseNet, and the average classification accuracy is 92.9%, an increase in approximately 3%; (2) for the U-net-DenseNet-coupled network (UDN) and OUDN, the urban forest extraction accuracies are higher than those of U-net and DenseNet, and the OUDN effectively alleviates the classification error caused by the fragmentation of urban distribution by combining object-based multiresolution segmentation features, making the overall accuracy (OA) of urban land use classification and the extraction accuracy of urban forests superior to those of the UDN algorithm; (3) based on the Spe-Texture (the spectral features combined with the texture features), the OA of the OUDN in the extraction of urban land use categories can reach 93.8%, thereby the algorithm achieved the accurate discrimination of different land use types, especially urban forests (99.7%). Therefore, this study provides a reference for feature setting for the mapping of urban land use information from VHSR imagery.


2019 ◽  
Vol 45 (2) ◽  
pp. 709
Author(s):  
J.D. Maldonado-Marín ◽  
L.C. Alatorre-Cejudo ◽  
E. Sánchez-Flores

This research incorporates new forms of analysis for urban planning and development in Ciudad Cuauhtémoc, Chihuahua (Mexico), providing elements of reference by identifying areas with potentiality and limitations for urban land use, as well as for agricultural and conservation activities. The general objective was to identify the main conflicts between land uses and coverages to determine the areas of greatest territorial suitability for the city's growth. For this purpose, the Land Use Conflict Identification Strategy (LUCIS) model was used to understand the spatial significance of the status of land use policies, including likely urban patterns associated with agricultural and conservation trends. In the case study, a total of 149,139 inhabitants are estimated for the year 2030, which represents the need for an additional 392.42 hectares to accommodate the population growth. For that of the 16,272.21 hectares that has the population limit, 38 % were allocated to the category of agriculture, 11.95% to conservation soils and 49.67% to urban land (including the existing urban area). There is a significant portion of the area that is in conflict between the different land uses. It concludes, that the integration of a conflict resolution model for land use and land cover represents a practical solution that contributes to the improvement of processes of urban development planning.


2020 ◽  
Vol 9 (9) ◽  
pp. 550
Author(s):  
Adindha Anugraha ◽  
Hone-Jay Chu ◽  
Muhammad Ali

The utilization of urban land use maps can reveal the patterns of human behavior through the extraction of the socioeconomic and demographic characteristics of urban land use. Remote sensing that holds detailed and abundant information on spectral, textual, contextual, and spatial configurations is crucial to obtaining land use maps that reveal changes in the urban environment. However, social sensing is essential to revealing the socioeconomic and demographic characteristics of urban land use. This data mining approach is related to data cleaning/outlier removal and machine learning, and is used to achieve land use classification from remote and social sensing data. In bicycle and taxi density maps, the daytime destination and nighttime origin density reflects work-related land uses, including commercial and industrial areas. By contrast, the nighttime destination and daytime origin density pattern captures the pattern of residential areas. The accuracy assessment of land use classified maps shows that the integration of remote and social sensing, using the decision tree and random forest methods, yields accuracies of 83% and 86%, respectively. Thus, this approach facilitates an accurate urban land use classification. Urban land use identification can aid policy makers in linking human activities to the socioeconomic consequences of different urban land uses.


Author(s):  
Maria A. Cunha-e-Sá ◽  
Sofia F. Franco

Although forests located near urban areas are a small fraction of the forest cover, a good understanding of the extent to which —wildland-urban interface (WUI) forest conversion affects local economies and environmental services can help policy-makers harmonize urban development and environmental preservation at this interface, with positive impact on the welfare of local communities. A growing part of the forest resource worldwide has come under urban influence, both directly (i.e., becoming incorporated into the interface or located at the interface with urban areas) and indirectly (as urban uses and values have come to dominate more remote forest areas). Yet forestry has been rather hesitant to recognize its urban mandate. Even if the decision to convert land at the WUI (agriculture, fruit, timber, or rural use) into an alternative use (residential and commercial development) is conditional on the relative magnitude and timing of the returns of alternative land uses, urban forestry is still firmly rooted in the same basic concepts of traditional forestry. This in turn neglects features characterizing this type of forestland, such as the urban influences from increasingly land-consumptive development patterns. Moreover, interface timber production-allocated land provides public goods that otherwise would be permanently lost if land were converted to an irreversible use. Any framework discussing WUI optimal rotation periods and conversion dates should then incorporate the urban dimension in the forester problem. It must reflect the factors that influence both urban and forestry uses and account for the fact that some types of land use conversion are irreversible. The goal is to present a framework that serves as a first step in explaining the trends in the use and management of private land for timber production in an urbanizing environment. Our framework integrates different land uses to understand two questions: given that most of the WUI land use change is irreversible and forestry at this interface differs from classic forestry, how does urban forestry build upon and benefit from traditional forestry concepts and approaches? In particular, what are the implications for the Faustmann harvesting strategy when conversion to an irreversible land use occurs at some point in the future? The article begins with a short background on the worldwide trend of forestland conversion at the WUI, focusing mostly on the case of developed countries. This provides a context for the theoretical framework used in the subsequent analysis of how urban factors affect regeneration and conversion dates. The article further reviews theoretical models of forest management practices that have considered either land sale following clear-cutting or a switch to a more profitable alternative land use without selling the land. A brief discussion on the studies with a generalization of the classic Faustmann formula for land expectation value is also included. For completeness, comparative statics results and a numerical illustration of the main findings from the private landowner framework are included.


Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 581
Author(s):  
Markandu Anputhas ◽  
Johannus Janmaat ◽  
Craig Nichol ◽  
Adam Wei

Research Highlights: Forest conservation policies can drive land-use change to other land-use types. In multifunctional landscapes, forest conservation policies will therefore impact on other functions delivered by the landscape. Finding the best pattern of land use requires considering these interactions. Background and Objectives: Population growth continues to drive the development of land for urban purposes. Consequently, there is a loss of other land uses, such as agriculture and forested lands. Efforts to conserve one type of land use will drive more change onto other land uses. Absent effective collaboration among affected communities and relevant institutional agents, unexpected and undesirable land-use change may occur. Materials and Methods: A CLUE-S (Conversion of Land Use and its Effects at Small Scales) model was developed for the Deep Creek watershed, a small sub-basin in the Okanagan Valley of British Columbia, Canada. The valley is experiencing among the most rapid population growth of any region in Canada. Land uses were aggregated into one forested land-use type, one urban land-use type, and three agricultural types. Land-use change was simulated for combinations of two forest conservation policies. Changes are categorized by location, land type, and an existing agricultural land policy. Results: Forest conservation policies drive land conversion onto agricultural land and may increase the loss of low elevation forested land. Model results show where the greatest pressure for removing land from agriculture is likely to occur for each scenario. As an important corridor for species movement, the loss of low elevation forest land may have serious impacts on habitat connectivity. Conclusions: Forest conservation policies that do not account for feedbacks can have unintended consequences, such as increasing conversion pressures on other valued land uses. To avoid surprises, land-use planners and policy makers need to consider these interactions. Models such as CLUE-S can help identify these spatial impacts.


2021 ◽  
Author(s):  
Kathleen Coupland ◽  
Juliana Magalhães ◽  
Verena C Griess

Abstract Applied educational opportunities in forestry undergraduate curricula are essential for a complete postsecondary degree program. Walking distance to local urban forests present a way to teach forestry students in applied settings, while reducing the time, cost, and travel logistics. A case study at a Canadian university (University of British Columbia) was used to connect urban forest canopy cover to forestry learning objectives and walking time to the main teaching building. Individual tree canopies were identified with light detection and ranging data and aggregated to 0.05 ha grid sections. Using canopy cover and forest arrangement, the urban forest was classified into closed, open, small, sparse, or non- forest classifications. Forestry learning objectives were matched with each forest classification in conjunction with walkability to identify critical local location for forestry education. Results identified key areas suitable for teaching forestry and for linking forestry educational values with easily accessible high value locations. Study Implications: Applied educational opportunities for undergraduate forestry students are critical for ensuring hands-on, real world experiences and essential in postsecondary forestry degrees. Local urban forests present an opportunity to allow students access to these experiences regularly. Connecting forestry learning objectives with local urban forest types allowed for the identification of key, high-value learning locations. The information and methodology from this research provide insight into explicitly classifying areas for forestry educational purposes with the goal of promoting outdoor applied educational opportunities for forestry undergraduate students.


2020 ◽  
Author(s):  
Wenhao Sun

&lt;p&gt;Changes in climate and land-use are altering soil respiration patterns and thus affecting C sequestration rates globally. This study aims to understand the effect of revegetation induced land-use change on the response of soil respiration to precipitation pulses during an extreme-drying-and-rewetting period. Soil respiration (SR) in cropland, grassland, shrubland, and orchard were intensively monitored along with environmental variables during an extreme drought period with precipitation pulse on China&amp;#8217;s Loess Plateau. SR was strongly correlated to soil water content for all land-uses. However, the relationship was highly dependent on land-use types: SR was only strongly suppressed in cropland and orchard when moisture content exceeded 10.8% and 13.7%, respectively, whereas no clear suppression was observed under other land-uses. As a result, the C loss in grassland and shrubland was 49.1-78.9% higher than in cropland following significant precipitation events. In addition, SR was negatively and weakly correlated with soil temperature, indicating the change in the dominant control on SR due to extreme drought. Land-use change alters the response of soil respiration to soil moisture during extreme-drying-and-rewetting periods in this revegetated ecosystem. Its effect on respiration pulses will amplify as extreme climate events increase in the future, which may potentially alter the existing C balance.&lt;/p&gt;


Land ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 240 ◽  
Author(s):  
Didik Suprayogo ◽  
Meine van Noordwijk ◽  
Kurniatun Hairiah ◽  
Nabilla Meilasari ◽  
Abdul Lathif Rabbani ◽  
...  

Forest conversion to agriculture can induce the loss of hydrologic functions linked to infiltration. Infiltration-friendly agroforestry land uses minimize this loss. Our assessment of forest-derived land uses in the Rejoso Watershed on the slopes of the Bromo volcano in East Java (Indonesia) focused on two zones, upstream (above 800 m a.s.l.; Andisols) and midstream (400–800 m a.s.l.; Inceptisols) of the Rejoso River, feeding aquifers that support lowland rice areas and drinking water supply to nearby cities. We quantified throughfall, infiltration, and erosion in three replications per land use category, with 6–13% of rainfall with intensities of 51–100 mm day−1. Throughfall varied from 65 to 100%, with a zone-dependent intercept but common 3% increase in canopy retention per 10% increase in canopy cover. In the upstream watershed, a tree canopy cover > 55% was associated with the infiltration rates needed, as soil erosion per unit overland flow was high. Midstream, only a tree canopy cover of > 80% qualified as “infiltration-friendly” land use, due to higher rainfall in this zone, but erosion rates were relatively low for a tree canopy cover in the range of 20–80%. The tree canopy characteristics required for infiltration-friendly land use clearly vary over short distances with soil type and rainfall intensity.


2018 ◽  
Vol 162 ◽  
pp. 03024
Author(s):  
Haifaa Husein ◽  
Oday Jasim ◽  
Saja Mahmood

The digital technologies represented by digital processing programs, local data bases and satellite receivers system is a set of technologies made to organize the process of building descriptive field database, and conveying them to computers, in order to store, analyze and manifest data as well as upgrade and extract it in the form of digital maps, which represent an asset in any engineering and planning study. For a variety of types of mixed land uses and others land uses in the urban city, which cause great difficulty in how to build spatial Geodatabase in terms of frequency of the land use and overlap between land uses, the paper will find the proposed standard Geomatics techniques to get rid of these difficulties. The paper will tackle the engineering and survey methods which could reinforce manifestation of uses of logical database in urban areas. Lastly, the research concludes that relying on important field survey and digital references in preparing suggested criteria for field uses, in addition to the recommendations provided in this field for the post graduate and undergraduate students as well governmental specialized departments.


2020 ◽  

<p>We utilized satellite and GIS technologies to address the relationship between urban land uses and Noise Pollution (NP) in one of the most crowded regions of Tehran city. Leq was determined in 170 stations of the studied area and an acoustic map was created. Moreover, using satellite remote sensing data and a land use map, the density map for nine types of the most important urban land use was provided and the relationship between different land use densities and NP was investigated. We found that the investigated region was highly polluted and the NP level was higher in the morning (76.29±5.61 dB[A]) and afternoon (76.46±4.88 dB[A]) in comparison to the noon period. Furthermore, the prepared acoustic map revealed that in the east and southwest of the studied area, the NP was highest and lowest, respectively. Also, cultural (73.48±4.7 dB[A]) and parking (79.02±4.3 dB[A]) areas had the lowest and highest levels of Leq. Also, the high density of road, commercial, industrial, mixed commercial and residential and parking land uses had a direct significant relationship with Leq and this relation was inverse for green space. It was concluded that land use variations significantly affect the NP levels and it can be utilized to predict and manage the NP in different cities.</p>


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