scholarly journals Context-Dependence of Urban Forest Vegetation Invasion Level and Alien Species’ Ecological Success

Forests ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 26 ◽  
Author(s):  
Marcin K. Dyderski ◽  
Andrzej M. Jagodziński

Research Highlights: Urban ecosystems are claimed to be more invaded than natural vegetation. Despite numerous studies, the patterns of alien species occurrence in urban forests are rarely linked to invasion ecology hypotheses. Background and Objectives: We assumed that patterns of invasion level (i.e., neophyte richness) and neophyte ecological success (cover) are context-dependent, i.e., depend on the type of vegetation, and that hypotheses connected with empty niche and biotic acceptance will have the strongest support in urban forests. We also tested biotic resistance, habitat filtering, disturbance, resource availability, and environmental heterogeneity hypotheses. Materials and Methods: Using a random forest algorithm, we tested the importance of factors related to invasion ecology hypotheses in a dataset of urban forest vegetation plots (n = 120). We studied seven types of forest plant communities occurring in Poznań (W Poland) and we assessed the vegetation’s taxonomic and functional composition. Results: We found that models of alien species richness and cover explained 28.5% and 35.0% of variance, respectively. Vegetation type was of the highest importance in both cases, suggesting that the occurrence of alien plant species is context-dependent. Resource availability and disturbance ecological indicator values were also of high importance. Conclusions: Our study supported resource availability and habitat filtering hypotheses as explanations of the level of invasion and ecological success of alien species in an urban forest, with partial support for the disturbance hypothesis. Our study revealed that predictors of invasion level are context-dependent, as patterns of alien species richness and cover differed among vegetation types. We highlight context-dependence of alien species invasion patterns in different vegetation types due to the habitat-forming role of dominant tree species and different availability of resources and disturbance levels, as well as different pools of native species. Thus, prevention and management of biological invasions in urban forests should account for forest vegetation type.

10.5109/27355 ◽  
2013 ◽  
Vol 58 (2) ◽  
pp. 253-258
Author(s):  
Suk–Hwan Hong ◽  
Ji–Suk Kim ◽  
Kyong–Seok Ki ◽  
Seok–Gon Park ◽  
Kiyoshi Kurosawa

2019 ◽  
Vol 11 (22) ◽  
pp. 6318 ◽  
Author(s):  
Ingo Kowarik ◽  
Anne Hiller ◽  
Greg Planchuelo ◽  
Birgit Seitz ◽  
Moritz von der Lippe ◽  
...  

Many cities aim to increase urban forest cover to benefit residents through the provision of ecosystem services and to promote biodiversity. As a complement to traditional forest plantings, we address opportunities associated with “emerging urban forests” (i.e., spontaneously developing forests in cities) for urban biodiversity conservation. We quantified the area of successional forests and analyzed the species richness of native and alien plants and of invertebrates (carabid beetles, spiders) in emerging forests dominated by alien or native trees, including Robinia pseudoacacia, Acer platanoides, and Betula pendula. Emerging urban forests were revealed as shared habitats of native and alien species. Native species richness was not profoundly affected by the alien (co-)dominance of the canopy. Instead, native and alien plant species richnesses were positively related. Numbers of endangered plants and invertebrates did not differ between native- and alien-dominated forest patches. Patterns of tree regeneration indicate different successional trajectories for novel forest types. We conclude that these forests (i) provide habitats for native and alien species, including some endangered species, (ii) allow city dwellers to experience wild urban nature, and (iii) support arguments for adapting forests to dynamic urban environments. Integrating emerging urban forests into the urban green infrastructure is a promising pathway to sustainable cities and can complement traditional restoration or greening approaches.


2020 ◽  
Vol 45 (3) ◽  
pp. 537-543
Author(s):  
Karinne Sampaio Valdemarin ◽  
Jair Eustáquio Quintino Faria ◽  
Fiorella Fernanda Mazine ◽  
Vinicius Castro Souza

Abstract—A new species of Eugenia from the Atlantic forest of Brazil is described and illustrated. Eugenia flavicarpa is restricted to the Floresta de Tabuleiro (lowland forests) of Espírito Santo state and is nested in Eugenia subg. Pseudeugenia. Considering all other species of the subgenus that occur in forest vegetation types of the Atlantic forest phytogeographic domain, Eugenia flavicarpa can be distinguished mainly by the combination of smooth leaves with indumentum on both surfaces, with two marginal veins, usually ramiflorous inflorescences, pedicels 4.5‐9.7 mm long, flower buds 3.5‐4 mm in diameter, and by the calyx lobes that are 2‐3 mm long with rounded to obtuse apices. Morphological analyses were performed to explore the significance of quantitative diagnostic features between the new species and the closely related species, Eugenia farneyi. Notes on the habitat, distribution, phenology, and conservation status of Eugenia flavicarpa are provided, as well as a key for all species of Eugenia subg. Pseudeugenia from forest vegetation of the Atlantic forest phytogeographic domain.


2020 ◽  
Vol 3 (1) ◽  
pp. 78
Author(s):  
Francis Oloo ◽  
Godwin Murithi ◽  
Charlynne Jepkosgei

Urban forests contribute significantly to the ecological integrity of urban areas and the quality of life of urban dwellers through air quality control, energy conservation, improving urban hydrology, and regulation of land surface temperatures (LST). However, urban forests are under threat due to human activities, natural calamities, and bioinvasion continually decimating forest cover. Few studies have used fine-scaled Earth observation data to understand the dynamics of tree cover loss in urban forests and the sustainability of such forests in the face of increasing urban population. The aim of this work was to quantify the spatial and temporal changes in urban forest characteristics and to assess the potential drivers of such changes. We used data on tree cover, normalized difference vegetation index (NDVI), and land cover change to quantify tree cover loss and changes in vegetation health in urban forests within the Nairobi metropolitan area in Kenya. We also used land cover data to visualize the potential link between tree cover loss and changes in land use characteristics. From approximately 6600 hectares (ha) of forest land, 720 ha have been lost between 2000 and 2019, representing about 11% loss in 20 years. In six of the urban forests, the trend of loss was positive, indicating a continuing disturbance of urban forests around Nairobi. Conversely, there was a negative trend in the annual mean NDVI values for each of the forests, indicating a potential deterioration of the vegetation health in the forests. A preliminary, visual inspection of high-resolution imagery in sample areas of tree cover loss showed that the main drivers of loss are the conversion of forest lands to residential areas and farmlands, implementation of big infrastructure projects that pass through the forests, and extraction of timber and other resources to support urban developments. The outcome of this study reveals the value of Earth observation data in monitoring urban forest resources.


Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 806
Author(s):  
Wan-Yu Liu ◽  
Yo-Zheng Lin ◽  
Chi-Ming Hsieh

Urban forests offer multiple functions: they can balance negative effects from the environment and provide the public with a place for leisure and recreation. Hence, urban forests are crucial to urban ecology and have been widely studied. In addition, relevant study results were applied for policymaking in urban development and forest park management. This study evaluated the ecological value of the Sinhua Forest Park and examined whether the socioeconomic background of participants influences their willingness to pay (WTP) for ecological conservation. Questionnaires were distributed to visitors in the Sinhua Forest Park in Tainan, Taiwan, and the payment card format of the contingent valuation method was employed to evaluate the ecological value. The results showed that the visitors had an annual WTP of $22.01 per person. However, when samples with protest responses were excluded, the WTP rose to $24.58. By considering the total number of visitors of a year, the total ecological value was $1,426,964.14/year and reached $1,593,257.31/year after excluding the protest samples. This study also analyzed participants’ within-variable socioeconomic background (e.g., gender and education) and discovered that male participants who are aged 60 years or older, with an education level of senior/vocational high school, and those who visited green spaces two to three times per week presented a high WTP score on average. A Tobit regression model was employed for examination, and the results indicated that participants’ education and frequency of visiting green spaces significantly influenced their WTP for the ecological conservation of the Sinhua Forest Park.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 394
Author(s):  
Xinhui Xu ◽  
Zhenkai Sun ◽  
Zezhou Hao ◽  
Qi Bian ◽  
Kaiyue Wei ◽  
...  

Forests can affect soil organic carbon (SOC) quality and distribution through forest types and traits. However, much less is known about the influence of urban forests on SOC, especially in the effects of different forest types, such as coniferous and broadleaved forests. Our objectives were to assess the effects of urban forest types on the variability of SOC content (SOC concentration (SOCC) and SOC density (SOCD)) and determine the key forest traits influencing SOC. Data from 168 urban forest plots of coniferous or broadleaved forests located in the Beijing urban area were used to predict the effects of forest types and traits on SOC in three different soil layers, 0–10 cm, 10–20 cm, and 20–30 cm. The analysis of variance and multiple comparisons were used to test the differences in SOC between forest types or layers. Partial least squares regression (PLSR) was used to explain the influence of forest traits on SOC and select the significant predictors. Our results showed that in urban forests, the SOCC and SOCD values of the coniferous forest group were both significantly higher than those of the broadleaved group. The SOCC of the surface soil was significantly higher than those of the following two deep layers. In PLSR models, 42.07% of the SOCC variance and 35.83% of the SOCD variance were explained by forest traits. Diameter at breast height was selected as the best predictor variable by comparing variable importance in projection (VIP) scores in the models. The results suggest that forest types and traits could be used as an optional approach to assess the organic carbon stock in urban forest soils. This study found substantial effects of urban forest types and traits on soil organic carbon sequestration, which provides important data support for urban forest planning and management.


Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 14
Author(s):  
Han Zhi-Ying ◽  
Youn Yeo-Chang

This paper aims to investigate the Beijing resident’s preferences over various options of urban forest management strategies. The literature investigation and expert Delphi method were conducted to classify the ecosystem services of urban forests into six categories: (1) fresh water provision, (2) noise reduction, (3) moderation of extreme events, (4) air quality regulation, (5) species diversity and wildlife habitat, and (6) recreation and spiritual experience. To elicit the relative preferences to ecosystem service (hereafter referred to as ES) of Beijing residents, we employed the choice experiment method. The data were collected by interviews with questionnaires conducted in October 2017, and a total of 483 valid questionnaires were analyzed. The subjects of this experiment were residents older than 19 years old who have lived in Beijing for more than 1 year and have visited any one of the urban forests located in Beijing more than once during 2016. The results were as follows: Firstly, the air quality regulation ES was considered as the most important service for Beijing residents in terms of their choices of urban forest. In addition, Beijing residents regarded the fresh water provision ES as the second most important ES. Beijing residents were willing to pay up to 1.84% of the average monthly income of Chinese households annually to expand urban forest ecosystems in order to improve air quality. Secondly, apartment owners were willing to pay more municipality tax for forest ESs than residents who did not own an apartment. Thirdly, residents were more willing to pay for urban forest ESs as their income increases. The results indicated that Beijing residents were willing to pay more tax in support of urban forestry for air quality improvement. This research suggests that urban environmental policy makers in Beijing should pay more attention to the regulation function of forests (especially improving air quality) when designing and managing urban forests.


Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 17 ◽  
Author(s):  
Justyna Jaworek-Jakubska ◽  
Maciej Filipiak ◽  
Adam Michalski ◽  
Anna Napierała-Filipiak

Knowledge about urban forests in Poland is still limited, as it is primarily based on aggregate, formal data relating to the general area, ignoring the spatial dimension and informal green areas. This article describes and analyses spatio-temporal changes in the actual urban forest resources in Wrocław in 1944–2017, which covers the first period of the city’s rebuilding after its destruction during World War II and its development during the nationalised, centrally-planned socialist economy, as well as the second period of intensive and only partly controlled growth under conditions of market economy. The study is based on current and historical orthophotomaps, which were confronted with cartographic data, as well as planning documents. We found that between 1944 and 2017, the percentage contribution of informal woodlands increased tenfold (from 0.5 to 4.9% of the present total area of the city). The area occupied by such forests has grown particularly during the most recent years of the city’s intensive development. However, the forests have been increasingly fragmented. During the first period, new forest areas were also created in the immediate vicinity of the city centre, while during the second one, only in its peripheral sections. The post-war plans regarding the urban green spaces (UGS), including the current plan, are very conservative in nature. On the one hand, this means no interference with the oldest, biggest, and most valuable forest complexes, but on the other hand, insufficient consideration of the intensive built-up area expansion on former agriculture areas. Only to a limited extent did the above-mentioned plans take into account the informal woodlands, which provide an opportunity for strengthening the functional connectivity of landscape.


2007 ◽  
Vol 7 (1) ◽  
pp. 69-79 ◽  
Author(s):  
T. Wagner ◽  
S. Beirle ◽  
T. Deutschmann ◽  
M. Grzegorski ◽  
U. Platt

Abstract. A new method for the satellite remote sensing of different types of vegetation and ocean colour is presented. In contrast to existing algorithms relying on the strong change of the reflectivity in the red and near infrared spectral region, our method analyses weak narrow-band (few nm) reflectance structures (i.e. "fingerprint" structures) of vegetation in the red spectral range. It is based on differential optical absorption spectroscopy (DOAS), which is usually applied for the analysis of atmospheric trace gas absorptions. Since the spectra of atmospheric absorption and vegetation reflectance are simultaneously included in the analysis, the effects of atmospheric absorptions are automatically corrected (in contrast to other algorithms). The inclusion of the vegetation spectra also significantly improves the results of the trace gas retrieval. The global maps of the results illustrate the seasonal cycles of different vegetation types. In addition to the vegetation distribution on land, they also show patterns of biological activity in the oceans. Our results indicate that improved sets of vegetation spectra might lead to more accurate and more specific identification of vegetation type in the future.


Biologia ◽  
2017 ◽  
Vol 72 (9) ◽  
Author(s):  
Aleksandra Cvetkovska-Gjorgjievska ◽  
Slavčo Hristovski ◽  
Dana Prelić ◽  
Lucija Šerić Jelaska ◽  
Valentina Slavevska-Stamenković ◽  
...  

AbstractCarabid fauna is not sufficiently explored in Central and Western Balkan areas, especially in mountain ecosystems with unique biodiversity which is a result of specific environmental factors and geologic history. Furthermore, distribution of species and adaptation to varying environmental parameters change along the altitudinal gradients. All this highlights the need for biodiversity and ecological studies in order to assess the state of the mountain ecosystems and conservation significance. Carabids as good bioindicator group can be used as a tool for monitoring those changes. The aim of this study was to analyse the differences of body size distribution and mean individual biomass (MIB) of ground beetle assemblages as a response of changing conditions and vegetation types along an altitudinal gradient on Belasitsa Mountain in south Macedonia. Both parameters significantly decreased with increasing altitude and were consequently associated with the vegetation type. Larger bodied individuals and higher values of MIB were recorded in the white oak and oriental hornbeam forest stands with the values decreasing in sessile oak forests towards submontane and montane beech forest stands. This research yielded first list of carabid species inhabiting Belasitsa Mountain with insight of carabid body length and biomass distribution along altitudinal gradient.


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