Hunting for a Larger Diversity of Urban Trees in Western Europe—A Case Study from the Southern Caucasus

2019 ◽  
Vol 45 (5) ◽  
Author(s):  
Henrik Sjöman ◽  
Simon Hannus ◽  
Patrick Bellan ◽  
Tinatin Barblishvili ◽  
Tamaz Darchidze ◽  
...  

The primary aim of this study was to communicate a method for locating natural habitats where trees grows under conditions that are comparable to those in urban environments in terms of water stress. This is presented by analyzing five different forest reserves in the southern Caucasus (Republic of Georgia) where calculation of net water balance over the period of a year was conducted. This provided an insight into the drought at the sites during the growing season. The data were thereafter compared with similar calculations for five different cities in Western Europe in order to see if there were any matches in drought stress between the cities and the forest reserves. To extend the analysis, conditions in the five cities were assessed for high density and low density areas, and for the current climate and a future climate scenario. The comparisons revealed some matches between conditions in the forest reserves and those in different scenarios/areas in the cities. A secondary aim was to identify specific ecotypes in the wild demonstrating great potential to handle growing conditions similar to those in urban environments based on inventories of woody plants in the forest reserves. A total of 44 woody species were found in the forest reserve systems with a random distribution throughout the five study sites. Based on the commitments presented above a preliminary screening can be done where future tree selection focus can be directed towards highly promising species and ecotypes, which would undoubtedly limit the time lag before proper plant material can be released.

2016 ◽  
Vol 44 (1/2) ◽  
pp. 186-208
Author(s):  
Hing Tsang

This article argues that the work of the late Johan van der Keuken offers a contribution to ecological semiotics, and that it also defines the relationship between the semiotic animal and nature in ways that avoid glottocentricism. Taking from the recent work of Kalevi Kull, Jesper Hoffmeyer, and John Deely amongst others, I will argue that van der Keuken’s documentaries offer a view of ecology that is broader than a study of bio-physical processes that might reduce ecology to a narrow political issue.In order to support this argument, I will be looking at two contrasting films from van der Keuken – Flat Jungle (1978) and Face Value (1991). The first film examines natural habitats within a confined coastal area in Western Europe, while the second film looks at human beings in the different urban environments of late-20th-century Europe. I will then argue that van der Keuken does not collapse the vital distinctions between umwelt and Lebenswelt, yet his films also succeed at reminding us of their constant interdependence.


2018 ◽  
Vol 373 (1740) ◽  
pp. 20160508 ◽  
Author(s):  
Sarah Benson-Amram ◽  
Geoff Gilfillan ◽  
Karen McComb

Playback experiments have proved to be a useful tool to investigate the extent to which wild animals understand numerical concepts and the factors that play into their decisions to respond to different numbers of vocalizing conspecifics. In particular, playback experiments have broadened our understanding of the cognitive abilities of historically understudied species that are challenging to test in the traditional laboratory, such as members of the Order Carnivora. Additionally, playback experiments allow us to assess the importance of numerical information versus other ecologically important variables when animals are making adaptive decisions in their natural habitats. Here, we begin by reviewing what we know about quantity discrimination in carnivores from studies conducted in captivity. We then review a series of playback experiments conducted with wild social carnivores, including African lions, spotted hyenas and wolves, which demonstrate that these animals can assess the number of conspecifics calling and respond based on numerical advantage. We discuss how the wild studies complement those conducted in captivity and allow us to gain insights into why wild animals may not always respond based solely on differences in quantity. We then consider the key roles that individual discrimination and cross-modal recognition play in the ability of animals to assess the number of conspecifics vocalizing nearby. Finally, we explore new directions for future research in this area, highlighting in particular the need for further work on the cognitive basis of numerical assessment skills and experimental paradigms that can be effective in both captive and wild settings. This article is part of a discussion meeting issue ‘The origins of numerical abilities’.


Author(s):  
Karamoko Sanogo ◽  
Birhanu B. Zemadim ◽  
Souleymane Sanogo ◽  
Ashatu Abdulkadiri ◽  
Abdramane BA

Forests constitute a key component of the Earth system but the sustainability of the forest reserves in the semi-arid zone is a real concern since its vegetation is very sensitive to the climate fluctuation. The understanding of the mechanisms for the interaction vegetation-climate is poorly studied in the context of African Sahel. In this study, the characteristics of the vegetation response to the fluctuations of precipitation and temperature is determined for the forest reserve of Fina. Rainfall estimates, air temperature and NDVI are used to establish the lag correlations between fluctuations of vegetation and climate variables at both seasonal and interannual bases. Results shows increasing tendency of NDVI started from the 1990s coinciding the recovery of the rainfall from the 1980s drought and the obtained correlation(r=0.66) is statistically significant (pvalue<0.01). The strongest responses of vegetation to rainfall and temperature fluctuations were found after 30 and 15 days, respectively. Moreover, at shorter time lag (e.g. 15 days) more pronounced vegetation responses to both rainfall and temperature were found in agricultural dominated land while at longer time lag (e.g. 30 days) stronger response was observed in Bare dominated land. The vegetation response to the climate fluctuation is modulated by the land use/cover dynamics. Keywords: NDVI, Rainfall, Air temperature, vegetation response, Fina Forest Reserve, Mali.


2019 ◽  
Vol 47 (1/2) ◽  
pp. 234-256 ◽  
Author(s):  
Riin Magnus ◽  
Heldur Sander

Urban trees are considered to be essential and integral to urban environments, to contribute to the biodiversity of cities as well as to the well-being of their inhabitants. In addition, urban trees may also serve as living memorials, helping to remember major social eruptions and to cement continuity with the past, but also as social disruptors that can induce clashes between different ideals of culture. In this paper, we focus on a specific case, a Ginkgo biloba specimen growing at Süda Street in the centre of Tallinn, in order to demonstrate how the shifts in the meaning attributed to a non-human organism can shape cultural memory and underlie social confrontations. Integrating an ecosemiotic approach to human-non-human interactions with Juri Lotman’s approach to cultural memory and cultural space, we point out how non-human organisms can delimit cultural space at different times and how the ideal of culture is shaped by different ways of incorporating or other species in the human cultural ideal or excluding them from it.


Author(s):  
Alex Stemmelen ◽  
Alain Paquette ◽  
Marie-Lise Benot ◽  
Yasmine Kadiri ◽  
Hervé Jactel ◽  
...  

AbstractInsect herbivory is an important component of forest ecosystems functioning and can affect tree growth and survival. Tree diversity is known to influence insect herbivory in natural forest, with most studies reporting a decrease in herbivory with increasing tree diversity. Urban ecosystems, on the other hand, differ in many ways from the forest ecosystem and the drivers of insect herbivory in cities are still debated.We monitored 48 urban trees from five species – three native and two exotic – in three parks of Montreal (Canada) for leaf insect herbivory and predator activity on artificial larvae, and linked herbivory with both predation and tree diversity in the vicinity of focal trees.Leaf insect herbivory decreased with increasing tree diversity and with increasing predator attack rate.Our findings indicate that tree diversity is a key determinant of multitrophic interactions between trees, herbivores and predators in urban environments and that managing tree diversity could contribute to pest control in cities.This article has been peer-reviewed and recommended by Peer Community in Ecologyhttps://doi.org/10.24072/pci.ecology.100061


Ecology ◽  
2021 ◽  
Author(s):  
Elise Damstra ◽  
Cristina Banks-Leite

Extending along the southern coast of Brazil, into Argentina and Paraguay, the Atlantic Forest is a domain that once covered 150 Mha and includes many distinct forest subtypes and ecosystems. Its large latitudinal (29˚) and altitudinal (0–2,800 m above sea level) range, as well as complex topography in the region, has created microclimates within forest subtypes, which has led to biodiversity specifically adapted to narrow ecological ranges. The region is incredibly species-rich and is home to charismatic or economically important species such as the black and golden lion tamarin, the red-browned Amazon parrot, and the highly prized palm heart from Euterpe edulis. Through widespread human-driven change dating back to the arrival of European settlers in 1500, this realm has been extensively reduced, fragmented, and modified. Nowadays, this region is home to about 130 million people (60 percent of the Brazilian population) and is responsible for producing 70 percent of Brazil’s GDP, putting a strain on natural resources and providing challenges to conservation. Due to its high levels of endemic species coupled with a high threat of habitat loss and fragmentation, the Atlantic Forest has been identified as a “biodiversity hotspot.” Numerous studies have assessed the effects of habitat transformation on biodiversity and the consensus is that the majority of species are negatively affected. It is puzzling however that few species have actually gone extinct in the wild, even if some extinctions might have gone undetected. Extinctions do not immediately follow habitat change, there is often a time lag of many decades between habitat transformation and extinction. This may suggest that many species in the Atlantic Forest are “living deads,” as despite their presence the available habitat no longer supports their requirements. It also suggests that there is a window of opportunity to restoring the domain to avert extinctions before they are realized. Current research and policy actions are geared toward optimizing restoration and increasing the extent of native forest cover, bringing hope to the conservation of this unique domain.


2009 ◽  
Author(s):  
Danny B Draper ◽  
Peter A Richards

Dictionary for Managing Trees in Urban Environments is a comprehensive list of terms used in the universal management of urban trees. Many of the terms are from arboricultural science, while others are derived from unproven but commonly applied concepts. Where the existing terminology to describe trees was limited or nonexistent, new terms have been introduced. This dictionary allows for broad application and use by a wide variety of people and conveys in plain language concepts that are sometimes complex. Most major terms have been cross referenced and diagrams have been added for greater understanding. While a number of pertinent botanical terms have been included, those readily found within dictionaries of general plant sciences and botany have been omitted. Dictionary for Managing Trees in Urban Environments promotes a greater understanding of arboriculture and urban forestry, and will assist in the preparation of reports for the management of trees, procedures and planning instruments, such as Tree Management Policies and Tree Management Orders.


Caldasia ◽  
2018 ◽  
Vol 40 (2) ◽  
pp. 390-393
Author(s):  
Arturo González-Zamora ◽  
Sónia Sánchez-López ◽  
Christian A. Delfín-Alfonso ◽  
Edgar Ahmed Bello-Sánchez

Oviposition in elusive reptiles has been poorly documented due to the difficulty in observing it in natural habitats. Here, we document the first egg-laying record in the Eastern Casque-headed Basilisk Laemanctus longipes in the wild. Our record adds novel information about the oviposition of this scarcely studied reptile species. 


2013 ◽  
Vol 50 (2) ◽  
pp. 270-283 ◽  
Author(s):  
M. K. V. CARR

SUMMARYPapaya has never been found in the wild, but is believed to have originated in tropical America from where it has spread throughout the tropics and subtropics. This fruit crop is particularly important in India and Brazil. Most research on the water relations of papaya has been undertaken in Brazil and on the island of Guam (United States of America). Papaya is a short-lived large herb, growing to a height of up to 10 m. Leaves emerge from the upper part of the unbranched stem. After a juvenile period, lasting for about two months, flowers begin to develop in leaf axils. Flowering continues throughout the year as new leaves emerge. The plants, which are dioecious, begin to bear fruit within a year after planting, sustaining high yields for two years before yields decline. The ‘effective’ root depth varies with the method of irrigation, but can reach 0.55 m. The seedlings and the trees are susceptible to wind damage, a topic that has been well researched. Stomata are only found on the abaxial leaf surface. They are sensitive to changes in the saturation deficit of the air. Stomata also respond quickly to changing light conditions. On clear days, midday suppression of photosynthesis occurs as a result of partial closure of the stomata. In the morning, there is a time lag between water loss by transpiration and sap flow, as water is taken from storage in the hollow stem. Few attempts have been made to measure the actual water use of papaya, and there are no reliable published values for the crop coefficient. Limitations to the design of the papaya irrigation experiments reported so far make it difficult to reconcile the results in practical ways. Water productivities equivalent to 1.8 to 2.8 kg (fresh fruit) m−3 (irrigation water) have been obtained. Although papaya is generally considered to be drought sensitive and responsive to irrigation, there is a shortage of good experimental evidence to support this view. There is a need to establish practical irrigation schedules for this remarkable crop. A uniformity of approach to irrigation experimentation and a common, universally agreed nomenclature would facilitate this process.


Sign in / Sign up

Export Citation Format

Share Document