We have examined shoot and root growth and the concentration of carbohydrates in seedlings of a northern (67 • N) and a southern (61 • N) ecotype of Betula pendula Roth. cultivated at root-zone temperatures of 2, 6, 12 and 17 • C. Three hydroponic experiments were conducted in controlled environments. We used three different pretreatments before seedlings were subjected to the experimental temperature treatments. Actively growing seedlings that were acclimated to the hydroponic solution for 3 weeks at a root temperature of 17 • C, continued to grow at all the experimental temperatures, with an expected increase in growth from 2 to 17 • C. However, if we started with ecodormant cold stored plants or used seedlings grown actively in perlite, no growth was observed at 2 • C and only minor growth was found at 6 • C. The highest root temperature always produced the best growth. The concentration of nonstructural carbohydrates was higher in seedlings grown at 2 • C than at 17 • C, and this is probably due to extensive incorporation of carbohydrates into cell walls and other structural elements at 17 • C. We found no evidence for differences between the two ecotypes in root growth, in timing of bud burst, but shoot growth terminated in the northern ecotype in the first experiment because the natural photoperiod was below the critical value. Our study highlights the importance of post-transplantation stress (planting check) related to root growth, and that root threshold temperatures may change according to the way plants are pretreated.
Individual perceptions of green space quality are essential when a user considers engaging in activities. This national-scale study provides insights into Norwegians’ quality perceptions of municipal green space, visit frequency and motivations for engaging in different activities. We applied regression analysis to investigate how various factors affect the outcome variables, quality perceptions and visit frequency from a sample of the Norwegian adult population. Results reveal that Norwegians perceive their green spaces as having good quality, and higher quality perceptions have a positive influence on green space visits. Half of the respondents visited green spaces out of intrinsic motives in high-quality environments providing fresh air, experiences of nature and quietness. It is essential, however, to take into account that less reported activity mirrors groups of respondents who least often visit green spaces.
Purpose – The purpose of this paper is to provide insights into the extent of, rationales for and outcomes of contracting out in the local road and park sectors in Norway. For understanding the use of contracting out in local governments, it highlights the relevance of the capability perspective in organisational literature as an alternative to the standard efficiency perspective. Design/methodology/approach – The paper draws on four expert interviews and survey data gathered from park and road managers in Norwegian municipalities in 2015. Findings – The study suggests that Norwegian municipalities primarily contract out park and road maintenance services when they do not have the capability to perform these services themselves. Cost concerns are also highlighted but of less importance. Moreover, lack of competition renders the use of contracting out as a potentially costly and less satisfying arrangement for organising service delivery. Research limitations/implications – While the scope is limited to one country, Norway, future research may benefit from the theoretical perspectives, which have been used. Practical implications – Policy guidelines should support a flexible use of various arrangements for service provision. Originality/value – The dominating view among proponents of marketisation in the public sector suggests that contracting out to private contractors is undertaken to enhance economic efficiency compared to keeping service production in-house. This study suggests that this is not always the case – even in “most likely” sectors such as park and road maintenance.
Societal Impact Statement Globally, cities are planning for resilience through urban greening initiatives as governments understand the importance of urban forests in improving quality of life and mitigating climate change. However, the persistence of urban forests and the ecosystem benefits they provide are threatened by climate change, and systematic assessments of causes of tree dieback and mortality in urban environments are rare. Long‐term monitoring studies and adaptive management are needed to identify and prevent climate change‐driven failures and mortality. Research and monitoring when coupled with systematic forecasting will enable governments to incorporate climate change resilience into urban forestry planning. Future scenarios in which urban forests are resilient or in decline will depend on the management and planning actions we make today. Summary The management of urban forests is a key element of resilience planning in cities across the globe. Urban forests provide ecosystem services as well as other nature‐based solutions to 4.2 billion people living in cities. However, to continue to do so effectively, urban forests need to be able to thrive in an increasingly changing climate. Trees in cities are vulnerable to extreme heat and drought events, which are predicted to increase in frequency and severity under climate change. Knowledge of species' vulnerability to climate change, therefore, is crucial to ensure provision of desired ecosystem benefits, improve species selection, maintain tree growth and reduce tree mortality, dieback and stress in urban forests. Yet, systematic assessments of causes of tree dieback and mortality in urban environments are rare. We reviewed the state of knowledge of tree mortality in urban forests globally, finding very few frameworks that enable detection of climate change impacts on urban forests and no long‐term studies assessing climate change as a direct driver of urban tree dieback and mortality. The effects of climate change on urban forests remain poorly understood and quantified, constraining the ability of governments to incorporate climate change resilience into urban forestry planning.
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