Tree seedlings planted in abandoned agricultural fields interact with herb communities through competition, tolerance, and facilitation. In addition, they are subject to herbivory by small mammals, ...deer or invertebrates. To increase the success of forest restoration in abandoned fields and reduce management costs, we should determine which species are tolerant to or facilitated by herbaceous vegetation and those which require protection from competition and predation. Eight native tree species were planted in plots covered by herbaceous vegetation, plots where herbaceous vegetation was removed, and plots where seedlings were surrounded by an organic mulch mat. Half of the seedlings were protected against small mammal damage. Results showed that two non-pioneer and moderately shade-tolerant species (yellow birch and red oak) were inhibited by herbaceous vegetation. Birch species were particularly affected by small mammal predation. No effects of predation or herbaceous competition were observed for conifer species. Rather, herbaceous vegetation had a positive effect on the survival and the height growth of tamarack (Larix laricina). None of the tested herb communities had a stronger competitive effect on tree growth than another. Restoration of abandoned fields using multi-tree species should be designed at the seedling scale rather than at the site scale to account for different tree responses to predation and competition as well as variable site conditions. An approach resembling precision agriculture is proposed to lower costs and any potential negative impact of more intensive vegetation management interventions.
Designing effective habitat and protected area networks, which sustain species-rich communities is a critical conservation challenge. Recent decades have witnessed the emergence of new computational ...methods for analyzing and prioritizing the connectivity needs of multiple species. We argue that the goal of prioritizing habitat for multispecies connectivity should be focused on
long-term persistence of a set of species
in a landscape or seascape. Here we present a review of the literature based on 77 papers published between 2010 and 2020, in which we assess the current state and recent advances in multispecies connectivity analysis in terrestrial ecosystems. We summarize the four most employed analytical methods, compare their data requirements, and provide an overview of studies comparing results from multiple methods. We explicitly look at approaches for integrating multiple species considerations into reserve design and identify novel approaches being developed to overcome computational and theoretical challenges posed by multispecies connectivity analyses. There is a lack of common metrics for multispecies connectivity. We suggest the index of metapopulation capacity as one metric by which to assess and compare the effectiveness of proposed network designs. We conclude that, while advances have been made over the past decade, the field remains nascent by its ability to integrate multiple species interactions into analytical approaches to connectivity. Furthermore, the field is hampered its ability to provide robust connectivity assessments for lack of a clear definition and goal for multispecies connectivity conservation.
Direct tree seeding is potentially an economical technique for restoring forests on abandoned fields. However, the success of tree establishment depends on many factors related to species and seed ...characteristics, environmental conditions, competition and predation. We compared seedling emergence, survival and growth of six tree species of different seed sizes in a forest restoration project of abandoned fields. Species were seeded in plots with and without herbaceous vegetation and with and without protection from bird and mammal predation. Yellow birch (Betula alleghaniensis) did not emerge in all treatments, paper birch (Betula papyrifera) and tamarack (Larix laricina) had a seedling emergence rate lower than 1%, and sugar maple (Acer saccharum) had a low overall emergence rate of 6%. Seedling emergence reached 57% for northern red oak (Quercus rubra) and 34% for red pine (Pinus resinosa), but survival of oak after one year was much higher (92%) than pine seedlings (16%). Overall, protection from birds and mammals and elimination of the herbaceous vegetation cover had no detectable effects on seedling emergence, survival and height. Nonetheless, red oak seedlings growing in the presence of vegetation had a smaller diameter and shoot biomass and a larger specific leaf area. We conclude that only large seeded species, such as oak, should be used for forest restoration of abandoned fields by direct seeding in our region.
•We analysed the content of 74 Canadian urban forest management plans.•Ideas referring to increasing tree abundance dominate.•Ideas related to increasing tree abundance and climate change increased ...in 20 years.•Administration and tree maintenance ideas are more mentioned in smaller cities.•Increasing urban forest abundance may have management trade offs.
Urban forests are a critical element of urban environmental planning. Greater awareness of the ecosystem services provided by urban forests over the last two decades has led to an increased interest in improving urban forest management. In Canada, the conditions of management are usually articulated by a municipal government in an urban forest management plan (UFMP). This study responds to previous studies on the content of Canadian UFMPs to provide a more comprehensive and updated comparison of UFMPs across Canada. While previous research has examined the content of UFMPs at a moment in time, and often when far fewer plans existed, in this study we consider changes in content over time and the influence of the social-ecological characteristics of municipalities on this content. We combined quantitative and qualitative content analyses, including topic modelling text analysis algorithms and interpretative thematic coding, to extract content, in the form of topics or themes, from 74 UFMPs. We assessed the distribution of these topics and themes by year of publication, and the influence of social-ecological characteristics upon this distribution using standard correlation and means differences analysis procedures. We found that Canadian UFMPs contain a broad number of themes and topics but are dominated by ideas referring to increasing tree abundance. Comparatively less attention is being paid to climate change and community stewardship. Mentions of increasing tree abundance and climate change rose over time. There was also a greater mention of administration, community education, and increasing tree abundance in smaller municipalities. Canadian municipalities may be well positioned to increase the abundance of urban forests given current management conditions. While abundance itself is beneficial, increasing abundance without addressing issues related to biodiversity, vulnerability of urban forests to climate change, and community stewardship, is a management trade-off that could, for example, increase abundance in the short term, but increase vulnerability in the long term. While focused on Canadian cities, this study also provides guidelines for possible cross-country comparisons and reflections on how UFMPs can be powerful management and planning tools for a climate-resilient and sustainable future.
•We assessed the implementation of urban forest management plans (UFMPs)•We used an online survey delivered to Canadian municipalities.•Climate change objectives are not being implemented.•Objective ...achievement does not depend on municipal characteristics considered.•There is consensus about financial resources as an expected outcome of having a UFMP.
Urban forest management plans (UFMPs) are a key element of the planning process in urban forestry. While we can learn about management intentions by analyzing the content of UFMPs, less is known about happens after plan implementation has begun. This study fills this gap by exploring how is UFMP implementation advancing. To do this we asked municipal urban forest professionals working in Canadian municipalities with a UFMP to answer an online survey. The survey: 1) characterized UFMP development; 2) assessed the level of achievement of UFMP objectives; 3) assessed which municipal characteristics led to UFMP objective achievement; and 4) assessed professional views on the outcomes of having a UFMP. Based on n = 118 responses across Canada, we found that UFMPs have been published frequently in the last 20 years, with a peak during the period 2010–2014. On average, and as shared by the respondents, the level of achievement of UFMP objectives was over 50 %, indicating good progress in UFMP implementation. We found no statistically significant differences in the level of UFMP objective achievement by type of city or language of community (English/French), among other factors. There was a consensus among professionals that increasing financial resources for urban forests was an expected outcome of having an UFMP, although there were also diverse and complementary views about the outcome of a UFMPs. A key finding was that climate change objectives are not being implemented or included in UFMPs at high levels. While focused on Canadian cities, this study also provides guidelines on how to assess UFMP implementation across case studies, as well as insights regarding the management objectives that are being overlooked in plan implementation. This may enable future work by researchers and practitioners working in fields related to nature-based solutions, green infrastructure, urban climate adaptation, and sustainable cities worldwide.
•Red ash and red maple seedlings responded weakly to forest soil inoculation.•Conspecific inoculum had negative effects on the growth of red oak seedlings.•Positive effects were observed on the ...growth of yellow birch seedlings.
Tree plantations are commonly used to restore abandoned agricultural fields with varying degrees of success. Agricultural soils differ from forest soils in nutrient availability and microbial communities. The objective of this study was to test the effect of adding small amounts of forest soil on the survival, growth and rates of mycorrhizal fungal colonization of trees planted in an abandoned agricultural field over the crucial first three growing seasons. Seedlings of two arbuscular mycorrhizal (AM) and two ectomycorrhizal (EM) tree species were planted in an abandoned agricultural field. Soil inocula were taken from four forest stands, each dominated by one of the planted species. Half of the soil samples were sterilized before inoculation to distinguish microbial from nutrient effects. The effect of the quantity of soil inoculum added was tested using 300 and 1500ml of forest soil. Tree mortality was low and did not vary between treatments. The growth of EM tree species responded, positively or negatively, to forest soil inoculation. A negative feedback was detected on the growth of red oak seedlings inoculated with red oak soil. Seedlings inoculated with EM sterilized soils were smaller than control seedlings, presumably due to lower nutrient availability of EM forest soils compared to agricultural field soil. The majority of the effects, either positive or negative, were observed the first year. After three seasons of growth, only yellow birch seedlings that had received 1500ml of non-sterilized red oak soil still benefited from soil inoculation. More research is needed in nutrient-limited soils to determine whether inoculation would have greater or longer term benefits on tree survival and growth.
Growing scientific literature evaluates the impact of traffic-calming devices in terms of mobility behavior and safety, but little is known about their perceived impact from the point of view of ...children. Our study asks children about their perceptions of different traffic-calming measures around their schools. It draws on data gathered through eight focus groups, followed by walking tours with Grade 6 children (11-12 years old) (n = 65, 27 boys, 38 girls) from elementary schools in different urban contexts in Quebec, Canada. Qualitative analysis of the discussions shows that (a) vehicle speed is the main perceived threat for participant children; (b) children are confident about the effectiveness of self-enforcing traffic-calming devices that reshape the street geometry; and (c) they are skeptical about the effectiveness of 'informative' measures such as signs and lines (marked pavement). Our findings inform public policy for a more effective promotion of walking and cycling among children.
Black spruce forests growing on clay soils in northwestern Quebec change structure from dense even-aged stands to open uneven-aged stands such that almost all forests older than 200 years have an ...open canopy. These forests become unproductive over time because they are prone to paludification. The main goal of our study was to document the transition between dense and open stands in terms of gap dynamics, with a focus on tree regeneration. Our objective was to determine whether forests remain open due to a lack of regeneration, a lack of growth or both. Nine stands along a 50–250-year-old time since fire gradient were sampled with the line intersect sampling method. Gap fraction increased with stand age and reached a maximum of 77% in the oldest site. In old-growth stands, gaps were interconnected due to the low density of these forests. Most of the gap makers were found with broken stems. Regeneration was dominated by black spruce layers and was relatively abundant (1.71stems/m2). However, the majority of gap fillers were smaller than 1m in height in stands of all ages. Instead of a lack of regeneration, the opening of the forests is due to a lack of growth associated with cold and wet organic deposits. Partial harvesting could be implemented on the most productive sites, while management techniques including soil disturbances will be required on low productivity sites to recreate good growth conditions.
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