Positive long-term impacts of restoration on soils in an experimental urban forest

The role of the plant microbiome for forestry, agriculture and urban greenspace in times of environmental change

This Lilliput article provides a literature overview on ecological effects of the plant microbiome with a focus on practical application in forestry, agriculture and urban greenspace under the spectre of climate change. After an overview of the mostly bacterial microbiome of the model plant Arabidopsis thaliana, worldwide data from forests reveal ecological differentiation with respect to major guilds of predominantly fungal plant root symbionts. The plant-microbiome association forms a new holobiont, an integrated unit for ecological adaptation and evolutionary selection. Researchers explored the impact of the microbiome on the capacity of plants to adapt to changing climate conditions. They investigated the impact of the microbiome in reforestation programs, after wildfire, drought, salination and pollution events in forestry, grasslands and agriculture. With increasing temperatures plant populations migrate to higher latitudes and higher altitudes. Ecological studies compared the dispersal capacity of plant seeds with that of soil microbes and the response of soil and root microbes to experimental heating of soils. These studies described a succession of microbiome associations and the kinetics of a release of stored soil carbon into the atmosphere enhancing global warming. Scientists explored the impact of synthetic microbial communities (SynComs) on rice productivity or tea quality; of whole soil addition in grassland restoration; or single fungal inoculation in maize fields. Meta-analyses of fungal inoculation showed overall a positive effect, but also a wide variation in effect sizes. Climate change will be particularly prominent in urban areas ("urban heat islands") where more than half of the world population is living. Urban landscape architecture will thus have an important impact on human health and studies started to explore the contribution of the microbiome from urban greenspace to ecosystem services.

Convergence and divergence in science and practice of urban and rural forest restoration

Forest restoration has never been higher on policymakers' agendas. Complex and multi-dimensional arrangements across the urban-rural continuum challenge restorationists and require integrative approaches to strengthen environmental protection and increase restoration outcomes. It remains unclear if urban and rural forest restoration are moving towards or away from each other in practice and research, and whether comparing research outcomes can help stakeholders to gain a clearer understanding of the interconnectedness between the two fields. This study aims to identify the challenges and opportunities for enhancing forest restoration in both urban and rural systems by reviewing the scientific evidence, engaging with key stakeholders and using an urban-rural forest restoration framework. Using the Society for Ecological Restoration's International Principles as discussion topics, we highlight aspects of convergence and divergence between the two fields to broaden our understanding of forest restoration and promote integrative management approaches to address future forest conditions. Our findings reveal that urban and rural forest restoration have convergent and divergent aspects. We emphasise the importance of tailoring goals and objectives to specific contexts and the need to design different institutions and incentives based on the social and ecological needs and goals of stakeholders in different regions. Additionally, we discuss the challenges of achieving high levels of ecological restoration and the need to go beyond traditional ecology to plan, implement, monitor, and adaptively manage restored forests. We suggest that rivers and watersheds could serve as a common ground linking rural and urban landscapes and that forest restoration could interact with other environmental protection measures. We note the potential for expanding the creative vision associated with increasing tree-containing environments in cities to generate more diverse and resilient forest restoration outcomes in rural settings. This study underscores the value of integrative management approaches in addressing future forest conditions across the urban-rural continuum. Our framework provides valuable insights for policymakers, researchers, and decision-makers to advance the field of forest restoration and address the challenges of restoration across the urban-rural continuum. The rural-urban interface serves as a convergence point for forest restoration, and both urban and rural fields can benefit from each other's expertise.

The Influence of Harbin Forest–River Ecological Corridor Construction on the Restoration of Mollisols in Cold Regions of China

Artificial ecological corridors (AECs) are internationally approved ecological restoration and climate mitigation strategies. The width and recovery time indices of AECs directly affect the restoration efficiency of degraded soil nutrients. However, there is a lack of comprehensive and quantitative evaluation research on the construction factors of AECs from the perspective of soil fertility improvement. This research aimed to examine the critical ecological corridor construction factors affecting Mollisols’ eco-chemometrics and give a scientific scope. We collected 55 Mollisol samples at different restoration years (0–35 years) and different distances (0–280 m) from the AEC of the Ashi River, a typical Mollisol restoration area in Harbin, and the cold regions of China. We measured the distances, restoration years, soil thickness, pH, electrical conductivity (EC), cation exchange capacity (CEC), soil total organic carbon (SOC), soil total organic matter (SOM), dry matter content (DMC), and the proportion of nitrogen (TN), phosphorus (TP) and potassium (TK). The results are as follows: (1) Within the AEC, there were significant differences in soil stoichiometric characteristics in different restoration years and locations; after restoration for 10–35 years, the soil stoichiometric characteristics reach or exceed the reference value of Mollisols. (2) It is feasible to restore large-scale degraded Mollisols through ecological corridors. In this recovery process, the soil nutrients first decreased, then increased, and finally reached and exceeded the reference value of normal Mollisols. (3) Soil nutrient accumulation was related to ecological corridor width and recovery time. The recommended unilateral width of the ecological corridor based on Mollisols’ CEC and SOC indices for restoration is 175–225 m, and the restoration period is 22.7–35 years based on Mollisols’ EC and SOC indices for restoration. This study demonstrated the change mechanism of Mollisols in AECs based on recovery time and location, and provided the basis for the Chinese government to formulate policies for Mollisol remediation.

Assessing ecosystem services of abandoned agricultural lands: a case study in the forested zone of European Russia

The massive abandonment of arable land in Russia in the 1990s had a heavy impact on the country’s land-use structure. The cessation of cultivation leads to a decrease of provisioning ecosystem services within the landscape, while creating an opportunity to enhance the supply of diverse regulation services. Consideration of this opportunity is increasingly important for environmental management and landscape planning. In this article, we present an approach for assessing the environmental benefits of ecosystems developing on abandoned arable lands in the forested zone of European Russia. The proposed methodology is established on a land-cover based framework – ecosystem services assessment matrix. For assessment purposes, abandoned arable lands at different stages of vegetation recovery succession (ruderal, grassland and small-leaved forest) are considered as different land-cover types. Four classes of regulating ecosystem services are subject to qualitative analysis: regulation of the chemical composition of the atmosphere, control of erosion rates, regulation of soil quality and pollination. An exemplary application of the proposed methodology for the case study area located in the Moscow Region of Russia is presented in the article. The results of the qualitative assessment revealed an association between the stage of vegetation recovery succession which corresponds with the time since land abandonment and the supply of regulating ecosystem services. The recovery of natural vegetation leads to higher levels of carbon sequestration, more effective erosion mitigation, soil recovery and increased pollinator abundance. Cropland was proven to be a recipient of the services provided by natural ecosystems. Thus, the return of all uncultivated fields to agricultural use will cause a substantial decrease in the ecological value of the study area.

Carbon Farming: Prospects and Challenges

Carbon farming is a capable strategy for more sustainable production of food and other related products. It seeks to produce a diverse array of natural farming methods and marketable products simultaneously. According to the food and agriculture organization (FAO), agriculture, forestry, and other land-use practices account for 24% of global greenhouse gas (GHG) emissions and total global livestock emissions of 7.1 gigatons of CO2-equivalent per year, representing 14.5% of total anthropogenic GHG emissions. For example, an agroforestry system that deliberately integrates trees and crops with livestock in agricultural production could potentially increase carbon sequestration and decrease GHG emissions from terrestrial ecosystems, thus helping to mitigate global climatic change. Also, agroforestry is capable of generating huge amounts of bio-mass and is believed to be particularly suitable for replenishing soil organic carbon (SOC). SOC is a crucial indicator for soil fertility since the change in SOC can explain whether the land use pattern degrades or improves soil fertility. Moreover, SOC found in soil in the form of soil organic matter (SOM) helps to improve soil health either directly or indirectly. Thus, efforts should be made to convince farmers to increase their resource-use efficiency and soil conserving ability to get maximum benefits from agriculture. Therefore, this review aimed at clarification about carbon farming, modifications in carbon cycle and carbon sequestration during agricultural development, and benefits of agroforestry.

Vulnerability of Street Trees in Upper Midwest Cities to Climate Change

Urban trees play an important role in helping cities adapt to climate change, but also are vulnerable to changes in climate themselves. We developed an approach for assessing vulnerability of urban tree species and cultivars commonly planted in cities in the United States Upper Midwest to current and projected climate change through the end of the 21st century. One hundred seventy-eight tree species were evaluated for their adaptive capacity to a suite of current and future-projected climate and urban stressors using a weighted scoring system based on an extensive literature review. These scores were then evaluated and adjusted by leading experts in arboriculture in the region. Each species or cultivar’s USDA Hardiness Zone and American Horticultural Society Heat Zone tolerance was compared to current and future heat and hardiness zones for 14 municipalities across Michigan, Wisconsin, and Minnesota using statistically downscaled climate data. Species adaptive capacity and zone tolerance was combined to assign each species one of five vulnerability categories for each location. We determined the number of species and trees in each category based on the most recent municipal street tree data for each location. Under a scenario of less climate change (RCP 4.5), fewer than 2% of trees in each municipality were considered highly vulnerable across all 14 municipalities. Under a scenario of greater change (RCP 8.5), upward of 25% of trees were considered highly vulnerable in some locations. However, the number of vulnerable trees varied greatly by location, primarily because of differences in projected summer high temperatures rather than differences in species composition. Urban foresters can use this information as a complement to other more traditional considerations used when selecting trees for planting.