Understanding environmental responses of recently disturbed forests and comparing these responses to those from forests in regions with a long history of human exploitation, is a promising way forward.
Along the 5 chapters of this report, you will find different examples of the experience and knowledge gathered by the exchange of researchers from two contrasting forests ecosystems:
Since global change is likely to result in new environmental conditions and pressures for future forests, learning from lessons obtained elsewhere can help gaining insight into potential futures.
Risks, challenges and services
There are some factors posing costs and risks that can compromise several key forest ecosystem functions, forest goods and ecological services. On your right, you can find some examples.
Today, scientists cope with the new challenge of anticipating impacts to forests. This means developing approaches, tools and guidelines to mitigate risks and adapt to changes.
The Newforests project
Newforests is an exchange program bringing together researchers from 5 research institutions: Forest Sciences Centre of Catalonia (CTFC), Forest Centre for Ecological Research and Forestry Applications (CREAF), Bio-Archaeology and Ecology Centre (CBAE), University of Quebec in Montreal (UQAM), and Abitibi-Témiscamingue (UQAT), hosting two of the main hubs of the Centre for Forest Research (CEF).
In this context, comparing and integrating approaches will not only increase our chances of anticipating global change effects on future forests, but will also allow the development of comprehensive management approaches that will help us to make smarter decisions matching the level of the current challenge.
During the Newforests project, 5 thematic work packages have been developed. They correspond with the 5 chapters you will find in this report.
Ranging from the basic understanding of forests dynamics, biodiversity and functioning (WP 1 and 2) to research on interactions between global change drivers determining disturbances regimes (WP 3) and the integration of the gathered knowledge into advanced modelling tools (WP 4) and sound management guidelines at different spatial scales (WP 5).
Ecological investigations are increasingly using functional diversity in order to understand different patterns among species (such as occurrence or competitive abilities) and the influence of biological communities on ecosystem functioning.
Gradually, functional diversity was conceived as an alternative classification to measure the ecological importance of species in a community, as well as a way to understand how biodiversity affects specific ecosystem functions.
More recently, the role of functional diversity was recognized as a key factor to maintain important functions and services of ecosystems.
The productivity and resilience of natural and managed ecosystems are greatly dependent on the maintenance of its biodiversity components and their interactions.
The Persistence Index allows us to learn more about the resistance of forests
A research group involving CTFC, CREAF and CÉF has defined an index to measure the capacity of a forest to cope with natural disturbances, such as fires, droughts or windthrows
The Persistence Index is based on the presence of certain features, called “response traits”, which help the species to resist or recover after a disturbance. Resprouting ability, deep roots and hard downy leaves are key traits for the forest species to withstand and recover after a disturbance.
This study not only helps to better understand the response of ecosystems, but it can become a very useful tool for decision making in forest management, especially in climate change context. The study has been published in Ecological Indicators.
Tree diversity might not protect forests against changes in climatic conditions
A study across five climate types in Spain and Canada
Results of ongoing research show whereas recent climate anomalies impacted forest productivity, it was not always negative. Furthermore, although diversity had a general positive impact on forest productivity, it did not offer any protection against the negative effect of climate anomalies where those existed, contrary to the initial hypothesis.
The research group in charge of this study (formed by members of CTFC, CREAF and CÉF) aimed at testing the hypothesis that more diverse forests are more capable of maintaining growth when facing stress due to either or both increased drought events and warmer conditions, with respect to previous 30-year (climate anomalies).
They used permanent forest plot data from Spain and Québec (eastern Canada), covering five of the most important climate types where forests grow on Earth and a large temperature and precipitation gradient.
Knowing how the degree of diversity varies in time and space and identifying the processes responsible for these patterns and how they function are fundamental objectives of ecological science.
Understanding the mechanisms that generate and maintain biodiversity in forest ecosystems, the analysis of the territorial patterns that characterize biodiversity and the study of factors that threaten it are the main objectives in this work package.
With the purposes of reducing the risk of species loss and increasing ecosystem stability, studies on Biodiversity Dynamics aim to integrate the resulting knowledge on the effects of land use change and stand structure and composition.
Habitat quality for woodpeckers in north western Québec
How woodpeckers in boreal forests of Québec are affected by landscape fragmentation caused by management?
Assu Gil-Tena from CTFC and Pierre Drapeau from CÉF have characterized habitat quality for woodpeckers in the Abitibi region.
They have formulated the hypothesis that other measures beyond the traditional landscape connectivity framework based on patch-link representations and a system-centric perspective can predict better the presence of woodpeckers in fragmented landscapes.
Connectivity analysis allowed them to detect which patches are key as flux receivers according to different habitat requirements and dispersal capacities.
The strength of their work resides in the availability of data on woodpecker cavities which confirms the suitability of the forest patches for the species and help the formulation of alternative models to better explain woodpecker presence.
Their conclusions will provide valuable guidelines for forest management aimed at wildlife conservation since woodpeckers are umbrella species.
Wood mouse population dynamics
The PhD student Pau Sunyer (CREAF) with Marc Mazerolle from UQAT demonstrated how wood mice demographic parameters varied strongly with the seasonal variations in acorn availability on the ground and not such to spatial variability in shrub cover as other studies suggested.
Mice survival and abundance drop drastically during summer, the period of acorn scarcity, but rise again in autumn when acorn-fall began. Their results support sexual differences in the population patterns of wood mice.
Females are randomly distributed along the study area, and their abundance is associated with the temporal changes in acorn availability on the ground. In contrast, males showed a more spatially aggregated pattern during the acorn fall seasons (autumn–winter). The different spatial distribution between males and females may probably respond to social interactions during the breeding season.
Small rodents play a key role in forest ecosystems as common prey, but also as prevalent seed consumers and dispersers. Hence, there is a great interest in disentangling the factors involved in their population dynamics
The research group conducted an intensive 2-year field study to test the relative role of seasonality in seed abundance, shrub cover and wild boar interference on the population dynamics of wood mice, Apodemus sylvaticus, in a Mediterranean oak forest.
Understanding natural disturbance dynamics and determining how human-induced changes are affecting current disturbance is of maximum importance to anticipate future impacts on forests.
Human activities are provoking a variety of changes on a global scale: climate change, changes in land use, species extinction and spread of invasive and pest species.
These different components of global change have a significant effect on terrestrial ecosystems through variability in disturbance regimes (extension, frequency, impact).
Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements. Major ecological disturbances may include fires, flooding, windstorms, insect outbreaks and trampling
Growth teleconnections as indicators of climate change impacts on forest ecosystems
The study case of North Atlantic boreal forests
The growth of boreal forests is usually favored by high summer temperatures. However, despite climate warming numerous growth declines and mortality waves have been observed in high latitude and mountains boreal regions since the 80s.
In such a context, Clementine Ols has completed her doctoral thesis testing two hypotheses:
(1) climate warming homogenizes tree growth responses to climate, and (2) the recently observed growth-temperature divergence is linked to a more limited access to water.
Analyses consisted in identifying spruce growth similarities (teleconnections) within and between boreal forests in Québec (black spruce) and in Sweden (Norway spruce) during the 20th century.
Results underline that climate warming does not homogenize but diversify boreal tree growth responses to climate. This heterogeneity is apparently triggered by (1) an increasing control of summer and dormancy climate upon maintenance respiration and carbon storage processes, and (2) the spatiotemporal variability in precipitations in a context of increasing temperatures.
All local factors possibly influencing the quantity (e.g. location, topography) and retention (e.g. soil type, ground vegetation, slope) of precipitations are therefore forecasted to become important modulators of boreal forests growth responses to climate.
To more accurately predict the impacts of future climate change on forest ecosystems, the increasing control of soil water availability upon growth calls for high quality and accurate climate data, and in particular of precipitation data in regions of low weather stations density
Integrating fire spread patterns in fire modelling at landscape scale
Fire spread modelling in landscape fire succession models needs to improve to handle uncertainty under global change processes and the resulting impact on forest systems.
In this context, Andrea Duane from CTFC in collaboration with other members from CREAF and CÉF, has been working in MedSpread, a model presented in a study published in Environmental Modelling and Software. MedSpread evaluates the weights of five landscape factors in fire spread performance.
Results show that for each of the three fire spread patterns, some landscape factors exert a higher influence on fire spread simulation than others. They have also found strong evidence that separating fires by fire spread pattern improves model performances.
This study shows a promising link between relevant fire weather information, fire spread and fire regime simulation under global change processes.
Changes in traditional farming have led to forest expansion in the Pyrenees
The treeline position has changed in the Pyrenees in the last 50 years. According to a study carried out in collaboration with CÉF, CTFC, CREAF and UB, the treeline has advanced 40 meters on average, and the decrease in livestock pressure is one of the main causes.
To understand which variables may affect these dynamics, Aitor Ameztegui and his team compared the changes in treeline position in the Catalan Pyrenees between 1956 and 2006. According to them, there were two key factors potentially playing a role in the dynamics of this limit: land-use changes and climate change.
The long-term objective of the FCM is the implementation of a forest management that uses simulation models and analytical tools incorporating complexity, uncertainty and novel numerical approaches to improve management and policy decisions.
Although we have accumulated relevant knowledge on how forest work and respond to environmental changes at many spatial scales, we currently lack adequate tools to integrate such available knowledge and derive predictions in the event of further environmental changes.
New approaches and modelling tools are needed that can deal with the large number of processes interacting at multiple spatial and temporal scales. One of this work package objectives is to develop greater practical expertise and knowledge of complex dynamics in our forest ecosystems.
Developing landscape dynamic models in a global change context
A spatial allocation procedure to model land-use/land-cover changes
Land-use/land-cover (LULC) change models integrate the effects of anthropogenic drivers of landscape change. Spatially explicit LULC change models help at understanding the landscape mosaic that emerges from the interplay between local-scale decisions as well as regional and national policies.
These models produce valuable spatially explicit scenarios of LULC change that underpin biodiversity impact and ecosystem services assessments.
As part of her PhD project, Nuria Aquilué has published a study where they propose a spatial allocation procedure that builds on the assumption that land transitions occur in two phases: change occurrence and change spreading (or contagion).
Aquilué and the other authors of the study provide a simple protocol to implement the allocation procedure as the core of a spatial explicit LULC change model, and they applied this protocol in the development of a new model, called MEDLUC. This model intends to replicate the most relevant transitions observed in Mediterranean landscapes: urbanisation, rural abandonment and agriculture conversion.
Overall, their allocation procedure performs better than a null model for urbanisation and rural abandonment at both resolutions, while it does worse when modelling agriculture conversion.
Modelling Forest Insect Outbreaks
Efforts Towards an Inverse Approach to Model Calibration
Modelling and simulation of epidemic insect outbreaks are powerful tools to be used in planning and preparing strategies for forest management under climate change. Calibration is a fundamental part of the modelling strategy.
Their study aims to find those parameter values that allow the best characterization of emergent spatiotemporal dynamics within the system being modelled. They have implemented a cellular automata (CA) model to simulate the mountain pine beetle (MPB) epidemic in western Canada, which has killed about 50% of the total volume of commercial lodgepole pine in the province since 1990. They have used spatial information on annual mortality of pine trees due to MPB attacks, provided by the Ministry of Forests of British Columbia.
Well-managed forests and woodlands are a renewable resource, producing essential raw material with minimum waste and energy use. Forest Ecosystem Management (FEM) provides a global way of managing resources with emphasis on the natural environment.
Appropriate tenure arrangements of adequate duration and area, the involvement of multiple stakeholders in establishing management goals and active management and marketing of multiple values at the landscape scale, are essential to achieve FEM.
This work package aims at fostering integrative discussions on how to implement various forest management and sylvicultural practices at different spatial scales in a context of rapid environmental change.
Forest biomass extraction for energy uses
An opportunity to reduce the impact of large forest fires in Mediterranean ecosystems
The integration of forest management with renewable energy uses may help land managers in optimizing firefighting programs. This strategy will be especially relevant in Mediterranean countries given the increasing intensity of forest fires caused by climate change and land abandonment.
This study, led by researchers of the CTFC, CREAF and CÉF, suggests that biomass extraction has the potential to substantially contribute to reshape fire regime towards a more desirable scenario by decreasing the number of large fires and, in turn, the amount of burned area. The study encourages land managers to consider this type of extraction as a cost-effective strategy to reduce forest fuel.
The study, published in Ecosystems journal, is based on a model that reproduces the interactions between fire, vegetation dynamics and biomass extraction in a Mediterranean landscape.
This report has been produced by the Forest Sciences Centre of Catalonia
For more information, please visit Newforest project website or email us at firstname.lastname@example.org
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