Susanna Nocentini

Viewing forests through the lens of complex systems science

Complex systems science provides a transdisciplinary framework to study systems characterized by (1) heterogeneity, (2) hierarchy, (3) self-organization, (4) openness, (5) adaptation, (6) memory, (7) non-linearity, and (8) uncertainty. Complex systems thinking has inspired both theory and applied strategies for improving ecosystem resilience and adaptability, but applications in forest ecology and management are just beginning to emerge. We review the properties of complex systems using four well-studied forest biomes (temperate, boreal, tropical and Mediterranean) as examples. The lens of complex systems science yields insights into facets of forest structure and dynamics that facilitate comparisons among ecosystems. These biomes share the main properties of complex systems but differ in specific ecological properties, disturbance regimes, and human uses. We show how this approach can help forest scientists and managers to conceptualize forests as integrated social-ecological systems and provide concrete examples of how to manage forests as complex adaptive systems.

Silvicultural alternatives to conventional even-aged forest management - what limits global adoption?

BackgroundThe development of forestry as a scientific and management discipline over the last two centuries has mainly emphasized intensive management operations focused on increased commodity production, mostly wood. This “conventional” forest management approach has typically favored production of even-aged, single-species stands. While alternative management regimes have generally received less attention, this has been changing over the last three decades, especially in countries with developed economies. Reasons for this change include a combination of new information and concerns about the ecological consequences of intensive forestry practices and a willingness on the part of many forest owners and society to embrace a wider set of management objectives. Alternative silvicultural approaches are characterized by a set of fundamental principles, including avoidance of clearcutting, an emphasis on structural diversity and small-scale variability, deployment of mixed species with natural regeneration, and avoidance of intensive site-preparation methods.MethodsOur compilation of the authors’ experiences and perspectives from various parts of the world aims to initiate a larger discussion concerning the constraints to and the potential of adopting alternative silvicultural practices.ResultsThe results suggest that a wider adoption of alternative silvicultural practices is currently hindered by a suite of ecological, economic, logistical, informational, cultural, and historical constraints. Individual contexts display their own unique combinations and relative significance of these constraints, and accordingly, targeted efforts, such as regulations and incentives, may help to overcome specific challenges.ConclusionsIn a broader context, we propose that less emphases on strict applications of principles and on stand structures might provide additional flexibility and facilitate the adoption of alternative silvicultural regimes in a broader set of circumstances. At the same time, the acceptance of alternative silvicultural systems as the “preferred or default mode of management” will necessitate and benefit from the continued development of the scientific basis and valuation of a variety of ecosystem goods and services. This publication is aimed to further the discussion in this context.

Forest Management Approaches for Coping with the Uncertainty of Climate Change: Trade-Offs in Service Provisioning and Adaptability

The issue of rapid change in environmental conditions under which ecosystem processes and human interventions will take place in the future is relatively new to forestry, whereas the provision of ecosystem services, e.g., timber or fresh water, is at the very heart of the original concept of forest management. Forest managers have developed ambitious deterministic approaches to provide the services demanded, and thus the use of deterministic approaches for adapting to climate change seem to be a logical continuation. However, as uncertainty about the intensity of climate change is high, forest managers need to answer this uncertainty conceptually. One may envision an indeterministic approach to cope with this uncertainty; but how the services will be provided in such a concept remains unclear. This article aims to explore the fundamental aspects of both deterministic and indeterministic approaches used in forestry to cope with climate change, and thereby point out trade-offs in service provisioning and adaptability. A forest owner needs to be able to anticipate these trade-offs in order to make decisions towards sustainable forest management under climate change.

Biodiversity conservation and systemic silviculture: Concepts and applications

Abstract Classic silviculture and management, with the aim of predicting regeneration rate and producing a constant yield of merchantable wood, have simplified many forests, often transforming natural forests into plantations or coppices. To conserve forest complexity and biodiversity, silviculture and forest management should change the reference paradigm and consider forest ecosystems as complex biological systems characterized by the inherent unpredictability of their trajectories in a continuously changing environment. The new Management Plan for the Vallombrosa Forest (Florence, Italy), a State Nature Reserve and a Natura 2000 Site, is based on this approach. The aim is the gradual evolution of the pure silver fir stands toward mixed stands with a complex structure. Most of the species considered by Natura 2000 depend on an increase of structural diversity at different space and time scales. The management approach proposed by the new plan is coherent with this aim and thus biodiversity conservation is not in conflict with forest management but is, instead, a direct consequence of the systemic approach.

Modeling the influence of alternative forest management scenarios on wood production and carbon storage: A case study in the Mediterranean region.

Forest ecosystems are fundamental for the terrestrial biosphere as they deliver multiple essential ecosystem services (ES). In environmental management, understanding ES distribution and interactions and assessing the economic value of forest ES represent future challenges. In this study, we developed a spatially explicit method based on a multi-scale approach (MiMoSe-Multiscale Mapping of ecoSystem services) to assess the current and future potential of a given forest area to provide ES. To do this we modified and improved the InVEST model in order to adapt input data and simulations to the context of Mediterranean forest ecosystems. Specifically, we integrated a GIS-based model, scenario model, and economic valuation to investigate two ES (wood production and carbon sequestration) and their trade-offs in a test area located in Molise region (Central Italy). Spatial information and trade-off analyses were used to assess the influence of alternative forest management scenarios on investigated services. Scenario A was designed to describe the current Business as Usual approach. Two alternative scenarios were designed to describe management approaches oriented towards nature protection (scenario B) or wood production (scenario C) and compared to scenario A. Management scenarios were simulated at the scale of forest management units over a 20-year time period. Our results show that forest management influenced ES provision and associated benefits at the regional scale. In the test area, the Total Ecosystem Services Value of the investigated ES increases 85% in scenario B and decreases 82% in scenario C, when compared to scenario A. Our study contributes to the ongoing debate about trade-offs and synergies between carbon sequestration and wood production benefits associated with socio-ecological systems. The MiMoSe approach can be replicated in other contexts with similar characteristics, thus providing a useful basis for the projection of benefits from forest ecosystems over the future.

Assessing and promoting old-growthness of forest stands: Lessons from research in Italy

Abstract Due to a long-standing history of human impact, it is rare to find in Europe old-growth stands associated to primary forests; the term “old-growthness” is more appropriate to assess old-growth forests in European countries: i.e. the degree to which forest stands, which may or may not have been impacted by humans, express the structural variability commonly found in old-growth forests. The paper focuses on operational methods to assess and promote old-growthness in countries, like Italy, where old-growthness detection is a difficult task because of the scarcity of “relatively old” forest stands. Lessons learnt from research experiences carried out in Italy are reviewed; research findings mostly come from unmanaged tracts of previously managed forest stands that have reached structural and compositional traits typical of the mature stage of forest dynamics. A commentary discussion is provided on the following topics: (i) how to operationally assess old-growthness of forest stands, by coupling remote sensing based approaches and snapshot inventories of structural features; (ii) what forest structural attributes appear to be more strictly related to old-growthness in Mediterranean forests and (iii) how to promote old-growthness in managed forest stands. The paper concludes pointing out open research questions and pragmatic considerations for managing forests for old-growthness.

Characterization, structure and genetic dating of an old-growth beech-fir forest in the northern Apennines (Italy)

Abstract An old-growth beech forest stand with silver fir within the strict forest reserve of Sasso Fratino has been examined with the following aims: to characterize forest stand on the basis of classic forest parameters and to assess forest stand structure by means of spatial functions; to provide genetic dating of the beech population. Total census of size and position of living trees and deadwood was performed on a 9200 m2 permanent plot. Vertical distribution of crowns in the stand was assessed using the TSTRAT function, horizontal stand structure using spatial point pattern analysis. Genetic dating was performed on a sample of beech trees. DNA was isolated and each individual was genotyped at four chloroplast microsatellite loci. Microsatellite profiles were compared with the profiles of control DNA of known haplotypes. Results show a multi-strata vertical structure, a horizontal structure characterized by small gaps (<160 m2) where silver fir regeneration sets in. Deadwood is present with all the decay classes and with relatively high volumes. Genetic dating ascribes the Sasso Fratino beech stand to the ancestral haplotype 2: this population can therefore be considered a hot spot of haplotype diversity of the glacial refugia present in central Italy.

Classifying silvicultural systems (coppices vs. high forests) in Mediterranean oak forests by Airborne Laser Scanning data

Abstract Forest classification by silvicultural systems (coppices vs. high forests) is important for forest resource assessment as such systems relate to a wide variety of ecosystem services. In this paper the potential of Airborne Laser Scanning (ALS) data for Mediterranean oak forests classification of coppices with standards vs. high forests was investigated in three study areas in Italy. We addressed the following issues: can coppices and high forests be distinguished using a raster Canopy Height Model (CHM)? Which are the most efficient CHM-derived metrics? Does the scale of analysis influence the classification potential of CHM metrics? Our results show that CHM in grid format (1-m2 pixel) provides support information to classify silvicultural systems.

The Role of Forestry in National Climate Change Adaptation Policy: Cases from Sweden, Germany, France and Italy

SUMMARY Forestry is one of Europes largest land uses, for which adaptation to climate change will require coordinated action among multiple actors. However, so far, adaptation has been less placed in focus than has mitigation, and adaptation in the forest sector has mainly been reactive. This paper explores and reviews the integration of forestry in the development of planned adaptation policy in different countries. Sweden, Germany and France are taken as examples of countries with different developments of their adaptation policies as well as different requirements of their forest systems and actors. Italy is utilised as an example of how adaptation actions for forestry have been defined in a country where no national adaptation policy currently exists; in general, the results illustrate the seemingly large role of extreme events in driving adaptation policy forward in different policy systems.

OLD-GROWTH FORESTS IN ITALY: RECENT RESEARCH DEVELOPMENTS AND FUTURE PERSPECTIVES

In Italy there are no truly primeval forests because forest exploitation has been very pervasive since Roman times. All along the centuries intensive silvicultural systems have heavily modified forest composition and structure. Nevertheless, in particular situations there are forest stands that have not been impacted by utilization for very long periods of time and show old-growth characters. The contribution recall the main projects dealing on characterization and monitoring of old-growth forests in Italy starting from the activities of Prof. Pavari in 1954. It then introduces the papers presented in this special issue resulting from the activities of different recent research projects funded by national authorities. Most of these contributions were presented in a national congress held in Prati di Tivo (TE) from 25 to 26 of June 2010 titled “Old-growth forests in Italy: identification, characterization, management”, organized with the support of the Gran Sasso and Monti della Laga National Park