Management Of Forest Systems Research Articles

Physiological and hormonal responses of drought‐stressed Eucalyptus seedlings infected with Neofusicoccum kwambonambiense

AbstractThe contribution of Eucalyptus globulus plantations to timber production for pulp, paper and energy production may be hampered by climate change. It is expected that Eucalyptus productivity may be affected through drought stress and changes to both pathogen distribution/pathogenicity and host–pathogen interactions. The impact of the fungal pathogen Neofusicoccum kwambonambiense on E. globulus, causing cankers and dieback, is well known but the impact of drought on disease development is still understudied. Our aim was to study the effect of drought on N. kwambonambiense infection by inoculating E. globulus plants under well‐watered conditions or with water limitation. Non‐infected plants for both water regimes were also analysed. Morphophysiological, biochemical and hormonal parameters were assessed 65 days post‐inoculation. Inoculation under conditions of water stress decreased water potential and photosynthetic efficiency and increased abscisic acid, jasmonic acid and lipid peroxidation. Water‐stressed infected plants also showed higher fungal colonization and external lesion length in comparison with well‐watered inoculated plants. Our results indicate that drought increased E. globulus predisposition to N. kwambonambiense infection and may also have promoted a change in the lifestyle of the fungus. Identifying host–pathogen interaction responses under different stress conditions is necessary to provide knowledge for decision‐making in the management of forest systems in general and of Eucalyptus production in particular.

Management of the Resource Potential of Forest Systems of the Irkutsk Region in Conditions of Subsurface Use

The article discusses the management of forest systems that face increasingly complex conditions and the possibility of developing the potential of these systems through inter-industry interaction. We conducted a comprehensive analysis of the negative impact of energy industry enterprises on the natural environment and, consequently, on forest systems when forests and oil and gas enterprises located in adjacent areas. The study found a negative impact of subsoil use enterprises on the state and development of forest systems in the Irkutsk region in the current environmental and economic situation. Considering the scale of the state of the quantitative, structural and qualitative potential of forests it is obvious that without changing the management of ongoing processes it is difficult to expect positive changes in the state of forest systems. We have established that there is a need for interaction between the management bodies of the forestry and mining industries in this situation. It is necessary to develop a well-founded regulatory mechanism for the preventive minimization of negative impacts on forests from the oil and gas complex, or a measure of economic liability for damage to change the situation in forests.

Planning coastal Mediterranean stone pine (Pinus pinea L.) reforestations as a green infrastructure: combining GIS techniques and statistical analysis to identify management options

Mediterranean stone pine reforestations are common characteristics of the Italian Tyrrhenian coast, which mostly maintain uniform and monolayered stand structures. However, improving structural diversity is an effective climate change adaptation strategy in forest management. The aim of this study was to implement a methodology which allows distinct reforested areas such as a single green infrastructure to be managed according to the surrounding land use and the characteristics of the forest stands. 240 hectares of Mediterranean stone pine forests located along a 16 km strip of the Lazio coast (Central Italy) were mapped. Twelve attributes describing the pine stands and showing possible constraints for future management decisions were associated to each forest patch. A hierarchical cluster analysis was performed to group the pinewood patches according to their similarity level and five different groups were identified. For each group, different silvicultural methods were proposed to guide the compositional and structural evolution of the stands, in order to make them suitable for providing services required locally and increasing overall diversity at landscape scale. The results of the study highlight how coastal land uses can offer effective inputs to differentiate the management of forest systems and therefore achieve greater variety and resilience in the landscape over time. This approach is particularly useful in the case of very homogeneous stands such as the stone pine reforestations under study.

Chemical Traits that Predict Susceptibility of Pinus radiata to Marsupial Bark Stripping.

Bark stripping by mammals is a major problem in managed conifer forests worldwide. In Australia, bark stripping in the exotic plantations of Pinus radiata is mainly caused by native marsupials and results in reduced survival, growth, and in extreme cases death of trees. Herbivory is influenced by a balance between primary metabolites that are sources of nutrition and secondary metabolites that act as defences. Identifying the compounds that influence herbivory may be a useful tool in the management of forest systems. This study aimed to detect and identify both constitutive and induced compounds that are associated with genetic differences in susceptibility of two-year-old P. radiata trees to bark stripping by marsupials. An untargeted profiling of 83 primary and secondary compounds of the needles and bark samples from 21 susceptible and 21 resistant families was undertaken. These were among the most and least damaged families, respectively, screened in a trial of 74 families that were exposed to natural field bark stripping by marsupials. Experimental plants were in the same field trial but protected from bark stripping and a subset were subjected to artificial bark stripping to examine induced and constitutive chemistry differences between resistant and susceptible families. Machine learning (random forest), partial least squares plus discriminant analysis (PLS-DA), and principal components analysis with discriminant analysis (PCA-DA), as well as univariate methods were used to identify the most important totals by compound group and individual compounds differentiating the resistant and susceptible families. In the bark, the constitutive amount of two sesquiterpenoids - bicyclogermacrene and an unknown sesquiterpenoid alcohol -were shown to be of higher levels in the resistant families, whereas the constitutive sugars, fructose, and glucose, as well individual phenolics, were higher in the more susceptible families. The chemistry of the needles was not useful in differentiating the resistant and susceptible families to marsupial bark stripping. After artificial bark stripping, the terpenes, sugars, and phenolics responded in both the resistant and susceptible families by increasing or reducing amounts, which leveled the differences in the amounts of the compounds between the different resistant and susceptible classes observedat the constitutive level. Overall, based on the families with extreme values for less and more susceptibility, differences in the amounts of secondary compounds were subtle and susceptibility due to sugars may outweigh defence as the cause of the genetic variation in bark stripping observed in this non-native tree herbivory system.

Diversity of mycorrhizal fungi and soil indicative species in coastal plantations of northeast Brazil

The aim of this work was to evaluate arbuscular mycorrhizal (AM) fungi as soil indicators and the mycorrhization of native and exotic tree species planted in the Acarau basin, a transition area from the coast to the Brazilian semiarid region. Plots with 6-year-old trees of four native and three non-native species as well as one non-forested area were evaluated in terms of the diversity of AM fungi in the mycorrhizosphere and the root colonization by AM and ectomycorrhizal (EcM) fungi. Twenty-four AM fungi were identified; Claroideoglomus etunicatum, Glomus sinuosum, Paraglomus albidum, Acaulospora laevis, and Acaulospora brasiliensis were abundant in the forest soil. Diversity, dominance, evenness and richness indices of AM fungi were higher in plots with native trees. All root samples were colonized by AM fungi and only Anadenanthera colubrina, Acacia mangium, Casuarina equisetifolia and Eucalyptus urophylla formed associations with EcM fungi. Acaulospora morphotypes served as soil indicators for coverings with the native species Astronium fraxinifolium and Colubrina glandulosa. Exotic species may favor the proliferation of rarer AM fungi. These fungi–plant relationships may be important in the management of forest systems, and the evidence with mycorrhizal associations allows the inclusion of Brazilian species in tropical reforestation.

Soil biological indicators and caesium-137 to estimate soil erosion in areas with different forest system management

In this study, the effects of innovative and traditional thinning on soil properties with respect to unmanaged forest were assessed with the aim to individuate early warning indicators of soil erosion for identifying the most appropriate forestry practices to sustainably manage an Italian beech (Fagus sylvatica) forest. Soil organic carbon (OC), microbial biomass C (MBC), ergosterol (ERG), humification rate, water-soluble phenols (WSP), fluorescein diacetate (FDA) hydrolysis, dehydrogenase (DHA) and catalase activities (CAT), ultrasonic aggregate stability and 137Cs were detected to asses soil health and erosion magnitude. The aim was to correlate 137Cs, as a basic indicator of soil erosion rate, with soil aggregate stability and biological activity parameters. 137Cs results evidenced that both thinning treatments affected soil properties. The innovative treatment showed the highest impact. The amount of small-sized particles enhanced when the intensity of thinning increased. A strong decrease in soil OC was related to thinning. In the upper soil layer, OC was found positively correlated with MBC, FDA, WSP, ERG, C/N, N and also with 137Cs. Moderate to no correlations, in the subsurface layer, highlighted the immediate impact of management techniques on the surface layer and then on the underlying ones. In the subsurface layer, OC maintained its positive correlation only with MBC, WSP and 137Cs. 137Cs was correlated in both soil layers with OC, N and WSP. The overall results suggest that the latter parameters may be considered as indicators of soil erosion. More specifically, WSP can be used, even in the case of the absence of 137Cs in the sediment, to evidence changes in soil properties that could be the starting point of soil fertility loss.

Cambiamento globale selvicoltura e sperimentazione

The rapidity of the global change and the complexity of the phenomena involved make any forecast of future environmental conditions rather uncertain: the only thing we can be sure of is that the future will be different from the present and that most ecosystems will be living in conditions never experienced before. The awareness of an uncertain but certainly different future motivates the search for new solutions for a sustainable management of forest systems. Accepting that the future will be different from both the past and the present makes it necessary to develop flexible management strategies to promote the proper adaptation: distinctively, it is expedient to fully recover the experimental character of silviculture, continuously monitoring the reactions of forest stands in order to introduce timely adjustments. From a scientific point of view, one of the most important premises under this perspective has been to consider the forest as a complex adaptive system. From this approach, some guiding principles for forest management in times of global change have been derived worldwide. However, managing a forest to increase its adaptability and resilience to global change still is a challenge for silvicultural research. Under such a distinctive perspective, this note highlights, in the form of a commented discussion, critical issues about experimental procedures in silviculture and relevant operational themes.

Adaptation of Leaf Water Relations to Climatic and Habitat Water Availability

Successful management of forest systems requires a deeper understanding of the role of ecophysiological traits in enabling adaptation to high temperature and water deficit under current and anticipated changes in climate. A key attribute of leaf water relations is the water potential at zero turgor (πtlp), because it defines the operating water potentials over which plants actively control growth and gas exchange. This study examines the drivers of variation in πtlp with respect to species climate of origin and habitat water availability. We compiled a water relations database for 174 woody species occupying clearly delineated gradients in temperature and precipitation across the Australian continent. A significant proportion of the variability in πtlp (~35%) could be explained by climatic water deficit and its interaction with summertime maximum temperature, demonstrating the strong selective pressure of aridity and high temperature in shaping leaf water relations among Australian species. Habitat water availability (midday leaf water potential), was also a significant predictor of πtlp (R2 = 0.43), highlighting the importance of species ecohydrologic niche under a set of climatic conditions. Shifts in πtlp in response to both climatic and site-based drivers of water availability emphasises its adaptive significance and its suitability as a predictor of plant performance under future climatic change.

Legacy effects of fire size and severity on forest regeneration, recruitment, and wildlife activity in aspen forests

Human activities and climate change are increasing the size and severity of wildfires globally, creating a need for research that links changes in fire regimes with community-level responses. The objective of this study was to understand how variability in fire regimes influences forest regeneration and recruitment patterns and wildlife activity at large temporal and spatial scales. Across 25 fires in five National Forests (Uinta-Wasatch-Cache NF, Ashley NF, Fishlake NF, Dixie NF, and Manti-La Sal NF) in the state of Utah, we examined aspen regeneration and recruitment levels, and wildlife and livestock fecal group counts along belt transects that spanned gradients of fire size and severity. Forest cover change was assessed by comparing pre-fire and post-fire satellite images. The fires dated from 1992 to 2002 and were at least 10years old when this study was conducted. Fire size and severity were positively related to aspen regeneration (density of saplings) and recruitment (saplings>2m in height). There was a significant fire size and severity interaction effect on aspen regeneration, such that the positive influence of fire size increased with greater fire severity (R2=0.40, P<0.001). Change in the extent of aspen cover was not correlated with fire size. Deer and cattle became more dispersed with increasing fire size and severity, but elk activity showed no difference. Deer preferred low severity burn patches in smaller fires, but appeared to avoid low severity patches as fires became larger. Our results suggest that fire size and severity are important ecological filters that can interact to affect forest development and the distribution and abundance of large herbivores. Effective management of forest systems in response to altered fire regimes will require an understanding of the legacy effects of fire size and severity at the landscape scale.

Influence of Different Forest System Management Practices on Leaf Litter Decomposition Rates, Nutrient Dynamics and the Activity of Ligninolytic Enzymes: A Case Study from Central European Forests

Leaf litter decomposition is the key ecological process that determines the sustainability of managed forest ecosystems, however very few studies hitherto have investigated this process with respect to silvicultural management practices. The aims of the present study were to investigate the effects of forest management practices on leaf litter decomposition rates, nutrient dynamics (C, N, Mg, K, Ca, P) and the activity of ligninolytic enzymes. We approached these questions using a 473 day long litterbag experiment. We found that age-class beech and spruce forests (high forest management intensity) had significantly higher decomposition rates and nutrient release (most nutrients) than unmanaged deciduous forest reserves (P<0.05). The site with near-to-nature forest management (low forest management intensity) exhibited no significant differences in litter decomposition rate, C release, lignin decomposition, and C/N, lignin/N and ligninolytic enzyme patterns compared to the unmanaged deciduous forest reserves, but most nutrient dynamics examined in this study were significantly faster under such near-to-nature forest management practices. Analyzing the activities of ligninolytic enzymes provided evidence that different forest system management practices affect litter decomposition by changing microbial enzyme activities, at least over the investigated time frame of 473 days (laccase, P<0.0001; manganese peroxidase (MnP), P = 0.0260). Our results also indicate that lignin decomposition is the rate limiting step in leaf litter decomposition and that MnP is one of the key oxidative enzymes of litter degradation. We demonstrate here that forest system management practices can significantly affect important ecological processes and services such as decomposition and nutrient cycling.

Correlation among soil enzyme activities under different forest system management practices

Soil enzyme activities were performed in three permanent no-till and unfertilised plots located in the South of Salamanca province (Spain), the first in a Castanea sativa Mill. paraclimax coppice (CC), the second in a chestnut orchard (CO) and the third in a Quercus pyrenaica Wild. climax forest (Oak), adjacent to the CO plot.We hypothesized that the activities of dehydrogenases, ureases, acid phosphatases, arylsulphatases and β-glucosidases in different forest ecosystems are involved in the carbon, nitrogen and phosphorus cycling and we report their relationship with each other and with physical, chemical and general biochemical parameters of the soils. The main aim of the study was to detect biological criteria for sustainable development in natural degenerate forests of Mediterranean Europe. For this, we used sweet Chestnut (C. sativa Mill) and Oak Q. pyrenaica Wild as models to better define the ecological conditions of these natural resources in terms of nutrient balance, physiology and biological diversity of their communities, to relate them to the conditions of exploitation and land-use changes, for the characterization of sustainable ecological systems.Furthermore, soil respiration was high and significantly different in the chestnut coppice stand than the other two stands, chestnut orchard and oak.Correlations between soil biochemical and soil microbiological variables showed that the three different forest management practices had also a strong effect on soil function conditions. In a discriminate analysis, CC and Oak were discriminated clearly, while CO was in the middle of the biplot sharing some properties with each of the two different groups. Thus, we proposed a soil property transition from the best soil structure and function properties at one chestnut management properties with low tree densities (CC and CO) to other with the worst ones at highest tree density conditions (Oak). According to natural soil conditions in Oak, we assumed that most of the enzyme activities reached their highest levels at highest C and N soil contents but at lowest soil base saturation percentage while they were not at all associated with P soil availability.

Induced resistance to pests and pathogens in trees

Tree resistance can be enhanced by a variety of biotic and abiotic inducers, including nonpathogenic and pathogenic microbes, and herbivores, resulting in enhanced protection against further biotic injury. Induced resistance (IR) could be a valuable tool in sustainable pest management. IR has been actively studied in herbaceous plant species, and, in recent years, in woody plant species, and is fast emerging as an intriguing, eco-friendly concept for enhancing tree resistance. However, before application of IR becomes possible, there is a need to increase our knowledge of the mechanisms of defence in forest trees. A richer understanding of these phenomena will play a critical role in developing sustainable integrated pest management strategies. This review summarizes our current knowledge of IR in forest trees, focusing on inducible defence mechanisms, systemic induction of resistance and phytohormone signalling networks. We conclude by discussing the potential advantages and limitations of applying IR-based management tools in forest systems.

Assemblages of soil macrofauna across a Scottish land‐use intensification gradient: influences of habitat quality, heterogeneity and area

Summary Land‐use intensification strongly influences biodiversity by altering habitat heterogeneity, the distribution of habitat types and their extent. This study explores these effects within mixed semi‐natural/agricultural mosaic habitats in Scotland, examining the effect of land‐use intensification on the soil macrofauna at point (m2), landscape (km2) and regional (&gt; 1 km2) scales. The soil macrofauna in six 1‐km2 sampling areas (land‐use units; LUU) were sampled using a combined hand‐sorting and Winkler bag extraction technique. Within each LUU, 16 1‐m2 samples were taken in each of 2 successive years. Each LUU had a mixture of land‐use types, representing an agricultural intensification gradient. The following hypotheses were tested: (i) the study area sustains a number of distinct habitats as defined by soil macrofaunal composition; (ii) a greater number of restricted range species are found in semi‐natural habitats; (iii) local (point) species density is related to habitat type; (iv) overall levels of species richness per habitat at regional scales are related to species‐area effects; and (v) landscape‐level species density is correlated with habitat heterogeneity. Initial analysis revealed five distinct habitat types: Caledonian forest (semi‐natural pine forest), closed canopy woodland (pine plantation and broadleaved woodland), riparian habitats (wet woodland and grassland), pasture (improved grassland) and arable (crop fields). As hypothesized, the Caledonian habitat contained a greater number of restricted‐range species than the other habitats. However, conifer plantations contained more restricted range species than expected, given their anthropogenic origin. Species density per m2 was most strongly affected by habitat type. At the regional level, the size of the species pool was correlated with the size of habitat areas. There were more species overall in LUU with greater habitat heterogeneity. Synthesis and applications. Caledonian pine forests have high species densities and contain species of conservation value. Mixed conifer plantations also appear to have a surprisingly high invertebrate conservation value. In contrast, intensively managed agricultural habitats have low species densities and conservation value. Generally, mixed land‐use areas have higher species densities than single land‐use areas. This emphasizes the need for careful management of forest systems within the matrix of agricultural habitats to maximize landscape diversity.

Sustainable Forest Ecosystems and Management: A Review Article

Abstract Concerns about the sustainability of forest resources and ecosystems have been expressed almost from the beginning of modern studies of forest management by ecologists, biologists, economists, and other specialists. However, the focus of this concern has gone through several transformations. Environmental scientists have emphasized the maintenance of forest ecosystems in the face of different types of human intervention. Economists and forest managers, on the other hand, have emphasized the capacity of forest systems to provide valued ongoing flows of goods and services for human societies. This paper takes stock of forest resource and ecosystem sustainability from both ecological and economic perspectives. It seeks to identify how these disciplinary perspectives contribute to a better understanding of sustainability, and where the most significant conceptual and factual gaps are found. Of particular interest are two related themes: how economic efficiency and sustainability may differ in their implications for forest system management, and how criteria for forest system sustainability are related to the scale of management decisions (e.g., individual forest site versus region versus the global biosphere). For. Sci. 42(3):366-377.

Evaluation of alternative forest system management policies the case of the spruce budworm in New Brunswick

A major difficulty in choosing a forest management policy that regulates yearly spraying and logging levels is the fact that such a choice involves comparisons among risky alternatives. Practical and theoretical constraints often make the specification of a utility function for the system infeasible. This paper demonstrates that by making reasonable and easily verifiable assumptions about some properties of preference profiles of participants in the system, it is possible to produce an effective algorithm for forest policy evaluation. The method proposed and applied to the case of the New Brunswick forests consists of: (1) construction of a forest simulation to generate policy contingent distributions of outcomes, and (2) employment of stochastic dominance to identify a nondominated set of policies.