Fire Ecology, Animal Populations and Man: a Study of some Ecological Relationships in Prehistory

Understanding long‐term forest fire histories of boreal landscapes is instrumental for parameterizing climate–fire interactions and the role of humans affecting natural fire regimes. The eastern sections of the European boreal zone currently lack a network of annually resolved and centuries‐long forest fire histories. To fill in this knowledge gap, we dendrochronologically reconstructed the 600‐year fire history of a middle boreal pine‐dominated landscape of the southern part of the Republic of Komi, Russia. We combined the reconstruction of fire cycle (FC) and fire occurrence with the data on the village establishment and climate proxies and discussed the relative contribution of climate versus human land use in shaping historic fire regimes. Over the 1340–1610 ce period, the territory had a FC of 66 years (with the 90% confidence envelope of 56.8 and 78.6 years). Fire activity increased during the 1620–1730 ce period, with the FC reaching 32 years (31.0–34.7 years). Between 1740–1950, the FC increased to 47 years (41.9–52.0). The most recent period, 1960–2010, marks FC's historic maximum, with the mean of 153 years (102.5–270.3). Establishment of the villages, often as small harbors on the Pechora River, was associated with a non‐significant increase in fire occurrence in the sites nearest the villages (p = 0.07–0.20). We, however, observed a temporal association between village establishment and fire occurrence at the scale of the whole studied landscape. There was no positive association between the former and the FC. In fact, we documented a decline in the area burned, following the wave of village establishment during the second half of the 1600s and the first half of the 1700s. The lack of association between the dynamics of FC and the dates of village establishments, and the significant association between large fire years and the early and latewood pine chronologies, used as historic drought proxy, indirectly suggests that the climate was the primary control of the landscape‐level FCs in the studied forests. Pine‐dominated forests of the Komi Republic may hold a unique position as the ecosystem with the shortest history of human‐related shifts in fire cycles across the European boreal region.

Accurate mapping of understory vegetation is critical for applications ranging from wildlife habitat and biodiversity monitoring to fire behavior modeling and ecosystem carbon accounting. Lidar offers unique potential for quantifying subcanopy vegetation structure, yet the relative performance of airborne laser scanning (ALS) and uncrewed aerial system (UAS) laser scanning (ULS) for this task remains poorly quantified across different forest types. We compared ALS and ULS estimates of low-lying vegetation density (0.5–2.0 m aboveground), using high-resolution mobile laser scanning (MLS) as reference data, across 26 field plots spanning seven common forest and woodland types in northern Utah, USA. We examined the effects of platform, spatial scale, overstory structure, and vegetation type on model performance, and tested whether predictive accuracy could be improved by incorporating vegetation type and overstory metrics into linear mixed-effects models. Our results show that ALS consistently outperformed ULS despite its lower point density and older acquisition dates, achieving stronger correspondence with MLS-based density across most scales and forest types. ULS was advantageous at very fine spatial resolutions (<2.5 m subplot radii). Across platforms, predictive accuracy was maximized at 4.5 m subplot radii, balancing spatial detail with sufficient point sampling. Vegetation type exerted a strong influence, as those with greater spatial variation in observed density yielded higher predictive performance. Incorporating vegetation type as a random effect and adding overstory density as predictors substantially improved predictive performance, especially for ALS. These findings highlight ALS as a robust and transferable platform for broad-scale mapping of low-lying vegetation density, while ULS provides complementary value for fine-scale, site-specific, and temporally flexible applications. Our results underscore the importance of accounting for overstory conditions and vegetation type when modeling understory structure, and demonstrate the benefits of mixed-effects modeling frameworks. Future research should extend these analyses to additional ecosystems, disturbance contexts, and temporal scales, and explore machine learning approaches that more fully integrate structural and ecological predictors for operational understory mapping.

Sustained elephant browsing and intense burning could result in the loss of woodlands under conditions where elephant densities are high, such as in northern Botswana. Three woodland types dominated by Acacia erioloba, Baikiaea plurijuga and Colophospermum mopane were monitored in plots and contemporary recruitment rates of woody plants were compared with the associated local elephant densities and fire occurrences. Woodland types differed with respect to structure, extent of elephant damage and the occurrence of fire. Canonical correlations indicated that high extent of fire damage and high elephant densities did not covary within the woodland types investigated. Low tree densities in some woodland types were associated with high elephant densities and new elephant damage to plants increased with high elephant densities during the dry season. Plots with an apparent high fire frequency had lower tree densities and higher cover abundance of shrubs and seedlings.

This research note aims to exemplify the potential of annual time series of wildfire geodatasets to quantify fire occurrence and recurrence amongst different woodland types at large scale, under an international forestry perspective. The study covers a time series of areas affected by wildfire between 2007 and 2014 in Italy. A GIS operation of geometric intersection was carried out between burned areas geodataset time series and Corine Land Cover. Mediterranean pine forest, high maquis, transitional woodland-shrub and high oro-Mediterranean pine forest are the woodland types most preferred in terms of fire occurrence and recurrence. Large fires and megafires hold a significant share of total burned area. An unexpected finding is the huge impact of fires in wildland-urban-interface areas. The proposed analysis provides spatial information that is central to any approach to fire management at large scale. Research findings provide support that can be used e.g. for advancements in research, prioritization of fire prevention, suppression measures, economic incentive allocation, and urban and peri-urban planning.

Abstract. Land flatworms (Platyhelminthes: Terricola) are sensitive to environmental changes and might be used as biological indicators of the degree of disturbance of their habitats. Nevertheless, studies on the structure of land flatworm communities are rare. In the present study, we investigated the terrestrial flatworm communities in two types of ombrophilous forest, Atlantic forest and Araucaria forest, aiming to answer the following questions: (1) Is the community structure of the two types of ombrophilous forest different? (2) Are there differences, regarding community structure, among distinct fragments of Araucaria forest? (3) Are there indicators of edge effects in these communities? The study site, the National Park of Aparados da Serra, is mainly covered, at high altitudes, by fragments of Araucaria forest immersed in a matrix of open areas (grasslands) and, in low altitudes, by a continuous Atlantic forest. We conducted monthly surveys in the two types of forest with three replications per forest type over a period of 2 years. Results indicated that: (1) community structure is clearly distinct between the two types of forest, as well as among fragments of the Araucaria forest; (2) there are no apparent edge effects; (3) the diversity indices of the two types of ombrophilous forest are not significantly different (Atlantic forest—H′=2.87, Araucaria forest—H′=2.55; p&gt;0.05); and (4) there are significant differences in diversity indices between two fragments of Araucaria forest (H′=2.92 and 2.47; p&lt;0.001). The following factors could affect community structure: type of vegetation, degree of human disturbance, and abiotic factors, such as pH and temperature.

Forest fire is one of the challenging issues of forest management in Nepal. Climate change has triggered forest fire occurrences in Nepal's hilly regions, increasing fire incidences and severity. This makes these regions more vulnerable to forest fires. The management of forest fires requires planning and effort from people to reduce its hazards effectively. This study aims to identify the forest fire risk zones across different forest types in Palpa district of western Nepal. We used different spatial variables related to land use and terrain to model the forest fire risk zones. Seven potential influential factors: land use land cover, slope, aspect, elevation, land surface temperature, distance to roads, and proximity to settlements were analyzed using a multi-parametric weighted index model to create a forest fire risk index and predict the overall forest fire risk map. The resulted fire risk map was classified into five risk zones: very low, low, medium, high, and very high, covering 3.11%, 12.55%, 12.88%, 45.07%, and 26.39% of the study area respectively. The prepared map was evaluated using field-level fire occurrence points and Visible Infrared Imaging Radiometer Suite (VIIRS) fire points. The fire occurrence points were overlaid on forest-type maps to assess fire occurrence across different forest types. The accuracy assessment result shows that the model effectively identified the forest fire risk zones as most of the fire locations fell within these predicted regions. By forest type, Pine Forest was found to be the most vulnerable to fire followed by Sal Forest. The findings of this study enhance the understanding of forest fire risk zones, which is helpful to community members, planners, policymakers, and government agencies in preparing effective forest fire management strategies for this vulnerable district of Nepal.

In this chapter we start by making an overview of plant adaptations to fire and post-fire response types, which will determine the post-fire management alternatives that might be used in specific forest and shrubland types. Some implications of climate change on fire regimes and plant responses are addressed, and the more fire prone forest types in Southern Europe are identified. We finish by discussing the major post-fire questions and management alternatives faced by forest managers, common to all forest and shrubland types affected by wildfires. These include measures to protect soil and reduce erosion risk, how to manage the burned trees, the use of restoration or conversion, active or indirect restoration, the management of herbivory, alien species, and pests and diseases.

Spatially explicit reconstructions of fire activity in northwestern boreal Canada are rare, despite their importance for modeling current and future disturbance regimes and forest dynamics. We provide a dendrochronological reconstruction of historical fire activity along Highway 3 in the Northwest Territories (NWT), Canada, within the boreal subarctic zone. We dated 129 fires that occurred between 1202 and 2015 CE, using samples from 479 fire‐scarred living and dead jack pine trees (Pinus banksiana Lamb.). Three distinct periods can be distinguished in terms of historical fire cycle (FC) and fire occurrence. Initially (1340–1440 CE), fire activity was low (FC = 572 years; 1 fire/decade), before increasing notably between 1460 and 1840 (FC = 171 years; 4.45 fires/decade), and even more in recent times (1860–2015 CE; FC = 95 years; 7.63 fires/decade). Climate has been an important factor controlling changes in fire frequency and FC in the NWT since the 1300s. The 1440s and 1850s correspond with periods of increased fire activity synchronized with shifts from negative to positive Pacific Decadal Oscillation (PDO) phases. Since the mid‐1800s, human activities may have contributed to the increase in fire activity, but climate remained the leading factor. During the 20th century, years with increased area burned corresponded to periods with drier‐than‐average conditions associated with positive PDO, suggesting fire activity in the study region is still influenced by climate. Spatial teleconnection patterns among PDO, drought, and large fire years (LFYs) in the NWT reveal persistent relationships between ocean‐atmosphere circulation patterns and fire activity. PDO dynamics hold strong potential for predicting regional fire hazards across northwestern North America.

<b>Key messages</b> <ul> <li>Remaining intact forests still covered 519 million ha in the Asia-Pacific region in 2020. Of these, 378 million ha are intact contiguous forests. This area is wider than the 140 million ha reported by countries to the FAO Global Forest Resources Assessment (2015) as “primary forests.”</li> <li>Large-scale remote-sensing assessments of some formations, notably seasonal forest and woodland types, need to be complemented by field surveys to properly identify and map the different primary forest types corresponding to FAO’s definition.</li> <li>While the vast diversity of forest formations in the Asia-Pacific region is known, there is a considerable lack of knowledge about the eco-floristic variation observed within each forest type, the possible causes of this variability, and the distribution and population dynamics of many tree species important for primary forest conservation. Large-scale ecological vegetation mapping and related socio-ecological surveys integrating altitudinal zonation, edaphic conditions and vegetation, including floristic information, need to be developed and become standard.</li> <li>Primary forests and natural landscapes in Asia and the Pacific are under increasing pressures and threats driven by population growth, migrations and conflicts, globalization and economic growth, urbanization, mining and infrastructure development, agriculture and planted forest expansion, forest fires, invasive species and disease outbreaks. Many of these threats are increasingly exacerbated by climate change. Policy coherence across sectors and scales and context-specific action plans, at fine scale of management, are needed to address these threats. A large part of the remaining intact forests falls outside protected areas and is used for multiple objectives. Hence, different mechanisms and tools, including other area-based conservation measures, integrated landscape approaches and community-based management, need to be mobilized at different scales. These mechanisms and tools come in addition to and in support of legal protection, to allow effective protection and conservation of primary forests to cope with a broad range of threats in a variety of situations and to ensure socio-ecological sustainability.</li> </ul>

Influence of fire regime on forest structure and restoration of a native forest type in the southern Andean Range

Based on the fire statistics, the Daxing’anling forest area were classified into three fire cycle regions: northern coniferous virgin forest region with a fire cycle ofl 10–120 years, middle conifer-broad-leaved mixed forest region with a fire cycle of 30–40 years, and southern broad-leaved secondary forest region with a fire cycle of 15–20. The percentage of conifers and broad-leaved trees, forest age and natural mature period of main tree species in different fire cycle regions were discussed in concern with fire occurrence. The characteristics of fire adaptation and fire resistance of main tree species, such as sexual and asexual reproduction, were discussed and evaluation of the synthetical fire adaptation was made.

The study of the diversity of plant species and communities on several mountain ridges of Subpolar and Northern Urals (Fig. 1) in the basins of the rivers Kozhym, Kosyu, Bolshaya Synya, Vangyr, Schugor, and Ilych was carried out in 2007–2018 by researches of the Institute of Biology of Federal Research Centre “Komi Science Centre Ural Branch Russian Academy of Sciences”. Special attention was paid to fir (Abies sibirica) forests as well as larch (Larix sibirica) forests and woodlands due to the luck of data on their diversity. The study following both traditional (Polevaya…, 1964) and modern (Ipatov, Mirin, 2008) approaches of geobotanical and floristic researches is based on 168 original relevés (on sample plots of 400 m2 or within the community limits). The geobotanical data set which contains 184 relevés is stored in the archive (phytocoenarium) of the Institute of Biology (above). The community vertical and horizontal structure as well as the diversity and abundance of vascular plants, bryophytes, and lichens were under study. Ecological-phytocoenotical (dominant) approach was used for classification of larch forests and woodlands in the study area using both the author’s and literature data (Yudin, 1954; Gorchakovskiy, 1966; Nepomilueva, 1974; Martynenko, 1999; Neshataeva, Neshataev, 2005; Rysin, 2010; Kucherov, 2019). Larch forests and woodlands of the study area belong to the Montano-Lariceta subformation of the Lariceta sibiricae formation, which belongs to the Therhodendrosa vegetation subtype of the Aciculilignosa vegetation type (Bykov, 1960). The list of syntaxa for subformation Montano-Lariceta (M.-L.) includes 20 associations, 2 subassociations, 23 variants, and 3 community types from 5 forest types — lichen, green moss, herbaceous, hair cap moss and sphagnum ones. Three associations are transitional between various types of forest (Table 2–6, Fig. 2–10). Forest types of this subformation are allocated in different ordination areas of ecological space according to vectors of soil nitrogen content and light (Table 7, Fig. 11). Larch forests and woodlands of type M.-L. cladinosa occur in dry habitats with poor acidic soils, while phytocenoses of M.-L. polytrichosa and M.-L. sphagnosa are common on wet poor and acidic soils and those of M.-L. hylocomiosa on more fertile soils. In the study area, they do not occupy large areas. The communities of type M.-L. herbosa are common in low elevated mesophyte habitats with more fertile soils. Communities of M.-L. hylocomiosa and M.-L. herbosa types widely occur both in mountain forest and woodland altitudinal belts at the western macroslope of the Subpolar Urals northward N 64°. The use of environmental scales and statistical methods to identify classification units of lower rank did not give well-interpreted results. Analysis of the cenotic significance of species in various forest types of Montano-Lariceta revealed the stable and compact “core” of the most frequent species: trees Betula pubescens, Larix sibirica, Picea obovata, Sorbus sibirica, shrubs Betula nana and Juniperus sibirica; dwarf shrubs Vaccinium myrtillus, V. uliginosum, V. vitis-idaea; herbs Avenella flexuosa, Bistorta major, Calamagrostis purpurea, Carex arctisibirica, Empetrum hermaphroditum, Festuca ovina, Trientalis europaea; mosses Dicranum flexicaule, D. scoparium, Pleurozium schreberi, Polytrichum commune (Table 2, 8, 9). Characteristic species of forest type of M.-L. cladinosa are lichens Cladonia arbuscula, C. stellaris, Flavocetraria nivalis, differential species are herbs Silene acaulis, S. pauciflora, Tephroseris residifolia, and lichens Alectoria nigricans, Asahinea chrysantha, Bryocaulon divergens, Cetraria nigricans. The most abundant are dwarf shrubs Arctous alpina, Empetrum hermaphroditum, Dryas octopetala, Ledum decumbens, Vaccinium uliginosum, and herbs Carex arctisibirica and C. globilaris. The moss-lichen layer is dominated by Cetraria islandica, Cladonia arbuscula, C. rangiferina, C. stellaris, Flavocetraria nivalis, and Stereocaulon paschale; also abundant are lichens Cladonia gracilis and C. uncialis, and mosses Dicranum flexicaule and Pleurozium schreberi. Characteristic species of M.-L. hylocomiosa is Avenella flexuosa, differential species are lichens Cetrariella delisei, C. laevigata, Cladonia subfurcata, Cladonia crispata, and mosses Dicranum polysetum and Polytrichum piliferinum; constant and highly abundant species are Avenella flexuosa, Betula nana, Empetrum hermaphroditum, Vaccinium myrtillus, V. uliginosum, and moss Pleurozium schreberi; species with average constancy — Vaccinium vitis-idaea, lichens Cladonia arbuscula, C. rangiferina, and mosses Dicranum flexicaule, Hylocomium splendens, Polytrichum commune. Sometimes dwarf shrubs Ledum decumbens and Rubus arcticus, and bryophytes Barbilophozia hatcheri, B. lycopodioides, Dicranum polysetum, D. scoparium, and Sphagnum angustifolium dominate or co-dominate (Table 8). The mostly diverse is M.-L. herbosa type of larch forests and woodlands (Table 5, 6, 9). Characteristic species are Anemonastrum biarmiense, Anthoxantum alpinum, Calamagrostis purpurea, Chamaenerion angustifolium, Geranium albiflorum, Milium effusum, Rumex acetosa, Veratrum lobelianum, Viola biflora; differential species are Angelica sylvestris, Phleum alpinum, Poa pratensis, Polemonium acutiflorum, Stellaria bungeana, Tanacetum bipinnatum, Trollius europaeus, Viola palustris; mosses Plagiomnium ellipticum, Rhizomnium pseudopunctatum, Rhodobryum roseum. The most constant and abundant are Bistorta major, Calamagrostis purpurea, Geranium albiflorum, Vaccinium myrtillus; abundant but not too constant — Avenella flexuosa; mosses Dicranum flexicaule, D. scoparium, Pleurozium schreberi. Rarely, herbs Aconitum septentrionale, Athyrium distentifolium, Equisetum pretense, Hieracium hypoglaucum, and bryophytes Barbilophozia hatcheri, B. lycopodioides, Hylocomium splendens, Plagiomnium ellipticum, Polytrichum commune, P. juniperinum, P. strictum, Rhizomnium pseudopunctatum dominate or co-dominate. Constant species with low and average frequency are Chamaenerion angustifolium, Solidago virgaurea, Trientalis europaea, Veratrum lobelianum. The most abundant species in tower layers of M. L. polytrichosa communities are herbs Avenella flexuosa, Carex globilaris, and mosses Polytrichum commune, Pleurozium schreberi, Sphagnum girgensohnii (Table 2). Also common are Bistorta major, Calamagrostis purpurea, Rubus chamaemorus, Vaccinium uliginosum. There are no so far characteristic and differential species in this type, perhaps due to lack of data. Shrubs typical for M.-L. cladinosa and M.-L. hylocomiosa types of larch forests and woodlands are abundant in the communities of M.-L. sphagnosa (Table 2): Empetrum hermaphroditum, Ledum decumbens, Vaccinium uliginosum. Some times Vaccinium myrtillus, and V. vitis-idaea dominants. The most abundant but with average or low cover are herbs Bistorta major and Carex arctisibirica. The most abundant in the moss-lichen layer is Sphagnum capillifolium (characteristic species); rarely, also abundant are Sphagnum fuscum, S. girgensohnii, and S. warnstorfii; constant with average abundance is Pleurozium schreberi; Cladonia stellaris and Polytrichum commune are of average constancy. Species of taiga-forest and tundra-mire eco-coenotical groups are common in the dwarf shrub–herb layer of all types of forests under study (Table 2, 8–10). Significance of mountain tundra species is higher in M.-L. cladinosa and M.-L. hylocomiosa types compare to other types. Species of taiga meadow-forest, valley meadow-forest, valley forest and mountain meadow groups are more abundant in the communities of M.-L. herbosa type. Our research contributed to the current literature data on the species and coenotic diversity of the larch forests and woodlands of the western macroslope of the Subpolar and Northern Urals. Although it is obvious that there is a lack of data both for some associations and forest types, so further researches are necessary to clarify the status of syntaxa and to get information about the characteristic and differential species.

The Influence of Island and Mainland Lakeshore Landscapes on Boreal Forest Fire Regimes

Influence of photosynthetic active radiation on sap flow dynamics across forest succession stages in Dinghushan subtropical forest ecosystem

In the African rim of the Western Mediterranean Basin, cork oak forests and pine plantations coexist. Under similar fire regimes, cork oak forest is more resilient in terms of habitat structure (canopy, understory, and complexity of vegetation strata) than pine plantation. By contrast, both woodland types show similar resilience in plant species composition. Resilience in habitat structure varies between the two woodland types because of the resprouting and seeding strategies of cork oak and pine species, respectively. These differences can be relevant for the conservation of biodiversity of forested ecosystems in a future scenario of increased fire frequency and scale in the Mediterranean basin. Wildfires have major impacts on ecosystems globally. In fire-prone regions, plant species have developed adaptive traits (resprouting and seeding) to survive and persist due to long evolutionary coexistence with fire. In the African rim of the Western Mediterranean Basin, cork oak forest and pine plantation are the most frequently burnt woodlands. Both species have different strategies to respond fire: cork oak is a resprouter while pines are mostly seeders. We have examined the hypothesis that pine plantations are less resilient in habitat structure (canopy, understory, diversity of vegetation strata) and plant composition than cork oak woodlands. The habitat structure and plant species composition were measured in 30 burnt and 30 unburnt 700-m transects at 12 burnt sites from north-western Africa, where the two forest types can coexist. Habitat structure and plant species composition were compared between burnt and unburnt transects from cork oak and pine plantation woodlands with generalized linear mixed models and general linear models. The results showed significant interaction effect of fire and forest type, since cork oak forest was more resilient to fire than was pine plantation in habitat structure. By contrast, both forest types were resilient to fire in the composition of the plant communities, i.e., plant composition prior to fire did not change afterwards. The higher structural resilience of cork oak forest compared to pine plantation is related to the resprouting and seeding strategies, respectively, of the dominant tree species. Differences in the responses to fire need to be considered in conservation planning for the maintenance of the Mediterranean biodiversity in a future scenario of changes in fire regime.