The role of fire in southern Scandinavian forests during the late Holocene

2010 ◽  
Vol 19 (8) ◽  
pp. 1040 ◽  
Author(s):  
Richard H. W. Bradshaw ◽  
Matts Lindbladh ◽  
Gina E. Hannon
Keyword(s):  
Anthropogenic Impact ◽  
Vegetation Change ◽  
Fire Regime ◽  
Strong Association ◽  
Regional Scale ◽  
Temperate Zone ◽  
Anthropogenic Factors ◽  
Clear Trend ◽  
Continuous Increase ◽  
Southern Scandinavia

Charcoal fragments preserved in small, wet basins are used to characterise the fire regime of temperate and mixed boreal forest (hemiboreal) zones of southern Scandinavia during the last 3500 years. There was far less charcoal recorded from the temperate zone than the hemiboreal zone during the last 3500 years, yet the low temperate zone values showed a clear trend of continuous increase until 1500 AD, after which the values decreased sharply. The record from the hemiboreal region showed a greater temporal variability with far higher charcoal influx values than in the temperate zone. There were significant positive correlations between charcoal influx and Betula, Calluna and Pinus pollen abundance and negative correlations with pollen indicators of anthropogenic impact such as Rumex and Cerealia. Charcoal influx in the temperate zone showed a strong association with the period of major anthropogenic impact, whereas the hemiboreal data reacted more to climatic change. The temporal and spatial pattern of charcoal influx was only a minor explanatory factor for vegetation composition at a regional scale in southern Scandinavia. The fire return interval was often long and irregular in most of the region and anthropogenic factors such as grazing, mowing and establishment of arable fields were probably more important than fire as drivers of vegetation change.

The Neogene transition from C3 to C4 grasslands in North America: assemblage analysis of fossil phytoliths

Paleobiology ◽  
2011 ◽  
Vol 37 (1) ◽  
pp. 50-71 ◽  
Author(s):  
Caroline A. E. Strömberg ◽  
Francesca A. McInerney
Keyword(s):  
North America ◽  
Great Plains ◽  
Late Miocene ◽  
Vegetation Change ◽  
Stable Carbon Isotopes ◽  
Fire Regime ◽  
Tooth Enamel ◽  
Regional Scale ◽  
Grassland Ecosystems ◽  
Isotopic Records

The rapid ecological expansion of grasses with C4 photosynthesis at the end of the Neogene (8–2 Ma) is well documented in the fossil record of stable carbon isotopes. As one of the most profound vegetation changes to occur in recent geologic time, it paved the way for modern tropical grassland ecosystems. Changes in CO2 levels, seasonality, aridity, herbivory, and fire regime have all been suggested as potential triggers for this broadly synchronous change, long after the evolutionary origin of the C4 pathway in grasses. To date, these hypotheses have suffered from a lack of direct evidence for floral composition and structure during this important transition. This study aimed to remedy the problem by providing the first direct, relatively continuous record of vegetation change for the Great Plains of North America for the critical interval (ca. 12–2 Ma) using plant silica (phytolith) assemblages.Phytoliths were extracted from late Miocene-Pliocene paleosols in Nebraska and Kansas. Quantitative phytolith analysis of the 14 best-preserved assemblages indicates that habitats varied substantially in openness during the middle to late Miocene but became more uniformly open, corresponding to relatively open grassland or savanna, during the late Miocene and early Pliocene. Phytolith data also point to a marked increase of grass short cells typical of chloridoid and other potentially C4 grasses of the PACMAD clade between 8 and 5 Ma; these data suggest that the proportion of these grasses reached up to ∼50–60% of grasses, resulting in mixed C3-C4 and highly heterogeneous grassland communities by 5.5 Ma. This scenario is consistent with interpretations of isotopic records from paleosol carbonates and ungulate tooth enamel. The rise in abundance of chloridoids, which were present in the central Great Plains since the early Miocene, demonstrates that the “globally” observed lag between C4 grass evolution/taxonomic diversification and ecological expansion occurred at the regional scale. These patterns of vegetation alteration imply that environmental change during the late Miocene-Pliocene played a major role in the C3-C4 shift in the Great Plains. Specifically, the importance of chloridoids as well as a decline in the relative abundance of forest indicator taxa, including palms, point to climatic drying as a key trigger for C4 dominance.

Eighty years of change: vegetation in the montane ecoregion of Jasper National Park, Alberta, Canada

2002 ◽  
Vol 32 (11) ◽  
pp. 2010-2021 ◽  
Author(s):  
Jeanine M Rhemtulla ◽  
Ronald J Hall ◽  
Eric S Higgs ◽  
S Ellen Macdonald
Keyword(s):  
National Park ◽  
Vegetation Change ◽  
Fire Regime ◽  
Reference Conditions ◽  
Habitat Diversity ◽  
Climatic Conditions ◽  
Aerial Photographs ◽  
Contributing Factors ◽  
Jasper National Park ◽  
Closed Canopy

Repeat ground photographs (taken in 1915 and 1997) from a series of topographical survey stations and repeat aerial photographs (flown in 1949 and 1991) were analysed to assess changes in vegetation composition and distribution in the montane ecoregion of Jasper National Park, in the Rocky Mountains of Alberta, Canada. A quantitative approach for assessing relative vegetation change in repeat ground photographs was developed and tested. The results indicated a shift towards late-successional vegetation types and an increase in crown closure in coniferous stands. Grasslands, shrub, juvenile forest, and open forests decreased in extent, and closed-canopy forests became more prevalent. The majority of forest stands succeeded to dominance by coniferous species. Changes in vegetation patterns were likely largely attributable to shifts in the fire regime over the last century, although climatic conditions and human activity may also have been contributing factors. Implications of observed changes include decreased habitat diversity, increased possibility of insect outbreaks, and potential for future high-intensity fire events. Results of the study increase knowledge of historical reference conditions and may help to establish restoration goals for the montane ecoregion of the park.

scholarly journals Grassland fire ecology has roots in the late Miocene

2018 ◽  
Vol 115 (48) ◽  
pp. 12130-12135 ◽  
Author(s):  
Allison T. Karp ◽  
Anna K. Behrensmeyer ◽  
Katherine H. Freeman
Keyword(s):  
Late Miocene ◽  
Fire Ecology ◽  
Vegetation Change ◽  
Global Climate ◽  
Indian Subcontinent ◽  
Strong Association ◽  
Feedback System ◽  
Terrestrial Vegetation ◽  
Precipitation Seasonality ◽  
Seasonal Extremes

That fire facilitated the late Miocene C4grassland expansion is widely suspected but poorly documented. Fire potentially tied global climate to this profound biosphere transition by serving as a regional-to-local driver of vegetation change. In modern environments, seasonal extremes in moisture amplify the occurrence of fire, disturbing forest ecosystems to create niche space for flammable grasses, which in turn provide fuel for frequent fires. On the Indian subcontinent, C4expansion was accompanied by increased seasonal extremes in rainfall (evidenced by δ18Ocarbonate), which set the stage for fuel accumulation and fire-linked clearance during wet-to-dry seasonal transitions. Here, we test the role of fire directly by examining the abundance and distribution patterns of fire-derived polycyclic aromatic hydrocarbons (PAHs) and terrestrial vegetation signatures inn-alkane carbon isotopes from paleosol samples of the Siwalik Group (Pakistan). Two million years before the C4grassland transition, fire-derived PAH concentrations increased as conifer vegetation declined, as indicated by a decrease in retene. This early increase in molecular fire signatures suggests a transition to more fire-prone vegetation such as a C3grassland and/or dry deciduous woodland. Between 8.0 and 6.0 million years ago, fire, precipitation seasonality, and C4-grass dominance increased simultaneously (within resolution) as marked by sharp increases in fire-derived PAHs, δ18Ocarbonate, and13C enrichment inn-alkanes diagnostic of C4grasses. The strong association of evidence for fire occurrence, vegetation change, and landscape opening indicates that a dynamic fire–grassland feedback system was both a necessary precondition and a driver for grassland ecology during the first emergence of C4grasslands.

scholarly journals FEATURES OF ASSESSMENT OF ANTHROPOGENIC LOADS ON NATURAL COMPLEXES

2020 ◽  
Vol 2 (5) ◽  
pp. 19-24
Author(s):  
P. Evdokimov
Keyword(s):  
Urban Environment ◽  
Urban Areas ◽  
Anthropogenic Impact ◽  
Urban Environments ◽  
Anthropogenic Factors ◽  
Factors Affecting ◽  
Main Research ◽  
Regulatory Documents ◽  
Dialectical Approach ◽  
The Impact

the article describes the problems of assessing the anthropogenic impact of human activity on natural com-plexes surrounding urbanized territories. Among the main research tasks are development of methodological foundations for assessing the quanti-tative and qualitative composition at anthropogenic impact on natural complexes surrounding urban areas. The main method of this research include a dialectical approach that focuses on generally accepted logi-cal research methods (analysis, systematic approach, generalization) and their synthesis using relevant in-formation materials. The author considered various methods of assessing the impact of various factors on the environment, and also carried out the examination of urban decisions related to the appointment of a category (status) the natural resources included in the urban environment in Moscow. The Russian capital is a European metropolis, the largest city-millionaire in Europe and a typical object of research to identify the effects of various anthropogenic factors. The implementation at economic activity in the metropolis is accompanied by the emergence of problems, the solution of which has not been found yet. Analysis of methods for assessing the impact at the various factors on the environment was carried out taking into account the provisions in regulatory documents governing the appointment for protected areas urban environment. Provisions of regulatory documents and decisions of executive authorities designed to use natural (forest) resources in urban environments. The absence of approved methods for assessing certain types of land plots with a protected status was identified. The main factors affecting the quality of biogeocenosis were identified. The main features of the applica-tion methods for assessing the status and possibility in recreational development in territories of varying de-grees at development are considered.

Anthropogenic impact on behavior of nutrients and potentially toxic elements in the Moskva River water

2021 ◽  
Author(s):  
Galina Shinkareva ◽  
Oxana Erina ◽  
Maria Tereshina ◽  
Dmitriy Sokolov ◽  
Mikhail Lychagin
Keyword(s):  
Urban Areas ◽  
Anthropogenic Impact ◽  
Toxic Elements ◽  
Potentially Toxic Elements ◽  
Low Flow ◽  
Total Petroleum Hydrocarbons ◽  
Anthropogenic Factors ◽  
Water Runoff ◽  
Large Reservoir ◽  
Moskva River

<p>The Moskva River catchment is a complex system consisting of a network of rivers affected by a wide variety of land- and water-use factors that create unique spatial and temporal patterns of their water quality. Major sources of anthropogenic impact on the Moskva River and its tributaries include multiple flow regulation structures on streams, direct pollution from municipal sewage and industrial wastewaters of Moscow megacity and smaller towns, runoff generated in agricultural areas and within multiple landfills located on the watershed, and many more. Only a short upstream section of the Moskva River remains relatively unchanged in terms of water runoff and geochemistry.</p><p>In 2019, we began a pioneering study focusing on collecting detailed field data on geochemistry of water, suspended matter and bottom sediments of the Moskva River and its major tributaries, including concentrations of nutrients, potentially toxic elements (PTEs), polyaromatic hydrocarbons and total petroleum hydrocarbons (TPH). The main purpose of this project is to obtain a holistic picture of material fluxes within the river system combined with an inventory of natural and anthropogenic factors controlling them.</p><p>Our results indicate gradual increase of total dissolved solids, and content of nutrients and some PTEs (i.e., Cu) in water along the course of Moskva River. It can be linked to non-point pollution, as well as drastic changes occurring downstream Moscow and other urban areas caused by direct pollution. Massive increase of chloride, sulfate, sodium, mineral phosphorus, nitrogen, Mo and Sr concentrations in water is observed downstream outlets of Moscow wastewater treatment plants, which is characteristic of insufficiently treated urban sewage. Concentrations of nutrients and PTEs only slightly decrease downstream the city, remaining at levels often exceeding environmental guidelines up to the river’s mouth, whereas increased concentrations of other pollutants, such as TPH, are more closely limited to urban areas and fade more quickly with distance from the source.</p><p>Nutrient pollution of the Moskva River, as well as concentrations of some PTEs (i.e., Sb, Pb), steadily increased during summer low-flow period, when low dilution capacity limits biochemical self-purification. On the other hand, Mn, Co and Zn reached maximum concentrations during the spring flood due to their accumulation in city road dust and subsequent concentrated inflow with snowmelt runoff.</p><p>The Moskva River tributaries that flow within close proximity to the metropolitan area were revealed to have significantly higher pollution levels than the Moskva River itself, indicating stronger anthropogenic stress.</p><p>Balance calculations performed on our database showed that during the flood the Mozhaysk Reservoir – the single large reservoir on the Moskva River – retains huge volumes of major elements and PTE, at times even greater than their subsequent input from urban areas downstream from the dam. It proves crucial role of the reservoir’s retention capacity in the Moskva River’s geochemical balance formation.</p><p>Authors acknowledge Russian Geographical Society (project 28/2019-I), Russian Science Foundation (project 19-77-30004) and Russian Foundation for Basic Research (project 19-05-50109) for financial support.</p>

Planned and unplanned fire regimes on public land in south-east Queensland

2020 ◽  
Vol 29 (5) ◽  
pp. 326 ◽  
Author(s):  
Martyn Eliott ◽  
Tom Lewis ◽  
Tyron Venn ◽  
Sanjeev Kumar Srivastava
Keyword(s):  
Fire History ◽  
Fire Regime ◽  
Regional Scale ◽  
Fire Regimes ◽  
The Public ◽  
Asset Protection ◽  
Occurrence Data ◽  
The Individual ◽  
Service State ◽  
Open Forests

Land management agencies in Queensland conduct planned burning for a variety of reasons, principally for management of fuels for human asset protection and biodiversity management. Using Queensland Parks and Wildlife Service’s archived manually derived fire reports, this study considered the individual components of the fire regime (extent, frequency and season) to determine variation between planned and unplanned fire regimes in south-east Queensland. Overall, between 2004 and 2015, planned fire accounted for 31.6% and unplanned fire 68.4% of all fire on Queensland Parks and Wildlife Service state-managed land. Unplanned fire was more common in spring (September–October), and planned fire was more common in winter (June–August). Unplanned fire affected 71.4% of open forests and woodlands (148563ha), whereas 58.8% of melaleuca communities (8016ha) and 66.6% of plantations (2442ha) were burnt with planned fire. Mapping fire history at a regional scale can be readily done with existing publicly available datasets, which can be used to inform the assessment of planned burning effectiveness for human asset protection and the management of biodiversity. Fire management will benefit from the continued recording of accurate fire occurrence data, which allows for detailed fire regime mapping and subsequent adaptive management of fire regimes in the public domain.

Were bivalves ecologically dominant over brachiopods in the late Paleozoic? A test using exceptionally preserved fossil assemblages

Paleobiology ◽  
2019 ◽  
Vol 45 (02) ◽  
pp. 265-279 ◽  
Author(s):  
Shannon Hsieh ◽  
Andrew M. Bush ◽  
J Bret Bennington
Keyword(s):  
Fossil Record ◽  
Energy Use ◽  
Regional Scale ◽  
Late Paleozoic ◽  
Ecosystem Structure ◽  
Relative Importance ◽  
Clear Trend ◽  
Fossil Assemblages ◽  
Ecological Importance ◽  
Preferential Dissolution

AbstractInterpreting changes in ecosystem structure from the fossil record can be challenging. In a prominent example, the traditional view that brachiopods were ecologically dominant over bivalves in the Paleozoic has been disputed on both taphonomic and metabolic grounds. Aragonitic bivalves may be underrepresented in many fossil assemblages due to preferential dissolution. Abundance counts may further understate the ecological importance of bivalves, which tend to have more biomass and higher metabolic rates than brachiopods. We evaluate the relative importance of the two clades in exceptionally preserved, bulk-sampled fossil assemblages from the Pennsylvanian Breathitt Formation of Kentucky, where aragonitic bivalves are preserved as shells, not molds. At the regional scale, brachiopods were twice as abundant as bivalves and were collectively equivalent in biomass and energy use. Analyses of samples from the Paleobiology Database that contain abundance counts are consistent with these results and show no clear trend in the relative ecological importance of bivalves during the middle and late Paleozoic. Bivalves were probably more important in Paleozoic ecosystems than is apparent in many fossil assemblages, but they were not clearly dominant over brachiopods until after the Permian–Triassic extinction, which caused the shelly benthos to shift from bivalve and brachiopod dominated to merely bivalve dominated.

Habitat selection by river otters (Lontra canadensis) under contrasting land-use regimes

2009 ◽  
Vol 87 (5) ◽  
pp. 422-432 ◽  
Author(s):  
D. Gallant ◽  
L. Vasseur ◽  
M. Dumond ◽  
E. Tremblay ◽  
C. H. Bérubé
Keyword(s):  
Land Use ◽  
Habitat Use ◽  
Regional Scale ◽  
Anthropogenic Disturbances ◽  
Lontra Canadensis ◽  
Anthropogenic Factors ◽  
Theoretic Approach ◽  
Related Factors ◽  
River Otters ◽  
Sign Distribution

Habitat preferences of river otters ( Lontra canadensis (Schreber, 1777)) are well known, but because most studies were conducted in regions with markedly low or high levels of anthropogenic disturbances, it is not well known how their habitat usage is affected by varied anthropogenic disturbances and land-use regimes on a regional scale. We studied habitat use by otters in eastern New Brunswick, Canada, in an area having both protected and disturbed riparian habitats. Using long-range winter riparian transects, we documented activity-sign distribution along riverbanks in relation to 12 habitat factors and 9 categories of anthropogenic disturbances. We documented variables at site with activity signs and at habitat stations along riverbanks at 500 m intervals. We used logistical regressions and Akaike’s information criterion in an information–theoretic approach to compare models and determine the important factors involved. Habitat-related factors were more important than anthropogenic ones in describing habitat use. The best performing models were those incorporating both habitat and anthropogenic factors. Beaver ( Castor canadensis Kuhl, 1820) ponds were the most important habitat factor, while fields were the most important anthropogenic factor. Our results indicate that otters responded mostly to the presence of habitat features they use and secondarily to the presence of anthropogenic structures or activities in an area.

scholarly journals An Analysis of Vegetation Change Trends and Their Causes in Inner Mongolia, China from 1982 to 2006

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Baolin Li ◽  
Wanli Yu ◽  
Juan Wang
Keyword(s):  
Vegetation Change ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Anthropogenic Factors ◽  
Simple Linear Regression ◽  
Ordos Plateau ◽  
Hetao Plain ◽  
Avhrr Data ◽  
The Relationship ◽  
Very High

This paper presents the vegetation change trends and their causes in the Inner Mongolian Autonomous Region, China from 1982 to 2006. We used National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) data to determine the vegetation change trends based on regression model by fitting simple linear regression through the time series of the integrated Normalized Difference Vegetation Index (NDVI) in the growing season for each pixel and calculating the slopes. We also explored the relationship between vegetation change trends and climatic and anthropogenic factors. This paper indicated that a large portion of the study area (17%) had experienced a significant vegetation increase at the 0.05 level from 1982 to 2006. The significant vegetation increase showed no positive link with precipitation and was mainly caused by human activities. In or to the south of Horqin Sandy Land, in the Hetao Plain, and at the northern foothills of the YinshanMountain, the significant NDVI increase trends were mainly caused by the increase of the millet yield per unit of cropland. In the east of Ordos Plateau, the significant NDVI increase trends were mainly determined by the fencing and planting of grasses and trees on grassland.

Fire regime and vegetation change in the transition from Aboriginal to European land management in a Tasmanian eucalypt savanna

2016 ◽  
Vol 64 (5) ◽  
pp. 427 ◽  
Author(s):  
Louise M. Romanin ◽  
Feli Hopf ◽  
Simon G. Haberle ◽  
David M. J. S. Bowman
Keyword(s):  
Vegetation Change ◽  
Fire Regime ◽  
Plantago Lanceolata ◽  
Sediment Cores ◽  
Open Water ◽  
Fire Regimes ◽  
Ecological Impacts ◽  
14C Dating ◽  
Early 19Th Century ◽  
European Settlement

Using pollen and charcoal analysis we examined how vegetation and fire regimes have changed over the last 600 years in the Midlands of Tasmania. Sediment cores from seven lagoons were sampled, with a chronology developed at one site (Diprose Lagoon) using 210Pb and 14C dating. Statistical contrasts of six cores where Pinus served as a marker of European settlement in the early 19th Century and showed significant changes in pollen composition following settlement with (a) influx of ruderal exotic taxa including Plantago lanceolata L., Brassicaceae, Asteraceae (Liguliflorae) and Rumex, (b) increase in pollen of the aquatics Myriophyllum spp. and Cyperaceae, (c) a decline in native herbaceous pollen taxa, including Chenopodiaceae and Asteraceae (Tubuliflorae) and (d) a decline in Allocasuarina and an initial decline and then increase of Poaceae. The presence of Asteraceae (Liguliflorae) in the pre-European period suggests that an important root vegetable Microseris lanceolata (Walp.) Sch.Bip. may have been abundant. Charcoal deposition was low in the pre-European period and significantly increased immediately after European arrival. Collectively, these changes suggest substantial ecological impacts following European settlement including cessation of Aboriginal traditions of fire management, a shift in hydrological conditions from open water lagoons to more ephemeral herb covered lagoons, and increased diversity of alien herbaceous species following pasture establishment.

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