Woodland Development Research Articles

Forest restoration on the former industrial land of Sulphur quarry in the Ukrainian Roztochya

This paper adds to the evidence base in the discussion to what extent woodland development can be a means to restoring the land affected by mining. We investigate the formation of vegetation communities in sites on a former Sulphur quarry in the Roztochya district of the Lviv region in Ukraine to answer the research questions: How can the formation of vegetation cover affect the disturbed sites and what knowledge can be used in restoration practices elsewhere? We perform an experiment examining which types of vegetation are suitable for the restoration. We explore the influence of restored vegetation and re-emerged woodlands have on the process of soil rehabilitation and the increasing organic substance in it. We examine the impact of various combinations of vegetation on land rehabilitation. Explaining the degree of colonization of waste land by various types of vegetation helps us to reveal the trends of regenerative processes and identify the most promising for restoration tree species in affiliation with the ground vegetation. The results can assist decision-makers in choosing compatibility alliances of vegetation to sustain regeneration processes. Although this research is location specific, the knowledge developed can to a degree be applied to similar places, in the temperate zone.

Prescribed fire effects on Pinus palustris woodland development after catastrophic wind disturbance and salvage logging

Scientifically informed strategies to manage naturally disturbed forests are critical to support the sustained provisioning of ecosystem goods and services. In fire-adapted ecosystems, catastrophic canopy removal can disrupt surface fuel continuity and challenge the continued use of low-intensity prescribed fire. Although salvage logging is used globally after natural disturbance events, little information is available on how salvage logging interacts with subsequent use of prescribed fire. This study investigated the impacts of operational-scale prescribed fire on Pinus palustris (longleaf pine) stand development in areas differentially impacted by an April 2011 EF3 tornado and a subsequent salvage logging operation. Twenty 0.04-ha nested plots were systematically established in mature, wind-disturbed, and salvage-logged sites (n = 60) to measure seedlings, saplings, woody fuels, organic litter, and mineral soil before and after prescribed fire. Prescribed fire-induced fine fuel consumption, mineral soil exposure, and substantial sapling density reductions were observed throughout the treatment area. Prescribed fire effects were not apparently impacted by salvage logging, which did not alter the amount of fine fuels available for prescribed fire consumption. Despite overall sapling density reductions, fire-resistant P. palustris saplings exhibited increased densities on wind-disturbed and salvage-logged sites. Pinus palustris seedlings, however, exhibited marked post-fire reductions, which contrasted with a strong resprouting response observed among top-killed hardwood species. Concerning woody plant recovery, this study indicated that salvage logging was not detrimental to P. palustris stand development and that prescribed fire effectively enhanced recovery in unlogged and logged wind-disturbed sites.

Ultrastructural study of the ovary and oogenesis of Polyonchobothrium clarias Woodland, 1925 (Cestoda: Bothriocephalidea) infecting Clarias gariepinus from Egypt.

The ovarian tissues and different stages of oocytes development of Polyonchobothrium clarias Woodland, 1925 recovered from the intestine of Clarias gariepinus Burchell, 1822 fish was investigated by transmission electron microscope (TEM). The ovarian follicles are enveloped by compressed epithelial sheath lying on basal layer that shows epithelial projection into the lumen of each follicle. The epithelial sheath filled with glycogen, mitochondria and solitary lipid droplets. The epithelial nuclei are appeared closed to the basal part of the ovarian follicle. Numerous heterogeneous electron dense myelin-like bodies observed within the ovarian cytoplasm they appeared different irregular shaped. Each ovarian follicle contains number of oocytes loosely packed within the follicle at different stages of differentiation developmental stages starting with oogonial cells, primary, secondary and mature oocytes. The Oogonia were undergoing characteristic cytological changes that lead to oocyte maturation. Vitelline material appears in early stages of primary oocytes. Lipid droplets appeared in late stages of secondary oocyte. Mature oocytes are filled with clusters of cortical granules adjacent to the oocyte plasma membrane. Syncytial interstitial tissue and number of myelin-like bodies are observed in the ovarian cytoplasm and they fill the cytoplasmic spaces. The results of the present study were compared with the previous reports in other cestode taxa, to define the ultrastructural observations of the female reproductive tissues for clarification the reproductive fecundity of the parasite.

Contribution of the land use allocation model for agroecosystems: The case of Torrecchia Vecchia

In this study, we developed a bio-economic model coupling land use and ecosystem services to investigate the role of forests on a broad set of ecosystem services, including carbon sequestration, soil quality and biodiversity. As a case study, the model was calibrated with economic, agronomic and ecological data from the Torrecchia Vecchia agroecosystem in Italy. In our analysis of optimal land use allocation, the results showed that diversified land use is required to provide a good balance between provisioning and non-provisioning ecosystem services. More specifically, the development of woodlands alongside farming activities had a positive impact on the soil quality score and on landscape heterogeneity, which is a proxy for ecosystem function and resilience. These findings demonstrate that the inclusion of woodlands can alleviate the trade-offs between provisioning and non-provisioning services as they can generate profit while allowing for better soil quality and biodiversity relative to more intensive land use. The study also confirms that a landscape-scale method can be used to investigate agroecosystem management problems when spatially explicit data is not available.

Effects of atmospheric CO<sub>2</sub> variability of the past 800 kyr on the biomes of southeast Africa

Abstract. Very little is known about the impact of atmospheric carbon dioxide pressure (pCO2) on the shaping of biomes. The development of pCO2 throughout the Brunhes Chron may be considered a natural experiment to elucidate relationships between vegetation and pCO2. While the glacial periods show low to very low values (∼220 to ∼190 ppmv, respectively), the pCO2 levels of the interglacial periods vary from intermediate to relatively high (∼250 to more than 270 ppmv, respectively). To study the influence of pCO2 on the Pleistocene development of SE African vegetation, we used the pollen record of a marine core (MD96-2048) retrieved from Delagoa Bight south of the Limpopo River mouth in combination with stable isotopes and geochemical proxies. Applying endmember analysis, four pollen assemblages could be distinguished representing different biomes: heathland, mountain forest, shrubland and woodland. We find that the vegetation of the Limpopo River catchment and the coastal region of southern Mozambique is influenced not only by hydroclimate but also by temperature and atmospheric pCO2. Our results suggest that the extension of mountain forest occurred during those parts of the glacials when pCO2 and temperatures were moderate and that only during the colder periods when atmospheric pCO2 was low (less than 220 ppmv) open ericaceous vegetation including C4 sedges extended. The main development of woodlands in the area took place after the Mid-Brunhes Event (∼430 ka) when interglacial pCO2 levels regularly rose over 270 ppmv.

Early Holocene wetland succession at Lake Flixton (UK) and its implications for Mesolithic settlement

This paper reports on new research into the timing and nature of post-glacial environmental change at Lake Flixton (North Yorkshire, UK). Previous investigations indicate a succession of wetland environments during the early Holocene, ultimately infilling the basin by ca 7,000 cal bp. The expansion of wetland environments, along with early Holocene woodland development, has been linked to changes in the human occupation of this landscape during the Mesolithic (ca 11,300–6,000 cal bp). However, our understanding of the timing and nature of environmental change within the palaeolake is poor, making it difficult to correlate to known patterns of Mesolithic activity. This paper provides a new record for both the chronology and character of environmental change within Lake Flixton, and discusses the implications for the Mesolithic occupation of the surrounding landscape.

Pollen analysis and tephrochronology of a MIS 13 lacustrine succession from Eastern Sabatini Volcanic District (Rignano Flaminio, central Italy)

Diatomite deposits in the Sabatini Volcanic District (central Italy) represent valuable archives to investigate both Middle Pleistocene vegetation dynamics and geochemistry of proximal products of volcanic eruptions, which provide crucial geochronological markers for a large region of Southern Europe. We present a new pollen record from a diatomite deposit at Rignano Flaminio, attributed to MIS 13 based on two major eruptive events from Monti Sabatini: the Grottarossa Pyroclastic Sequence (513 ± 3 ka) and the Fall A unit (499 ± 3 ka). We also add insights into the geochemical and mineralogical composition of the proximal deposits of the Fall A tephra, whose products are found in several sites of the central Mediterranean. Our pollen record shows marked vegetation turnovers, reflecting changes in regional and global climate conditions, local environmental factors and ecological processes within refuge areas. The lower part of the record points to a forested environment dominated by both deciduous and evergreen broadleaved taxa, indicating wet and temperate climate conditions. This interval was punctuated by two phases of slight forest declines, where a general increase in Poaceae and Artemisia, coupled with the development of Ericaceae and evergreen Quercus communities, suggests the establishment of mediterranean-type climatic conditions with increased aridity. The upper part of the sequence shows the development of Abies and Pinus woodlands, reflecting a change towards cooler and possibly wetter climate. The pollen richness, accompanied by a fossil leaf of Laurus, confirms the role of the Sabatini Volcanic District as a Pleistocene biodiversity hot-spot and refuge area for many trees.

Trees for bees

Limited resources and land-use pressures require more efficient conservation strategies, from increasingly limited input. Pollinator declines are threatening food security and natural capital. I present a novel perspective on landscape level pollinator conservation from across multiple scientific fields. I examine the value of landscape structure provided by trees and hedgerows compared with floral strips, and discuss use of computer simulation technologies for understanding how spatial structure impacts pollinators’ ability to forage.All bees forage on a mixture of both flowering plants and tree species. Honeybees have a detectable preference for foraging on trees, even when sparse. The spatial information provided by trees and hedgerows positively impacts formation of the “cognitive map”, making pollination and foraging more efficient. Woody habitat features like trees and hedgerows provide more efficient resources for pollinators in a number of ways. They are more efficient forage targets due to absolute resource density; tree and hedgerow planting could provide more optimised foraging landscapes for pollinators. Using computer simulation may enable us to study pollinator responses to landscape development at this scale. Woodland development results in non-pollinator ecosystem services, representing a more cost-effective conservation strategy. Moving forward we need to identify the key impediments to its successful implementation.

Persist or take advantage of global warming: A development of Early Holocene riparian forest and oxbow lake ecosystems in Central Europe

In this study, we focus on the environmental changes recorded in the San River valley (Stubno–Nakło site, south-eastern Poland) at the beginning of the Holocene. This multi-proxy study for the first time in the region of the northern foreland of the Western Carpathians included quantitative thermal reconstruction based on Chironomidae and high-stratigraphic resolution of 14C AMS dating. We hypothesised that (i) climate events during the Early Holocene contributed to ecosystem turnovers via stimulating disturbances related to the river's fluvial activity and (ii) woodland and oxbow lake ecosystems became more resilient to flood disturbances along with the advance of forest succession on the floodplain. The results revealed that the response of ecosystems on the Early Holocene warming was strongly linked with the decrease in fluvial activity of the river. The reconstruction of the mean July temperature based on Chironomidae revealed the exceptionally high rate of warming during the period of ca. 11,490–11,460 cal. BP (at least 1 °C per decade) up to values > 2 °C than modern ones. During this period, the lake trophy and productivity started to increase with a simultaneous spread of Betula woodlands on the alluvial plain. The “Preboreal oscillation” cooling was dated at ca. 11,450–11,250 cal. BP. At that time, an increased climate instability led to a higher rate of extremal events such as flood at ca. 11,400–11,330 cal. BP, which probably led to the disruption of the Betula population. The development of riparian woodlands, initiated by the expansion of Ulmus from ca. 11,100 cal. BP, and further spread of Quercus and Fraxinus excelsior on the alluvial plain and lower river terraces increased plant transpiration and therefore limited the river runoff and its fluvial activity. This, together with the expansion of reed belt communities, probably limited the impact of floods on the oxbow lake. However, ca. 10,010–9880 cal. BP traces of higher fluvial activity, but of lower impact, were recorded.

Towards a refined understanding of the use of coastal zones in the Mesolithic: New investigations on human–environment interactions in Telemark, southeastern Norway

The study of the effects of human presence on vegetation in the Mesolithic has been controversial. It is often assumed that hunter-gatherers did not change or affect their environment in a way that can be detected by means of pollen analysis. In this paper, we explore potential human impact on the vegetation during the Mesolithic by comparing pollen data from a high-resolution sediment core from Lake Skogstjern with archaeological data obtained through extensive excavation and survey in Bamble, in the county of Telemark, southeastern Norway. The aim of this interdisciplinary approach is to reach a better understanding of the development and use of Mesolithic woodlands with regard to the availability of different resources, but also to put the question of human impact on Mesolithic vegetation on the agenda. Mesolithic settlement in southeastern Norway was to a very large degree shore bound, and the pollen analysis from Lake Skogstjern, situated in the coastal hinterland, allows for new perspectives on and interpretations of the use of the coastal wider landscape.

A multi-proxy view of exceptionally early postglacial development of riparian woodlands with Ulmus in the Dniester River valley, western Ukraine

This article presents the first multi-proxy study of palaeoecosystem changes during the Late Weichselian and Early Holocene in western Ukraine. The site is a former oxbow lake situated in the Dniester River valley (western Ukraine). We hypothesised that this area may have been one of the nuclei for the Holocene expansion of elm (Ulmus), a primary arboreal taxon in riparian woodlands, in the Central and Eastern European lowlands. Our study was undertaken on a profile encompassing the period ca. 12,900–9880cal. BP. We applied selected palaeobotanical, palaeozoological and geochemical analyses. During the Younger Dryas the area was dominated by well-developed Pinussylvestris-Betula woodlands. Drier habitats were overgrown by Juniperus shrublands and steppe communities. Patches of tundra with Betulanana were also present. Ulmus started to spread on the lower river terraces before ca. 11,840cal. BP i.e., during the late Younger Dryas, which suggests this area as a nucleus for its Holocene expansion. A chironomid-based reconstructed mean July temperature (MJT) of 15–17°C is suggested during the Younger Dryas. The main Ulmus expansion started ca. 11,160cal. BP and its optimum in local woodlands lasted until ca. 10,340cal. BP, when Pinussylvestris rapidly expanded. The reconstructed MJT varied between 18 and 21°C during the Ulmus optimum; however, it rapidly declined to 16°C around ca. 10,800cal. BP. Fire activity increased before ca. 10,870cal. BP, concurrent with the climate warming at the Younger Dryas-Holocene transition, but did not affect the population of Ulmus, a taxon intolerant of fires. Wildfires probably affected patches of steppe vegetation and Pinussylvestris-Betula woodlands occupying higher elevations of the valley and watersheds. However, changes in the fire activity may have stimulated Ulmus retreat at ca. 10,340cal. BP.

Response of bird community structure to habitat management in piñon-juniper woodland-sagebrush ecotones

Piñon (Pinus spp.) and juniper (Juniperus spp.) woodlands have been expanding their range across the intermountain western United States into landscapes dominated by sagebrush (Artemisia spp.) shrublands. Management actions using prescribed fire and mechanical cutting to reduce woodland cover and control expansion provided opportunities to understand how environmental structure and changes due to these treatments influence bird communities in piñon-juniper systems. We surveyed 43 species of birds and measured vegetation for 1–3years prior to treatment and 6–7years post-treatment at 13 locations across Oregon, California, Idaho, Nevada, and Utah. We used structural equation modeling to develop and statistically test our conceptual model that the current bird assembly at a site is structured primarily by the previous bird community with additional drivers from current and surrounding habitat conditions as well as external regional bird dynamics. Treatment reduced woodland cover by >5% at 80 of 378 survey sites. However, habitat change achieved by treatment was highly variable because actual disturbance differed widely in extent and intensity. Biological inertia in the bird community was the strongest single driver; 72% of the variation in the bird assemblage was explained by the community that existed seven years earlier. Greater net reduction in woodlands resulted in slight shifts in the bird community to one having ecotone or shrubland affinities. However, the overall influence of woodland changes from treatment were relatively small and were buffered by other extrinsic factors. Regional bird dynamics did not significantly influence the structure of local bird communities at our sites. Our results suggest that bird communities in piñon-juniper woodlands can be highly stable when management treatments are conducted in areas with more advanced woodland development and at the level of disturbance measured in our study.

Paleoenvironmental and Paleoclimatic Approach to the Upper Pleistocene Site of Artazu Vii (Arrasate, Northern Iberian Peninsula) Using Small Vertebrates

Artazu VII site (Arrasate, northern Iberian Peninsula) is a fossiliferous deposit accidentally discovered at the Kobate Quarry in 2012. During the next year, all the vertebrate remains attributed to the late Pleistocene (~ 93 ka) were recovered in an emergency excavation project. Here we describe, for the first time, the small vertebrate assemblage (amphibians, reptiles and small mammals) recovered at the site and the environmental and climatic results estimated from the palaeoecological affinities of the studied taxa. More than 50,000 microvertebrate elements were recovered, comprising 24 taxa and belonging seven to the Order Rodentia, five to Order Eulipotyphla, one to Order Chiroptera, seven to Order Anura and four to Order Squamata. This assemblage, measured in terms of relative abundance, and taking into account their environmental attributions, has been used to reconstruct the palaeoenvironmental and palaeoclimatic conditions in all recovered samples. In this way, we have divided the stratigraphic sequence in three different phases. Although the presence of woodland mass is presented along all the sequence, growth and reduction changes can be observed. Thus, the stratigraphic sequence begins with a landscape by open spaces. As we move forward to the top of the stratigraphic column, woodland development increases, and is in the second phase where it reaches his maximum greatest development. Finally, wood environment descends again, reaching similar values as the beginning. These forestry biotopes were related to temperate and humid conditions, comparable to the nowadays landscape. Besides, the existence of a watercourse nearby the site has been concluded.

Exposure-related forest-steppe: A diverse landscape type determined by topography and climate

Topographic heterogeneity under dry continental climate can create a landscape mosaic called “exposure-related forest-steppe”, characterized by a regular pattern of forest on the north- and steppe on the south-facing slopes. Here we identify the climatic and topographic determinants of this landscape type, using a model of the Altai Mountains in southern Siberia because they (1) contain large areas of forest-steppe together with forested and steppe landscapes, and (2) possess well-preserved natural land-cover. Based on the Landsat land-cover classification and digital elevation model we identified areas containing exposure-related forest-steppe and modeled their climatic and topographic thresholds using regression trees. The models showed that in the Altai exposure-related forest-steppe is most common in topographically heterogeneous areas with May–September precipitation of 226–377 mm and a mean July temperature of 13.8–15.6 °C. Its existence is jointly determined by hilly topography and a climate that is moist enough to support tree growth on north-facing slopes, but insufficiently so to support woodland development on south-facing slopes. This is consistent with the concept of effective topographic heterogeneity, suggesting that topographic heterogeneity on the landscape level is translated into high habitat diversity and species diversity only within a certain range of climatic conditions.

Сільськогосподарське порушення екологічної стійкості басейну річки Дніпро

The transboundary basin of the Dnieper is a diversified complex having a high natural and socio-economic value for three neighboring countries (Russia, Belarus, Ukraine); however, the ecological crisis caused by considerable anthropogenic transformations has led to the deterioration in the functioning of the integrity of the basin’s geohydroecosystem and decrease in the quality of drinking water, and, as a result, to the deterioration of public health. The main reason for the destabilization of the environmental sustainability is agricultural development in the catchment area of the river Dnieper. The area of arable land of the transboundary basin is 283 thousand km 2 , or 55,4% of the total area of the basin, including 206 thousand km 2 (72,8%) located on the territory of Ukraine. The principles of a basin approach constitute the basis for the objective of studying basin organization, environmental condition and space-time transformation of landscape ecosystems in the catchment area of the Dnieper river. Geo-modeling and identification of the Dnieper sub-basins have been carried out based on the SRTM-90 digital elevation model with the application of the Hydrology tools of Spatial Analyst Tools working module of the ArcGIS 10.1 licensed software product. For a catchment area of 511 thousand km 2 , 776 sub-basins with a size from 1,9 to 22680,2 km 2 of orders IV-IX were identified. Agricultural development and distribution of woodland within the boundaries of the Dnieper basin are determined based on the data of the National Atlas of Transboundary States and decryption of remote sensing (RS) data using a series of well-calibrated MODIS satellite images. Almost 67,4% of sub-basins of the steppe and forest steppe zones with a total area of about 324,4 km 2 (63,5%) have less than 20% of woodland, which indicates a low ability to preserve the natural ecological balance in the areas of the middle and lower reaches of the Dnieper. Almost three-fifths of the basin area have completely lost their natural landscape due to the intensive agricultural use. About 416 catchment sub-basins occupying 60,2% of the Dnieper basin area have a strong degree of land fund transformation. Analysis of the share of arable land and forest cover indicates high ecological vulnerability and manifestation of strong land degradation processes at an area of more than 70% of the transboundary basin territory, which leads to a significant disturbance in the functioning of the Dnieper geohydroecosystem. The results obtained will provide an opportunity to substantiate the introduction of specific land and water conservation measures for optimizing the land fund based on basin position-dynamic and adaptive landscaping principles that will create conditions for rational use and rehabilitation of land and water resources of the transboundary Dnieper river basin.

Grassland to woodland transitions: Dynamic response of microbial community structure and carbon use patterns

AbstractWoodland encroachment into grasslands is a globally pervasive phenomenon attributed to land use change, fire suppression, and climate change. This vegetation shift impacts ecosystem services such as ground water allocation, carbon (C) and nutrient status of soils, aboveground and belowground biodiversity, and soil structure. We hypothesized that woodland encroachment would alter microbial community structure and function and would be related to patterns in soil C accumulation. To address this hypothesis, we measured the composition and δ13C values of soil microbial phospholipids (PLFAs) along successional chronosequences from C4‐dominated grasslands to C3‐dominated woodlands (small discrete clusters and larger groves) spanning up to 134 years. Woodland development increased microbial biomass, soil C and nitrogen (N) concentrations, and altered microbial community composition. The relative abundance of gram‐negative bacteria (cy19:0) increased linearly with stand age, consistent with decreases in soil pH and/or greater rhizosphere development and corresponding increases in C inputs. δ13C values of all PLFAs decreased with time following woody encroachment, indicating assimilation of woodland C sources. Among the microbial groups, fungi and actinobacteria in woodland soils selectively assimilated grassland C to a greater extent than its contribution to bulk soil. Between the two woodland types, microbes in the groves incorporated relatively more of the relict C4‐C than those in the clusters, potentially due to differences in below ground plant C allocation and organo‐mineral association. Changes in plant productivity and C accessibility (rather than C chemistry) dictated microbial C utilization in this system in response to shrub encroachment.

Predation and aridity slow down the spread of 21-year-old planted woodland islets in restored Mediterranean farmland

Planted woodland islets act as sources of seed that may accelerate woodland development in extensive agricultural landscapes. We assessed a 1-ha plot that was planted with 16 100-m2 islets of holm oak Quercus ilex subsp. ballota seedlings near Toledo (Spain) in 1993. In spring 2014 we measured (1) acorn predation and (2) seedling emergence from seeded acorns at different distances from and orientations around the islets with half of the acorns protected to prevent predation, (3) survival of emerged seedlings, and (4) natural tree establishment outside of the planted islets. Most (96.9 %) unprotected acorns were removed or predated. Seedling emergence from protected acorns ranged from 42.9 % on the northern side of the islets to 13.2 % on the southern side, suggesting a less stressful microclimate on the northern side. Survival of naturally established seedlings was 28.6 % by the end of first summer; seedling mortality was chiefly due to drought (45.0 %) and herbivory (35.0 %). Density of emerged seedlings, surviving seedlings after first dry season, and established oaks >1-year old was similar at different distances from the islets. Over the 21 year time period, 58 new oak individuals >1-year old have established (an average of 3.3 established individuals per ha per year) at an average distance of 6.3 ± 5.4 m away from the closest islet. We conclude that initial oak regeneration triggered by small planted islets in Mediterranean abandoned farmland is slowed down by high acorn predation, seedling herbivory, and stressful microclimatic conditions. Regardless, these islets are a viable tool for regeneration of Mediterranean oak woodland.

Life on the periphery is tough: Vegetation in Northwest Iceland and its responses to early-Holocene warmth and later climate fluctuations

Long- and short-term climate variations in the North Atlantic have been of sufficient magnitude to leave a discernible mark on the history of vegetation and landscape stability in Iceland during the Holocene. A reconstruction of early- and mid-Holocene vegetation around Lake Kagaðarhóll, Northwest Iceland, examines how climate fluctuations have affected the terrestrial ecosystem. A thorough reconstruction has been made using pollen and plant macrofossil analyses combined with proxies for organic and inorganic matter. The record shows the development from a period of pioneer vegetation towards a woodland ecosystem. The deposition of the Saksunarvatn tephra at c. 10,300 cal. yr BP caused a 100-year period of instability, followed by a gradual trend of stabilization over several centuries while material left behind by retreating glaciers and tephra was being contained by expanding and developing vegetation. Early-Holocene warmth is indicated by high pollen production of Juniperus communis around the lake by c. 10,100 cal. yr BP and birch woodland being established around the lake by c. 9200 cal. yr BP, much earlier than previously believed for this locale. Cooling climate between c. 8700 and 8200 cal. yr BP halted woodland development, with reduced plant reproduction likely caused by cold spring and summer temperatures. Woodlands became re-established from c. 7900 cal. yr BP before entering a decline from c. 6000 cal. yr BP, with harsher environmental conditions apparent after c. 4200 cal. yr BP. The Kagaðarhóll record compares favourably with other palaeoclimatic data from the North Atlantic, demonstrating the potential of pollen and macrofossil data for reconstructions of environmental change in Iceland and as an indicator of climate variability in the North Atlantic during the Holocene.

Palaeoenvironmental changes in Central Europe (NE Poland) during the last 6200 years reconstructed from a high-resolution multi-proxy peat archive

Peat deposits from an ombrotrophic bog (north-eastern Poland) were analysed to reconstruct peatland development and environmental changes. This paper presents reconstructions of hydrological changes and plant succession over the last 6000 years. The methods included the high-resolution analysis of plant macrofossils, pollen and testate amoebae, supported by radiocarbon dating. Three main phases were identified in the history of the bog and surrounding woodland vegetation: 4000–400 BC, 400 BC–AD 1700 and AD 1700–2011. Except for terrestrialisation and the fen-to-bog transition phase, the development of bog vegetation was mainly dependent on the climate until approximately AD 1700. The dominant taxon in Gązwa bog was Sphagnum fuscum/rubellum. Woodland development was significantly affected by human activity at several time periods. The most visible human activity, manifested by the decline of deciduous species, occurred ca. 350 BC, ca. AD 250, ca. AD 1350 and after AD 1700. These events correspond to phases of human settlement in the area. During 400–300 BC, the decline of deciduous trees, primarily Carpinus, coincided with an increase in indicators of human activity and fire frequency. At ca. AD 200, Carpinus and Tilia abundance decreased, corresponding to an increased importance of cereals ( Secale and Triticum). Since ca. AD 1350, the impact of Teutonic settlement is apparent, and after AD 1700, deciduous forests largely disappeared.

To what extent did changes in July temperature influence Lateglacial vegetation patterns in NW Europe?

What was the impact of July temperature changes on vegetation patterns during the Lateglacial period in north-west Europe? Chironomid-inferred mean July air temperature estimates (C-Tjul) are proxy temperature records independent of terrestrial vegetation. The relationships between Lateglacial vegetation inferred from pollen percentages and these temperature estimates are explored using data synthesised geographically from 15 sites where both pollen percentages and C-Tjul are published to assess the influence of temperature and of temperature changes on regional vegetation.Direct impacts of temperature on a species involve passing the range limits or realised niche of that species. The Bølling warming allowed vegetation to develop. The Younger Dryas cooling had direct impacts on species and vegetation types that were at a critical ecotone and thus sensitive to change. Precipitation is extremely important and its interaction with temperature controlled most of the vegetation patterns inferred from these NW European pollen data. High precipitation was important in W Norway, whereas aridity in the YD was a controlling factor in N Norway, the Netherlands, and NE Germany. Under constant climate, ecological processes occurred such as immigration, succession, and soil development that resulted in vegetation changes. Biotic interactions were also important, such as the impact of grazing by mega-herbivores during Allerød time in Ireland that may have restricted the development of birch woodland. At the coarse scale of this synthesis, July temperature alone is seen not to be a good predictor of the patterns of pollen percentages and hence of vegetation through the Lateglacial. Rather, it is the interactions of temperature and precipitation, combined with ecological processes that appear to be the major factors influencing Lateglacial palynological and vegetation patterns in NW Europe.