Bog Pine Research Articles

Hydrological variability of middle European peatland during the Holocene, inferred from subfossil bog pine and bog oak dendrochronology and high-resolution peat multiproxy analysis of the Budwity peatland (northern Poland)

Subfossil pine and oak tree trunks were excavated during exploitation of the Budwity peatland in Northern Poland. Based on dendrochronological analysis, the woodland successions in peatland were reconstructed and correlated with moisture dynamics of the peatland ecosystem inferred from the high-resolution multi-proxy analysis of the peatland deposits. From the results of dendrochronological analysis and the 14C wiggle matching methods, four floating pine chronologies (5882–5595; 5250–5089; 3702–3546; and 2222–1979 mod. cal BP) and two oak chronologies (4932–4599 and 4042–3726 mod. cal BP) were developed. The organic sediments of the peatland (6 m thick) were deposited over approximately nine thousand years. The lower complex (525–315 cm) comprises minerogenic peat, while the upper complex (315.0–0.0 cm) is composed of ombrogenic peat. Subfossil tree trunks are distributed across various peat horizons, which suggests multiple stages of tree colonisation followed by subsequent dying-off phases. Multiproxy sediment analyses (lithological, geochemical and δ13C stable isotope, pollen, plant macrofossils, Cladocera, diatom, and Diptera analyses) indicate that the two earliest phases of pine colonisation (5882–5595 and 5250–5089 mod. cal BP) and the two stages of oak colonisation (4932–4599 and 4042–3726 mod. cal BP) were associated with periodic drying of the peatland. Conversely, tree dying-off phases occurred during periods of increased water levels in the peatland, coinciding with stages of increasing climate humidity during the Holocene. The two most recent phases of pine colonisation occurred during the ombrogenic stage of mire development. Remnants of the dead forest from these phases, marked by subfossil trunks still rooted in the ground, were preserved and exposed presently during peat exploitation, approximately 2.5 m below ground level. The identified phases of tree colonisation and subsequent dying-off phases show correlation with analogical phenomena observed in the other investigated European peatlands.

‘Pine Decline or pine declines?’ Analysis and Interpretation of Bog-Pines from Wem Moss, Shropshire, UK

A dendrochronological investigation was undertaken on subfossil Scots pine (Pinus sylvestris L.) stumps following their discovery during conservation management at Wem Moss, a small (28 ha) former raised mire in Shropshire, UK. Two ring-width chronologies were constructed from 14 of the 17 trees sampled spanning 198 and 208 years, respectively. Whilst dendrochronological dating was not possible, radiocarbon assays provided an estimated age for this mire-rooting woodland of between 3015 and 2505 years cal. BCE, coinciding with the age traditionally associated with the widespread mortality of pine trees throughout much of the UK and Ireland, often referred to as the Pine Decline (ca. 4000 radiocarbon years BP). Placed in a wider geographical context, the Wem Moss pines are located within the lowland Meres and Mosses region, where previous studies on subfossil pine have demonstrated protracted declines in mire-rooting trees. These have included tree mortality significantly post-dating the Pine Decline, especially at larger peatland sites that exceed 5 km2. Such macrofossil evidence for the presence of Scots pine into the late Holocene is supported by continuous Pinus pollen representation at peatland sites in the Welsh Marches (English–Welsh border), suggesting the possible survival of native Scots pine trees in this area up to the present day. The investigation of Wem Moss bog pines and their wider geographical context highlights the incomplete and patchy nature of palaeo-vegetational records and also the need for future genetic research on living Scots pine in possible refugial areas in Britain and Ireland.

BOG PINE AND DECIDUOUS TREES CHRONOLOGIES RELATED TO PEAT SEQUENCES STRATIGRAPHY OF THE PODEMSZCZYZNA PEATLAND (SANDOMIERZ BASIN, SOUTHEASTERN POLAND)

ABSTRACTThe Podemszczyzna peatland (Sandomierz Basin, SE Poland) is a place of peat exploitation for balneological purposes. The thickness of organic sediments (minerogenic peat) reaches 4.0 m, while the beginning of peat accumulation was dated using the radiocarbon method (14C) at 13,517–13,156 cal BP. During the peat exploitation numerous fragments of subfossil wood (of various species) were excavated and, based on dendrochronological analyzes and 14C dating (wiggle-matching), two short floating chronologies were elaborated: bog pine chronology (147 years long) and deciduous trees (oak, elm) chronology (139 years long). 14C dating has shown that the bog pine chronology (ca. 9980–9830 mod. cal BP) is the oldest pine chronology found in the Polish peatlands so far. It was synchronous with the Preboreal decline of fluvial activity and peat formation, whereas dying off of trees was connected with distinct rise of fluvial activity. Floating chronology of deciduous trees is much younger and encompasses time interval of ca. 680–545 cal BP. The trees’ encroachment on the peatland was related to the terrestrialization of the depositional fen, recorded in the loss on ignition curve in the form of mineral sediment delivery to the bog, as well as it is marked in the pollen record.

Bog pine dendrochronology related to peat stratigraphy: Palaeoenvironmental changes reflected in peatland deposits since the Late Glacial (case study of the Imszar raised bog, Northeastern Poland)

Resultsof dendrochronological analysis of subfossil pine (Pinus sylvestris) buried in the Imszar raised bog deposits (NE Poland, Podlasie Region), were compared with multiproxy analysis of peat deposits (pollen and Non Pollen Palynomorphs, plant macrofossils, Cladocera, and geochemical analyses). The peat (3.3 m thick) accumulation started in the Allerød interstadial. The oldest pine tree population grew in this peatland in ca 6790–6530 cal yrs. BP: floating chronology (determined with the wiggle–matching method) covers this period is 255 years long. The growth of trees on the fen was related to the drying out of the fen at that time, which caused the break in peat accumulation (hiatus). Apart from numerous fallen trees excavated during the peat extraction, a horizon of vertical in situ tree trunks ingrown to the ground, were exposed during peat exploitation. On the basis of a dozen or so trees, a second, “dead forest” floating chronology 197 years long, was compiled with a time range of ca 4255-4060 cal yrs. BP. The youngest, third pine floating chronology (310 years long), elaborated on the basis of ex situ tree trunks, covers the time frame of ca 3130-2820 cal yrs. BP. Multiproxy analyzes of fen deposits indicate that the three stage colonization of the peatland by bog pine was associated with the periods of warming and overdrying in the climate of the Holocene, during which the groundwater table in the Imszar peatland significantly lowered. In turn, the dying off stages of the pine trees occurred in the phases of climate humidity growth, during which the groundwater level in the fen raised. They are well correlated with analogous bog pine germination and dying-off phases in the other European peatlands.

Molecular and paleo‐climatic data uncover the impact of an ancient bottleneck on the demographic history and contemporary genetic structure of endangered Pinus uliginosa

AbstractWith the current rate of biodiversity loss, conservation management practices require a comprehensive understanding of eco‐evolutionary relationships, history, and genetic structure of species. Assessments of genetic diversity are crucial, especially in rare, endemic, or threatened forest tree species with small and isolated populations, such as peat bog pine (Pinus uliginosa N.). Here, we used a novel approach, combining genetic diversity assessment, ecological niche modeling, and population demography inference to explore the complex history of a few remnant populations of this endangered pine. To asses the relative influence of isolation and fragmentation on genetic diversity in the taxonomic context, the patterns of genetic variation found in P. uliginosa were contrasted with those observed in its close relatives with much bigger distribution ranges and larger populations (Pinus sylvestris, Pinus mugo, and Pinus uncinata). We found a similar level of genetic diversity across the species at nuclear loci but contrasting patterns of variability distribution at chloroplast markers. We detected the signatures of an ancient genetic bottleneck dated at around 26 400 years ago, indicating a drastic reduction in the population size of P. uligionosa during the Last Glacial Maximum. In addition, we found substantial differentiation between current populations as a result of enhanced genetic drift during long‐lasting isolation. The research suggests potential conservation management strategies for peat bog pine and emphasizes the importance of using complementary approaches for their successful development.

Patterns of mtDNA variation reveal complex evolutionary history of relict and endangered peat bog pine (Pinus uliginosa).

Estimates of genetic differentiation at intra- and interspecific level are often hindered by the lack of suitable molecular markers. Low phylogeographic resolution limits development of appropriate conservation strategies especially in case of endangered forest tree species with small and disjunct distribution. In this study, we assessed fine-scale genetic structure of relict and endangered peat bog pine (Pinus uliginosa) and two other closely related European pine species (Pinus mugo and Pinus uncinata) using a set of 15 newly developed maternally inherited and seed-mediated mitochondrial DNA (mtDNA) markers and two previously known polymorphic mtDNA regions (nad1, nad7). Three main groups, corresponding in general to three investigated species were revealed in the haplotype network analysis. However, only P. uncinata was clearly distinct at all levels of analysis, whereas great genetic similarity and haplotype sharing was observed between P. uliginosa and P. mugo. Strong phylogeographic structure was found in P. uliginosa that showed high differentiation at relatively short geographical distance among populations and the existence of mitochondrial lineages of different evolutionary history. Hybridization with other pine species has likely contributed to genetic differentiation of P. uliginosa as indicated by contemporary distribution of mtDNA haplotypes. The research emphasizes the importance of accurate assessments of genetic structure of endangered species with complex evolutionary history for development of efficient conservation strategies.

The history of mycological studies in Khanty-Mansi autonomous okrug: 2) studies of Macromycetes, Lichens and Myxomycetes, state of mycological collections and fungal records database

В предыдущей части работы мы затронули вопросы актуальности развития микологических исследований на территории севера Западной Сибири (конкретно – ХМАО) и необходимость проведения ревизии уже выполненных за 100 лет работ. Был сделан обзор первых разрозненных работ, проведенных в начале 20 века, описание истории изучения дереворазрушающих базидиомицетов и фитопатологических исследований. Во второй части мы продолжаем анализ других направлений и подводим некоторые итоги.
 Большое внимание на территории ХМАО уделено также изучению наземных макромицетов (в узком смысле – агарикоидных базидиомицетов), однако исследования носят локальный характер. Хорошо изучены две территории – в окр. г. Ханты-Мансийска и Юганский заповедник. Изучается как видовой состав, так и количественная структура сообществ макромицетов лесных и болотных экосистем, а также особенности биологии и экологии отдельных редких видов. Ввиду высокой заболоченности территории округа особое внимание в исследованиях было уделено сообществам грибов верховых болот (макро- и микромицеты, дрожжи, ксилотрофные базидиомицеты, миксомицеты). Выявление видового состава лихенобиоты проходило лишь в отдельных районах ХМАО, однако суммарный список видов достаточно велик. Выявлено видовое разнообразие миксомицетов на территориях некоторых ООПТ. В контексте таксономических исследований всего за период микологической истории ХМАО было описано четыре новых вида и одна комбинация, в работах сообщаются сведения о новых, еще не описанных видах. Охрана грибов в ХМАО началась с выпуска Красной книги региона в 2003 г. (второе издание вышло в 2013 году). За это время вышел ряд публикаций, посвященных микологическим природоохранным мероприятиям. Коллекции грибов являются неотъемлемой частью развития микологических исследований: на территории мы насчитываем около 5 фунгариев. Кроме того, большое число коллекций грибов, собранных в ХМАО, хранятся в исследовательских институтах других регионов. На основе опубликованных работ нами была составлена база данных находок грибов и грибоподобных организмов ХМАО (Fungal Records Database of Yugra). В настоящее время база включает около 14 тыс. записей находок грибов. Ссылка на базу данных размещена на странице сайта Фунгария ЮГУ и база данных доступна для скачивания. Анализ базы данных показал, что для территории ХМАО опубликовано около 2600 видов и подвидовых таксонов грибов и грибоподобных организмов. Из них большая часть приходится на агарикоидные базидиомицеты (30%), лишайники (37%), а также афиллофоровые базидиомицеты (19%).

Effect of temperature and precipitation on linear increment of Sphagnum fuscum and S. magellanicum in Western Siberia

The linear increment of Sphagnum fuscum and S. magellanicum in ombrotrophic mires of Western Siberia has been measured during two years over a transect about 2500 km long extending from forest–steppe to forest–tundra. Along the latitudinal gradient, the increment of both species has proved to be correlated with annual average air temperature and, in S. magellanicum, also with annual precipitation. The determinants of their growth differ between the southern, central, and northern parts of the study region. At the regional level, the annual and summer precipitation plays a more important role than the average air temperature. The increment of S. fuscum in the southern part is positively correlated with the amount of precipitation and negatively correlated with summer temperature, whereas the situation in the central part is inverse. In S. magellanicum, the linear increment is directly dependent on the annual average temperature and annual and summer precipitation in the south and on the annual and summer precipitation in the north of Western Siberia. The dynamics of linear growth of both species in bog pine forests during the growing season are similar: its rate is the highest in June, when the linear increment of S. fuscum and S. magellanicum amounts to 60 and 85% of the annual total, respectively.

Bottlenecks in bog pine multiplication by somatic embryogenesis and their visualization with the environmental scanning electron microscope.

Somatic embryogenesis (SE) is an important biotechnological technique used for the propagation of many pine species in vitro. However, in bog pine, one of the most endangered tree species in the Czech Republic, limitations were observed, which negatively influenced the development and further germination of somatic embryos. Although initiation frequency was very low-0.95%, all obtained cell lines were subjected to maturation. The best responding cell line (BC1) was used and subjected to six different variants of the maturation media. The media on which the highest number of early-precotyledonary/cotyledonary somatic embryos was formed was supplemented with 121μM abscisic acid (ABA) and with 6% maltose. In the end of maturation experiments, different abnormalities in formation of somatic embryos were observed. For visualization and identification of abnormalities in meristem development during proliferation and maturation processes, the environmental scanning electron microscope was used. In comparison to the classical light microscope, the non-commercial environmental scanning electron microscope AQUASEM II has been found as a very useful tool for the quick recognition of apical meristem disruption and abnormal development. To our knowledge, this is the first report discussing somatic embryogenesis in bog pine. Based on this observation, the cultivation procedure could be enhanced and the method for SE of bog pine optimized.

Impacts of regional climatic fluctuations on radial growth of Siberian and Scots pine at Mukhrino mire (central-western Siberia)

Ring width (TRW) chronologies from Siberian (Pinus sibirica) and Scots (Pinus sylvestris) pine trees were sampled at Mukhrino – a large mire complex in central-western Siberia – to evaluate the impacts of hydroclimatic variability on tree growth over the last three centuries. For this purpose, we compared climate-growth correlation profiles from trees growing on peat soils with those growing on adjacent mineral soils. Tree growth at both peat and mineral soils was positively correlated to air temperature during the vegetation period. This finding can be explained by (i) the positive influence of temperature on plant physiological processes (i.e. growth control) during the growing season and (ii) the indirect impact of air temperatures on water table fluctuations. We observe also a strong link between TRW and the winter Palmer Drought Severity Index (PDSI), especially in Siberian pine, reflecting the isolating effect of snow and limited freezing damage in roots. Significant negative relations were, by contrast, observed between bog TRW chronologies and hydroclimatic indices during spring and summer; they are considered an expression of the negative impacts of high water levels and moist peat soils on root development. Some unusually old bog pines – exhibiting >500 growth rings – apparently colonized the site at the beginning of the Little Ice Age, and therefore seem to confirm that (i) peat conditions may have been drier in Siberia than in most other regions of western Europe during this period. At the same time, the bog trees also point to (ii) their strong dependence on surface conditions.

Late Holocene palaeoclimate variability: The significance of bog pine dendrochronology related to peat stratigraphy. The Puścizna Wielka raised bog case study (Orawa – Nowy Targ Basin, Polish Inner Carpathians)

Abstract The results of dendrochronological and palynological analyses of subfossil pine trees occurring in the peat deposits of the Puścizna Wielka raised bog (Polish Carpathians, Southern Poland) – the only site with numerous subfossil pine trees in the mountainous regions of Central Europe presently known – indicate that the majority of the tree populations grew in the peat bog during the periods ca 5415–3940 cal BP and 3050–2560 cal BP. Several forestless episodes, dated to 5245–5155 cal BP, 4525–4395 cal BP and 3940–3050 cal BP, were preceded by tree dying-off phases caused by an extreme periodical increase in humidity and general climate cooling trends. These events are documented based on analyses of pollen and non-pollen palynomorph assemblages, dendrochronological analyses of the trees, as well as numerous radiocarbon datings of the sediment horizons occurring within the peat bog profile. The phases of germinations, and, in turn, of tree and shrub invasions of the peat bog areas have been closely connected to drying and occasional warming of the regional climate. The last of the forestless periods began about 2600 years ago and continued up to the very recent times. Currently, as a result of desiccation of the peat bog and the lowering of the groundwater level (due to improved water drainage system), pine trees have returned the peat bog again. These results demonstrate that studies of subfossil bog-pine trees are quite effective in documenting and reconstructing periods of humidity fluctuation that occurred within the Carpathian region over the last several millennia.

Asynchrony in key Holocene chronologies: Evidence from Irish bog pines

The Greenland Ice Core Chronology 2005 (GICC05) and the radiocarbon calibration curve (IntCal) are the foremost time scales used in paleoclimatic and paleoenvironmental studies of the most recent 10 k.y. Due to varying and often insufficient dating resolution, opportunities to test the synchrony of these two influential chronologies are rare. Here we present evidence for a phase of major pine recruitment on Irish bogs at ca. 8160 yr B.P. Dendrochronological dating of subfossil trees from three sites reveals synchronicity in germination across the study area, indicative of a regional forcing. The concurrent colonization of pine on peatland is interpreted in terms of drier surface conditions and provides the first substantive proxy data in support of a significant hydroclimatic change in the north of Ireland accompanying the 8.2 ka climate cooling event. The date of pine establishment does not overlap with the GICC05 age range for the event, and possible lags between responses are unlikely to explain the full difference. In light of recent studies highlighting a possible offset in GICC05 and IntCal dates, the Irish pine record supports the notion of ice core dates being too early during the period of study. If the suggested discrepancy in timing is an artifact of chronological error, it is likely to have affected interpretations of previous proxy comparisons and alignments.

Pine stumps in Irish peats: is their occurrence a valid proxy climate indicator?

ABSTRACTWe investigate the temporal and spatial distribution of pine (Pinus sylvestris) stumps preserved in peat deposits to test whether their occurrence can be used as an indicator of climatic shifts to drier conditions. Radiocarbon dates of sub‐fossil stumps were collected from the literature, along with environmental data throughout the island of Ireland. Data were analysed using non‐parametric statistical techniques. There was no distinct geographical pattern observed in the distribution of pine stumps on bog surfaces. Tree ages ranged from 66 to 500 years with 85.7 % of these <300 years. Pines occurred on bogs from ca. 8500 to 500 cal a BP. The temporal distribution during the Holocene was characterized as a mid‐Holocene peak in sites supporting pine, with two gaps either side of this peak. Our current understanding of past climate dynamics failed to explain this temporal distribution. The onset, mid‐Holocene peak and cessation of bog sites supporting the presence of bog pines appears to be driven by changes in pine seed and bog surface area availability during the Holocene rather than changes in climate. We conclude that variability in the occurrence of Irish bog pines is not a valid climate proxy as factors other than climate influence their presence and thereby disrupt the climate signals.

Multiannual hydrological responses in Scots pine radial growth within raised bogs in southern Sweden

To explore interactions between climate and peatland hydrology, Scots pine ( L.) growing at four raised bogs in southern Sweden were subject to a dendroclimatological study. Radial tree growth reflecting climate and water table fluctuations over multiannual periods was detected as significant negative correlations between tree-ring width (TRW) chronologies and the preceding one to four years total precipitation or river discharge. Systematically stronger negative correlations were obtained when river discharge instead of precipitation was compared to radial tree growth. This indicates that river discharge reflect moisture variability of peat bogs better than what precipitation data does. Meanwhile, monthly precipitation and radial tree growth did not show any clear correlation, whereas spring and early summer temperatures had a positive influence on the tree growth. Our study shows that growth variability of bog pines in the Boreal zone reflect hydrological responses related to a synthesis of climate controlled moisture variability over several year periods.Pinus sylvestris

Záchrana cenného genotypu borovice blatky s využitím mikropropagačních technik

Bog pine (Pinus uncinata DC. subsp. uliginosa (Neumann) Businský) is a subendemic species and appears to be one of the most endangered tree species of the Czech Republic. Its rare populations are at the present time greatly endangered namely by spontaneous hybridization with the Scots pine (Pinus sylvestris L.). Regarding the fact that its protection is insufficient even in national nature reserves (NNR) and the classical propagation by cuttings is problematic, modern methods were adopted for a long-term preservation of the taxon. Growth regulation conditions were investigated for the induction of organogenesis and somatic embryogenesis. Mature seeds were obtained from selected trees in the Žofinka NNR and from a locality near the village of Krajková in the Sokolov district. Cotyledon and hypocotyl segments from seedlings pregerminated in sterile conditions were used to induce the organogenesis. Bud proliferation was observed on the cotyledons after 4 weeks. The largest amount of buds was found on the medium with 1.5 mg . l−1 benzyladenine (BA) and 0.5 mg . l−1 1-naphtylacetic acid (NAA) after 12 weeks. The hypocotyl segments showed only the formation of green callus. Isolated mature zygotic embryos were used for the induction of somatic embryogenesis. Development of mucilaginous callus was recorded after 3 weeks of cultivation on media with different combinations of BA, NAA and 2,4-dichlorophenoxy acetic acid (2,4-D) concentrations. When the callus induced on the medium with the combination of 0.56 (1.13) mg . l−1 BA and 1.86 mg.l−1 NAA was transferred on the medium with lower BA (0.113 mg . l−1) and 2,4-D (0.44 mg.l−1) concentrations, the first somatic embryos started to emerge after a period of other two weeks.

Increased tree establishment in Lithuanian peat bogs — Insights from field and remotely sensed approaches

Over the past century an ongoing establishment of Scots pine (Pinus sylvestris L.), sometimes at accelerating rates, is noted at three studied Lithuanian peat bogs, namely Kerėplis, Rėkyva and Aukštumala, all representing different degrees of tree coverage and geographic settings. Present establishment rates seem to depend on tree density on the bog surface and are most significant at sparsely covered sites where about three-fourth of the trees have established since the mid-1990s, whereas the initial establishment in general was during the early to mid-19th century. Three methods were used to detect, compare and describe tree establishment: (1) tree counts in small plots, (2) dendrochronological dating of bog pine trees, and (3) interpretation of aerial photographs and historical maps of the study areas. In combination, the different approaches provide complimentary information but also weigh up each other's drawbacks. Tree counts in plots provided a reasonable overview of age class distributions and enabled capturing of the most recently established trees with ages less than 50years. The dendrochronological analysis yielded accurate tree ages and a good temporal resolution of long-term changes. Tree establishment and spread interpreted from aerial photographs and historical maps provided a good overview of tree spread and total affected area. It also helped to verify the results obtained with the other methods and an upscaling of findings to the entire peat bogs. The ongoing spread of trees in predominantly undisturbed peat bogs is related to warmer and/or drier climatic conditions, and to a minor degree to land-use changes. Our results therefore provide valuable insights into vegetation changes in peat bogs, also with respect to bog response to ongoing and future climatic changes.

Exploring climate forcing of growth depression in subfossil South Swedish bog pines using stable isotopes

Comparison between growth variability, based on ring-width (RW) analysis, and moisture-sensitive signals in tree-ring carbon and oxygen stable-isotope composition provides increased understanding of how climate and hydrology influenced bog pines (Pinus sylvestris L.) at two sites in southern Sweden during the mid- and late Holocene. Tree-ring sequences from two subfossil trees collected at raised bogs having different hydrology and catchment size were analyzed to probe the stable-isotope signals associated with two bog-wide episodes of growth depression, one during the Holocene Thermal Maximum and the other during the Neoglacial Transition. The occurrence of lower whole-wood δ13C and cellulose δ13C and δ18O values immediately prior to the onset of growth depression in both trees, suggesting increased atmospheric relative humidity, is consistent with the notion that excessive effective moisture impeded tree growth. Correlation analysis indicates that the growth response lagged about three years behind the decline in δ13C and δ18O values in each tree, possibly reflecting relatively slow rise in the local water table in response to wetter climate.

Kuivenduse mõju rabamänniku arengule Järvselja Õppe- ja Katsemetskonna kuivendatud puistu näitel / Effect of drainage on the development of an oligotrophic bog Scots pine (P. sylvestris L.) stand in Järvselja

Abstract The effect of drainage in peatland forests has been studied in Estonia but research on bog pine (Pinus sylvestris L.) stands is lacking and mixed opinions on the expediency of amelioration in this site type are found. In order to obtain more information on the post drainage effects, measurements were conducted in a drained oligotrophic bog Scots pine stand (with a relatively thin peat layer) in Järvselja. Relationship between stand characteristics and distance from the drainage ditch was described and measurement data was compared with data that had been collected 59 years earlier in the same stand. Over time the stand structure and productivity had changed. Due to lengthy drainage, increase in several stand characteristics became evident: mean height 84% (8.60 ± 0.39 m), mean DBH 48% (6.55 ± 0.59 cm), basal area 59% (10.6 ± 3.4 m2 ha-1) and growing stock 179% (169 ± 32 m3 ha-1). Growth conditions had improved (site class improvement 1.8 units) and since earlier comparison data was from an already drained stand, actual change in stand characteristics and productivity compared to pre-drained state, has to be even greater. The studied stand is a good example of successful forest drainage in a bog pine forest and these results contribute to a better understanding of post drainage developments in these types of forests

Bog Pines, Track Ways and Man – The Influence of Climate Change on Neolithic Settlements in the Duemmer Area (Northwest Germany)

Bog Pines, Track Ways and Man – The Influence of Climate Change on Neolithic Settlements in the Duemmer Area (Northwest Germany)

Development of a Neolithic pine tree‐ring chronology for northern Scotland

AbstractThe peatlands of northern Scotland (one of the largest and most intact areas of blanket bog in the world) contain a rare widespread horizon of subfossil pine in stratigraphic context. Eighteen bog pine from three new sites are incorporated into a mean Neolithic pine chronology now composed of subfossil pine from 12 sites, which is tree‐ring‐dated against Irish bog pine chronologies to span 3198–2757 BC. Germination and peaks of radial growth infer drier conditions between 3199 and 3130 BC. Dying‐off phases and depression of growth reflect a change to wetter conditions between 3023 and 3002 BC and a terminal decline of pine between 2809 and 2782 BC. The close synchronization of germination/die‐off phases and major ring‐width variations between sites across this region indicates that the environmental changes are probably triggered by climate change. Twenty‐four bog pine samples remain unmatched. Future multi‐discipline research into this important example of climatic change at the Neolithic/Bronze Age transition is recommended. Copyright © 2012 John Wiley & Sons, Ltd.