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Glacier forelands are among the most rapidly changing landscapes on Earth. Stable ground is rare as geomorphic processes move sediments across large areas of glacier forelands for decades to centuries following glacier retreat. Yet, most ecological studies sample exclusively on stable terrain to fulfill chronosequence criteria, thus missing potential feedbacks between geomorphic disturbances and vegetation colonization. By influencing vegetation and soil development, such vegetation-geomorphic disturbance feedbacks could be crucial to understand glacier foreland ecosystem development in a changing climate. We surveyed vegetation and environmental properties, including geomorphic disturbance intensities, in 105 plots located on both stable and unstable moraine terrain in two geomorphologically active glacier forelands in New Zealand and Switzerland. Our plot data showed that geomorphic disturbance intensities permanently changed from high/moderate to low/stable when vegetation reached cover values of around 40%. Around this cover value, species with response and effect traits adapted to geomorphic disturbances dominated. This suggests that such species can act as “biogeomorphic” ecosystem engineers that stabilize ground through positive feedback loops. Across floristic regions, biogeomorphic ecosystem engineer traits creating ground stabilization, such as mat growth and association with mycorrhiza, are remarkably similar. Nonmetric multidimensional scaling revealed a linked sequence of decreasing geomorphic disturbance intensities and changing species composition from pioneer to late successional species. We interpret this linked geomorphic disturbance-vegetation succession sequence as “biogeomorphic succession,” a common successional pathway in unstable river and coastal ecosystems across the world. Soil and vegetation development were related to this sequence and only advanced once biogeomorphic ecosystem engineer species covered 40%–45% of a plot, indicating a

Marble has been extracted from the Carrara quarries (Apuan Alps, Italy) for over two millennia. This cultural landscape is characterised by singular landforms called ravaneti, causing environmental problems due to debris flow, thus imperilling human settlements and natural heritage. Geomorphological and vegetation analyses have highlighted that in a decade, vegetation cover greatly increased, indicating potential for passive restoration of dump deposits. The assessment of plant assemblages indicates a decrease in plant richness and endemics, and an increase in wood and alien species. The conservation of historical ravaneti landscape requires weighted restoration actions to reduce geomorphological hazards and preserve native biodiversity.

Input materials, scripts and results for: - Trend analyses in MODIS Enhanced Vegetation Index for 2000-2019 in the Indigirka Lowlands, Sakha Republic, Russian federation. - Land Cover Change Detection of Vegetation Functional Groups in an Arcitc tundra site using very high resolution (0.5) satellite images in a focus area in the Kytalyk Reserve, Indigirka Lowlands over the period 2010-2019., Input materials, scripts and results for: - Trend analyses in MODIS Enhanced Vegetation Index for 2000-2019 in the Indigirka Lowlands, Sakha Republic, Russian federation. - Land Cover Change Detection of Vegetation Functional Groups in an Arcitc tundra site using very high resolution (0.5) satellite images in a focus area in the Kytalyk Reserve, Indigirka Lowlands over the period 2010-2019.

Vegetation change, permafrost degradation and their interactions affect greenhouse gas fluxes, hydrology and surface energy balance in Arctic ecosystems. The Arctic shows an overall “greening” trend (i.e. increased plant biomass and productivity) attributed to expansion of shrub vegetation. However, Arctic shrub dynamics show strong spatial variability and locally “browning” may be observed. Mechanistic understanding of greening and browning trends is necessary to accurately assess the response of Arctic vegetation to a changing climate. In this context, the Siberian Arctic is an understudied region. Between 2010 and 2019, increased browning (as derived from the MODIS Enhanced Vegetation Index) was observed in the Eastern Siberian Indigirka Lowlands. To support interpretation of local greening and browning dynamics, we quantified changes in land cover and transition probabilities in a representative tundra site in the Indigirka Lowlands using a timeseries of three very high resolution (VHR) (0.5 m) satellite images acquired between 2010 and 2019. Using spatiotemporal Potts model regularization, we substantially reduced classification errors related to optical and phenological inconsistencies in the image material. VHR images show that recent browning was associated with declines in shrub, lichen and tussock vegetation and increases in open water, sedge and especially Sphagnum vegetation. Observed formation and expansion of small open water bodies in shrub dominated vegetation suggests abrupt thaw of ice-rich permafrost. Transitions from open water to sedge and Sphagnum, indicate aquatic succession upon disturbance. The overall shift towards open water and wetland vegetation suggests a wetting trend, likely associated with permafrost degradation. Landsat data confirmed widespread expansion of surface water throughout the Indigirka Lowlands. However, the increase in the area of small water bodies observed in VHR data was not visible in Landsat-derived surface water da

Mediterranean mid-altitude sites are critical for the survival of plant species allowing for elevational vegetation shifts in response to high-amplitude climate variability. Pollen records from the southern Balkans have underlined the importance of the region in preserving plant diversity over at least the last half a million years. So far, there are no records of vegetation and climate dynamics from Balkan refugia with an Early Pleistocene age. Here we present a unique palynological archive from such a refugium, the Lake Ohrid basin, recording continuously floristic diversity and vegetation succession under obliquity-paced climate oscillations. Palynological data are complemented by biomarker, diatom, carbonate isotope and sedimentological data to identify the mechanisms controlling shifts in the aquatic and terrestrial ecosystems within the lake and its catchment. The study interval encompasses four complete glacial-interglacial cycles (1365–1165 ka; MIS 43–35). Within the first 100 kyr of lake ontogeny, lake size and depth increase before the lake system enters a new equilibrium state as observed in a distinct shift in biotic communities and sediment composition. Several relict tree genera such as Cedrus, Tsuga, Carya, and Pterocarya played an important role in ecological succession cycles, while total relict abundance accounts for up to half of the total arboreal vegetation. The most prominent biome during interglacials is cool mixed evergreen needleleaf and deciduous broadleaf forests, while cool evergreen needleleaf forests dominate within glacials. A rather forested landscape with a remarkable plant diversity provide unique insights into Early Pleistocene ecosystem resilience and vegetation dynamics.

Unmanned Aerial Vehicles (UAV) greatly extended our possibilities to acquire high resolution remote sensing data for assessing the spatial distribution of species composition and vegetation characteristics. Yet, current pixel- or texture-based mapping approaches do not fully exploit the information content provided by the high spatial resolution. Here, to fully harness this spatial detail, we apply deep learning techniques, that is, Convolutional Neural Networks (CNNs), on regular tiles of UAV-orthoimagery (here 2–5 m) to identify the cover of target plant species and plant communities. The approach was tested with UAV-based orthomosaics and photogrammetric 3D information in three case studies, that is, (1) mapping tree species cover in primary forests, (2) mapping plant invasions by woody species into forests and open land and (3) mapping vegetation succession in a glacier foreland. All three case studies resulted in high predictive accuracies. The accuracy increased with increasing tile size (2–5 m) reflecting the increased spatial context captured by a tile. The inclusion of 3D information derived from the photogrammetric workflow did not significantly improve the models. We conclude that CNN are powerful in harnessing high resolution data acquired from UAV to map vegetation patterns. The study was based on low cost red, green, blue (RGB) sensors making the method accessible to a wide range of users. Combining UAV and CNN will provide tremendous opportunities for ecological applications.

Thermokarst features, such as thaw ponds, are hotspots for methane emissions in warming lowland tundra. Presently we lack quantitative knowledge on the formation rates of formation of thaw ponds and subsequent vegetation succession, necessary to determine their net contribution to greenhouse gas emissions. This study set out to identify development trajectories and formation rates approximate rates of of small-scale (< 1 km2) arctic thaw ponds in north-eastern Siberia. We selected 40 ponds of different age classes based on a time-series of satellite images and measured vegetation composition, microtopography, water table and active layer thicknessthaw depth in the field and measured age of recruiting colonizing shrubs in thaw ponds using dendrochronology. We found that young thaw ponds are characterised by dead shrubs, while older ponds show rapid paludification through colonization bycontain mostly sedges and Sphagnum moss. While dead shrubs and open water are associated with permafrost degradation (lower surface elevation, high active layer thicknesslarger thaw depth), sites with sedge and in particular Sphagnum display indications of permafrost recovery. Recruitment of Betula nana on Sphagnum carpets in ponds indicates a potential recovery towards shrub dominated vegetation, although it remains unclear if and on what timescale this occurs. Our results suggest that thaw ponds display potentially cyclic vegetation succession associated with permafrost degradation and recovery. Thaw pond formation and initial colonization by sedges can occur on subdecadal timescales, which is relatively fast compared to rates known for ice wedge degradation (subdecadal to century-scale). The rates of formation and recovery of small-scale thaw ponds have implications for the greening/browning dynamics and carbon balance of this ecosystem., Thermokarst features, such as thaw ponds, are hotspots for methane emissions in warming lowland tundra. Presently we lack quantitative knowledge on the formation rates of formation of thaw ponds and subsequent vegetation succession, necessary to determine their net contribution to greenhouse gas emissions. This study set out to identify development trajectories and formation rates approximate rates of of small-scale (< 1 km2) arctic thaw ponds in north-eastern Siberia. We selected 40 ponds of different age classes based on a time-series of satellite images and measured vegetation composition, microtopography, water table and active layer thicknessthaw depth in the field and measured age of recruiting colonizing shrubs in thaw ponds using dendrochronology. We found that young thaw ponds are characterised by dead shrubs, while older ponds show rapid paludification through colonization bycontain mostly sedges and Sphagnum moss. While dead shrubs and open water are associated with permafrost degradation (lower surface elevation, high active layer thicknesslarger thaw depth), sites with sedge and in particular Sphagnum display indications of permafrost recovery. Recruitment of Betula nana on Sphagnum carpets in ponds indicates a potential recovery towards shrub dominated vegetation, although it remains unclear if and on what timescale this occurs. Our results suggest that thaw ponds display potentially cyclic vegetation succession associated with permafrost degradation and recovery. Thaw pond formation and initial colonization by sedges can occur on subdecadal timescales, which is relatively fast compared to rates known for ice wedge degradation (subdecadal to century-scale). The rates of formation and recovery of small-scale thaw ponds have implications for the greening/browning dynamics and carbon balance of this ecosystem.

Thermokarst features, such as thaw ponds, are hotspots for methane emissions in warming lowland tundra. Presently we lack quantitative knowledge on the formation rates of thaw ponds and subsequent vegetation succession, necessary to determine their net contribution to greenhouse gas emissions. This study sets out to identify development trajectories and formation rates of small‐scale (<100 m2), shallow arctic thaw ponds in north‐eastern Siberia. We selected 40 ponds of different age classes based on a time‐series of satellite images and measured vegetation composition, microtopography, water table, and thaw depth in the field and measured age of colonizing shrubs in thaw ponds using dendrochronology. We found that young ponds are characterized by dead shrubs, while older ponds show rapid terrestrialization through colonization by sedges and Sphagnum moss. While dead shrubs and open water are associated with permafrost degradation (lower surface elevation, larger thaw depth), sites with sedge and in particular Sphagnum display indications of permafrost recovery. Recruitment of Betula nana on Sphagnum carpets in ponds indicates a potential recovery toward shrub‐dominated vegetation, although it remains unclear if and on what timescale this occurs. Our results suggest that thaw ponds display potentially cyclic vegetation succession associated with permafrost degradation and recovery. Pond formation and initial colonization by sedges can occur on subdecadal timescales, suggesting rapid degradation and initial recovery of permafrost. The rates of formation and recovery of small‐scale, shallow thaw ponds have implications for the greening/browning dynamics and carbon balance of this ecosystem.

U radu je analizirana flora i vegetacija Deliblatske peščare. Cilj istraživanja bio je utvrđivanje recentnog stanja i osnovnih karakteristika flore Deliblatske peščare, ali i analiza dinamike flore Deliblatske peščare u poslednjih 220 godina. Jedan od ciljeva je bila analiza sukcesivnih promena u flori i vegetaciji Deliblatske peščare i predikcija njihovog pravca i kvaliteta, kao i utvrđivanje diverziteta i sintaksonomske šeme vegetacije Deliblatske peščare uz klasifikaciju problematičnih vegetacijskih grupa u širem aspektu- na nivou čitave Srbije, ali i Pontskog i Panonskog regiona. Terenska istraživanja su vršena u periodu 2012-2018 godine. Floristički podaci su uzimani na istim lokalitetima kao i fitocenološki snimci. Ukupno je uzeto 282 fitocenološka snimka metodom po Braun-Blankeu. Za florističku analizu je obrađena 301 referenca, a na terenu su prikupljeni podaci za 440 vrsta, od kojih je 6 po prvi put registrovano na ovom području. U florističku analizu je uključeno ukupno prikupljenih 9.887 podataka. U radu je dat floristički pregled u vidu spiska taksona koji su zabeleženi na Deliblatskoj peščari (ima ih 1072), sa lokalitetima na kojima su do sada pronađeni, obeleženi su prvi nalazi za vrste i podvrste, a obeležene su i vrste koje su potvrđene na terenskim istraživanjima u okviru ove disertacije. Floristička analiza je realizovana klasičnim numeričkim metodama, u cilju prezentacije najzastupljenijih familija, rodova, životnih formi i horotipova. Predstavljene su endemične, reliktne i ugrožene i ivnazivne vrste Peščare. Na Deliblatskoj peščari je zabeleženo 16 endemskih, 22 reliktnih, 49 strogo zaštićenih, 8 iz Crvenje knjige flore Srbije i 54 invazivna taksona. Dinamika florističkih istraživanja je predstavljena analizom literaturnih podataka i dinamike istraživanja ovog područja, a u skladu sa značajnim društvenim promen, In this research was analyzed flora and vegetation of the Deliblato Sands. The aim of the study was to determine the recent state and basic characteristics of the flora of Deliblato Sands, as well as to analyze the dynamics of flora in the last 220 years. One of the aims was to analyze the successive changes in the flora and vegetation of Deliblato Sands and the prediction of their direction and quality. Also, one of the goals was to determine the diversity and syntaxonomical scheme of vegetation through classification of problematic vegetation groups in the wider aspect - at the level of the whole Serbia, but also of Pontic and Pannonian region. Field research were carried out in the period 2012-2018. Floristic data were taken at the same sites as phytocenological plots. In total, 282 phytosociological relevés were taken using the Braun-Blanquet method. 301 different references were processed for floristic analysis and data for 440 species were collected in the field (6 of them were registered for the first time in this area). A total of 9,887 data collected were included in the floristic analysis. The research gives a floristic overview in the form of a list of taxa recorded in Deliblato Sandst (there are 1072 taxa), with the localities where they have been found so far, and the first findings for species and subspecies are marked, as well as the species confirmed in the field research within this dissertation. Floristic analysis was performed using classical numerical methods, in order to present the most represented families, genera, life forms and chorotypes. Endemic, relict and endangered and invasive species of Sandstone are presented. 16 endemic, 22 relicts, 49 strictly protected, 8 from the Red Data Book of Serbian flora and 54 invasive taxa have been recorded in Deliblato Sands. The dynamics of florist

We followed how forest thinning, repeated twice during a period of 93 years, altered understorey plant community composition, affected the succession of forest understorey vegetation and the accumulation of logs in the long-term. The study was carried out in northern Finland by resampling 20 permanent experimental plots, established after a wildfire in 1920. Understorey vegetation was inventoried in 1961, 1986 and 2013 with forest thinning treatments done in 1953 and 1987, using four and three different harvesting intensities, respectively. We found succession to override the effects of forest logging until the latest study period (2013). We observed negligible long-term effects of logging on understorey communities during the two mid-successional stages (1961, 1986), when the forest was 41 and 66 years old respectively. The impacts of logging on understorey vegetation were strongest in the latest successional stage (2013), the forest being at the age of 93 years. In the latest successional stage (2013) logged plots had less coarse woody debris than unlogged plots. Forest management thus influenced the key feature for forest biodiversity and potential habitats for endangered species. These findings are of major interest since the studies of long-term impacts of less intensive forest management practices are scarce. Our results suggest that in addition to possible immediate impacts, harvesting treatments have legacy effects (subtle or delayed inherited effects of forestry in the past) that influence the forest understorey vegetation community composition and the amount of coarse woody debris. This finding deserves special attention when planning of species conservation, multiple use of forests and sustainable forestry.

We followed how forest thinning, repeated twice during a period of 93 years, altered understorey plant community composition, affected the succession of forest understorey vegetation and the accumulation of logs in the long-term. The study was carried out in northern Finland by resampling 20 permanent experimental plots, established after a wildfire in 1920. Understorey vegetation was inventoried in 1961, 1986 and 2013 with forest thinning treatments done in 1953 and 1987, using four and three different harvesting intensities, respectively. We found succession to override the effects of forest logging until the latest study period (2013). We observed negligible long-term effects of logging on understorey communities during the two mid-successional stages (1961, 1986), when the forest was 41 and 66 years old respectively. The impacts of logging on understorey vegetation were strongest in the latest successional stage (2013), the forest being at the age of 93 years. In the latest successional stage (2013) logged plots had less coarse woody debris than unlogged plots. Forest management thus influenced the key feature for forest biodiversity and potential habitats for endangered species. These findings are of major interest since the studies of long-term impacts of less intensive forest management practices are scarce. Our results suggest that in addition to possible immediate impacts, harvesting treatments have legacy effects (subtle or delayed inherited effects of forestry in the past) that influence the forest understorey vegetation community composition and the amount of coarse woody debris. This finding deserves special attention when planning of species conservation, multiple use of forests and sustainable forestry.

Recently, riparian zone of East Asian rivers are intensively forested, which provides a number of problems in the river management especially at the downstream of dams (Asaeda et al. 2012, 2015a). One of the major causes is likely the reduction of sediment in the river channel. Hence, sediment bypass tunnels, which transport sediment from the upstream to the downstream reach of a dam, may have a potential to reduce impacts of the structure in the channel. Under this background, a dynamic riparian vegetation model (DRIPVEM) is developed to predict the colonization and succession of vegetation in a river channel, aiming to predict the vegetation succession in the downstream of a sediment bypass tunnel (Asaeda et al. 2012b, Sanjaya and Asaeda 2017). After the validation on the vegetation succession with observed data using measured morphological data of several rivers, then the model is combined with the 2-dimensional river bed deformation model, and is applied to the targeted river (i.e. Kuzuryugawa (river) in Fukui, Japan) to obtain the effects of the morphological change of the river channel on the vegetation patterns after a flood. The comparison of trials with and without the bed deformation model indicated that morphological change during the flood period has a substantial effect on the vegetation pattern after a flood. Furthermore, simulations were conducted for the future condition of vegetation, showing possible wide applications of the present model for river management works.

"This is the peer reviewed version of the following article: Muñoz-Mas, R., V. Garófano-Gómez, I. Andrés-Doménech, D. Corenblit, G. Egger, F. Francés, M.T. Ferreira, et al. 2017. ¿Exploring the Key Drivers of Riparian Woodland Successional Pathways across Three European River Reaches.¿ Ecohydrology 10 (8). Wiley: e1888. doi:10.1002/eco.1888, which has been published in final form at https://doi.org/10.1002/eco.1888. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.", [EN] Climate change and river regulation are negatively impacting riparian vegetation. To evaluate these impacts, process-based models are preferred over data-driven approaches. However, they require extensive knowledge about ecohydrological processes. To facilitate the implementation of such process-based models, the key drivers of riparian woodland successional pathways across three river reaches, in Austria, Portugal, and Spain, were explored, employing two complementary approaches. The principal component analyses highlighted the importance of the physical gradients determining the placement of the succession phases within the riparian and floodplain zones. The generalized additive models revealed that the initial and pioneer succession phases, characteristic of the colonization stage, appeared in areas highly morphodynamic, close in height and distance to the water table, and with coarse substrate, whereas elder phases within the transitional and mature stages showed incremental differences, occupying less dynamic areas with finer substrate. The Austrian site fitted well the current successional theory (elder phases appearing sequentially further up and distant), but at the Portuguese site, the tolerance of the riparian species to drought and flash flood events governed their placement. Finally, at the Spanish site, the patchy distribution of the elder phases was the remnants of formative events that reshaped the river channel. These results highlight the complex relationships between flow regime, channel morphology, and riparian vegetation. The use of succession phases, which rely on the sequential evolution of riparian vegetation as a response to different drivers, may be potentially better reproducible, within numerical process-based models, and transferable to other geographical regions.

"This is the peer reviewed version of the following article: Muñoz-Mas, R., V. Garófano-Gómez, I. Andrés-Doménech, D. Corenblit, G. Egger, F. Francés, M.T. Ferreira, et al. 2017. ¿Exploring the Key Drivers of Riparian Woodland Successional Pathways across Three European River Reaches.¿ Ecohydrology 10 (8). Wiley: e1888. doi:10.1002/eco.1888, which has been published in final form at https://doi.org/10.1002/eco.1888. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.", [EN] Climate change and river regulation are negatively impacting riparian vegetation. To evaluate these impacts, process-based models are preferred over data-driven approaches. However, they require extensive knowledge about ecohydrological processes. To facilitate the implementation of such process-based models, the key drivers of riparian woodland successional pathways across three river reaches, in Austria, Portugal, and Spain, were explored, employing two complementary approaches. The principal component analyses highlighted the importance of the physical gradients determining the placement of the succession phases within the riparian and floodplain zones. The generalized additive models revealed that the initial and pioneer succession phases, characteristic of the colonization stage, appeared in areas highly morphodynamic, close in height and distance to the water table, and with coarse substrate, whereas elder phases within the transitional and mature stages showed incremental differences, occupying less dynamic areas with finer substrate. The Austrian site fitted well the current successional theory (elder phases appearing sequentially further up and distant), but at the Portuguese site, the tolerance of the riparian species to drought and flash flood events governed their placement. Finally, at the Spanish site, the patchy distribution of the elder phases was the remnants of formative events that reshaped the river channel. These results highlight the complex relationships between flow regime, channel morphology, and riparian vegetation. The use of succession phases, which rely on the sequential evolution of riparian vegetation as a response to different drivers, may be potentially better reproducible, within numerical process-based models, and transferable to other geographical regions.

"This is the peer reviewed version of the following article: Muñoz-Mas, R., V. Garófano-Gómez, I. Andrés-Doménech, D. Corenblit, G. Egger, F. Francés, M.T. Ferreira, et al. 2017. ¿Exploring the Key Drivers of Riparian Woodland Successional Pathways across Three European River Reaches.¿ Ecohydrology 10 (8). Wiley: e1888. doi:10.1002/eco.1888, which has been published in final form at https://doi.org/10.1002/eco.1888. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.", [EN] Climate change and river regulation are negatively impacting riparian vegetation. To evaluate these impacts, process-based models are preferred over data-driven approaches. However, they require extensive knowledge about ecohydrological processes. To facilitate the implementation of such process-based models, the key drivers of riparian woodland successional pathways across three river reaches, in Austria, Portugal, and Spain, were explored, employing two complementary approaches. The principal component analyses highlighted the importance of the physical gradients determining the placement of the succession phases within the riparian and floodplain zones. The generalized additive models revealed that the initial and pioneer succession phases, characteristic of the colonization stage, appeared in areas highly morphodynamic, close in height and distance to the water table, and with coarse substrate, whereas elder phases within the transitional and mature stages showed incremental differences, occupying less dynamic areas with finer substrate. The Austrian site fitted well the current successional theory (elder phases appearing sequentially further up and distant), but at the Portuguese site, the tolerance of the riparian species to drought and flash flood events governed their placement. Finally, at the Spanish site, the patchy distribution of the elder phases was the remnants of formative events that reshaped the river channel. These results highlight the complex relationships between flow regime, channel morphology, and riparian vegetation. The use of succession phases, which rely on the sequential evolution of riparian vegetation as a response to different drivers, may be potentially better reproducible, within numerical process-based models, and transferable to other geographical regions.

Habitat management and restoration in buffer zones of national parks is critical for maintaining ecosystem services and biological connectivity in and around the parks’ core protected areas. Vegetation succession in abandoned plantations in buffer zones may take different paths that reach climax ecosystems in more or less time depending on the conditions of initial succession, thus enhancing or hindering biological connectivity and ecosystem services. This study documents the dominance of tree ferns in the initial stages of vegetation succession on abandoned pineapple plantations on the Andean foothills around Manu National Park, Peru, and discusses the role it may have on ecosystem restoration. Four years after abandonment, tree fern gametophytes grow under the shade of pineapple plants and melastomes. After 6-10 years of succession, the vegetation is dominated by a tree fern community composed of at least eight species, of which the most common are by far Cyathea delgadii and Cyathea microdonta. Cyathea microdonta functions as a short-lived pioneer, reaching its peak of live stem density in 6 to10 years and dying off in older plots. Cyathea delgadii, on the other hand, continues to grow and persists beyond 10 years of succession. Areas adjacent to abandoned pineapple fields have few tree ferns and higher tree species diversity, suggesting that pineapple agriculture and the resulting tree fern community may be a longer pathway to reach climax vegetation stages than other types of plantation., El manejo y la restauración de hábitats en áreas de amortiguamiento de parques nacionales son críticos para mantener los servicios ecosistémicos y la conectividad biológica alrededor de las zonas núcleo de las áreas protegidas. La sucesión ecológica en plantaciones abandonadas en áreas de amortiguamiento pueden seguir cursos diferentes que alcanzan estabilidad en más o menos tiempo en dependencia de las condiciones iniciales de la sucesión, mejorando u obstaculizando los servicios ecosistémicos y la conectividad biológica. Este estudio documenta la dominancia de los helechos arborescentes en las etapas iniciales de la sucesión ecológica en piñales abandonados en el piedemonte Amazónico de los Andes en el Parque Nacional del Manu. Cuatro años después del abandono de las plantaciones, los gametofitos de helechos arborescentes se encuentran creciendo a la sombra de plantas de piña y de la familia Melastomataceae. Después de 6–10 años de sucesión, la vegetación aparece dominada por una comunidad de helechos arborescentes de al menos ocho especies, entre las cuales las más comunes son Cyathea delgadii y Cyathea microdonta . Cyathea microdonta funciona como una especie pionera de vida corta, alcanzando su pico de densidad a los 6–10 años y prácticamente desapareciendo en parcelas más antiguas. Cyathea delgadii, por otro lado, continua creciendo y persiste más allá de los diez años. Las áreas adyacentes a los piñales abandonados muestran relativamente pocos helechos arborescentes y mayor diversidad de árboles, lo cual sugiere que el cultivo de piña y la comunidad de helechos arborescentes que le sucede puede ser un mecanismo de sucesión más largo hacia la recuperación de la vegetación clímax que otros tipos de cultivos.

The Frisian islands (Southern North Sea) have extensive island tails, i.e. the entire downdrift side of an island consisting of salt marshes, dunes, beaches and beach plains, and green beaches. Currently, large parts of these tails are ageing and losing dynamics, partly due to human influence. This may mean a loss of young stages on the long term, and current management is not enough to counteract this. To aid the development of new interventions aiming at (re)introducing natural dynamics, a conceptual model of island-tail development under natural and disturbed conditions was developed, based on existing data, field visits and literature. The development of an island tail follows the general pattern of biogeomorphic succession. The first phase consists of a bare beach plain. In the second phase, embryonic dunes form. In the third phase, green beaches, dunes and salt marshes form, including drainage by creeks and washovers. In the fourth phase, vegetation succession continues and the morphology stabilises. Human interference (such as sand dikes and embankments) reduces natural dynamics and increases succession speed, leading to a reduction in the diversity in landforms and vegetation types. Both for natural and human-influenced island tails, succession is the dominant process and large-scale rejuvenation only occurs spontaneously when large-scale processes cause erosion or sedimentation. Island tails cannot be kept permanently in a young successional stage by reintroducing natural dynamics through management interventions, as biogeomorphic succession is dominant. However, such interventions may result in local and temporal rejuvenation when tailored to the specific situation.

The paper presents the results of Quaternary palaeoecology and geoarchaeology studies in the Zerkal'naya Basin, with new insights about sequenced natural shifts during the prehistoric occupation of this marginally explored NE Asian maritime territory. The Basin is part of the continental drainage system and the main physiographic and biotic corridor for peopling of the transitive coastal interior SE Primor'ye Region. The Final Pleistocene and Holocene environmental (biotic and abiotic) proxy records from the Upper/Final Palaeolithic to early historical sites document a dynamic climate change with vegetation cover transformations within riverine and mountain valley ecosystems of the Russian Far East. Most of the archaeological sites located on the low terraces and bedrock promontories along the main river channel and its tributary streams suggest traditional hunter gathered lifestyles based on seasonal salmon-fishing supplemented by pastoral economy.Tundra-forests with larch trees, dwarf birch thickets and polypod ferns from the basal stratigraphic units of the late Last Glacial occupation sites associated with the Upper Palaeolithic micro-blade and bifacial stone tool traditions (14C-dated to 19,000-12,000 cal yrs BP) indicate rather pronounced conditions and much lower MAT comparing today. Following a final Pleistocene cooling event, a major climate warming marked the onset of Holocene accompanied by a regional humidity increase promoting the formation of a mixed broadleaved-coniferous oak-dominant taiga, and culminating in the mid-Holocene Climatic Optimum. The appearance of mosaic parklands ca. 5,000-4,000 cal yrs BP. may be partly attributed to the expansion of the Far Eastern Neolithic cultures practicing forest clearance for pastures and dwellings. A progressing landscape opening indicated by the spread of light-demanding thickets and birch-dominated riverine biotopes with Artemisia suggests a further vegetation cover transformation during the late Neolithic a

The paper presents the results of Quaternary palaeoecology and geoarchaeology studies in the Zerkal'naya Basin, with new insights about sequenced natural shifts during the prehistoric occupation of this marginally explored NE Asian maritime territory. The Basin is part of the continental drainage system and the main physiographic and biotic corridor for peopling of the transitive coastal interior SE Primor'ye Region. The Final Pleistocene and Holocene environmental (biotic and abiotic) proxy records from the Upper/Final Palaeolithic to early historical sites document a dynamic climate change with vegetation cover transformations within riverine and mountain valley ecosystems of the Russian Far East. Most of the archaeological sites located on the low terraces and bedrock promontories along the main river channel and its tributary streams suggest traditional hunter gathered lifestyles based on seasonal salmon-fishing supplemented by pastoral economy.Tundra-forests with larch trees, dwarf birch thickets and polypod ferns from the basal stratigraphic units of the late Last Glacial occupation sites associated with the Upper Palaeolithic micro-blade and bifacial stone tool traditions (14C-dated to 19,000-12,000 cal yrs BP) indicate rather pronounced conditions and much lower MAT comparing today. Following a final Pleistocene cooling event, a major climate warming marked the onset of Holocene accompanied by a regional humidity increase promoting the formation of a mixed broadleaved-coniferous oak-dominant taiga, and culminating in the mid-Holocene Climatic Optimum. The appearance of mosaic parklands ca. 5,000-4,000 cal yrs BP. may be partly attributed to the expansion of the Far Eastern Neolithic cultures practicing forest clearance for pastures and dwellings. A progressing landscape opening indicated by the spread of light-demanding thickets and birch-dominated riverine biotopes with Artemisia suggests a further vegetation cover transformation during the late Neolithic a

We investigated spontaneous vegetation succession and the relationship between time and vegetation patterns in several abandoned quarries of the Botticino extraction basin (Lombardy, Italy) and then assigned plant assemblages to a predetermined theoretical successional phase using an original procedure. To recognise and validate the gradient due to time, an ordination approach of vegetation plots linked to constant variables and time since last mining Canonical Correspondence Analysis was conducted first. Then, to determine the durations of the vegetation succession phases and trends between the colonisers and late successional species, we used an original six-step procedure based primarily on the regression curve of the percent relative abundance of life forms (RALFs) over time. The results demonstrated that time is the primary factor that significantly affects life form turnover during succession. Vegetation establishment and development in the “pioneer phase” (0–6 years) were affected by abiotic filters, which determined the dominance of a few ruderal and annual/alien species, mostly therophytes. The successive phases were characterised by an increasing presence of perennial species (mostly phanerophytes) with a consequent influence of biotic filters. The RALF procedure may be applied to other environments to investigate the time trends of plant communities during successions.

Policy-oriented successive land use conversion intensively occurred in seasonally frozen zones of China during the past five decades. However, responses of soil carbon (C) and nitrogen (N) to land use conversion under cold temperate climates are not fully understood. The objective was to characterize C and N variations following a succession of forest, dryland and paddy. Soil cores were collected for 6 layers with a 10 cm increment from three adjacent chronosequences to determine concentrations of soil organic carbon (SOC), total nitrogen (TN), dissolved organic carbon (DOC) and alkaline hydrolysable nitrogen (HN). Analysis of variance with multivariate general linear model was operated on data sets. Significant losses of SOC and TN storages subject to land use conversion were merely confined within 0 - 10 cm layer, decreasing by 16 % and 38 % for forest to dryland and by 23 % and 43 % for forest to paddy, respectively. Cultivation also influenced SOC and TN stocks at 20 - 40 cm depth for dryland and 20 - 60 cm depth for paddy with increases by 38 Mg C ha(-1) and 2.8 Mg N ha(-1) for forest to dryland, and by 56 Mg C ha(-1) and 4.1 Mg N ha(-1) for forest to paddy, respectively. Successive land use conversion from forest to cropland affected C and N levels in deeper layers, demonstrating the high potentials of subsoil in sequestrating C and N. The extents of cultivation-induced SOC and TN redistribution along soil profile varied among different agricultural systems. DOC and HN changes interpreted SOC and TN changes with land use, presenting high involvements of soluble compartments in SOC and TN variations. The net variation in SOC/TN ratio effectively indicated C and N changes when dryland was converted to paddy.

Trends in the proportions of plants differently interacting with mycorrhizal fungi in the course of pasture digression have been analyzed in the steppe zone of the Southern Urals. Estimates of species richness and abundance of plant groups with different mycorrhizal status have been obtained by comparing original data on the structure of phytocenoses with published data on the ability of plant species to form mycorrhizae. It has been shown that the proportions and abundance of obligate mycorrhizal species decrease significantly in the course of digression, with consequent increase in those of species less dependent on or independent of symbiosis with fungi, i.e., facultative mycorrhizal or obligate nonmycorrhizal plants. © 2013 Pleiades Publishing, Ltd.

Mining and extraction of metals generates huge amounts of tailings waste (a mixture of water, finely ground ore rock and processing effluents, which remains after removal of mineral concentrate). Unfortunately, accidental release of mine tailings into river systems and their further deposition in floodplains, often over arable land, has been reported from many parts of the world, with environmental implications difficult to predict. Mine tailings from sulphidic metal ores combine high potential for generating soil acidity, and high concentrations of plant available heavy metals, which are the two most intractable issues in restoration of post-mining sites. On the other hand, barren land degraded by mining waste provides an exciting opportunity to reveal some important ecological principles which might not be apparent under ?normal? conditions. Understanding of the process of primary vegetation succession is in particular crucial for the practice of ecological restoration, which is increasingly seen as a preferable alternative to technical reclamation of land degraded by mining. This work addresses the two major issues relevant for ecology and restoration of alluvial arable land polluted by mining waste, which have so far been very poorly understood: Firstly, the long-term fate of contaminants and their actual impact on soil quality and crop production under true field conditions. Secondly, the process of spontaneous revegetation of barren land under the extreme soil conditions and the environmental setup considerably different from the well-studied Central European. The explorative study was undertaken on an exceptional locality created by long-term and large scale-fluvial deposition of sulphidic copper (Cu) tailings over alluvial fields in Eastern Serbia. Comprehensive surveys of spontaneous vegetation, weed assemblages and cereal crops (species cover-abundance; biomass per m2; and foliar mineral analyses), and concomitant surveys of rhizosphere soils (31 physical, Bergbau und Erzgewinnung erzeugen ungeheure Mengen an Abraum (eine Mischung aus Wasser, Grundgestein, Prozessabwässern, die nach dem Metallaufschluss verbleiben). Unglücklicherweise geschieht es immer wieder, dass Bergbau Schlämme in die Vorfluter gelangen, sich in den Auen absetzen oft auch auf fruchtbaren landwirtschaftlichen Flächen. Derartige Unfälle werden aus aller Welt immer wieder gemeldet mit nicht vorhersehbaren Folgen für die Umwelt. Schlämme sulfidischer Metalle haben ein hohes Potenzial für Bodenversauerung und hohe Konzentrationen pflanzenverfügbarer Schwermetalle. Das sind die größten Probleme bei der Restaurierung ehemaliger Bergbaugebiete. Auf der anderen Seite bieten durch Bergbau und dessen Abfälle verwüstete Gebiete die Möglichkeit ökologische Prinzipien zu entdecken, die unter ?normalen? Bedingungen nicht so offensichtlich erscheinen. Das Verständnis für die primäre Sukzession der Vegetation ist besonders wichtig für die Restaurations-Ökologie, die zunehmend als Alternative gegenüber rein technischen Wiederherstellungsmaßnahmen für degradierte Bergbaustandorte zu sehen ist. Diese Arbeit behandelt vornehmlich zwei für die Restaurierung von Auenflächen, die mit Bergbauschlämmen bedeckt wurden, wichtige Feststellungen, die bisher kaum geklärt wurden: erstens, das Langzeitverhalten der kontaminierenden Substanzen auf Bodenqualität und Getreide-Produktion unter Feldbedingungen. Zweitens, den Entwicklungsprozess spontaner Vegetation auf Offenland unter extremen Bodenbedingungen und Umweltbedingungen die beachtlich von den sehr gut bekannten Mitteleuropas abweichen. Diese Untersuchung wurde auf einem außergewöhnlichen Standort durchgeführt, der sich durch langzeitliche und großflächige Auen-Deposition von sulfidischen Kupfer-Schlämmen (Cu) über Alluvionen in Ost-Serbien auszeichnet. Gründliche Untersuchungen der spontanen Vegetation (Arten-Gemeinschaften) und Getreide (Abundanz-Dominanz der Arten; Biomasse pro m2 und Blatt-Mineral-Analysen), Analyse de

We surveyed plant community development at the abandoned Ogushi sulfur mine. We found seven communities dominated by the following respective species: Deschampsia flexuosa, Miscanthus sinensis, shrub willow, Gaultheria miqueliana-Betula ermanii, Sasa senanensis-Betula ermanii, willow-Betula ermanii, and Sasa kurilensis-Abies veitchii. We examined the succession of these communities, in which younger communities of low height and ground cover contained seedlings of the successive communities that were taller and had higher ground cover. To understand the development of these different communities, we surveyed damage from mining pollution and effects of immature soils formed by landslides. The average pH (H(2)O) was 4.12, and aluminum concentrations were not sufficiently high to damage plant growth, except in areas where sulfur had been mined. The organic carbon and nitrogen content in soil samples were very low because of a delay in soil development caused by a large landslide in 1937. Hence, succession was positively correlated with the soil development stage. The delay in soil development after a large landslide influenced the seven successional steps of the plant communities, but mineral poisons at the abandoned Ogushi sulfur mine had no effect on succession.

Four populations of Saponaria bellidifolia situated at the species’ northern range periphery (Apuseni Mountains, southeastern Carpathians) were monitored over a period of 5 years. They were chosen to represent different habitat types (rocky, fixed screes, open screes and grassy), disturbance regime (fire), and population sizes (categorized as large and small). The reproductive effort was quantified, and matrix models were used to describe the population dynamics and to assess population viability. Saponaria bellidifolia had very stable population dynamics in the harsh and stable abiotic conditions of the outcrops where populations occur. Habitat conditions exerted a notable influence on the species’ population reproductive performance, growth rate, and vital rates, whereas population size and climate did not have a clear-cut effect on the dynamics of the species. Saponaria bellidifolia maintains viable populations in the southeastern Carpathians, at its northern range periphery.

Forests line the course of the Kuiseb River, an ephemeral river in the Namib Desert, and several areas of these forests are characterized by high concentrations of tree death (Mizuno, 2005; Mizuno & Yamagata, 2005). We sought to clarify the relationship between recent environmental changes and such tree deaths in the region. In November 2007, we examined the roots of a seedling of Acacia erioloba that was germinated by rainfall beginning in January 2006. The Acacia erioloba had grown to a height of 10cm and its roots to over 230cm, within two years. In the sapling (seedling) stage, Acacia erioloba extends its main roots deeply until it reaches a moist, fine-grained soil layer (sandy silt) and can absorb water through lateral roots. When it reaches the stage at which the water supply from the moist, fine-grained soil layer is insufficient for its growing size, the tree extends innumerable lateral roots within a 50cm depth from the land surface, where they absorb water that has been transported to a shallow depth by fog and other sources. Acacia erioloba dies when its lateral roots are unable to absorb water. Until the mid-1970s, successive floods repeatedly deposited fine-grained materials (e.g., sandy silt) that create water-bearing sediments for the growth of Acacia erioloba, and the trees died only rarely. However, from 1980 to 1985 these materials became increasingly scarce due to the decreasing occurrence of flooding, and consequently many trees died. It is reasonable to infer that the trees died because fine sediments were no longer being regularly deposited, and because of the drawdown of the groundwater level, both of which are making it difficult for the shallow roots of the trees to absorb the water necessary to survive.

Forests line the course of the Kuiseb River, an ephemeral river in the Namib Desert, and several areas of these forests are characterized by high concentrations of tree death (Mizuno, 2005; Mizuno & Yamagata, 2005). We sought to clarify the relationship between recent environmental changes and such tree deaths in the region. In November 2007, we examined the roots of a seedling of Acacia erioloba that was germinated by rainfall beginning in January 2006. The Acacia erioloba had grown to a height of 10cm and its roots to over 230cm, within two years. In the sapling (seedling) stage, Acacia erioloba extends its main roots deeply until it reaches a moist, fine-grained soil layer (sandy silt) and can absorb water through lateral roots. When it reaches the stage at which the water supply from the moist, fine-grained soil layer is insufficient for its growing size, the tree extends innumerable lateral roots within a 50cm depth from the land surface, where they absorb water that has been transported to a shallow depth by fog and other sources. Acacia erioloba dies when its lateral roots are unable to absorb water. Until the mid-1970s, successive floods repeatedly deposited fine-grained materials (e.g., sandy silt) that create water-bearing sediments for the growth of Acacia erioloba, and the trees died only rarely. However, from 1980 to 1985 these materials became increasingly scarce due to the decreasing occurrence of flooding, and consequently many trees died. It is reasonable to infer that the trees died because fine sediments were no longer being regularly deposited, and because of the drawdown of the groundwater level, both of which are making it difficult for the shallow roots of the trees to absorb the water necessary to survive.

火山性撹乱地における植生の再生過程と、菌根形成の実態、菌種構成の把握、菌接種試験を通じて、植物の定着に菌根共生が与える影響を明らかにした。調査地は2000年に噴火した有珠山の西山火口付近とした。スギナやオオイタドリ、アキタブキなどの多年生植物が、噴火直後から広範囲に裸地に侵入し、被覆を増加させていた。木本植物ではドロノキ、オノエヤナギ、エゾノバッコヤナギが優占し、着実に成長していた。全ての植物種において菌根形成が確認された。スギナ、オオイタドリにおける菌根の形成頻度は低かったが、その他の植物種では高い値を示していた。ヤナギ科3種では、全個体で外生菌根（ECM）が確認され、ウラムラサキ、ワカフサタケ、イボタケ、ラシャタケ属菌が比較的高い形成割合を示していた。接種試験より、優占的に確認された菌種は、樹高、各器官部乾燥重量、根長を増加させることが明らかとなった。噴火直後の植生再生初期の立地においても、侵入してきた植物は高頻度で菌根を形成しており、ECM共生がヤナギ科木本植物の成長を促進させていると考えられた。

Conservation of rare habitats and species are central elements in the management of semi-natural grasslands of high biodiversity. Understanding the impacts of various abiotic and biotic interactions and management methods on threatened species is fundamental to their conservation. In the present study, effects of competition, plant parasitism, grazing and mowing were studied at the community level in Bothnian Bay coastal meadows and in greenhouse. This was the first time when the impacts of various biotic interactions on the critically endangered creeping alkali grass (Puccinellia phryganodes) have been explored in detail in one of its rare occurrences in the boreal vegetation zone in Europe. In addition, questions related to ecological and economical sustainability of cattle grazing on coastal meadows were examined. Puccinellia phryganodes was found to suffer severely from competition with taller graminoids. Simulated and actual grazing by greylag goose, Anser anser, as well as infection by a hemiparasitic plant, Odontites litoralis, were found to indirectly benefit P. phryganodes by decreasing the competitive advantage of its competitors. In spite of the relatively intensive grazing by greylag goose in the field, P. phryganodes experienced a drastic decrease during four years in the grazed experimental quadrats and simultaneously the proportion of the taller graminoids increased substantially. Primary succession of coastal meadow vegetation was found to progress rapidly and continuous formation of suitable open habitats is therefore crucial for the subordinate species. Mowing was found to be an effective management method for some threatened plant species in coastal meadows, but not for P. phryganodes, which would probably benefit more, for example, from livestock grazing. Both lightly and rather intensively managed large open meadows could provide optimal habitats for the critically endangered lesser white fronted goose (Anser erythropus) as well as for

Long-term vegetation succession and permafrost dynamics in subarctic peat plateaus of west-central Canada have been studied through detailed plant macrofossil analysis and extensive AMS radiocarbon dating of two peat profiles. Peatland inception at these sites occurred around 5800-5100 yr BP (6600-5900 cal. BP) as a result of paludification of upland forests. At the northern peat plateau site, located in the continuous permafrost zone, palaeobotanical evidence suggests that permafrost was already present under the forested upland prior to peatland development. Paludification was initiated by permafrost collapse, but re-aggradation of permafrost occurred soon after peatland inception. At the southern site, located in the discontinuous permafrost zone, the aggradation of permafrost occurred soon after peatland inception. In the peat plateaus, permafrost conditions have remained very stable until present. Sphagnum fuscum-dominated stages have alternated with more xerophytic communities characterized by ericaceous shrubs. Local peat fires have occurred, but most of these did not cause degradation of the permafrost. Starting from 2800-1100 yr BP (2900-1000 cal. BP) consistently dry surface conditions have prevailed, possibly related to continued frost heave or nearby polygon crack formation.

Based on field investigations in the East River basin in Guangdong Province, south China, the processes of vegetation development and vegetation succession on bare slopes with high erosion rates are studied. Different reforestation measures have been applied to the slopes, which have resulted in very different processes of vegetation development and succession. On an experimental plot with burned forest but surviving roots, the vegetation restored naturally and quickly because there was little soil erosion. However, in the plots suffering from long-term severe soil erosion, natural vegetation recovery on these barren slopes is very slow. After 26 years, a barren slope has only been partly colonized by poorly developed vegetation composed of heliophilous herbages and scattered shrubs. On the other hand, plantation of some selected wood species on the slope land has dramatically accelerated the vegetation recovery and succession. The plots were reforested with plantation of Acacia auriculiformis in the early 1980s. Twelve years later, the vegetation cover of the artificial forests reached 90% and an understory vegetation community consisting of local species had naturally developed. Reforestation with suitable strategies may control erosion and greatly accelerate vegetation succession in the eroded slope land in the subtropical zones. © 2007 Elsevier B.V. All rights reserved.

Based on field investigations in the East River basin in Guangdong Province, south China, the processes of vegetation development and vegetation succession on bare slopes with high erosion rates are studied. Different reforestation measures have been applied to the slopes, which have resulted in very different processes of vegetation development and succession. On an experimental plot with burned forest but surviving roots, the vegetation restored naturally and quickly because there was little soil erosion. However, in the plots suffering from long-term severe soil erosion, natural vegetation recovery on these barren slopes is very slow. After 26 years, a barren slope has only been partly colonized by poorly developed vegetation composed of heliophilous herbages and scattered shrubs. On the other hand, plantation of some selected wood species on the slope land has dramatically accelerated the vegetation recovery and succession. The plots were reforested with plantation of Acacia auriculiformis in the early 1980s. Twelve years later, the vegetation cover of the artificial forests reached 90% and an understory vegetation community consisting of local species had naturally developed. Reforestation with suitable strategies may control erosion and greatly accelerate vegetation succession in the eroded slope land in the subtropical zones. © 2007 Elsevier B.V. All rights reserved.

Studies in tropical regions have shown that trees and grasses respond differently to fire, grazing and browsing. In African savannas, the responses to fire, grazing and browsing are different, determined by negative or positive correlations. Browsing may have other consequences than grazing because instead of increasing woody biomass it reduces it, causing increase in grass growth, leading to increase in fuel that results in more intense fires and decrease in woody biomass. Fire and herbivory are an important interactive disturbance factors affecting vegetation succession and the tree-grass dynamics in savanna environment. Several of the fire-herbivory interactions are landscape level effects, which is shown in 2 models. My hypothesis is that the tree-grass balances are determined by interactions of both grazing and fire. There have come new scientific data about fire and herbivory and the interaction effects on tree-grass dynamic and succession in the savanna. By analyzing my hypothesis through a comparison between hypotheses, Intermediate disturbance hypothesis, Janzen-Connell hypothesis and the Huston hypothesis, I propose several scenarios of the savanna tree-grass dynamics in East Africa, as a result of this comparison.

The aim of this study was to clarify the relationship between environmental change and vegetational succession in the Kuiseb River area of the Namib Desert. The results reveal the following: 1. About 5000–7000 years ago, wetter conditions prevailed in the Kuiseb River basin, forming a wider riverbed than at present. 2. About 600 years ago, a low terrace formed. The low terrace was characterized by the growth of acacia trees and other vegetation, which trapped and accreted aeolian sand. 3. About 400 years ago, the trapped and accumulated sand began to form a sand dune, eventually killing the tree population. 4. At the present time, all of the buried acacia trees have died and have been replaced by salvadora bushes, which continue to trap sand and increase the size of the dune. 5. Plants such as Acacia erioloba, Faidherbia albida, and Acanthosicyos horridus are very important food sources and shade plants for the local Topnaar people and their livestock. The succession of vegetation in response to environmental change has a profound impact on life in the Kuiseb River area, owing to the harsh environmental conditions and scarce plant life in the region.

The aim of this study was to clarify the relationship between environmental change and vegetational succession in the Kuiseb River area of the Namib Desert. The results reveal the following: 1. About 5000–7000 years ago, wetter conditions prevailed in the Kuiseb River basin, forming a wider riverbed than at present. 2. About 600 years ago, a low terrace formed. The low terrace was characterized by the growth of acacia trees and other vegetation, which trapped and accreted aeolian sand. 3. About 400 years ago, the trapped and accumulated sand began to form a sand dune, eventually killing the tree population. 4. At the present time, all of the buried acacia trees have died and have been replaced by salvadora bushes, which continue to trap sand and increase the size of the dune. 5. Plants such as Acacia erioloba, Faidherbia albida, and Acanthosicyos horridus are very important food sources and shade plants for the local Topnaar people and their livestock. The succession of vegetation in response to environmental change has a profound impact on life in the Kuiseb River area, owing to the harsh environmental conditions and scarce plant life in the region.

Studies in tropical regions have shown that trees and grasses respond differently to fire, grazing and browsing. In African savannas, the responses to fire, grazing and browsing are different, determined by negative or positive correlations. Browsing may have other consequences than grazing because instead of increasing woody biomass it reduces it, causing increase in grass growth, leading to increase in fuel that results in more intense fires and decrease in woody biomass. Fire and herbivory are an important interactive disturbance factors affecting vegetation succession and the tree-grass dynamics in savanna environment. Several of the fire-herbivory interactions are landscape level effects, which is shown in 2 models. My hypothesis is that the tree-grass balances are determined by interactions of both grazing and fire. There have come new scientific data about fire and herbivory and the interaction effects on tree-grass dynamic and succession in the savanna. By analyzing my hypothesis through a comparison between hypotheses, Intermediate disturbance hypothesis, Janzen-Connell hypothesis and the Huston hypothesis, I propose several scenarios of the savanna tree-grass dynamics in East Africa, as a result of this comparison.

The vegetation in a retrogressive thaw slump, first surveyed and documented in 1987, was revisited 10 years later to investigate its subsequent development and to test a chronosequence-based successional model. The thaw slump stabilized in 1994, when the headwall became covered by organic and mineral debris. As a result, the meltwater supply from headwall ablation ceased. Alteration of environmental conditions due to stabilization of the headwall diverted the vegetation succession from the chronosequence determined in 1987. Areas that were marshy in 1987 dried up, and an area dominated by Polygonum alaskanum appeared close to the headwall. Much of the thaw slump was dominated by Salix spp. in 1997, rather than the Equisteum of 1987. However, the ground more than 200 m from the headwall, over a decade old in 1987, experienced less change in edaphic conditions, and the communities there continued to develop a structure approaching the surrounding undisturbed forest.

The species composition, the above-ground biomass of woody plants, herbs and mosses, and the age-structure of trees and shrubs were studied in an Alnus glutinosa and a Betula pubescens dominated patch of wetland forest in the nature reserve ‘Het Molenven’, The Netherlands. These patches were more or less similar in stand age and height of the water table, but differed in nutrient content of the substrate. Insight into the vegetational history of these sites was obtained by analysing the micro-fossils and macro-remains embedded in the peat. Man’s impact on the hydrology of the reserve triggered the observed changes in vegetation in both woodland patches. The different routes in vegetation succession and the differences in above-ground phytomass observed between the two sites can be explained, at least in part, by the differences in chemistry of the substrate. Betula pubescens seems to be more sensitive to a rise in water table than Alnus glutinosa, Frangula alnus and Salix cinerea, particularly because of its poorly developed ability to rejuvenate under water-logged conditions.