Vegetation succession on the dunes near Oostvoorne,The Netherlands,since 1934, interpreted from air photographs and vegetation maps

The vegetation succession on the dunes near Oostvoorne, The Netherlands has been followed by means of a novel combination of repeated large-scale vegetation mapping and air photograph interpretation. Vegetation units have been discerned on the formation level because these could be distinguished fairly easily on the photographs and because the rates of change are appropriate to the time interval chosen. Nineteen formations were distinguished. Five 1:6250 maps were constructed, reflecting the formation pattern in 1934, 1943, 1959, 1972 and 1980. An overlay with 2736 grid points at 25 m field distance was used to quantify changes in the formation pattern.The results suggest a pronounced multiple pathway succession with nevertheless three principal trajectories of succession from pioneer to woodland vegetation. The outer dunes, which have originated since 1910, are distinct in successional characteristics from the inner dunes, which already existed but were released from heavy grazing pressure in 1910. The rate of change in the outer dunes was high in the beginning and is slowly decreasing eversince. In the inner dunes it went the other way around. Through visual extrapolation the likely formation patterns in 1910 and in 2000 were estimated.Transition frequencies proved highly variable for most formations. Moreover, strong spatial dependence was found. Limitations in the use of Markov models in cases of long-term succession in heterogeneous environments are discussed.Nomenclature follows the same sources as in van der Maarel et al. (1984).Field work carried out 1980–1981 when the authors were at the Division of Geobotany, University of Nijmegen. We thank Jos Rijntjes, Nijmegen, for his cooperation in the field. Vegetation maps were prepared and calculations performed at Uppsala. We thank the Foundation Het Zuid-Hollands Landschap, Rotterdam, for providing facilities and a grant for fieldwork as well as additional means to reproduce the vegetation maps. Two reviewers gave useful comments.     

Vegetation differentiation and secondary succession on a limestone hill in southern Poland

Abstract. The vegetation of the SkoHzanka Reserve, situated on a limestone hill near Krakow, was examined over a 30 year period, using the Braun-Blanquet method. With the help of a numerical classification eight types of grassland communities were distinguished, belonging to the classes Sedo-Scleranthetea, Nardo-Callunetea and Festuco-Brometea, and 11 types of woodland communities, both remnants of ancient woodlands from the classes Querco-Fagetea and Vaccinio-Piceetea and more recent woods. In the case of grasslands the results of detrended correspondence analysis (DCA) indicated that the largest variation was associated with the soil type. Woods on sandy soils are very different from those on calcareous soils, and the younger recent woods are very different from the ancient woodlands. An analysis of historical cartographic material and aerial photographs shows that in the last few decades the area of recent woods has increased considerably at the expense of grasslands. Changes in species diversity in the woods during secondary succession and their successional convergence were examined and discussed. It was found that young and mature woods on sandy soils are more similar to each other than young and mature woods on calcareous soils. These differences are mainly related to the fact that many woodland herb species growing in rich, broadleaved ancient woods are unable to colonize recent woods since they have a limited colonization capacity.     

Climate and pH as determinants of vegetation succession in Central European man‐made habitats

Questions: (1) What are the most important abiotic environmental variables influencing succession in central European man‐made habitats? (2) How do these variables interact with one another and with variation in community properties? Location: Central, western and southern parts of the Czech Republic. Habitats included old fields, urban sites, spoil heaps after coal mining, sites at water reservoirs, extracted sand pit and peatland and reclaimed sites in areas deforested by air pollution. Methods: We investigated vegetation patterns on 15 succes‐sional seres, sampled by the same methods. Time of succession over which the data were available ranged from 12 to 76 years. The cover of vascular plant species (in %) was estimated in 5 m × 5 m plots. The relationships between vegetation characteristics (species composition, total cover, cover of woody species, species number and rate of dominant species turnover) and 13 abiotic site factors, including climatic and soil variables, were tested using CCA ordination and regression models. Results: Substratum pH, the only substratum characteristic, and climate were the environmental variables significantly affecting the vegetation patterns in the course of succession. The rate of succession, measured as the turnover of dominant species, was significantly more rapid in lowland than in mountain climates. On alkaline soils, species numbers in succession increased towards warmer climates. However, acid soils prevented any increase in species numbers, regardless of the climate. Surprisingly, forms of nitrogen and contents of C, P and cations did not exhibit any significant effect on the vegetation characteristics studied. Conclusions: Our approach, to compare a number of seres, can contribute not only to our understanding of succession, but also to help restoration projects to predict vegetation change because the crucial environmental variables, as identified by this study, are easy to measure.     

云南大山包黑颈鹤自然保护区草甸植被的数量分类和排序

在法瑞学派样地调查法的基础上,采用双向指示种分析（TWINSPAN）和趋势对应分析（DCA）对大山包黑颈鹤自然保护区草甸植被进行数量分类和排序研究。调查样地包含114个物种,分属31科72属,其中禾本科（14种）、菊科（13种）、蓼科（8种）、石竹科（6种）、玄参科（6种）等科所含物种较多。经TWINSPAN分类,106个样地分为20个聚组,根据其指示种确定为20个群丛。样地DCA和物种DCA排序结果反映了植物群丛与指示种之间的一致关系,排序轴的生态学意义说明水分和海拔两个环境因子同时影响该区草甸植被的分布。     

广西阳朔岩溶植被演替过程种群变化及物种多样性

采用时空替代法研究广西阳朔岩溶植被在演替过程中的种群变化和物种多样性。研究表明,随着演替的进展,耐荫种群增加,乔木种群增加,优势种的更替呈现出一定的连续性,后一演替阶段的优势种往往已经隐含在前一演替阶段中;物种丰富度随演替进展表现出草丛<落叶阔叶林<灌丛<常绿落叶阔叶混交林的趋势;灌木层的物种丰富度在各演替阶段中均是最高的;在各演替阶段中,落叶阔叶林阶段的群落均匀度均表现为最大。     

Changes in soil and vegetation following stabilisation of dunes in the southeastern fringe of the Tengger Desert, China

Properties of the soil and sand-binding vegetation were measured at five sites plus a control on dunes of the Tengger Desert stabilized for periods of up to 50 years. In the topsoil, fine particles, total N, P, K and organic matter increased significantly with increasing site age. However, there were no significant changes in deeper soil profiles (>0.4 m depth). Soil pH, calcium carbonate content, and total salt content tended to increase with age. Soil water in the topsoil changed little with increasing age, but was closely related to rainfall during the 50-year period. For deeper soil layers (0.4–3.0 m) soil water decreased significantly with age. After revegetation, the number of herbaceous species increased up to 30 years and then levelled off to 12–14 species, whereas the number of shrub species decreased from the 10 initial sand-binding species to only 3 species. Shrub cover decreased from a highest average of about 33% to the current 9%, whereas cover and biomass of herbaceous species increased throughout succession from 1956 to 2006. The development of soil and cryptogamic crusts on the surface of stabilized dunes enhanced the colonization and establishment of herbaceous plants due to increasing water availability, clay and silt content and soil nutrients. We propose that changes in properties of the surface soil led to increased interception of water, favoring shallow rooted grasses and forbs over perennial shrubs.     

Quantitative Classification and Ordination of Meadow Vegetation in Dashanbao Black necked Crane Nature Reserve,Yunnan

Based on the Braun Blanquet method of Relev é synthesis, TWINSPAN quantitative classification and DCA ordination of meadow vegetation was studied in Dashanbao Black necked Crane Nature Reserve. Finally, samples contained 114 species which belong to 31 families and 72 genus. The most abundant families were Poaceae, Asteraceae, Polygonaceae, Caryophyllaceae, and Scrophulariaceae. One hundred and six samples were categorized into 20 groups and divided into 20 associations according to the indicator species. The result of samples and species DCA ordination inflected the consistent relationship between the associations and indicator species. The ecological explanation of ordination axis illustratted that both of the soil moisture and elevation affected the distribution of meadow vegetation in this area.     

The relationship between the soil seed bank and above-ground vegetation of a coastal barrier island

Abstract. The germinable soil seed bank is described from a coastal barrier island off the northwest coast of Florida, USA. Soil samples collected from seven vegetation types, recently deposited dredge spoil and unvegetated areas in autumn 1990 and spring 1991 were placed out in greenhouse trays. 110 taxa germinated from the samples with the largest number (41) being C₃ perennial dicots. The largest number of taxa germinated from dry (57) and wet (54) swales, the fewest (one species: Heterotheca subaxillaris) from strand. Similarity of seed bank densities to above-ground species cover was low (Jaccard's Index = 0.36), not different between vegetation types, but higher in the autumn than in the following spring. Compositional gradients in the seed bank and above-ground vegetation determined using DCA ordination were highly correlated and related to distance from mean high water, and plot elevation. At the landscape scale, the seed bank provided an equally clear delineation of vegetation types to that based upon the above-ground vegetation. The seed bank of low disturbance, late-succession vegetation types (wooded dunes, swales, marshes) was well developed (high species richness, emergent density, and percentage annual species) with the exception that the large-seeded woody species (i.e. Quercus spp.) were absent from the wooded dune seed bank. By contrast, a poorly developed and transient seed bank occurred in more frequently disturbed (extensive sand movement, salt spray), early successional dredge spoil, unvegetated areas and strand. These contrasts support a general pattern of increasing seed bank development and a persistent rather than transient seed bank with decreasing disturbance frequency, increasing time since disturbance and successional maturity.     

Vegetation development on newly embanked sandflats in the Grevelingen (The Netherlands) under different management practices

In 1971 the Grevelingen estuary was embanked. In the newly created lake Grevelingen the tidal movements stopped and a few thousand ha of sandflats fell permanently dry. Ca 40% of the surface of those flats was immediately afterwards sown with rye and other grasses to prevent wind erosion. This fixation of a rather uniform environment resulted in a monotonous vegetation cover. Grazing with domestic animals is now applied as management practice to create more environmental variation and thereby a higher species diversity.The present study gives the results of eleven years of comparing vegetation development under various management practices, including non-interference in the spontaneous and sown vegetation. Sequential vegetation mapping, repeated inventories of selected areas and studies in permannent plots are the main techniques used.On the unsown shore zones interesting vegetation types are developing where species diversity is higher than in the sown areas. In the shore zones not only a faster succession occurred compared with the sown areas, but also a shifting of environmental gradients, e.g. in moisture and salinity conditions, encouraged vegetation changes. After 10 yr grazed areas had a higher number of species than ungrazed equivalent areas. The results also indicated that grazing slows down the establishment of (tall) woody species and shrub development.Nomenclature of angiosperms and syntaxa follows Heukels & van Ooststroom (1977) and Westhoff & den Held (1975), respectively.The authors are indebted to Dr W. G. Beeftink (Yerseke) who initiated and supervised the early stages of the Grevelingen research work and W. de Munck (Yerseke) who assisted in the first steps. The logistic assistance of Rijkswaterstaat and Staatsbosbeheer made it all possible, especially the services of the bargemen A. van den Berg, G. W. van Leeuwen and J. M. Smits (Zonnemaire). Dr W. G. Beeftink, Dr D. C. P. Thalen (Leersum) and Dr A. D. Q. Agnew (Aberystwyth) reviewed earlier drafts and their constructive criticism is gratefully acknowledged.     

Consequences of a tidal reduction for the salt-marsh vegetation in the Oosterschelde estuary (The Netherlands)

A storm-surge barrier was constructed in the mouth of the Oosterschelde, a euhaline mesotidal estuary in the SW Netherlands (mean tidal range 3.6 m). As a consequence, the tidal range and the Mean High Water in the estuary have been reduced to about 88% of their original values.During the final construction stage of this barrier (1986–87) both were reduced to a maximum of 65% for more than 18 months. During this period, large-scale die-back of the vegetation occurred in vast areas on the salt marshes; locally, a complete die-back of the vegetation took place. Glycophytes and disturbance indicating species appeared on a large scale and grew abundantly. After the new tidal regime had been established, the vegetation recovered. The species characteristic of disturbance, are gradually being replaced by perennial salt marsh species. In addition, most species are shifting into zones of lower elevation, which correspond (in 1990/1991) more or less with the original flooding frequencies. Moreover, in many basins the levee-species Halimione portulacoides and Elymus pycnanthus are far more prominent than before, probably as a result of the strong ripening of the soil that has occurred in these basins during the extra tidal reduction. In 1991, four years after the establishment of the new tidal regime, the salt marsh vegetation had still not been stabilized.     

Vegetation development after the exclusion of grazing cattle in a meadow area in the south of Sweden

A study of 24 years of secondary succession was based on data from semi-permanent quadrats from investigations in 1952, 1955, 1968 and 1976, involving two exclosures, the first in a meadow grazed for hundreds of years but now abandoned, the second in a meadow mowed for hundreds of years and grazed for the last 50 years. A first order classification of quadrats produced units, which formed distinct spatial patterns indicating similar gradients, but also differences in response to the ceased grazing, in the two exclosures. A second order classification of units into groups revealed a rather simple structure of spatial and temporal relations. Eleven groups of species with similar behaviour could be recognized within a system of spatial and temporal species distributions. The vegetation in both exclosures developed towards an increased differentiation and heterogeneity or patchiness. The border between two soil types was clearly reflected in the spatial pattern of units. Rates of change were greatest in the beginning and were shown to closely follow logarithmic functions of time. The average number of species per m² decreased in all plots, in some cases as much as 50%. It was concluded that the diversity had decreased as a consequence of decreased species richness, decreased evenness and decreased pattern diversity. Many individual species distributions showed a pattern of nuclei surrounded with marginal belts. Differences in rate of change and persistence of spatial patterns between the plots, could be attributed to the differences in management history. These differences have disappeared as the succession has proceeded. The two exclosures have instead both conformed to the same floristic gradient, in turn based on a similar pattern of environmental gradients, primarily moisture. In the observed changes the emphasis was on the shifting importance of competing species populations, as some gained in importance at the expense of others. Competition has so far been a more important process in the vegetation development than immigration/extinction rates.Nomenclature follows Lid (1974) for vascular plants and Nyholm (1954–69) for mosses.This paper is the third part of a doctor's thesis from the Department of Plant Ecology, University of Lund. I wish to thank Prof. Nils Malmer for valuable advice and discussions, Mrs Mimmi Varga for drawing the figures and all my colleagues at the Department for their help and support.     

Vegetation,land use and management of the inner-dune zone in the North-Holland Dune Reserve,The Netherlands

The inner-dune zone between the villages of Bakkum and Egmond in the North-Holland Dune Reserve is one of the few remaining examples of the semi-natural boundary between the dunes and the polders. For several centuries this area has been used for various purposes, in particular for grazing. Large-scale excavating, especially after about 1900, has encroached upon the dunes. Vegetation and land-use history were studied and a provisional scheme on the vegetation development is presented. Management policies discussed are non-intervention, mowing in order to start natural processes such as rabbit grazing, and the continuation of traditional livestock grazing. Proposals for external management policies were made in order to maintain or enhance the original transition zone, based on comprehensive physical-geographical studies of the whole inner-dune zone.     

Vegetation classification,mapping, and monitoring at Voyageurs National Park,Minnesota: An application of the U.S. National Vegetation Classification

Question: How can the U.S. National Vegetation Classification (USNVC) serve as an effective tool for classifying and mapping vegetation, and inform assessments and monitoring? Location: Voyageurs National Park, northern Minnesota, U.S.A and environs. The park contains 54 243 ha of terrestrial habitat in the sub-boreal region of North America. Methods: We classified and mapped the natural vegetation using the USNVC, with ‘alliance’and ‘association’as base units. We compiled 259 classification plots and 1251 accuracy assessment test plots. Both plot and type ordinations were used to analyse vegetation and environmental patterns. Color infrared aerial photography (1:15840 scale) was used for mapping. Polygons were manually drawn, then transferred into digital form. Classification and mapping products are stored in publicly available databases. Past fire and logging events were used to assess distribution of forest types. Results and Discussion: Ordination and cluster analyses confirmed 49 associations and 42 alliances, with three associations ranked as globally vulnerable to extirpation. Ordination provided a useful summary of vegetation and ecological gradients. Overall map accuracy was 82.4%. Pinus banksiana - Picea mariana forests were less frequent in areas unburned since the 1930s. Conclusion: The USNVC provides a consistent ecological tool for summarizing and mapping vegetation. The products provide a baseline for assessing forests and wetlands, including fire management. The standardized classification and map units provide local to continental perspectives on park resources through linkages to state, provincial, and national classifications in the U.S. and Canada, and to NatureServe's Ecological Systems classification.     

Phytosociological and ecological aspects of the dunes on the Isle of Rügen,Baltic sea

Foredunes, white-, grey- and brown dunes have an important function in coastal protection. Although a close syngenetic connection exists between these neighbouring ecosystems, they are considerably differentiated phytosociologically and ecologically. Whilst on foredunes and white dunes the predominating plant species are characteristic of Ammophiletea, on the grey dunes, species characteristic of the Festuco-Brometea and the Sedo-Scleranthetea are found, and on the brown dunes species of the Nardo-Callunetea.Going through the white-, grey- and brown dunes, the salt and lime content and the pH are decreasing. In grey- and brown dunes the formation of humus starts and a lower pH develops. On the grey dunes, which are sparsely vegetated, the air temperature, soil moisture, air moisture and evaporation are extremely fluctuating daily. The climate values in the brown dunes are relatively constant. There is a close connection between the ecology of the dune types and their specific function in coastal protection.Nomenclature of syntaxa follows Rothmaler (1976).     

The significance of waterfowl grazing in the primary vegetation succession on embanked sandflats

In the annual stage of a primary plant succession on desalinating sandflats of the Lauwerszeepolder, N Netherlands, grazing by waterfowl is a dominant factor, as is illustrated by exclosures. It is concluded from population dynamical data, that both the removal of biomass and the predation of seeds sustain the annual species and retard succession to wards the next stage of a perennial grassland by several years. Yearly mowing in September slightly enhances succession by selectively affecting the dominant annual Salicornia species. The recurrence of high salinities in the upper soil layer of bare, c.q. grazed surfaces is expected to limit the invasion of grass species and other perennials.Nomenclature of plant taxa follows Heukels/van der Meijden (1983), Flora van Nederland, 20th ed. Wolters-Noordhoff, Groningen.This article would not have been written without the contributions of many students and colleagues, equally aware of the rare opportunity we had to study a genuine primary succession. I wish to thank them all. The help in the moving experiment of J. Franke, S. Nijdam, the late M. Robertus, H. Vrieling and J. D. D. Hofman is gratefully acknowledged. Thanks are due to the State Authority of the IJssellake Polders, for permitting access to and use of the experimental areas.     

Interactions between Limonium vulgare and Plantago maritima in the Plantagini-Limonietum on the Boschplaat,Terschelling, The Netherlands

Limonium vulgare and Plantago maritima are growing together over large areas and in varying proportions on the Boschplaat salt marsh. The question is how both species interact and which environmental factors play a role in those interactions.There are indications of different measures of niche differentiation in the Plantagini-Limonietum association related to differences in flooding frequency and substrate. Interactions between both species are described according to three models (related to de Wit's competition model). Mechanisms that may cause niche differentiation are: differences in growth rhythm, in salt tolerance, in rooting depth, in preference to types of substrate, in morphology, in mycorrhizae and diseases.On a small scale (spatial heterogeneity in the marsh and variation in subsequent seasons) Limonium can achieve a bigger portion in the vegetation by occupying open sites faster than Plantago. On a larger scale (the whole marsh, decades) the impossibility of Plantago to germinate and rejuvenate after sedimentation of silt and salinisation of the soil is the determining factor causing an overall decrease of this species (compared with Limonium) and increase of Limonium.The life cycle of both species, criteria for scale in space and time, and the question whether the Plantagini-Limonietum should be considered a syntaxon, are discussed.Nomenclature follows Heukels-van Ooststroom (1977).I like to thank Dr. P. Ketner and Dr. C. J. T. Spitters for their accompaniment and their ideas, so that I was aware of the wood (Boschplaat) for the trees. I also like to thank Drs. A. J. M. Roozen and Prof. Dr. E. van der Maarel for their discussions about this subject on many occasions. Finally I would like to thank Dr. W. G. Beeftink for his ideas and support and Ron Don, Wim van Hooff, Sjef Jansen, Alex Jonker, Annemiek Demon, Wim Heijligers, Marlie Becks and Frans Wilms for providing the basic concept (the Plantagini-Limonietum) and for their help.