Total Plant Density Research Articles

Changes of Winter Oilseed Rape Plant Survival During Vegetation

Abstract Winter oilseed rape (Brassica napus L.) significance among field crops is unchangeable in Latvia in the last decade. Plant density of winter oilseed rape during growth period is influenced by plant development in autumn and plant wintering. The aim of four year (2008 – 2011) research in the LLU Research and Study farm “Vecauce” was to investigate the influence of agronomical factors (sowing date, sowing rate, fungicide (metkonazole)) application and meteorological factors on two type (line, hybrid) winter oilseed rape varieties plant density changes from sowing till harvesting. Plant density in autumn, spring and during harvesting was influenced also by meteorological parameters such as air temperature and precipitation. On four year average, field germination was observed from 66% to 95%. Sowing date significantly (p<0.05) impacted plant survival during winters in all trial years for both varieties – ‘Californium’ and ‘Excalibur’, except for ‘Excalibur’ in the year 2008. Plant survival during winter for ‘Excalibur’ (hybrid) was higher compared to ‘Californium’ (line). Higher plant losses during winter were noted on the latest sowing date for both varieties. Winter oilseed rape plant survival was not significantly (p>0.05) influenced by fungicide as growth regulator application in autumn in any trial year. Influence of sowing date and sowing rate on the total plant density at harvest time was significant in all trial years (p<0.05) for both varieties. At higher sowing rate the plant loss during growing period was higher than at lower rates.

No influence of water limitation on the outcome of competition between diploid and tetraploid Chamerion angustifolium (Onagraceae)

Summary Polyploid plants often occupy different geographic ranges than their diploid progenitors, but the causes of this segregation are poorly understood. Differential competitive abilities of cytotypes across an environmental gradient could be responsible for these observed geographic range differences. Cytotypes of Chamerion angustifolium (Onagraceae) are mostly allopatric, and prior research indicates that tetraploids are more physiologically tolerant of water limitation and occupy drier habitats than diploids. We hypothesized that tetraploids are stronger competitors than diploids in soils where water is limited, which allows them to persist in dry habitats while diploids cannot. We grew both cytotypes together in competition under water‐limited and well‐watered conditions. We varied both total plant density and the relative frequency of cytotypes among pots, which allowed us to separate the effects of intra‐cytotypic and inter‐cytotypic competition. Both diploid and tetraploid plants were smaller in the water‐limited treatment than in the well‐watered treatment. Nevertheless, there were no differences in the relative strength of intra‐cytotypic and inter‐cytotypic competition experienced by either cytotype across the watering treatments, indicating that diploids and tetraploids had equal competitive abilities in both treatments. Synthesis. Competition for limiting resources is often proposed as a mechanism causing ecological and geographic segregation between diploid and polyploid cytotypes. Our results do not support the hypothesis that tetraploid Chamerion angustifolium plants are stronger competitors than diploids when water is limited. A differential ability to compete for water is likely not responsible for the observed ecological and geographic segregation between cytotypes in this species. Competition may not be a general mechanism that causes segregation between diploid and polyploid cytotypes in nature.

Simultaneous effect of disease and toxicant on a plant population: a model

In this paper, we have studied the effect of disease separately on the plant population and the simultaneous effect of diseaseand toxicant on plant population. The disease is caused to the plants by vector population and toxicants are effecting the total plant density directly through air. The local and global stability conditions for both the models have been derived and numerical simulation is done using MATLAB software. Keywords: Plant population, Vector population, Disease, Toxicant, Stability.

Increased compensatory ability of an invasive plant to above- and below-ground enemies in monocultures

Above- and below-ground enemies have prominent influence on plant invasions, and increasing evidence has shown that plant invasions are also affected by inter- or intraspecific interactions between individual plants. However, how these two factors interactively affect plant invasions has rarely been tested. Here, we examined the response of the invasive plant Alternanthera philoxeroides (Mart.) Griseb. to above- and below-ground enemies at varying plant densities in a greenhouse experiment in Wuhan, China. We found that both above- and below-ground enemies decreased the plant total and root mass at individual and population levels, but that of the two, below-ground enemies had a greater effect than above-ground enemies, and that the two guilds of enemies acted additively on the plant. However, their impacts decreased as the plant density increased, due to enhanced plant tolerance to both guilds of enemies. The increased plant tolerance may result from changes in plant resource allocation patterns, corresponding to a positive linear relationship between the ratio of fine root mass to total root mass and plant density. Given that forming dense monocultures in their new ranges is one of the most important characteristics of invasive plants, we propose that the high compensatory ability at dense monocultures may be an important mechanism underlying exotic species invasion.

Changes in Vegetation Proprieties under Short- and Long-Term Protection in North African Arid Land

The objective of this study was to quantify the effects of protection on herbaceous species composition, total plant cover, dry matter, plant density, floristic richness and diversity. Characteristics of vegetation under continued grazing and protected area for 10 and 65 years were examined in a degraded arid environment in South Tunisia. Our results show that protection enhances significantly (two times) different vegetation parameters. However, long-term protection was found to reduce biomass production, plant density and floristic diversity. Some palatable species such as Stipagrostis ciliata, Helianthemum sessiliflorum, Eragrostis papposa, Echiochilon fruticosum and Cenchrus ciliaris were frequently found in the protected sites. In the grazed site, these species were being replaced by less desirable species: Astragalus armarus, Peganum harmala and Artemisia compestris. This emphasized the importance of conservation stocking rates and proper pasture management.

Experimental evidence that soil heterogeneity enhances plant diversity during community assembly

Aims Environmental heterogeneity is a primary mechanism explaining species coexistence and extant patterns of diversity. Despite strong theoretical support and ample observational evidence, few experimental studies in plant communities have been able to demonstrate a causal link between environmental heterogeneity and plant diversity. This lack of experimental evidence suggests that either fine-scale heterogeneity has weak effects on plant diversity or previous experiments have been unable to effectively manipulate heterogeneity. Here, we utilize a unique soil manipulation to test whether fine-scale soil heterogeneity will increase plant richness through species sorting among experimental patch types. Methods This experiment was conducted in the tallgrass prairie region of south-central Kansas, USA. We utilized the inherent variation found in the vertical soil profile, which varied in both biotic and abiotic characteristics, and redistributed these strata into either homogeneous or heterogeneous spatial arrangements in 2.4 × 2.4 m plots. After the soil manipulation, 34 native prairie species were sown into all plots. We conducted annual censuses at peak biomass to quantify species composition and plant density by species within the experimental communities. Important Findings After 2 years, species richness was significantly higher in heterogeneous relative to homogeneous plots and this pattern was independent of total plant density. In the heterogeneous plots, 13 species had higher establishment in a specific patch type representing one of the three soil strata. Conversely, no species had greater establishment in the mixed stratum, which comprised the homogeneous plots, relative to the heterogeneous strata. These species sorting patterns suggest that fine-scale heterogeneity creates opportunities for plant establishment due to niche differences, which translates into increased plant diversity at the plot scale. Species richness was more strongly related to plant density among patches comprising homogenous plots—where fine-scale heterogeneity was minimized, but weak in heterogeneous plots. This pattern is consistent with the idea that richness–density relationships dominate when neutral processes are important but are weak when niche processes operate. Unlike many previous attempts, our results provide clear, experimental evidence that fine-scale soil heterogeneity increases species richness through species sorting during community assembly.

The effect of Sarcopoterium spinosum on soil and vegetation characteristics

Abstract This study addressed the effect of the dwarf shrub Sarcopoterium spinosum on soil properties, soil moisture and vegetation characteristics (plant density and richness) in a semi-arid ecosystem. Vegetation characteristics and soil sample data were obtained from three areas: 1) beneath the S. spinosum patch, 2) between the patches and 3) from the open area. The results showed that the area beneath S. spinosum had significantly higher soil moisture content, organic matter, available ammonium, nitrate, and phosphorus compared to the areas between shrubs and open areas. The results also showed that the total plant density and richness decreased significantly beneath the shrub canopy compared to the areas between shrubs and open areas. Certain plant species are found only beneath the shrub canopy. Our results indicated that S. spinosum creates habitat heterogeneity by modifying the area beneath its canopy and influencing the community structure. Interactions and the mechanisms of interactions between S. spinosum and other annual plants play an important role in determining community structure and affecting the distribution of plant species beneath and around the shrub canopy. Thus, understanding such interactions and understanding their mechanisms are important issues that should be considered for rangeland management and conservation.

Are macrophyte-dwelling Chironomidae (Diptera) largely opportunistic in selecting plant species?

In this study we evaluate how variations in taxonomic composition and physical structure of macrophyte stands affect plant-dwelling chironomid assemblages in highly variable macrophyte assemblages in two densely vegetated backwaters. By using multivariate explanatory techniques we found that similar vegetation composition did not unequivocally relate to similar chironomid assemblages, moreover the diversity of macrophyte stands did not correlate with the taxonomic diversity of chironomid assemblages in the backwaters investigated. Taxonomic composition and structural characteristics of the vegetation had little influence on the taxonomic or functional (i.e. feeding groups) composition of chironomid assemblages inhabiting them. Similarly, there are only weak relationships between the distribution of certain chironomid species or functional feeding groups and the environmental variables investigated. In general, the structure of the vegetation was more closely associated with the distribution of dominant chironomid taxa than compositional variables (i.e. density of specific macrophyte taxa). In summary, the structure of aquatic vegetation (i.e. position, size of a stand of vegetation, total plant density) and characteristics of the environment where it develops may be more important in shaping plant-dwelling chironomid assemblages than the taxonomic composition of the vegetation.

Effects of exotic grass invasion on spatial heterogeneity in the ground-layer of grassy woodlands

We quantified the effects of exotic annual grass invasion on the ground-layer structure of grassy eucalypt woodlands, with the aim of determining if weed invasion decreased gap size and plant basal area leading to reduced spatial heterogeneity. We measured plant density, distance between plants and basal plant area in woodland sites which ranged from zero to 100% exotic plant cover in the ground-layer. The ground-layer in uninvaded woodlands was heterogeneous, with a large variation in basal plant area and distance between plants. Exotic annual grass density was positively correlated with total plant density, whereas native plant density was negatively correlated. Total plant basal area decreased as total plant density increased, with a lower total plant area in exotic dominated transects compared to native dominated. Variation in basal plant area decreased with increasing plant density. Exotic annual grasses were more closely spaced together (smaller gap size) and had a smaller basal area than the native grasses and rushes. There was also less variation in basal area and gap size with individual exotic annual grasses compared to the native grasses. Inter-plant distance was greater for both the native and exotic grasses when they had native grasses neighbouring them instead of exotic grasses. These findings show that woodlands invaded by exotic annual grasses have relatively less spatial heterogeneity in the ground-layer. These results have implications for other aspects of perennial grassy ecosystems invaded by annual grasses, including plant recruitment and restoration strategies.

Nardostachys jatamansi DC. and its phyto-associates in different alpine areas of Garhwal Himalaya

The present study was undertaken to understand the population and its distribution of Nardostachys jatamansi in response to its associating species in three different sites of alpine region i.e. Yamunotri, Kedarnath and Dayyara of Garhwal Himalaya. Vegetation analysis to determine community composition associating with N. jatamansi was studied using quadrat sampling method. Analysis of vegetation revealed that the community composition of N. jatamansi in different sites did not vary much. Site-1 (Yamunotri) and Site-3 (Dayyara) showed a total of fifteen species each, while Site-2 (Kedarnath) represented by a total of twelve plant species. Species diversity was slightly higher in Site-1 than Site-2 and Site-3. The comparative analysis of total plant density at each site versus the individual contribution of N. jatamansi at Site-1, Site-2 and Site-3 showed the 33.62 %, 25.12%, and 14.92 % contribution in total density of all species.

Using Mounds to Create Microtopography Alters Plant Community Development Early in Restoration

One potential means of promoting diversity in restoration is to use microtopographic features to increase habitat heterogeneity and concentrate resources. In this study, small mounds of sand or topsoil mix were constructed. We hypothesized that these features would improve the establishment and survival of seeded prairie plants. After the first growing season both seeded and total (seeded plus unseeded) plant density/m2 were greater on the mound features than other areas, although, in subsequent years, these differences were erased or reversed. Grass (seeded plus unseeded) density/m2, however, was always larger on the mounded features. Position within the mound also affected plant community development; the base, followed by the top, improved both seeded and total plant density. Mound aspect also interacted with year; the lee and windward sides had similar seeded species richness in the first and third field seasons, but during the second year the lee side had higher seeded species richness and seeded plant density. Grasses (seeded plus unseeded) were also denser on the lee side of the mound in the second year. Finally, the material of the mound created differences in the community response. Sand mounds supported a greater proportion of seeded to total plant density compared with the topsoil mounds. There was also a larger proportion of grasses to total plant density on the sand mounds. This topographic heterogeneity plays an important role in improving the development of both temporal and spatial vegetation variability in grassland restoration.

Commercial generations of Brassica napus cause greater yield loss in Triticum aestivum, than volunteer B. napus generations

Volunteer canola (Brassica napus L.) has become a common weed in producer fields, due to the large area cropped, and inherent harvest losses. Commonly grown B. napus varieties which segregate in subsequent generations to create volunteers with unknown competitive capabilities are developed by hybrid genetics. The objective of this study was to evaluate the effect of volunteer B. napus variety and generation on competition yield loss in hard red spring wheat (Triticum aestivum L.). Two hybrid and one open-pollinated B. napus varieties with three consecutive generations produced from each variety were grown at varying densities in a wheat stand over 5 site-years. Yield loss depended on the density of B. napus in relation to total plant density. Generational differences in B. napus seedlings resulted in differences in wheat yield losses. Brassica napus densities at maturity provided a more robust model of wheat yield loss, as there were differences in wheat yield losses due to the interaction of generation and variety of B. napus. Commercial seed generations were the most competitive plants, while volunteer generations were less competitive. The amount of yield loss caused by volunteer B. napus was highly variable. The availability of low-priced herbicides, and the competitive ability of volunteer B. napus may allow for economic thresholds concerning weed control to be surpassed at low densities of volunteer B. napus populations. Key words: Competition, hybrid, open-pollinated, volunteer weed, seedling mortality, mature density, seedling density, feral

Local floral composition and the behaviour of pollinators: attraction to and foraging within experimental patches

1. Understanding how foraging decisions take place at the local scale is relevant because they may directly affect the fitness of individual plants. However, little is known about how local diversity and density affect the foraging behaviour of most pollinator groups.2. By introducing two potted plant species (Salvia farinacae and Tagetes bonanza) into two populations of Taraxacum officinale, we investigated how plant identity, the mixtures of these plant species, and total plant density affected the attraction to and the foraging within a patch for six pollinator groups.3. The foraging behaviour was mainly driven by the availability of the preferred plant species, and secondly by patch diversity and density. In general, dense patches and those containing the three‐species mixture were preferred by all insect groups for arrival, although muscoid and hover flies responded less to local floral composition than bees. Local diversity and density had, however, a weaker effect on foraging behaviour within patches. Site dependence in response to floral treatments could be attributable to differences between sites in pollinator assemblage and Taraxacum density.4. Studies like ours will help to understand how foraging decisions occur at the local scale and how foraging patterns may differ between pollinators and sites.

Pea–barley intercropping and short-term subsequent crop effects across European organic cropping conditions

Grain legumes are known to increase the soil mineral nitrogen (N) content, reduce the infection pressure of soil borne pathogens, and hence enhance subsequent cereals yields. Replicated field experiments were performed throughout W. Europe (Denmark, United Kingdom, France, Germany and Italy) to asses the effect of intercropping pea and barley on the N supply to subsequent wheat in organic cropping systems. Pea and barley were grown either as sole crops at the recommended plant density (P100 and B100, respectively) or in replacement (P50B50) or additive (P100B50) intercropping designs. In the replacement design the total relative plant density is kept constant, while the additive design uses the optimal sole crop density for pea supplementing with ‘extra’ barley plants. The pea and barley crops were followed by winter wheat with and without N application. Additional experiments in Denmark and the United Kingdom included subsequent spring wheat with grass-clover as catch crops. The experiment was repeated over the three cropping seasons of 2003, 2004 and 2005. Irrespective of sites and intercrop design pea–barley intercropping improved the plant resource utilization (water, light, nutrients) to grain N yield with 25–30% using the Land Equivalent ratio. In terms of absolute quantities, sole cropped pea accumulated more N in the grains as compared to the additive design followed by the replacement design and then sole cropped barley. The post harvest soil mineral N content was unaffected by the preceding crops. Under the following winter wheat, the lowest mineral N content was generally found in early spring. Variation in soil mineral N content under the winter wheat between sites and seasons indicated a greater influence of regional climatic conditions and long-term cropping history than annual preceding crop and residue quality. Just as with the soil mineral N, the subsequent crop response to preceding crop was negligible. Soil N balances showed general negative values in the 2-year period, indicating depletion of N independent of preceding crop and cropping strategy. It is recommended to develop more rotational approaches to determine subsequent crop effects in organic cropping systems, since preceding crop effects, especially when including legumes, can occur over several years of cropping.

Land use and drought interactively affect interspecific competition and species diversity at the local scale in a semiarid steppe ecosystem

AbstractFew studies have considered interactive effects of grazing and drought on species composition and the relative contribution of species to total biomass, although it is important to understand the short‐term dynamics and community succession in grazed ecosystems. We monitored species diversity and relative biomass contribution at one site protected from grazing since 1979 (UG79), and at winter grazing (WG) and heavily grazed (HG) sites. Continuous heavy grazing resulted in lower plant height and more but small individuals (tillers or stolons). Drought significantly reduced total plant density on all sites. Grazing affected species diversity more than drought. Species richness at site UG79 was significantly higher than at sites WG and HG, while drought only tended to reduce species diversity. Drought stress and grazing disturbance interactively controlled species competition and functional groups. Both perennial grasses and forbs had greater contribution to total biomass at site UG79, and perennial grasses contributed more than 97% of total biomass at site WG. The contribution to total biomass of annual forbs and semi‐shrubs significantly increased at site HG after two dry years. The significant decrease in Potentilla acaulis and a substantial increase in annual species at this site indicate that the perennial vegetation of this ecosystem is in great danger of extinction under conditions of prolonged drought.

Soil Nitrogen and Carbon after Twenty Years of Riparian Forest Development

Soil C and N were measured from a chronosequence of adjacent riparian forest sites located along the floodplain terrace of the San Antonio River. The communities were 25, 39, 45, 47, 49, and 53 yr past long‐term farmland use. Four of these sites (25, 45, 49, and 53 yr old) were also sampled 20 yr ago. Soil C was significantly greater after 20 yr of community development; however, the increase was dependent on the community age. Soil C increased by 38 g kg−1 in the 49‐yr‐old community during the 20‐yr period, but only 11 to 15 g kg−1 in the 25‐, 45‐, and 53‐yr‐old communities. Soil N was significantly greater (1.7–2.5 g kg−1) after 20 yr of development for communities 25, 45, and 49 yr old. In the oldest community (53 yr old), no significant increase was seen in soil N after 20 yr. No significant spatial differences [underneath the canopy of Acacia farnesiana (L.) Willd. vs. intercanopy grassland] were found in soil C and N in the 25‐yr‐old community. The late successional dominant Celtis laevigata Willd., total woody plant density, and total woody plant basal area could be explained by soil C or N. Changes in soil C and N through time parallel other studies, increasing through the early‐ and mid‐successional stages and decreasing from the mid‐ to late‐successional stages. Spatial differences in soil C and N that existed in the 15‐yr‐old community disappeared in the 25‐yr‐old community as A. farnesiana basal area increased from 0.7 to13 m2 ha−1

Seedling interactions in a tropical forest in Panama

Competition is believed to be a central force limiting local diversity and controlling the structure of plant communities. However, it has been proposed that the stressed understory environment limits total understory plant density to such low levels that competitive exclusion cannot be an important factor limiting the local diversity of understory plants. To evaluate the importance of inter-seedling competition, we performed a seedling competition experiment with five shade-tolerant species in a tropical moist forest in Panama. Three-month-old seedlings were transplanted into the forest singly or with their roots intertwined with a single conspecific or heterospecific seedling in all pairwise species combinations. If competition is important, performance (survival, stem height, and number of leaves after one and six years) would be expected to be lowest with a conspecific neighbor and greatest without a neighbor. The experiment was replicated in five 0.24-m(2) plots at each of 20 sites in tall secondary forest. To test whether seedling performance differed among treatments we fitted linear mixed models (LMM) and generalized linear mixed models (GLMM), treating species identity and microsite (site and plot) as random effects. The five shade-tolerant study species all experienced good establishment with relatively high survival and growth rates. The neighbor treatment consistently affected seedling performance, but the effect was always very small, both in absolute terms and relative to the much stronger species and microsite effects. Seedlings with a conspecific neighbor consistently performed worse than seedlings with a heterospecific neighbor, but having no neighbor generally did not cause superior performance relative to the other treatments. We conclude that direct competitive interactions are relatively unimportant among understory plants in humid tropical forests.

Endangered crayfish in northern Japan: Distribution, abundance and microhabitat specificity in relation to stream and riparian environment

Japan’s only native crayfish species Cambaroides japonicus has been declining dramatically in the past few decades. For the purpose of conservation planning, twenty-two coastal streams were surveyed to investigate summer distributions of crayfish in relation to stream and riparian environment. Classification and regression trees were used to predict the occurrence and abundance of crayfish. The classification tree model with stream variables as predictors showed that crayfish would occur in swift or high gradient streams (correct classification rate = 91%). Within those streams, however, crayfish only inhabited depositional microhabitats, in which the areas are limited in availability. Crayfish were not found in gentle, low gradient streams containing abundant depositional microhabitats. This paradoxical distribution pattern was attributed to availability of boulder substrates in swift or high gradient streams. The regression tree model indicated that crayfish abundance was determined primarily by the percentage of boulder substrates and the presence of fish (observed vs. predicted r = 0.64). The classification tree model using only riparian variables indicated that the total woody plant (mainly broadleaf species) density followed by the percentage of early successional species such as alder and willow determined the splits of the tree model (correct classification rate = 95%). A leaf processing experiment on 10 riparian plant species suggested that crayfish preferred high nitrogen (or low C/N) leaves. These results suggest that swift or high gradient fishless streams associated with abundant cover in dense broadleaf forest serve conservation areas for this endangered crayfish, and that consideration of riparian composition may facilitate conservation efforts.

The role of the perch effect on the nucleation process in Mediterranean semi-arid oldfields

Oldfield succession in Mediterranean ecosystems has been studied extensively in mesic conditions. However, this phenomenon is still poorly understood in semi-arid Mediterranean areas, where reduced plant cover, the importance of facilitation processes and the role of abiotic factors make these environments distinct. We first test whether the carob tree (Ceratonia siliqua) generates nucleation patterns in semi-arid oldfields, and to what extent such patterns change with abandonment age. Then we test to what extent nucleation can be explained by the perch effect. And finally, we test whether the nucleated pattern around carob trees is a source of diversity in the oldfields studied. To answer these questions we located oldfields abandoned 25 and 50 years ago (20 in each case) in the Alacant Province (SE Spain, Iberian Peninsula) on the basis of aerial photographs and personal interviews with local landowners and managers. In each oldfield woody plant density and richness were sampled on two microsites: under the carob tree and in the open field. Analysis was performed on all woody plants and by separating the species in two functional groups: fleshy-fruited (with fleshy mesocarp) and non-fleshy-fruited species. The results suggest that woody vegetation colonising abandoned C. siliqua fields in SE Spain is not randomly distributed but follows a nucleation pattern with higher plant density under the trees. However, the nucleation pattern is only significant for fleshy-fruited species, suggesting that facilitative interactions alone cannot explain the nucleation pattern and that the perch effect plays an important role. The results also show that the nucleation pattern (total plant density and density of non-fleshy-fruited plants) did not increase with abandonment age, while the perch effect (density of fleshy-fruited plants) did increase significantly. Furthermore, the results also show that the nucleation pattern is not only a loci of high plant density but also a loci of high species richness. Thus we can conclude that the nucleation pattern found in oldfield succession is best explained by the perch effect, while facilitation has a secondary importance. This emphasises the key role that dispersal mode has on the dynamics of vegetation recovery in formerly cropped areas.

Impact of management and habitat on demographic traits of Primula vulgaris in an agricultural landscape

AbstractQuestion: Is demographic performance of Primula vulgaris correlated with habitat characteristics of the small landscape elements in which it occurs? Can we use this species as an indicator for species‐rich semi‐natural habitats?Location: Flanders, Belgium.Methods: To capture differences in demographic traits and habitat characteristics, both within and between populations, a two‐level survey was carried out. Population size and structure of 89 P. vulgaris populations in different types of small landscape elements was recorded in 1999. At plot level, densities of different life stages were determined and these were related to edaphic conditions and vegetation structure and composition.Results: Three different population types were distinguished: (1) dynamic populations, characterized by seedling and juvenile proportions, (2) normal populations with relatively more adults, but with considerable numbers of seedlings and juveniles and (3) senescent populations, mainly consisting of adults. Senescent populations were significantly smaller than populations with a dynamic demographic structure. At plot level, comparison of demographic characteristics between different management regimes revealed that recruitment rates and total plant density of P. vulgaris were highest in plots that received a regime that included mowing and clearing of ditch banks whereas densities were lower along forest edges. For these plots, it was shown that nutrient levels were higher. Densities of adults as well as juvenile and seedling densities were negatively correlated with vegetation height.Conclusions: Local disturbance and heterogeneity may mask the relationship between unfavourable conditions and demographic characteristics at population level, but it is clear that in small populations recruitment needs to be lifted to guarantee its persistence. Performance of P. vulgaris in small landscape elements can be a first indication of plant species diversity in small landscape elements.