Small Meadows Research Articles

First record of the seagrass Halophila stipulacea (Forsskal) Ascherson in the waters of the continental United States (Key Biscayne, Florida)

The first record of Halophila stipulacea is reported for the continental waters of the United States. In August 2024, a small meadow was identified inside Crandon Marina on Key Biscayne, Florida, USA. Following surveys have revealed that H. stipulacea has spread to adjacent areas immediately outside of the marina, often growing either in close proximity to, or interspersed with, the native seagrasses Thalassia testudinum, Syringodium filiforme, and Halodule wrightii. This serves as an initial report and extends the geographic scope of this introduced species in the Western Atlantic basin.

Trends of Aboveground Net Primary Productivity of Patagonian Meadows, the Omitted Ecosystem in Desertification Studies

The United Nations defines desertification as the loss of productivity in arid and semiarid environments. The extended steppes of Patagonia harbor small meadows whose compounded area is comparatively small, but their aboveground net primary production (ANPP) is up to ten times higher than their surroundings. These meadows then represent a key ecosystem for cattle grazing systems, but there are no descriptions of the trends in their ANPP and, consequently, their carrying capacity, and, as a result, their degradation syndromes. Our objectives were as follows: (1) analyze the trends of mean and spatial heterogeneity of annual ANPP in meadows and neighboring steppes and relate them with precipitation and temperature, (2) evaluate the impact on the livestock carrying capacity of meadows in the region, and (3) evaluate the degradation trends of these meadows, based on a novel description proposed to characterize the trend syndromes of these type of ecosystems. We identified meadow areas across a subcontinental scale in Patagonia, covering a mean annual precipitation range from 129 to 936 mm. We estimated ANPP on a monthly basis from 2000 to 2019 via regional calibrated remote sensing information. In the last two decades, ANPP decreased in 74% of the studied meadow areas, while remaining relatively stable in the nearby steppes. This decrease was relatively higher in the arid end of the analyzed precipitation gradient. Hence, the global carrying capacity for all the studied meadow areas decreased by 8%. Finally, we identified four trend syndromes based on the combination of the ANPP trend and its spatial heterogeneity, calculated as the spatial standard deviation. The predominant trend syndrome, in 55% of the area, was associated with a negative trend of both ANPP and spatial heterogeneity. These results could help prioritize areas where specific management decisions, given the different trend syndromes, could help revert ANPP negative trends.

Seagrass Zostera In the Russian Section Of the Baltic Sea

Information on seagrass in the Russian section of the Baltic Sea – Sambia Peninsula, Curonian Spit, and Gulf of Finland (water area of Kaliningrad and Leningrad regions) is generalized based on a recent survey, literature search, and study of herbarium samples. Seagrasses are found in the emissions of most of the coast of the Kaliningrad region, but they are extremely few. All discovered seagrasses belong to one species – Zostera marina L. In the absence of an opportunity to distinguish the emissions of Zostera marina brought in by currents from other regions of the Baltic Sea from local emissions, the possibility of the presence of a small number of single individuals of this species in the seawater area of the Sambia Peninsula and the Curonian Spit remains. Specimens of Zostera marina brought in by storms from the western part of the Baltic Sea, as well as an individual found during diving studies in 2009, can take root and form small meadows in the future, provided they are protected from surf waves and a stable substrate, settling with the help of vegetative shoots. Poorly rooted seagrasses can also be washed ashore. The mobile sandy ground found in most of the study area may be the reason why seagrass plants do not form stable communities. In the Russian section of the Gulf of Finland, seagrass had not been recorded. Probably, they occur in small numbers in its northern part.

Psorosa mediterranella (Amsel, 1954) (Lepidoptera: Pyralidae, Phycitinae) – a new species for the Croatian pyraloid moth fauna, with an updated checklist

From 2016 to 2020 numerous surveys were undertaken to improve the knowledge of the pyraloid moth fauna of Biokovo Nature Park. On August 27th, 2020 one specimen of Psorosa mediterranella (Amsel, 1954) from the family Pyralidae was collected on a small meadow (985 m a.s.l.) on Mt Biokovo. In this paper, the first data about the occurrence of this species in Croatia are presented. The previous mention in the literature for Croatia was considered to be a misidentification of the past and has thus not been included in the checklist of Croatian pyraloid moth species. P. mediterranella was recorded for the first time in Croatia in recent investigations and, after other additions to the checklist have been counted, is the 396th species in the Croatian pyraloid moth fauna. An overview of the overall pyraloid moth fauna of Croatia is given in the updated species list.

Flora and vegetation features of the stow «Chalk slopes to the Proval river» (Ulyanovsk Region)

The paper contains the vegetation study results of the valuable botanical object Chalk slopes to the Proval river.The stow is located in thevicinitiesof the villageBeketovka(Veshkaymsky District of Ulyanovsk Region) and is proposed for inclusion in the regional network ofprotected areas.The data of floral and phytocenotic studies are presented.The flora of the stow Chalk slopes to the Proval river contains 287 species of vascular plants including 8 species listed in Red data book of the Russian Federation:Hedysarumgmelinii,Irisaphylla,Koeleriasclerophylla,Matthiolafragrans,Pinus cretacea[P.sylvestrisvar.cretacea],Stipapennata,S.pulcherrima,Thymusdubjanskyi[Th. cimicinusauct. p. max. p.]. The regional rare and requiring protection plants areAdonanthe vernalis,Anemone sylvestris,Asperulaexasperata,Aster alpinus,Betula krylovii,Bupleurum falcatum,Carex pediformis,Centaurearuthenica,Crepispannonica,Delphinium cuneatum,Galatellalinosyris,Galiumhexanarium,Gentianacruciata,Gentianellaamarella,Helianthemumcanum,H.nummularium,Helictotrichondesertorum,Herminiummonorchis,Jurinealedebourii,Linumflavum,L.uralense,Onosmasimplisissimas.str.,O.volgensis,Otitesbaschkirorum,Parnassiapalustris,Polygalacretacea,P.sibirica,Pulsatillapatens,Scabiosaisetensis,Schoenus ferrugineus. Calcephitic florocoenotic complex of the stow Chalk slopes to the Proval river (Ulyanovsk Region) is characterized by a mosaic of vegetation. Here, in a relatively small area, meadow, petrophytic and grass-mixed steppes, forest edges communities are presented. The floristic composition of these communities is peculiar and characterized by the presence of a large number of rare species including relict and endemic elements. In addition, in the central part of the Volga Upland, only a small amount of erosion-chalk landscapes with a high degree of preservation is known. The studied stow is recommended for inclusion in the system of protected areas of the Ulyanovsk Region.

The impact of disturbance intensity on spatial variability of habitat conditions and seedling recruitment of selected rare, medicinal plants in Molinion patches

The investigations were conducted in two Molinion patches dominated by small meadow species (ME) and overgrown by tall-growing macroforbs (MAC). Observations were carried out in systematically arranged permanent experimental plots divided in experimental subplots. The subplots were subjected to: I) no disturbances; II) low level of disturbance, corresponding with trampling consisting of the litter and moss layer removal; III) intermediate level of disturbance, corresponding with mowing consisting of the litter, moss, and above-ground part of plants removal; and IV) high level of disturbance, corresponding with rooting by wild mammals consisting of the litter, moss and the plants removal, as well as top soil raking with a metal scraper about 7 cm deep. The light availability was greater in Patch ME, while the soil humidity achieved higher values in Patch MAC. At the same time, the light availability increased in consecutive subplots, whereas the soil humidity showed a reversed trend. The cumulative number of seedlings Betonica officinalis and Succisa pratensis in Patches ME and MAC was similar, while Sanguisorba officinalis recruited more abundantly in Patch ME. The greatest number of offspring of all studied taxa was noticed in subplots III and IV. The obtained results might contribute to creating of succesful plans of enlargement of natural resources of medicinal plants in Molinia meadows-one of most valuable semi-natural communities in Europe.

Grazing and wildfire effects on small mammals inhabiting montane meadows

ABSTRACTLivestock grazing and fire can intensively modify montane meadows. Understanding how these factors affect habitat, species richness, and diversity of small mammals can inform management decisions. Few studies have investigated the independent and synergistic effects of grazing and wildfire on vegetation and small‐mammal communities, and none have focused on montane meadows in the southwestern United States. In 2012 and 2013, we captured small mammals at 105 sites to contrast occupancy, species richness, and diversity among livestock grazing levels (present, absent), wildfire severity (unburned, low, or moderate), and meadow classifications (small or large, wet or dry) in Arizona, USA. During 13,741 trap nights, we captured 1,885 rodents of 8 species. Two species represented 88% of captures: deer mouse (Peromyscus maniculatus) and Arizona montane vole (Microtus montanus arizonensis). Deer mice, Navajo Mogollon voles (Microtus mogollonensis navaho), and thirteen‐lined ground squirrels (Ictidomys tridecemlineatus monticola; a subspecies endemic to the White Mountains, AZ) had higher occupancy in large, ungrazed meadows compared to small, grazed meadows. Species richness was greater in unburned than burned sites and small meadows than large. However, higher diversity occurred in ungrazed and dry compared to grazed and wet meadows. Three species demonstrated weak relationships between wildfire and occupancy, suggesting short‐term (<2 yrs) effects of low to moderate burn severity for these species or their habitat. Livestock grazing had a greater effect than wildfire on the small‐mammal community by altering vegetation or other habitat elements and thus decreasing population sizes. Reducing livestock grazing would benefit small‐mammal species and increase diversity and abundance of the small‐mammal community in montane meadows. © 2019 The Wildlife Society.

Landscape patterns and diversity of meadow plants and flower-visitors in a mountain landscape

Wild flowering plants and their wild insect visitors are of great importance for pollination. Montane meadows are biodiversity hotspots for flowering plants and pollinators, but they are contracting due to tree invasion. This study quantified flowering plants and their flower-visitor species in montane meadows in the western Cascade Range of Oregon. Species diversity in small, isolated meadows was expected to be lower and nested relative to large meadows. Alternatively, landform features may influence richness and spatial turnover. Flowering plants and their visitors were sampled in summers of 2011–2017 in twelve montane meadows with varying soil moisture. All flowering plants and all flower-visitors were recorded during five to seven 15 min watches in ten 3 × 3 m plots in each meadow and year. A total of 178 flowering plant species, 688 flower-visitor species and 137,916 interactions were identified. Richness of flower-visitors was related to meadow patch size, but neither plant nor flower-visitor richness was related to isolation measured as meadow area within 1000 m. Species in small meadows were not nested subsets of those in large meadows. Species replacement accounted for more than 78% of dissimilarity between meadows and was positively related to differences in soil moisture. Although larger meadows contained more species, landform features have influenced meadow configuration, persistence, and soil moisture, contributing to high plant and insect species diversity. Hence, conservation and restoration of a variety of meadow types may promote landscape diversity of wild plants and pollinators.

Interannual Change Detection of Mediterranean Seagrasses Using RapidEye Image Time Series.

Recent research studies have highlighted the decrease in the coverage of Mediterranean seagrasses due to mainly anthropogenic activities. The lack of data on the distribution of these significant aquatic plants complicates the quantification of their decreasing tendency. While Mediterranean seagrasses are declining, satellite remote sensing technology is growing at an unprecedented pace, resulting in a wealth of spaceborne image time series. Here, we exploit recent advances in high spatial resolution sensors and machine learning to study Mediterranean seagrasses. We process a multispectral RapidEye time series between 2011 and 2016 to detect interannual seagrass dynamics in 888 submerged hectares of the Thermaikos Gulf, NW Aegean Sea, Greece (eastern Mediterranean Sea). We assess the extent change of two Mediterranean seagrass species, the dominant Posidonia oceanica and Cymodocea nodosa, following atmospheric and analytical water column correction, as well as machine learning classification, using Random Forests, of the RapidEye time series. Prior corrections are necessary to untangle the initially weak signal of the submerged seagrass habitats from satellite imagery. The central results of this study show that P. oceanica seagrass area has declined by 4.1%, with a trend of −11.2 ha/yr, while C. nodosa seagrass area has increased by 17.7% with a trend of +18 ha/yr throughout the 5-year study period. Trends of change in spatial distribution of seagrasses in the Thermaikos Gulf site are in line with reported trends in the Mediterranean. Our presented methodology could be a time- and cost-effective method toward the quantitative ecological assessment of seagrass dynamics elsewhere in the future. From small meadows to whole coastlines, knowledge of aquatic plant dynamics could resolve decline or growth trends and accurately highlight key units for future restoration, management, and conservation.

Seagrass blue carbon spatial patterns at the meadow-scale.

Most information on seagrass carbon burial derives from point measurements, which are sometimes scaled by meadow area to estimate carbon stocks; however, sediment organic carbon (Corg) concentrations may vary with distance from the meadow edge, resulting in spatial gradients that affect the accuracy of stock estimates. We mapped sediment Corg concentrations throughout a large (6 km2) restored seagrass meadow to determine whether Corg distribution patterns exist at different spatial scales. The meadow originated from ≤1-acre plots seeded between 2001 and 2004, so we expected Corg to vary spatially according to the known meadow age at sample sites and with proximity to the meadow edge. Applying spatial autoregressive models allowed us to control for spatial autocorrelation and quantify the relative effects of edge proximity and age on Corg concentrations. We found that edge proximity, not age, significantly predicted the meadow-scale Corg distribution. We also evaluated relationships between Corg and a variety of specific explanatory variables, including site relative exposure, shoot density, sediment grain size, and bathymetry. Factors known to affect carbon burial at the plot-scale, such as meadow age and shoot density, were not significant controls on the meadow-scale Corg distribution. Strong correlations between Corg, grain size, and edge proximity suggest that current attenuation increases fine-sediment deposition and, therefore, carbon burial with distance into the meadow. By mapping the sediment Corg pool, we provide the first accurate quantification of an enhanced carbon stock attributable to seagrass restoration. The top 12 cm of the bed contain 3660 t Corg, approximately 1200 t more Corg than an equal area of bare sediment. Most of that net increase is concentrated in a meadow area with low tidal current velocities. Managers should account for the effects of meadow configuration and current velocity when estimating seagrass blue carbon stocks. Our results suggest that a large, contiguous meadow should store more blue carbon than an equal area of small meadow patches.

Survival rates and causes of mortality of roe deer Capreolus capreolus in a rural landscape, eastern Poland

Game species in the cultural landscapes of Europe are exposed to several sources of anthropogenic pressure. Whilst hunting is part of coordinated wildlife management, poaching is difficult to quantify, and hence, relatively little is known about its impact on survival patterns of game species. We estimated survival and cause-specific mortality rates of 31 roe deer Capreolus capreolus in the surroundings of the Białowieża Primeval Forest, eastern Poland, from 2010 to 2013. The study area consisted of large, extensively used agricultural fields and a mosaic of pine plantations, which were interspersed with natural forest stands and small agricultural fields and meadows. Roe deer were regularly hunted and the forested part of the study area was traversed by large carnivores. Annual survival rate of all deer was 0.69 and did not differ between seasons. Annual survival rates of females and males in each age class (young and adult) were similar. Poaching was a major source of mortality (6 out of 13 roe deer deaths), and poachers did not prefer any sex or age. Adult survival (0.77) was higher than survival of young individuals (0.53); this trend was stronger when poaching was excluded from the analysis. All cases of poaching were recorded between mid-September and February. Although the two parts of the study area were exposed to a similar degree of anthropogenic pressure, all poached individuals occupied home ranges in the mosaic, where the forest cover in home ranges of roe deer was significantly higher than in the field.

Historical and recent fragmentation of temperate floodplain grasslands: Do patch size and distance affect the richness of characteristic wet meadow plant species?

Patch size and isolation are thought to have a large influence on the extinction risk of specialist plant species in grassland fragments in the modern agricultural landscape. We combined a re-sampling study in semi-permanent floodplain grassland plots with a GIS-based analysis of historical (1950s/1960s) and recent landscape patterns. Based on historical and recent vegetation maps and releves from six study areas (plus a protected reference area) covering 50–60 years of vegetation change following agricultural intensification, we aimed at analysing the importance of fragmentation on the diversity of potentially sensitive specialist species of wet floodplain meadows in northern Germany. On the plot scale, we found 30–66 % reductions in species richness of these characteristic wet meadow plant species over time and an associated increase in the fragmentation of grassland habitats. Distance to the nearest suitable habitat had a modest negative effect on modern plot-scale richness, while the other tested landscape metrics (total meadow area, mean patch size and landscape proximity index distribution) had no significant influence. There was also no evidence for a legacy of historical landscape structure on current richness of specialist species. Instead, management intensity and its change over the past decades, as indicated by altered Ellenberg indicator values for nutrients and moisture, had a strong influence on plot-scale diversity. The results suggest that fragmentation is not the proximate cause of impoverishment and point to habitat deterioration as a main driver. We conclude that conservation measures in Central-European floodplain meadows should not only focus on large continuous grassland areas, but should also consider small meadow patches if they remained species-rich.

Sources and pathways of stream generation in tropical proglacial valleys of the Cordillera Blanca, Peru

Summary Tropical glaciers supply approximately half of dry-season stream discharge in glacierized valleys of the Cordillera Blanca, Peru. The remainder of streamflow originates as groundwater stored in alpine meadows and other proglacial geomorphic features. A better understanding of the hydrogeology of alpine groundwater, including sources, storage zones, and the locations and magnitudes of contributions to streamflow, is important for making accurate estimates of glacial inputs to the hydrologic budget, and for our ability to make predictions about future water resources as glaciers retreat. This field study focuses on two high-elevation meadows in valleys of the Cordillera Blanca, in headwaters and mid-valley locations. Tracer measurements of stream and spring discharge and groundwater-surface water exchange were combined with synoptic sampling of water isotopic and geochemical composition in order to characterize and quantify contributions to streamflow from different groundwater reservoirs. At the headwaters site, groundwater supplied approximately half of stream discharge from a small meadow, with most originating in an alluvial fan adjacent to the meadow and little (6%) from the meadow itself; however, at the mid-valley site, where meadows are extensive, local groundwater has a large impact on streamflow and chemistry through large net contributions to discharge and turnover of surface water due to gross exchanges with groundwater. At the mid-valley site, stream discharge increased by 200 L s−1 (18% of average discharge) over 1.2 km as it descended a moraine between two meadows. Such valley-crossing moraines, which create significant steps in the down-valley slope, are likely locations of substantial groundwater contribution to streams.

AreDeschampsia caespitosa(L.) Beauv. Tussocks Safe Sites for Seedling Recruitment in the Succession of Wet Meadows?

In stressful and harsh environments, safe sites for seedling recruitment may be created by nurse plants, which accumulate propagules and subsequently facilitate the establishment of individuals. The main goal of the presented studies focused on observations of seedling recruitment in small and large tussocks of Deschampsia caespitosa derived from patches of unmanaged Molinietum caeruleae meadows situated along the successional gradient and dominated by small meadow species (Patch I), by macroforbs (Patch II), or overgrown by trees and shrubs (Patch III).The studies showed that, irrespective of patch character, Serratula tinctoria, Selinum carvifolia, Lysimachia vulgaris and Filipendula ulmaria are among the best colonizers of Deschampsia caespitosa tussocks. The gradual decrease in number of species and offspring abundance along the successional gradient may be connected with a prolonged period of water stagnation accelerating the development of fungal pathogens, a major cause of mortality for buried diaspores. The growing frequency of species present in standing vegetation and the gradually rising contribution of swamp and forest taxa in consecutive patches may be due to the production of non-persistent diaspores by early successional species, as well as reduced seed immigration from neighboring sites.The obtained results included evidence that, regardless of patch character, the percentage of seedlings representing species present in and absent from existing vegetation as well as taxa with various vegetation types is similar in small and large tussocks. Furthermore, in small tussocks, regardless of patch character, anemochorous and hydrochorous taxa dominated, the frequency of endo- and epizoochorous taxa was much lower, while the percentage of species characterized by other modes of diaspore dispersal attained the lowest rates. In large tussocks, anemochorous and epizoochorous species prevailed, the share of endozoochorous and hydrochorous taxa was lower, and the contribution of species characterized by other modes of dissemination was very scarce.On the basis of these studies it might be concluded that, despite the successive decrease of species and seedling abundance, and along with the increase in the recruitment of taxa resident in standing vegetation, especially woody species, the tussocks of Deschampsia caespitosa are reservoirs of meadow species even in advanced successional stages and may play a significant role in the process of long-term species turnover.

The Effect of Neighbouring Plant Height, Disturbance Level and Gap Size on Spontaneous Recruitment of Large-Seeded And Small-Seeded Species in Molinietum caeruleae Meadows

The seed size is considered as a key feature, which effects both: colonizing and competitive abilities of species. The disturbance dependent small-seeded taxa are regarded as superior colonists, whereas the large-seeded taxa are considered as best competitors able to survive the competition from adjacent plants and negative effect of litter. The impact of character of standing vegetation, disturbance level and size of gaps on spontaneous recruitment of seedlings of selected light-seeded species (Gentiana pneumonanthe L., Dianthus superbus L.) and heavy-seeded taxa (Serratula tinctoria L., Gladiolus imbricatus L.) were conducted. The investigations were carried out in two areas (A and B). Both of them were consisted of three adjacent patches of Molinietum caeruleae: dominated by small meadow species (labeled MC), prevailed by large-tussocks grasses (labeled GR), and overgrown by willows (labeled SA). In the year 2007, in all patches, ten permanent experimental plots were randomly arranged. In Area A, plots were divided in four square-shaped, neighboring subplots subjected to: no treatment; the removal of litter and moss layers; the removal of litter, bryophytes, and above-ground parts of plants; the removal of litter, moss and the plants, as well as top soil stripping. In the Area B, plots were divided into four subplots measuring from 0.16 m2 to 0.01 m2. In each of them the litter and above-ground part of plant biomass were clipped and removed. The recruitment of seedlings was monitored from 2007 through 2010. In both studied areas, regardless of seed mass, the greatest abundance of seedlings were found in patches MC, and decreased gradually in sites GR and SA. Irrespective of seed size, in subplots where plant cover and litter stayed intact no new genets was noted, moderate appearance of seedlings was observed in subplots without plant necromass, whereas the greatest number of generative progeny was found in subplots without necromass and aboveground parts of plants. The lower abundance of seedlings in subplots without litter, plants and topsoil might have been caused by depletion of seed bank reserves. Moreover, in all patches the number of seedlings of small- and large-seeded taxa increased significantly with augmentation of gap size. In light of performed studies it might be concluded, that the disturbances might play very important role in active protection of studied taxa. The positive impact of disruption diminishes with increasing of plant canopy height. The removal of plant cover and litter contributes to the greatest seedling recruitment but its beneficial effect diminishes with decreasing of opening size.

The Variability of Selected Features of Gladiolus imbricatus L. in Relation to Successive Stages of Meadow Communities Following the Mowing Cessation

ABSTRACT: Molinietum caeruleae meadows belong to the most endangered plant communities in Central Europe, nowadays suffering due to the lack of management. The land abandonment promotes strong secondary expansion of macroforbs, sedges or willows, contributing to decrease of the species diversity. In light of these findings very interesting seems to be the evaluation of the variability of features of populations of rare meadow species. In Poland one of strictly protected plant is Gladiolus imbricatus L. It is a tuberous, clonal plant with sword-like leaves and tall stalks bearing purple flowers collected in one-sided inflorescence. The studies of spatio-temporal variability of selected features of subpopoulations of Gladiolus imbricatus were carried out in the years 2009– 2011 in Krakow-Kostrze (Southern Poland) in patches of Molinietum caeruleae with different species composition. In Patch I chiefly occurred small meadow species, Patch II was prevailed by shrub willow, Patch III was dominated by tall-grow...

The effectiveness of asexual and sexual reproduction in clonal species Dianthus superbus L. in different site conditions – the consequences for population development

The effectiveness of asexual and sexual reproduction of rare, clonal species Dianthus superbus L. were conducted in the years 2008-2010 in Kostrze (Southern Krakow). The observations were carried out in Molinietum caeruleae patches dominated by small species creating delicate, erect or procumbent stems (MC) , prevailed by tall grasses (GR), and overgrown by willows (SA). The number of above-ground units per ramet cluster were much greater in MC patch, than in sites GR and SA. Controversially, the number of fruit per generative shoot and seed production were greater in GR and SA patches, than in MC patch. The highest seedling recruitment, occurring only in artificially created gaps in plant canopy and litter was noted in patch MC, while the decline of genet emergence were found in SA and GR patches. In light of performed studies, it should be concluded, that population established in patch dominated by small meadow species has the greatest chance for survival, whereas populations inhabiting sites prevailed by tall grasses or overgrown by willows have much lower possibilities of persistence in occupied places

The Influence of Standing Vegetation Height on the Reproductive Allocation in Populations ofSerratula tinctoriaL. (Asteraceae)

ABSTRACT: The advantage of the clonal plants over the nonclonal species in colonization of all biomes and biogeographical regions primarily is due to occurrence of two modes of reproduction. The creating of vegetative propagules with high vitality and survivability, enables the spread in the newly colonized site, while seed production increases the chances for successful recruitment of seedlings, ensuring the genetic diversity of the population. The differences in allocation into vegetative reproduction and generative propagation in relation to rising height of adjacent plants was investigated in populations of Serratula tinctoria L., occurring in Molinietum caeruleae meadows localized in Southern Poland. Each locality was represented by randomly established three permanent study plots: dominated by small meadow species (LOW), prevailed by large-tussock grasses (INTER) and overgrown by shrubs and trees (HIGH). In the years 2009–2011 the number of leaf rosettes and length of the longest leaf in rosette (as...

The effects of successional stage and size of gaps on recruitment of clonal plants in overgrowing Molinietum caeruleae meadows

<p>In majority of plant communities with a closed canopy, the disturbances created by abiotic factors and biotic agents contribute to origin of an area free of existing vegetation and considered as safe sites for seedling recruitment. Although the gaps are characterized by several features, the size is proposed to be the most important characteristic. The investigations of recruitment of clonal taxa in different–sized gaps were conducted in the years 2011–2012 in <em>Molinietum caeruleae</em> meadows representing various successional stages and dominated by different species. Patch ES, representing early-successional stage, was dominated by small meadow species, Patch MS, representing mid-successional stage, was prevailed by tall-growing macroforbs, while Patch LS representing late-successional stage was overgrown by macroforbs and willows. In the successive sites the mean height of plant canopy, as well as the period of spring inundation increased gradually.</p><p>The total number of species and seedlings decreased from the Patch ES, through the Patch MS, to the Patch LS. Almost all plants presenting positive correlation between seedling number and gap area created hypogeogenous stems with substantial lateral growth and considerable number of short-lived daughter ramets allowing the fast colonization of neighbourhood. The majority of species showing negative relationship formed epigeogenous stems with slight lateral growth, as well as low number of long-lived ramets contributing to slow colonization of area.</p><p>In light of performed studies, it might be concluded, that making disturbance in continuous plant canopy and litter might be very effective way of conservation of <em>Molinietum caeruleae</em> meadows. The creation of different-sized gaps seems to be especially valuable due to the maintenance of heterogeneity of clonal species, which is particularly important in advanced successional stages.</p>

The life-history traits influencing reproduction success and the recruitment of seedlings of Dianthus superbus L. in different stages of meadow overgrowing

<p>A study of the life-history traits and seedling recruitment in small and isolated populations of a rare clonal species, <em>Dianthus superbus </em>L., was carried out in the years 2011–2012 in Kraków-Kostrze (Southern Poland)<em>. </em>Observations were conducted in unmanaged <em>Molinietum caeruleae </em>meadows situated along the successional gradient. The patch representing the initial stage of succession (P1) was dominated by small species creating delicate erect or procumbent stems<em>, </em>the patch representing the temporary stage of succession (P2) was prevailed by large-tussock grasses and tall-growing macroforbs, while the patch representing the terminal stage of succession (P3) was partly overgrown by bushes and trees. The number of generative shoots, flowers, fruits and seeds of <em>Dianthus superbus </em>L. diminished gradually from P3 <em>via </em>P2 to P1. The increase in abundance of generative shoots and flower number in the vicinity of tall plants contributes to increased visibility of inflorescences and may enhance the chances for nocturnal pollinator visits. A significant production of fruits and seeds in competitive neighborhood may augment the chances for successful dispersal and colonization of new, perhaps more favorable habitats. The recruitment of seedlings occurred only in artificially created gaps in plant canopy and litter. The appearance of seedlings and their survivorship were better in P1 than in P2 and P3. Such a phenomenon might be due to the locally rising water level and the diminishing amount of light reaching to the soil area along the successional gradient.</p><p>Concluding, it should be asserted that a low production of generative shoots, flowers, fruits and seeds by the population of <em>Dianthus superbus </em>L. established in the patch dominated by small meadow species is compensated by the highest seedling recruitment and their survival. On the other hand, a substantial production of generative structures is not sufficient to ensure the persistence of populations in meadows in advanced stages of secondary succession.</p>