Milium Effusum Research Articles

The response of forest plant regeneration to temperature variation along a latitudinal gradient.

The response of forest herb regeneration from seed to temperature variations across latitudes was experimentally assessed in order to forecast the likely response of understorey community dynamics to climate warming. Seeds of two characteristic forest plants (Anemone nemorosa and Milium effusum) were collected in natural populations along a latitudinal gradient from northern France to northern Sweden and exposed to three temperature regimes in growth chambers (first experiment). To test the importance of local adaptation, reciprocal transplants were also made of adult individuals that originated from the same populations in three common gardens located in southern, central and northern sites along the same gradient, and the resulting seeds were germinated (second experiment). Seedling establishment was quantified by measuring the timing and percentage of seedling emergence, and seedling biomass in both experiments. Spring warming increased emergence rates and seedling growth in the early-flowering forb A. nemorosa. Seedlings of the summer-flowering grass M. effusum originating from northern populations responded more strongly in terms of biomass growth to temperature than southern populations. The above-ground biomass of the seedlings of both species decreased with increasing latitude of origin, irrespective of whether seeds were collected from natural populations or from the common gardens. The emergence percentage decreased with increasing home-away distance in seeds from the transplant experiment, suggesting that the maternal plants were locally adapted. Decreasing seedling emergence and growth were found from the centre to the northern edge of the distribution range for both species. Stronger responses to temperature variation in seedling growth of the grass M. effusum in the north may offer a way to cope with environmental change. The results further suggest that climate warming might differentially affect seedling establishment of understorey plants across their distribution range and thus alter future understorey plant dynamics.

Temperature effects on forest herbs assessed by warming and transplant experiments along a latitudinal gradient

AbstractSlow‐colonizing forest understorey plants are probably not able to rapidly adjust their distribution range following large‐scale climate change. Therefore, the acclimation potential to climate change within their actual occupied habitats will likely be key for their short‐ and long‐term persistence. We combined transplant experiments along a latitudinal gradient with open‐top chambers to assess the effects of temperature on phenology, growth and reproductive performance of multiple populations of slow‐colonizing understorey plants, using the spring flowering geophytic forbAnemone nemorosaand the early summer flowering grassMilium effusumas study species. In both species, emergence time and start of flowering clearly advanced with increasing temperatures. Vegetative growth (plant height, aboveground biomass) and reproductive success (seed mass, seed germination and germinable seed output) ofA. nemorosabenefited from higher temperatures. Climate warming may thus increase future competitive ability and colonization rates of this species. Apart from the effects on phenology, growth and reproductive performance ofM. effusumgenerally decreased when transplanted southwards (e.g., plant size and number of individuals decreased towards the south) and was probably more limited by light availability in the south. Specific leaf area of both species increased when transplanted southwards, but decreased with open‐top chamber installation inA. nemorosa. In general, individuals of both species transplanted at the home site performed best, suggesting local adaptation. We conclude that contrasting understorey plants may display divergent plasticity in response to changing temperatures which may alter future understorey community dynamics.

An intraspecific application of the leaf-height-seed ecology strategy scheme to forest herbs along a latitudinal gradient

We measured LHS traits in 41 Anemone nemorosa and 44 Milium effusum populations along a 1900-2300 km latitudinal gradient from N France to N Sweden. We then applied multilevel models to identify th ...

Land use effects on soil N, P, C and pH persist over 40–80 years of forest growth on agricultural soils

Previous cultivation may have long-lasting effects on oak forests, e.g., nitrogen (N) and carbon (C) depletion, phosphorus (P) enrichment and lowered soil acidity, which may influence soil processes, wood production and plant diversity. We used a large database on land use to sample 18 sites where oak had been planted 40–80 years ago on continuously forested land and formerly cultivated fields that had similar soil properties before the different land uses. We estimated the ‘total’ pools of N, P and C and ‘available’ fractions of N and P at three soil depths. The soil data were compared with element concentrations in leaves of four plant species. Soil solution concentration of nitrate at 50–60 cm was used as an estimate of nitrate leaching. Total N and mineralisable N in the soil were higher in the continuously forested land than in the formerly cultivated fields and this was reflected in the N concentration in Dryopteris filix-mas. Total P and available P tended to be lower in the continuously forested land than in the formerly cultivated fields which were reflected in the P concentrations in Dryopteris and Quercus robur. Soil C was higher and pH was lower in the continuously forested land than in the formerly cultivated fields. Leaching of NO 3 −-N started to appear in higher concentrations below pH 4.5 and the leaching is interpreted more as a pH than a land use effect. Aluminium (Al) concentrations were higher in Dryopteris and Quercus and the iron (Fe) concentration in Milium effusum, while calcium (Ca) was lower in all plant species. Potassium (K) was lower in Stellaria holostea and no difference was found for the magnesium (Mg) concentration in plants. As previous land use seems to affect soil nutrients and potentially toxic elements it is important to identify the limiting factors for the different ecosystem components to be able to manage the forests correctly. It is probable that areas with significant N deposition are not N-limited even in the N-depleted formerly cultivated fields and that a higher P content and soil pH there may result in higher biomass production and changes in plant diversity. The risk of nitrate leaching in the most acidic, continuously forested land must also be taken into consideration in the management of forests.

Plant nitrate use in deciduous woodland: the relationship between leaf N, 15N natural abundance of forbs and soil N mineralisation

Our aim was to study whether the in situ natural abundance 15N (δ15N)-values and N concentration of understory plants were correlated with the form and amount of mineral N available in the soil. Also to determine whether such differences were related to earlier demonstrations of differences in biomass increase in the same species exposed to nutrient solutions with both NO3− and NH4+ or to NH4+ alone. Several studies show that the δ15N of NO3− in soil solution generally is isotopically lighter than the δ15N of NH4+ due to fractionation during nitrification. Hence, it is reasonable to assume that plant species benefiting from NO3− in ecosystems without significant NO3− leaching or denitrification have lower δ15N-values in their tissues than species growing equally well, or better, on NH4+. We studied the δ15N of six understory species in oak woodlands in southern Sweden at 12 sites which varied fivefold in potential net N mineralisation rate (minNH4++NO3−). The species decreased in benefit from NO3− in the following order: Geum urbanum, Aegopodium podagraria, Milium effusum, Convallaria majalis, Deschampsia flexuosa and Poa nemoralis. Four or five species demonstrated a negative correlation between minNO3− and leaf δ15N and a positive correlation between minNO3− and leaf N concentration. In wide contrast, only D. flexuosa, which grows on soils with little nitrification, showed a positive correlation between minNH4+ and the leaf N concentration and δ15N-value. Furthermore, δ15N of plants from the field and previously obtained indices of hydroponic growth on NH4+ relative to NH4++NO3− were closely correlated at the species level. We conclude that δ15N may serve as a comparative index of uptake of NO3− among understory species, preferably in combination with other indices of N availability. The use of δ15N needs careful consideration of known restrictions of method, soils and plants.

The importance of recruitment limitation in forest plant species colonization: a seed sowing experiment

Summary Flora and vegetation of ancient forests differ from that of new forests. Former agricultural use is still detectable in the composition of the flora centuries after new forests are established. The reason for the very slow migration of some forest species has been discussed and it has been suggested that establishment of ancient forest species in new forests may be hampered by altered soil conditions and competitive species in new forests. In the present paper we tested whether ancient and other forest species are able to germinate and establish in new or ancient forest after seed addition. Eight herb species were sown in 5 ancient forests and 4 recent forests in Eastern Denmark in 1998. Four of the species had been shown in previous investigations to occur more often in ancient forests (Vicia sepium, Roegneria canina, Impatiens noli-tangere, Rumex sanguineus); whereas the remaining four occurred equally in ancient and recent forests (Galium odoratum, Milium effusum, Impatiens parviflora, Circaea lutetiana). Two of four ancient forest species (Impatiens noli-tangere and Rumex sanguineus) seemed unable to germinate in the experiment wherever they were sown. The two other ancient forest species and the four forest species with no preference for ancient forests all increased their abundance after seed addition in both forest types, but most in new forests. Though soil variables were important for the distribution of most species, germination seemed less affected except for one ancient forest species. The general picture was that soil variables did not influence the germination and establishment of new plants, and did not inhibit establishment more in new forests than in ancient, but this experiment only recorded the effect for two years after sowing and the soil variables may prove to be important over a longer period of time series. Seed size was not related to germination of species.

Additions to the flora of the Khentei, Mongolia

Dulamsuren, C. & Mühlenberg, M.: Additions to the flora of the Khentei, Mongolia. — Willdenowia 33: 149–158. 2003. — ISSN 0511-9618; © 2003 BGBM Berlin-DahlemForty-four species of vascular plants are reported as new for the phytogeographical region Khentei in northern Mongolia. Five of them, i.e., Carex chordorrhiza, C. praecox, Cinna latifolia, Matteuccia struthiopteris and Milium effusum are new for Mongolia.

Interspecies differences in the preference of ammonium and nitrate in vascular plants.

Three solution experiments were performed to test the importance of NH 4+ versus NO 3- +NH 4+ to growth of 23 wild-forest and open-land species, using field-relevant soil solution concentrations at pH 4.5. At N concentrations of 1-200 μM growth increased with increasing N supply in Carex pilulifera, Deschampsia flexuosa, Elymus caninus and Bromus benekenii. Geum urbanum was the most N demanding species and had little growth below 200 μM. The preference for NH 4+ or NO 3- +NH 4+ was tested also at pH 4.0; no antagonism was found between NH 4+ and H+, as indicated by similar relative growth in both of the N treatments at both pH levels. Growth in solution with NH 4+ relative to NO 3- +NH 4+ , 200 μM, was negatively related to the mean pH of the field occurrence of the species tested; acid-tolerant species grew equally well with only NH 4+ as with NO 3- +NH 4+ (Oxalis acetosella, Carex pilulifera, Festuca gigantea, Poa nemoralis, Deschampsia flexuosa, Stellaria holostea, Rumex acetosella), while species of less acid soils were favoured by NO 3- +NH 4+ (Urtica dioica, Ficaria verna, Melandrium rubrum, Aegopodium podagraria, Geum urbanum, Bromus benekenii, Sanguisorba minor, Melica ciliata, Silene rupestris, Viscaria vulgaris, Plantago lanceolata). Intermediate species were Convallaria majalis, Elymus caninus, Hordelymus europaeus and Milium effusum. No antagonism between NH 4+ and Ca2+, Mg2+ and K+ was indicated by the total uptake of the elements during the experiment.

Relative importance of exchangeable and soil solution cation concentrations to the distribution of vascular plants

The distribution of the 11 most frequent vascular plant species in a beech forest with highly variable top-soil chemistry in southern Sweden was compared to the concentrations of cations in the soil solution (obtained by centrifugation) and the exchangeable soil pool (obtained by extraction with 0.1 M BaCl 2). Cations analyzed were H, K, Ca, Mg, Mn and Al (in soil solution, both total and easily-reacting Al). The plant species considered were Anemone nemorosa, Deschampsia flexuosa, Gagea spathacea, Galium odoratum, Lamium galeobdolon, Luzula pilosa, Melica uniflora, Milium effusum, Oxalis acetosella, Stellaria holostea and Stellaria nemorum. The exchangeable and soil solution fractions of most cations accounted to the same extent for the distribution of plants. Close relationships to plant distributions were found at the upper and lower pH intervals studied. The distribution of species at intermediate pH could only marginally be accounted for by soil cation concentrations.

Importance of ammonium and nitrate to the performance of herb-layer species from deciduous forests in Southern Sweden

Experiments were performed on the effect on growth and uptake of nitrogen given as NH 4 and/or NO 3 in a nutrient solution (pH 4.2) of a composition similar to that of the rhizosphere soil solution of an acidic beech forest but lacking Al. Seven treatments (0.2 and 0.4 mM NH 4 and NO 3, respectively, and 0.1 + 0.1, 0.2 + 0.2, 0.4 + 0.4 mM of NH 4 + NO 3) were used in a flowing solution culture without recirculation. The seven species tested have ecological distributions which range from very acid soils with low nutrient levels and nitrogen mainly present as NH 4, to less acidic and nitrifying soils. In the solution experiment, species occurring in very acidic soils had small preferences for nitrogen form or combination ( Deschampsia flexuosa, Carex pilulifera, Milium effusum), while Aegopodium podagraria of less acidic soils preferred NO 3. The other three species, Poa nemoralis, Bromus benekenii and Carex sylvatica, grew best in a mixed solution. Results of a short-term (2–24 hr) exposure experiment showed that all species had a higher nitrogen uptake from NH 4 in the solo and mixed solutions. Total N uptake was, however, similar for the solo NH 4 and mixed solutions for all species except D. flexuosa and C. pilulifera, which had the highest N uptake with solo NH 4. It was concluded that none of the species studied grew best when NH 4 was supplied as the sole N source. This may restrict the distribution of species in very acid soils, where nitrification may be lacking.

Experimental evidence for the relative sensitivity of deciduous forest plants to high soil acidity

Thirteen species of deciduous forest vascular plants were established from seeds: Brachypodium sylvaticum, Carex sylvatica, Circaea lutetiana, Deschampsia flexuosa, Galium odoratum, Lamium galeobdolon, Lathyrus vernus, Luzula pilosa, Milium effusum, Poa nemoralis, Sanicula europaea, Stellaria holostea and Stellaria nemorum. An acid beech forest soil was variously treated with carbonates (CaCO 3 + MgCO 3 or SrCO 3) to obtain a soil solution pH of 3.3–5.2. The experimental results were compared with the field distribution of the same species in 230 south Swedish deciduous forests with regard to soil pH. In general, the species reacted to increasing soil pH in accordance with their field distribution. Addition of SrCO 3 was almost equally effective as CaCO 3 + MgCO 3 (both at pH 4.2 in the soil solution) in promoting establishment and growth, whereas most species failed in the untreated soil (pH 3.3). There were no indications that the Ca or Mg concentrations of the soil solution were below minimum or even suboptimal for plant growth in the untreated soil. Within the pH range (pH ⩽ 3.5–4.3) which proved critical to establishment and growth in most of the species, the reactive Al 3+ concentration of the soil solution did not vary significantly. It is suggested that the high acidity of the rhizosphere solution, possibly aggravated by Al 3+, obstructed the uptake or retention of mineral nutrients by the roots in the untreated acid beech forest soil.

Variation in nuclear DNA amount between wild and cultivated populations of Milium effusum (2n = 28)

Mean 2C DNA amounts varied by 35.6%, ranging from 7.52 to 10.20 pg, between 10 populations of the grass Milium effusum L. Such intraspecific variation occurred despite a constant chromosome number (2n = 28) and no obvious differences in karyotype. Plants originating from botanic garden populations growing in cultivation had significantly (P < 0.001) larger DNA amounts than plants collected from wild populations. Moreover, variation in DNA amount within either the "cultivated" or the "wild" groups was not significant. As the environment in which plants are kept in botanic gardens is clearly different to the natural habitat for M. effusum, it seems likely that the difference in nuclear DNA amount is causally related, perhaps through its nucleotypic effects, to microclimate adaptation. These results suggest that at least some genotypes of M. effusum are fluid and sensitive to environmental change. Such data may have broad practical importance regarding plant responses to various environmental changes such as a nuclear winter and global warming, and implications for plant conservation and reintroduction. Milium effusum is a potentially useful plant material for studying the nature of intraspecific variation in DNA amount.Key words: Milium effusum, nuclear DNA amounts, nucleotype, environmental adaptation.

Karyological analysis and genome size in Milium (Gramineae) with special reference to polyploidy and chromosomal evolution

Karyotypes, nuclear DNA amounts, and meiotic behaviour are presented for Milium effusum L. (2n = 28), Milium montianum Parl. (2n = 22), and two cytotypes of Milium vernale Bieb. (2n = 8, 10). The bimodal karyotype of M. montianum (8 large and 14 small chromosomes) is described for the first time. Evidence from C-banding and geographical distribution suggests an ancient interracial allopolyploid origin for M. effusum (2n = 28). Although M. montianum is undoubtedly allopolyploid, its parentage is unconfirmed. A strong resemblance between the M. vernale (2n = 8) karyotype and the eight large chromosomes in M. montianum suggests a common ancestry. It is possible that a diploid form of M. effusum contributed the remaining 14 chromosomes. A selective loss of DNA sequences from the smaller chromosomes during the subsequent reorganization of the allopolyploid genome may have enhanced the bimodality of the karyotype. Geographical distribution and a change in the breeding system support the direction of the change x = 5 to x = 4 in M. vernale. Allopolyploidy appears to have played a central role in the chromosome evolution and speciation of Milium.Key words: Milium (Gramineae), karyotype analysis, genome size, polyploidy, chromosome evolution.

Dynamic floristic changes of Swedish beech forest in relation to soil acidity and stand management

This study reports dynamic changes in the beech forest vegetation during one decade, using 95 permanent observation areas representing a wide variety of soils and management regimes. Current soil acidification, including decreasing pH and base cation pools, increasing solubility of toxic elements and increasing deposition of N, as well as recent changes in the beech forest management have created good conditions for the study. Most species of vascular plants increased their frequencies during the 1980's. However, there were several notable exceptions, in particularGalium odoratum, Viola riviniana/reichenbachiana, Polygonatum multiflorum, andMercurialis perennis. These species, demanding a comparatively low soil acidity for survival, are distinctly disfavoured by the long-term soil changes in the forests, which seem to have approached or exceeded their limits of existence in many sites. With most other species, differences in management regimes between the beginning and the end of the observation period were more important to the frequency changes. Sensitive to heavy thinning of the stands were, e.g.Oxalis acetosella, Lamium galeobdolon andMelica uniflora, favoured by thinning wereStellaria nemorum, Carex pilulifera, Milium effusum and an appreciable number of more ephemeral species normally occurring in clear-cut areas or otherwise open land, e.g.,Rubus idaeus, Galeopsis tetrahit, Athyrium filix-femina, Juncus effusus, Agrostic capillaris, Veronica officinalis, Urtica dioica, andMoehringia trinervia. Saplings of woody plants usually also became more frequent during the 1980's.

Verteilung von Schwermetallen im Wurzelbereich und den Organen von Waldbodenpflanzen aus Buchenwäldern

Heavy metal distribution in the root area and in organs of three plant species ( Milium effusum, Athyrium filix-femina, Avenella flexuosa ) was investigated. Correlations were calculated between plant available heavy metal contents in the root area of the soil and the total element contents of roots, rhizoms and leaves. It was shown that heavy metals are accumulated selectively in different plant organs. The highest contents of Cd, Pb and Cu were found in the roots. Increasing lead contents in the roots of Athyrium filix-femina may lead to a reduction of root dry mass and to a decrease of root density.

Distribution of field layer species in Swedish deciduous forests in 1929-54 and 1979-88 as related to soil pH

Literature data on vascular plant distribution in deciduous forests were compared in 1929-54 and 1979-88. pH in the topsoil was related to the occurrence of 13 common vascular plants. The median of pH (H2O) was 5.2 for the old (n=105) and 4.4 for the new plots (n=132). New plots of pH>5 were scarce and soils of pH<4 were limited to the new plots. Comparison of the pH related frequency curves gave four patterns: (A) a displacement of frequency curves towards lower pHs for the new plots (Stellaria holostea, Milium effusum, Melica uniflora); (B) a widening of the frequency curves into lower pH for the new plots (Viola riviniana/reichenbachiana, Galium odoratum, Lamium galeobdolon, Oxalis acetosella, Maianthemum bifolium); (C) a raised frequency curve for the new plots at all pHs (Stellaria nemorum, Poa nemoralis, Rubus idaeus, Mercurialis perennis); (D) a lowered frequency curve for the new plots at all pHs (Deschampsia flexuosa). It is deduced, that the pH related frequency curves are not stable over long periods as e.g. the studied 40–60 years. The increased amounts of nitrogen and acidifying substances in deposition probably caused an altered soil chemistry and a change in competition among nitrogen favoured and acid tolerant species. As the soil in the new plots was more acidic, the total frequency was higher for many species. However, the frequency of most species decreases with soil pH, and if soil acidification continues without further plant adaptation to low soil pH, there will be a decrease of many species.

The major flavonoids in the leaves of Milium effusum L.

Specimens from natural populations of Milium effusum were analysed for their flavonoid contents. Four major flavonoids were commonly found and these were identified as quercetin 3- O-rutinoside, quercetin 3- O-glucoside, kaempferol 3- O-rutinoside and kaempferol 3- O-glucoside. In addition, most populations showed some other flavonoids which were present in trace amounts. Miliumis rare amongst the grasses in having flavonols as the major leaf flavonoids.

The resource balance of Milium effusum with emphasis on environmental resource supply.

Growth of the broad-leaved graminoid Milium effusum, occurring in shady deciduous forests, was matched with periods of high light influx through the tree canopy in spring and autumn. Fertile shoots grew faster than sterile shoots. Leaves on flowering shoots were fully developed when the budbreak started on the trees, whereas nonflowering shoots had fully developed leaves when the tree canopy closed. Leaf concentrations of N and P were high (6.1 and 0.74% respectively) in spring but decreased as the leaves expanded. Maximum pool sizes of N and P in whole tillers were reached about one month after the onset of spring growth, whereas maximum spring pools of K, Mg, and Ca were timed with peak biomass about one month later. The leaves lost nutrients during summer when no growth took place. Since leaching losses were negligible, nutrients were probably allocated from the leaves to support root growth. Autumn reallocation to winter stores was low. The pattern of growth and nutrient use suggests that light availability, i.e., the resource in relatively lowest supply, regulates the investment of the resource in highest supply, i.e., nutrients. This is consistent with previously reported observations on Eriophorum vaginatum, a graminoid of low nutrient - high light environments. This species utilizes nutrients efficiently at the expense of less efficient acquisition of carbon. We suggest that selection for efficient utilization of the resource in lowest relative supply has been a strong driving force behind the physiological adaptation of both species to their environments.

Buried germinative seeds in mature beech forests with different herbaceous vegetation and soil types

The seed banks in the soils of seven mature beech forests in southern Sweden were examined using the seedling‐emergence method. Seedling emergence in the field was also studied. In the studied forests, covering a wide range of vegetation and soil types, between 1020 and 4500 germinating seeds m−2 were found in the seed bank. Seed abundance showed no apparent relationship with the type of soil or vegetation at the sites, but the highest number of species in the seed bank was found on the mull sites. The species diversity of germinative seeds increased strongly with increasing soil fertility.Only a minor part (10–35%) of the species in the germinable part of the seed bank were represented in the vegetation. Soil samples from the oligotrophic sites mainly contained graminoids, notably Carex spp., while herbs dominated the seed banks of the rich mull sites. Seeds of e.g. Stellaria nemorum, Oxalis acetosella, Moehringia trinervia, Viola rivinianalreichenbachiana, Melica uniflora, and Milium effusum were especially abundant in the mull soils. Woody species were infrequent on all sites, and no representatives of the early spring flora were noted in the germination tests.In the mor and moder soils most seeds were recovered from the mineral soil, and they were believed to originate from early stages in the succession of the forest. Several sites had comparatively large seed banks of species that typically occur in disturbed forests, e.g. Juncus effusus and Rubus idaeus, but very few germinating seeds belonged to species restricted to non‐forest habitats. Emerging seedlings in the field were only observed on the mull and moder sites. With few exceptions they belonged to species, which were common both in the seed banks and in the vegetation.

Effects of phenolic acids on growth, mineral composition and chlorophyll content of some herbaceous woodland species

AbstractFive herbaceous plant species from woodland(‐clearings), Silene dioica, Scrophularia nodosa, Holcus lanatus, Milium effusum and Deschampsia flexuosa were tested for their sensitivity for phenolic acids. These are important intermediate products in the decomposition of litter material. A mixture of 7 commonly occuring phenolic acids was added to nutrient solutions in concentrations of 10−5, 10−4 and 10−3M. Growth was reduced at the highest concentration; S. dioica was the most and D. flexuosa the least influenced species. Both chlorophyll and mineral contents of the plants were influenced by phenolic acids, but the effects seemed to be species dependent. The results are discussed in view of their importance for the relationship between trees and understory vegetation.