Preference of lichens for shady habitats is correlated with intolerance to high nitrogen levels

2010 ◽  
Vol 42 (4) ◽  
pp. 475-484 ◽  
Author(s):  
Markus HAUCK ◽  
Volkmar WIRTH
Keyword(s):  
Vascular Plants ◽  
Ammonium Assimilation ◽  
Ordinal Scale ◽  
Ecological Indicator ◽  
Indicator Values ◽  
High Nitrogen ◽  
Central European ◽  
Nitrogen Levels ◽  
Terricolous Lichens ◽  
Shade Adaptation

AbstractBased on findings in vascular plants showing that the capacity to provide enough carbon skeletons for rapid ammonium assimilation into amino acids is a prerequisite for tolerance to eutrophication, we tested the hypothesis that lichens from shady habitats are particularly sensitive to nitrogen pollution. We tested this hypothesis using published ecological indicator values (estimates of eutrophication tolerance and light preferences on an ordinal scale) for more than 500 central European lichen species. Our results show that shade-adapted lichens are indeed at the same time intolerant to eutrophication. However, not all eutrophication-sensitive lichens inhabit shady environments, suggesting the existence of several independent mechanisms causing intolerance of high nitrogen levels in lichens. The correlation of shade adaptation with nitrogen intolerance is limited to epiphytic and saxicolous species, since terricolous lichens are out-competed by vascular plants in dense vegetation. Our results suggest that lichen communities of shady bark, wood and rock are particularly sensitive to eutrophication.

scholarly journals Responses of Root Characteristic Parameters and Plant Dry Matter Accumulation, Distribution and Transportation to Nitrogen Levels for Spring Maize in Northeast China

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 308
Author(s):  
Yang Yu ◽  
Chunrong Qian ◽  
Wanrong Gu ◽  
Caifeng Li
Keyword(s):  
Surface Area ◽  
Nitrogen Fertilizer ◽  
Root Length ◽  
Dry Matter ◽  
Projection Area ◽  
Dry Matter Accumulation ◽  
Characteristic Parameters ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Matter Transport

Improving nitrogen use efficiency is a significant scientific problem to be solved. Two maize hybrids JD27 (Jidan 27) and SD19 (Sidan 19) were selected to study the effects of nitrogen levels on root characteristic parameters and plant dry matter accumulation, distribution and transportation. We set five different nitrogen levels, which were nitrogen deficiency (000N), low nitrogen (075N), medium nitrogen (150N), high nitrogen (225N) and excessive nitrogen (300N). The results showed that the root length and root surface area of JD27 were significantly higher than those of SD19 under 075N. With the increase of nitrogen levels, the root difference among varieties gradually decreased. The root length, projection area, total surface area and total volume reached the maximum values at silking stage. The average root diameter kept stable or decreased slowly with the growth stage. The dry matter accumulation of JD27 was higher than that of SD19 at all growth stages. Increasing the amount of nitrogen fertilizer can promote the transport of dry matter to grain and improve dry matter transport efficiency after anthesis. Under the treatment of medium and high nitrogen fertilizer, maize was easy to obtain a higher yield, but excessive nitrogen fertilizer inhibited the increase of yield. This study provides theoretical and practical guidance for maize production techniques.

scholarly journals The influence of different moisture contents and nitrogen levels on the formation of empty cavities in cucumbers (Cucumis sativus L.)

2013 ◽  
Vol 35 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Krystyna Elkner
Keyword(s):  
Soil Moisture ◽  
Cucumis Sativus ◽  
Nitrogen Fertilization ◽  
Fruit Development ◽  
High Nitrogen ◽  
Mechanical Tension ◽  
Cucumis Sativus L ◽  
Nitrogen Levels ◽  
Moisture Contents ◽  
Empty Cavity

Empty cavities were found already in very young cucumber fruits with diameter 1.5 cm. As the fruit develops the empty cavities augment and the number of fruits showing this defect increases. Low soil moisture and high nitrogen fertilization favour the formation of empty cavities. Their origination and changes were traced with anatomical methods in the course of fruit development. As a most plausible cause of their origination the author considers the enlargement of only part of the cells of the suture between the two (or three) carples. Due to this uneven enlargement of neighbouring cells strong mechanical tension probably arises amoung them, leading to the formation of ruptures separating these cells, consequently causing the separation of the carpel edges. Besides that, some of the cells of the suture which have markedly enlarged, often burst which also contributes to the formation of an empty cavity and enlarges its dimensions.

scholarly journals The role of European rare habitats in conservation of rare phytodiversity of «Drevlianskyi» Nature Reserve

2021 ◽  
pp. 31-41
Author(s):  
O. Orlov ◽  
V. Konishchuk ◽  
V. Martynenko
Keyword(s):  
Rare Species ◽  
Vascular Plants ◽  
Classification Scheme ◽  
Nature Reserve ◽  
Field Research ◽  
Habitat Directive ◽  
Central European ◽  
Bern Convention ◽  
Scots Pine Forests

Classification scheme of rare habitats of Europe according to Bern Convention and Habitat Directive of EU was presented for the territory of Drevlianskyi nature reserve. It was shown significant habitat’s diversity of nature reserve from all main types of habitats — water (permanent and temporary lakes (waterbodies), watercources, reedbeds habitats), bog (eutrophic and mesotrophic mires), grassland (dry, mesic and wet grassland, floodplain and fen scrub, heaths), forest (leaved and conifer forests (woodland), rock (rocks and talus of silicate rocks). According to the results of field research, the territory of the reserve represented by 30 habitats (1 — ІІ leaves, 4 — ІІІ leaves, 25 — ІV leaves). It is established that the most common habitat 91T0 (Central European lichen Scots pine forests), which represented by 153 localities in A1C (dry pine forest) on an area of 421.5 ha. It was made a conclusion that the role of rare habitats in nature reserve Drevlianskyi is determinant for conservation of rare species of vascular plants that are protected by the Bern Convention, European Red List and included to the Red Book of Ukraine. The results of the analysis of the role of rare biotopes of Europe in the conservation of species of flora of different protection status on the territory of Drevlianskyi nature reserve show that most of the rare plant species of reserve listed in Resolution № 6 of the Bern Convention (Annex I), revised in 2011, are present in its rare settlements. The role of rare habitats of Drevlianskyi nature reserve in the conservation of rare species of flora is decisive — of the 29 species of plants of supranational and national levels of protection in rare habitats there are 24 species or 82.8% of their total number.

Survival and Growth of Seedlings of Three Sclerophyll Species at High Levels of Phosphorus and Nitrogen

1976 ◽  
Vol 24 (6) ◽  
pp. 681 ◽  
Author(s):  
RH Groves ◽  
K Keraitis
Keyword(s):  
Sand Culture ◽  
Growth Responses ◽  
High Nitrogen ◽  
Nutrient Contents ◽  
Rooting Zone ◽  
Nitrogen Levels ◽  
High Phosphorus ◽  
Survival And Growth ◽  
Four Levels ◽  
Growth Of Seedlings

Seedlings of Banksia serrata, Acacia suaveolens and Eucalyptus pilularis were grown in sand culture for 3-4 months at four levels of phosphorus (0, 5, 50, and 100 ppm) and three of nitrogen (0, 25 and 250 ppm) applied gradually in all combinations. B.serrata died at high phosphorus-high nitrogen levels, A.suaveolens died with high phosphorus irrespective of the nitrogen level, and E. pilularis did not survive high phosphorus or high nitrogen levels. There were differences between species in their growth responses to increasing levels of phosphorus and nitrogen. Dry weights of seedlings were greatest at P5N25 for B.serrata, at P5N250 for A.suaveolens, and at P5N250 for E.pilularis. Shoot phosphorus concentrations greater than 1% were directly associated with 'toxicity' and death of A.suaveolens seedlings only, and not of the other two species. The species differ in the weights and nutrient contents of their seeds, and this is discussed in relation to the different responses obtained. Growth of sclerophyll species on areas subject to disturbance (e.g. sand-mining) will be determined in large part by the levels of phosphorus and nitrogen applied and the rate at which nutrients are leached from the rooting zone.

scholarly journals Vegetation of Croatia: Phytosociological classification of the high-rank syntaxa

2017 ◽  
Vol 76 (2) ◽  
pp. 200-224 ◽  
Author(s):  
Željko Škvorc ◽  
Nenad Jasprica ◽  
Antun Alegro ◽  
Sanja Kovačić ◽  
Jozo Franjić ◽  
...  
Keyword(s):  
Vascular Plants ◽  
High Rank ◽  
Vegetation Diversity ◽  
Central European ◽  
Floristic Richness ◽  
Level Of Knowledge ◽  
European Method ◽  
Number Of Classes ◽  
Rich Countries

AbstractCroatia is among the most ecologically diverse and floristically rich countries in Europe, with a great variety of communities. The vegetation elaboration according to the standard central European method was initiated in Croatia at the beginning of the 20thcentury. In previous overviews of Croatian vegetation, the number of classes and alliances was underrepresented in relation to the country’s floristic richness. Furthermore, the level of knowledge and the amount of available data varied greatly among the various types of vegetation. The aims of this paper are mainly to compile a stabile syntaxonomic list of classes, orders and alliances dominated by vascular plants in Croatia and to adjust Croatian vegetation to the new European syntaxonomic system (EuroVegChecklist). It introduces a consistent description of high-rank syntaxa in Croatian. In conclusion, the vegetation of Croatia comprises 66 classes, 121 orders and 201 alliances. The number of syntaxa shows vegetation diversity that is rather high compared to most other European countries; this is related to the high floristic richness and endemism. The list points out the obvious problems and gaps in our knowledge of vegetation in Croatia and can serve as a baseline for the future vegetation studies.

Proteomic Analysis for Low and High Nitrogen-Responsive Proteins in the Leaves of Rice Genotypes Grown at Three Nitrogen Levels

2012 ◽  
Vol 168 (4) ◽  
pp. 834-850 ◽  
Author(s):  
Khalid Rehman Hakeem ◽  
Ruby Chandna ◽  
Altaf Ahmad ◽  
Mohd. Irfan Qureshi ◽  
Muhammad Iqbal
Keyword(s):  
Proteomic Analysis ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Rice Genotypes

Competition between skeleton weed (Chondrila juncea L) and cereals in relation to nitrogen supply

1958 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
LF Myers ◽  
J Lipsett
Keyword(s):  
Crop Yields ◽  
Nitrogen Supply ◽  
Weed Competition ◽  
Nitrogen Application ◽  
High Nitrogen ◽  
Nitrogen Levels ◽  
Grain Nitrogen ◽  
Low Nitrogen ◽  
Yield Of Oats ◽  
Plant Growth Regulating Substances

The effect of skeleton weed competition on the yield of wheat and oats was investigated in seasons when rainfall was plentiful. Nitrogen was found to be the major factor limiting crop yields. In soils with comparable nitrogen-supplying powers, skeleton weed density governed the crop's response to applied nitrogen. Competition between skeleton weed and crop was severe at low nitrogen levels, but minor at the high nitrogen levels achieved either by nitrogen application, or when the crop followed a legume-rich pasture. Competition had its effect early in the crop's growth. Temporary removal of competition, by spraying with plant growth regulating substances (JICPA) at different times, was used to determine when competition was critical, and measure its effects. Skeleton weed reduced nitrogen supply early in the crop's growth, and so depressed yield. An application of 1 lb MCPA per acre in the fallow 54 days before sowing, or 10 days after crop emergence, increased the yield of oats from 710 to 1350 lb grain per acre: a response equal to that from 32 lb nitrogen per acre applied at planting in the same experiment. In each case, the response to spraying at the different times was analogous to the effect of a nitrogen application at these times. Early spraying gave responses in yield; later spraying gave responses in grain nitrogen. The results provide a new estimate of the reduction in crop yield due to skeleton weed.

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