Spring ephemerals of deciduous forest are adapted to take advantage of the high-light period available in early spring. They appear shortly after snow melt and complete their aboveground growth, including fruit production, within 2 months. After they produce new buds, they senesce and enter dormancy. Dormancy is not very deep in spring ephemerals and during summer differentiation occurs in the bud of the apparently resting organ. Low soil temperatures release dormancy, and the shoots and roots then grow slowly over autumn and winter. The goal of this paper is to show how this characteristic phenology influences many aspects of spring ephemerals' physiology, and the influences these different physiological parameters have on each other. Spring ephemerals have high photosynthetic rates that allow them to rapidly accumulate carbohydrates and complete their aboveground growth in a few weeks. To sustain high photosynthetic rates in early spring, the plants must be able to absorb water efficiently at low soil temperatures and to allocate large amounts of nutrients to the shoot to compensate for lower enzymatic activity at low temperatures. Nutrients are mainly absorbed in spring, although the root system is established in autumn. This means that a large amount of both carbohydrates and nutrients is translocated from the perennial organ to the developing shoot starting in autumn through early spring. Spring ephemerals have low nutrient absorption rates, but high resorption efficiency during leaf senescence. Nevertheless, their high nutrient needs restrict them to rich forest soils. The annual growth rate of spring ephemerals is very slow and this is more likely related to the inherent slow growth rate of the perennial organ than to their short leaf life. As soon as carbohydrate reserves are replenished in spring, sink limitation apparently builds up and induces leaf senescence. A better understanding of the factors controlling the growth rate of spring ephemerals is needed before we can predict these plants' response to climatic changes.

How phenology influences physiology in deciduous forest spring ephemerals: minireview [review]

For the purpose of the present study we considered as Italian endemics those specific and subspecific taxa occurring in Italy that are not found elsewhere with the exception of Corsica (France) and Malta. This study presents an updated list of the endemic taxa in the Italian flora, including their geographical distribution at regional level. Italy is characterized by 1371 endemic species and subspecies (18.9% of the total vascular flora): three taxa belong to Lycopodiidae, one to Polypodiidae, two to Pinidae and 1365 to Magnoliidae (three paleoherbs, 221 monocots and 1144 eudicots). The endemic flora belongs to 29 orders, 67 families and 304 genera. Sicily, Sardinia, Calabria and Abruzzo are the four regions richest in endemics. About 58% of endemics are confined to a single administrative region. The most represented orders, families and genera are: Asterales, Caryophyllales and Asparagales, Asteraceae, Plumbaginaceae and Caryophyllaceae, Limonium , Centaurea and Hieracium , respectively. The phytogeographic isolation of Sardinia and Sicily and the separation of peninsular Italy from Northern Italy is confirmed. The relative isolation of Puglia with respect the remaining southern Italian pensinsular regions is also confirmed. Alpine region endemics (from northern Italy) are underrepresented.

http://bot.biologia.unipi.it/chiavi/Endemiti_Peruzzi.pdf

An inventory of vascular plants endemic to Italy

Red Listing plants under full national responsibility: Extinction risk and threats in the vascular flora endemic to Italy

Biogeography of the Carpathians: evolutionary and spatial facets of biodiversity

Upward migration of plant species due to climate change has become evident in several European mountain ranges. It is still, however, unclear whether certain plant traits increase the probability that a species will colonize mountain summits or vanish, and whether these traits differ with elevation. Here, we used data from a repeat survey of the occurrence of plant species on 120 summits, ranging from 2449 to 3418 m asl, in south-eastern Switzerland to identify plant traits that increase the probability of colonization or extinction in the 20th century. Species numbers increased across all plant traits considered. With some traits, however, numbers increased proportionally more. The most successful colonizers seemed to prefer warmer temperatures and well-developed soils. They produced achene fruits and/or seeds with pappus appendages. Conversely, cushion plants and species with capsule fruits were less efficient as colonizers. Observed changes in traits along the elevation gradient mainly corresponded to the natural distribution of traits. Extinctions did not seem to be clearly related to any trait. Our study showed that plant traits varied along both temporal and elevational gradients. While seeds with pappus seemed to be advantageous for colonization, most of the trait changes also mirrored previous gradients of traits along elevation and hence illustrated the general upward migration of plant species. An understanding of the trait characteristics of colonizing species is crucial for predicting future changes in mountain vegetation under climate change.

/pdf/elevation-gradient-of-successful-plant-traits-for-colonizing-534274pon8.pdf

Elevation gradient of successful plant traits for colonizing alpine summits under climate change

Aeschimann, D., N. Rasolofo & J.-P. Theurillat (2011). Analysis of the flora of the Alps. 1: historical account and biodiversity. Candollea 66: 27–55. In French, English and French abstracts. First in a series, this paper statistically analyzes some of the data published in «Flora alpina», i.e. that relating to the nomen-clature and to the chorology in the Alps. An historical account of the knowledge of vascular plants recorded in the Alps is given: numbers of described taxa and new combinations made over time (two periods highlighted), principal authors and books. Biodiversity is characterized: number of taxa per taxonomic category, country, geographic sector and administrative division. The average taxonomic richness of the Alps is estimated at about 2200 taxa per 10,000 km2 and a map shows the values calculated for each region. Endemism is also evaluated: by family, genus, country, sector, regrouping of sectors, division and the regrouping of divisions. The southern end of the western Alps and...

Analyse de la Flore des Alpes. 1: Historique et Biodiversité

Aeschimann, D, N Rasolofo & J-P Theurillat (2011) Analysis of the flora of the Alps 2: biodiversity and chorology Candollea 66: 225–253 In French, English and French abstracts The second in a series, this paper continues the statistical analysis of the data published in «Flora alpina» The characterization of biodiversity encompasses the altitudinal and worldwide distribution of the taxa For each vegetation belt, the following results are provided: the numbers of families and genera, as well as lists of the most important ones, characteristic ones, and ones richest in endemics; the number of taxa that are present or exclusive; the rate of endemism; a cartographic pattern of endemism; and the number of taxa from each floristic contingent Comparisons are made between the western and the eastern Alps, showing that the bicentrism is more pronounced in the lower belts The relative weight of each floristic contingent is provided for the total flora and for the xenophytes, as well as being p

https://www.ville-ge.ch/cjb/publications/cando662/C662_225-253.pdf

Analyse de la Flore des Alpes. 2: Biodiversité et Chorologie

La grande flore en couleurs de Gaston Bonnier : France, Suisse, Belgique et pays voisins

Aeschimann, D., N. Rasolofo & J.-P. Theurillat (2012). Analysis of the flora of the Alps. 4: ecology. Candollea 67: 193–219. In French, English and French abstracts. The fourth in a series, this paper continues the statistical analysis of the data published in “Flora Alpina”, treating that which concerns the ecology: preferred substrate and indicator values of the soil (humidity and trophic level). Expressed as percentages, the results concerning the flora are envisaged globally, by vegetation belt, by administrative division, by floristic contingent, by family, by genus and by biological form. Among the 4485 taxa studied in the Alps, a xerophilous, calcicole and oligotrophic tendency is prominent. Within the endemics, this trend is clearly more pronounced and, moreover, they are mostly stenoecious for the substrate, because they are often in extreme habitats where edaphic determinism is considerable. On the other hand, the profile of the xenophytes is more balanced: mesophilous, euryoecious for ...

https://www.ville-ge.ch/cjb/publications/cando672/C672_193-219.pdf

Analyse de la flore des Alpes. 4: Écologie

Aeschimann, D., N. Rasolofo & J.-P. Theurillat (2012). Analysis of the flora of the Alps. 3: biology and phenology. Candollea 67: 5–21. In French, English and French abstracts. The third in a series, this paper continues the statistical analyses of the data published in «Flora alpina», focusing on that which concerns the biology (longevity, biological forms and plant height) and phenology of taxa. Expressed as percentages, the results concerning the flora are envisaged globally, by vegetation belt, by administrative division and by floristic contingent. Several cartographic patterns are presented and it is shown that, in the Alps, the percentage of annual taxa is positively correlated with the relative weight of the Mediterranean contingent, as well as with the taxonomic richness. Inversely, the percentage of perennial taxa is negatively correlated with the same data. The results confirm the predictive value of the percentages of chamaephytes in bioclimatology. Overall, more than 63% of the taxa ...

http://www.ville-ge.ch/cjb/publications/cando671/C671_5-21-abstr.pdf

David Aeschimann

Papers

Analyse de la Flore des Alpes. 1: Historique et Biodiversité

Analyse de la Flore des Alpes. 2: Biodiversité et Chorologie

La grande flore en couleurs de Gaston Bonnier : France, Suisse, Belgique et pays voisins

Analyse de la flore des Alpes. 4: Écologie

Analyse de la Flore des Alpes. 3: Biologie et Phénologie