In forestry and ecology, understory comprises plant life growing beneath the forest canopy without penetrating it to any great extent, but above the forest floor. Only a small percentage of light penetrates the canopy so understory vegetation is shade tolerant; the understory consists of trees stunted through lack of light, other small trees with low light requirements, shrubs and undergrowth. Small trees such as holly and dogwood are understory specialists. In temperate deciduous forests, many understory plants start into growth earlier than the canopy trees to make use of the greater availability of light at this time of year. A gap in the canopy caused by the death of a tree stimulates the potential emergent trees into competitive growth as they grow upwards to fill the gap; these trees tend to have straight trunks and few lower branches. At the same time, the bushes and plant life on the forest floor become more dense; the understory experiences greater humidity than the canopy, the shaded ground does not vary in temperature as much as open ground.

This causes a proliferation of ferns and fungi and encourages nutrient recycling, which provides favorable habitats for many animals and plants. The understory is the underlying layer of vegetation in a forest or wooded area the trees and shrubs growing between the forest canopy and the forest floor. Plants in the understory comprise an assortment of seedlings and saplings of canopy trees together with specialist understory shrubs and herbs. Young canopy trees persist in the understory for decades as suppressed juveniles until an opening in the forest overstory permits their growth into the canopy. In contrast understory shrubs complete their life cycles in the shade of the forest canopy; some smaller tree species, such as dogwood and holly grow tall and are understory trees. The canopy of a rainforest is about 10m thick, intercepts around 95% of the sunlight; the understory receive less intense light than plants in the canopy and such light as does penetrate is impoverished in wavelengths of light that are most effective for photosynthesis.

Understory plants therefore must be shade tolerant—they must be able to photosynthesize adequately using such light as does reach their leaves. They are able to use wavelengths that canopy plants cannot. In temperate deciduous forests towards the end of the leafless season, understory plants take advantage of the shelter of the still leafless canopy plants to "leaf out" before the canopy trees do; this is important because it provides the understory plants with a window in which to photosynthesize without the canopy shading them. This brief period is a crucial period in which the plant can maintain a net positive carbon balance over the course of the year; as a rule forest understories experience higher humidity than exposed areas. The forest canopy reduces solar radiation, so the ground does not heat up or cool down as as open ground; the understory dries out more than more exposed areas do. The greater humidity encourages epiphytes such as ferns and mosses, allows fungi and other decomposers to flourish.

This drives nutrient cycling, provides favorable microclimates for many animals and plants, such as the pygmy marmoset. Overgrazing Layers of rainforests

Quercus rubra

Quercus rubra, the northern red oak, is an oak tree in the red oak group. It is a native of North America, in the eastern and central United States and southeast and south-central Canada, it grows from the north end of the Great Lakes, east to Nova Scotia, south as far as Georgia, Mississippi and Louisiana, west to Oklahoma, Kansas and Minnesota. It has been introduced to small areas in Western Europe, where it can be seen cultivated in gardens and parks, it prefers good soil, acidic. Called red oak, northern red oak is so named to distinguish it from southern red oak known as the Spanish oak, it is sometimes called champion oak. It is the state tree of New Jersey and the provincial tree of Prince Edward Island. In many forests, this deciduous tree grows straight and tall, to 28 m, exceptionally to 43 m tall, with a trunk of up to 50–100 cm diameter. Open-grown trees can develop a stouter trunk, up to 2 m in diameter, it has stout branches growing at right angles to the stem. It grows and is tolerant of many soils and varied situations, although it prefers the glacial drift and well-drained borders of streams.

In the southeastern United States, it is a part of the canopy in an oak-heath forest, but not as important as some other oaks. Under optimal conditions and full sun, northern red oak is fast growing and a 10-year-old tree can be 5–6 m tall. Trees may live up to 400 years and a living example of 326 years was noted in 2001. Northern red oak is easy to recognize by its bark, which features ridges that appear to have shiny stripes down the center. A few other oaks have bark with this kind of appearance in the upper tree, but the northern red oak is the only tree with the striping all the way down the trunk. Northern red oak is the most common species of oak in the northeastern US after the related pin oak; the red oak group as a whole are more abundant today than they were when European settlement of North America began as forest clearing and exploitation for lumber much reduced the population of the dominant white oaks. As with most other deciduous oaks, leafout takes place in spring when day length has reached 13 hours--it is tied to photoperiod and will take place regardless of air temperature.

As a consequence, in cooler regions, northern red oaks lose their flowers to late spring frosts, resulting in no seed crop for the year. The catkins and leaves emerge at the same time; the ripe acorns are released from the tree in early October, leaf drop begins when day length falls under 11 hours. The timing of leafout and leaf drop can vary by as much as three weeks in the northern and southern US. Seedlings emerge in spring when soil temperatures reach 70°F. Bark: Dark reddish gray brown, with broad, rounded ridges, scaly. On young trees and large stems and light gray. Rich in tannic acid. Branchlets slender, at first bright green, shining dark red dark brown. Bark is brownish gray. Wood: Pale reddish brown, sapwood darker, hard, coarse-grained. Cracks in drying, but when treated could be used for furniture. Used in construction and for interior finish of houses. Sp. gr. 0.6621. Winter buds: Dark chestnut brown, acute 6 mm long Leaves: Alternate, seven to nine-lobed, oblong-ovate to oblong, five to ten inches long, four to six inches broad.

Lobes are less cut than most other oaks of the red oak group. Leaves emerge from the bud convolute, covered with soft silky down above, coated with thick white tomentum below; when full grown are dark green and smooth, sometimes shining above, yellow green, smooth or hairy on the axils of the veins below. In autumn they turn a rich red, sometimes brown; the petiole and midvein are a rich red color in midsummer and early autumn, though this is not true of all red oaks. The acorns mature in about 18 months after pollination, its kernel is white and bitter. Despite this bitterness, they are eaten by deer and birds. Red oak acorns, unlike the white oak group, display epigeal dormancy and will not germinate without a minimum of three months' exposure to sub-40 °F temperatures, they take two years of growing on the tree before development is completed. Over the last few decades, the northern red oak has dealt with several environmental factors disease, predation by insects, limited opportunities for dispersal.

These stresses have impacted the species' ability to proliferate in both the Europe. The various environmental responses observed in Quercus rubra across several temperate environmental conditions have allowed for it to serve as a model organism for studying symbiotic relationships and habituation between tree species. Canker pathogen, Diplodia corticola, has become a major pathogen to the species over the last decade, causing leaf browning, bark cracking an

Fanndís Friðriksdóttir

Fanndís Friðriksdóttir is an Icelandic football player who plays as a left winger for Valur in the Icelandic Úrvalsdeild kvenna, for Australian club Adelaide United for the 2018–19 W-League season. She spent the 2017-2018 season with Olympique de Marseille in the French Division 1 Féminine and has played in the Úrvalsdeild kvenna for Breiðablik and the Norwegian Toppserien for Kolbotn and Arna-Bjørnar. Fanndís has been a part of the Iceland's national team since 2009 and represented her country at the 2009, 2013 and 2017 editions of the UEFA Women's Championship. Born in Akureyri, Fanndís grew up in Vestmannaeyjar where she start playing in the youth teams of ÍBV before moving to Kópavogur in 2004, to play professionally for Breiðablik. After eight seasons at the Icelandic Úrvalsdeild kvenna with Breiðablik, where she scored 50 goals in 107 league matches, Fanndís decided to join Norwegian Toppserien club Kolbotn, signing a year contract on 6 December 2012. Ahead of her second season in Norway, she moved from Kolbotn to Arna-Bjørnar in December 2013.

On 15 May 2014, Fanndís was released from her contract by Arna-Bjørnar after requesting a move back to Iceland to play for Breiðablik. As the request happened during Icelandic's last players transfer registration day, it was only confirmed on the following day, that Fanndís was registered as a Breiðablik player, her second spell at the club. At the end of the 2017 season, after four seasons of her second spell at Breiðablik, she had a combined total of 104 goals scored in 197 matches in all Icelandic domestic competitions, of which 97 goals were scored in 173 league matches. In August 2017, she became the first Icelandic female player to join a French Division 1 Féminine club by signing a year contract to play for Olympique de Marseille. On June 27, 2018, Fanndís signed with Úrvalsdeild kvenna club Valur. In September 2018, she was loaned to Adelaide United of the Australian W-League, she scored 2 goals in 11 matches for the club, witch finished 6th in the league, 1 point out of the playoffs.

Fanndís has represented Iceland since 2005 at the under 17 team, progressing to the under 19 and arriving at the senior team in 2009, making her senior international debut on 9 March 2009 in a 2–0 defeat by Denmark at the 2009 Algarve Cup. A few months she was called up to be part of Iceland squad at the UEFA Women's Euro 2009, where she made two brief substitute appearances as Iceland were eliminated in the first round, she played matches at the 2011 FIFA Women's World Cup qualification, 2010 Algarve Cup, 2011 Algarve Cup and UEFA Women's Euro 2013 qualification before scoring her first goal for Iceland on 5 March 2012 in a 1–0 win over China at the 2012 Algarve Cup. Her second goal came on 15 September 2012 at a UEFA Women's Euro 2013 qualification 2–0 win over Northern Ireland. After playing the 2013 Algarve Cup and friendly matches, national team coach Siggi Eyjólfsson selected Fanndís in the Iceland squad for the UEFA Women's Euro 2013, she started three out of the four matches Iceland played in the tournament, including the Quarterfinal 4–0 defeat by Sweden.

Fanndís scored her third goal on 10 March 2014 in a 1–0 win over China at the 2014 Algarve Cup. Her fourth and fifth goals came during the 2015 FIFA Women's World Cup qualification, the fourth on 10 April 2014 in an 8–0 win over Malta and the fifth on 13 September 2014 in a 3–0 win over Israel. After playing the 2015 Algarve Cup and 2016 Algarve Cup, Fanndís scored again during the UEFA Women's Euro 2017 qualification matches, with her first brace for Iceland on 7 June 2016 in an 8–0 win over Macedonia and one more goal came on 20 September 2016 in a 2–1 defeat by Scotland, taking her tally to eight goals, her ninth and tenth were scored at the 2016 Sincere Cup, on 20 October 2016 in a 2–2 draw with China and on 24 October 2016 in a 1–0 win over Uzbekistan. She took part at the 2017 Algarve Cup and played in some friendly matches before national coach Freyr Alexandersson selected her to the national team for the UEFA Women's Euro 2017. Fanndís started all three matches Iceland played in the tournament, scoring the country's only goal in the tournament and her 11th goal for Iceland, on 22 July 2017 in a 2–1 defeat by Switzerland.

Fanndís scored her second brace for the national team during Iceland opening match of the 2019 FIFA Women's World Cup qualification on 18 September 2017 in an 8–0 win over Faroe Islands, it took her tally to 13 goals. Fanndís's father is former Iceland men's national football team goalkeeper Friðrik Friðriksson and her mother is former Olympic alpine skier Nanna Leifsdóttir. Úrvalsdeild kvenna: Winner 2005, 2015 Icelandic Women's Cup: Winner 2005, 2016 Most Promising Player in Breiðablik in 2008 Úrvalsdeild kvenna Player of the year in 2015 Fanndís Friðriksdóttir Profile at KSÍ Fanndís Friðriksdóttir at the Norwegian Football Federation Player French domestic stats at