Importance of Trees in our life You must be known

Common ash (Fraxinus excelsior), a deciduous broad-leaved (angiosperm) tree

European larch (Larix decidua), a coniferous tree which is also deciduous

In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. Trees are not a taxonomic group but include a variety of plant species that have independently evolveda woody trunk and branches as a way to tower above other plants to compete for sunlight. Trees tend to be long-lived, some reaching several thousand years old. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees have been in existence for 370 million years. It is estimated that there are just over 3 trillion mature trees in the world.^[1]

A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier. Below the ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development.

Earth

Earth is the third planet from the Sun, and the only astronomical object known to harbor life. According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago.^[24][25][26] Earth's gravityinteracts with other objects in space, especially the Sun and the Moon, Earth's only natural satellite. Earth orbits around the Sunin 365.26 days, a period known as an Earth year. During this time, Earth rotates about its axis about 366.26 times.^{[n 5]}

Earth

The Blue Marble, the first full-view photograph of the planet, was taken by Apollo 17 astronauts en route to the Moon in 1972
Designations
Adjectives	Earthly, terrestrial
Orbital characteristics
Epoch J2000[n 1]
Aphelion	152100000 km[n 2] (94500000 mi; 1.017 AU)
Perihelion	147095000 km[n 2] (91401000 mi; 0.98327 AU)
Semi-major axis	149598023 km[1] (92955902 mi; 1.00000102 AU)
Eccentricity	0.0167086[1]
Orbital period	365.256363004 d[2] (1.00001742096 yr)
Average orbital speed	29.78 km/s[3] (107200 km/h; 66600 mph)
Mean anomaly	358.617°
Inclination	7.155° to the Sun's equator; 1.57869°[4] to invariable plane; 0.00005° to J2000 ecliptic
Longitude of ascending node	−11.26064°[3] to J2000 ecliptic
Argument of perihelion	114.20783°[3]
Satellites	1 natural satellite: the Moon 5 quasi-satellites >1 800 operational artificial satellites[5] >16 000 space debris[n 3]
Physical characteristics
Mean radius	6371.0 km (3958.8 mi)[6]
Equatorial radius	6378.1 km (3963.2 mi)[7][8]
Polar radius	6356.8 km (3949.9 mi)[9]
Flattening	0.0033528[10] 1/298.257222101(ETRS89)
Circumference	40075.017 km equatorial(24901.461 mi)[8] 40007.86 km meridional(24859.73 mi)[11][12]

The Sun is the star at the center of the Solar System

The Sun is the star at the center of the Solar System. It is a nearly perfect sphere of hot plasma,^[15][16] with internal convective motion that generates a magnetic field via a dynamo process.^[17] It is by far the most important source of energy for life on Earth. Its diameter is about 1.39 million kilometers (864,000 miles), or 109 times that of Earth, and its mass is about 330,000 times that of Earth. It accounts for about 99.86% of the total mass of the Solar System.^[18] Roughly three quarters of the Sun's mass consists of hydrogen(~73%); the rest is mostly helium (~25%), with much smaller quantities of heavier elements, including oxygen, carbon, neon, and iron.^[19]

Sun

Sun with sunspots and limb darkening as seen in visible light with solar filter.
False-color photo of the Sun as seen in ultraviolet light (wavelength of 30.4 nm)
Observation data
Mean distance from Earth	1 au ≈ 1.496×108 km[1] 8 min 19 s at light speed
Visual brightness (V)	−26.74[2]
Absolute magnitude	4.83[2]
Spectral classification	G2V[3]
Metallicity	Z = 0.0122[4]
Angular size	31.6–32.7 minutes of arc[5]
Adjectives	Solar
Orbital characteristics
Mean distance from Milky Way core	≈ 2.7×1017 km 27,200 light-years
Galactic period	(2.25–2.50)×108 yr
Velocity	≈ 220 km/s (orbit around the center of the Milky Way) ≈ 20 km/s (relative to average velocity of other stars in stellar neighborhood) ≈ 370 km/s[6] (relative to the cosmic microwave background)
Physical characteristics
Equatorial radius	695,700 km,[7] 696,342 km[8] 109 × Earth[9]
Equatorial circumference	4.379×106 km[9] 109 × Earth[9]
Flattening	9×10−6
Surface area	6.09×1012 km2[9] 12,000 × Earth[9]
Volume	1.41×1018 km3[9] 1,300,000 × Earth
Mass	1.9885×1030 kg[2] 333,000 × Earth[2]
Average density	1.408 g/cm3[2][9][10] 0.255 × Earth[2][9]
Center density(modeled)	162.2 g/cm3[2] 12.4 × Earth
Equatorial surface gravity	274 m/s2[2] 28 × Earth[9]
Moment of inertia factor	0.070[2] (estimate)
Escape velocity (from the surface)	617.7 km/s[9] 55 × Earth[9]
Temperature	Center (modeled): 1.57×107 K[2] Photosphere (effective): 5,778 K[2] Corona: ≈ 5×106 K
Luminosity (Lsol)	3.828×1026 W[2] ≈ 3.75×1028 lm ≈ 98 lm/W efficacy
Color (B-V)	0.63
Mean radiance (Isol)	2.009×107 W·m−2·sr−1
Age	≈ 4.6 billion years[11][12]
Rotation characteristics
Obliquity	7.25°[2] (to the ecliptic) 67.23° (to the galactic plane)
Right ascension of North pole[13]	286.13° 19 h 4 min 30 s
Declination of North pole	+63.87° 63° 52' North
Sidereal rotation period (at equator)	25.05 d[2]
(at 16° latitude)	25.38 d[2] 25 d 9 h 7 min 12 s[13]
(at poles)	34.4 d[2]
Rotation velocity (at equator)	7.189×103 km/h[9]
Photospheric composition (by mass)
Hydrogen	73.46%[14]
Helium	24.85%
Oxygen	0.77%
Carbon	0.29%
Iron	0.16%
Neon	0.12%
Nitrogen	0.09%
Silicon	0.07%
Magnesium	0.05%
Sulfur	0.04%