Transcript MEMELIHARA POHON UNTUK MENABUNG AIR TANAH

MENANAM POHON
UNTUK MENABUNG
AIR-HUJAN
Diabstraksikan: smno.psdl.ppsub.2013
Pohon ialah tumbuhan dengan batang dan
cabang yang berkayu.
Pohon memiliki batang utama yang tumbuh
tegak, menopang tajuk pohon.
Pohon dibedakan dari semak melalui
penampilannya.
Semak juga memiliki batang berkayu, tetapi
tidak tumbuh tegak.
Dengan demikian, pisang bukanlah pohon
sejati karena tidak memiliki batang sejati
yang berkayu.
Jenis-jenis mawar hias lebih tepat disebut
semak daripada pohon karena batangnya
walaupun berkayu tidak berdiri tegak dan
habitusnya cenderung menyebar menutup
permukaan tanah.
Diunduh dari:
.
Diunduh dari: www.thecottagekey.com/watershed.htm
POHON adalah tumbuhan berkayu yang perennial.
Kadangkala pohon didefinisikan sebagai tanaman berkayu yang mencapai diameter
10 cm (lingkaran batangnya 30 cm) atau lebih besar pada ketinggian nafas manusia
(130 cm di atas permuakan tanah).
Ada kesepakatan ukuran minimum, istilah yang biasanya digunakan bagi tanaman
yang tumbuh tingginya minimal 5-6 meter (15-20 ft) pada saat ia dewasa dan
mempunyai percabangan sekunder yang bertumpu pada batang utama, yang
disebut “a trunk”.
Kebanyakan pohon menunjukkan dominasi pucuk yang jelas, meskipun tidak selalu
demikian. Kalau dibandingkan dengan tumbuhan lainnya, pohon umurnya lebih
panjang, ada yang mencapai beberapa ratus tahun dan tingginya mencapai
115 meter (375 ft).
Peran pohon dalam siklus air
POHON merupakan komponen penting dari bentang-lahan alami karena
kemampuannya untuk mencegah erosi dan menyediakan ekosistem khas di dalam
dan di bawah naungan tajuknya.
Poon juga mempunyai peranan penting dalam menghasilkan oksigen dan mereduksi
CO2 di atmosfir, juga mampu memoderasi suhu permukaan bumi. Pohon juga
merupakan komponen penting dari bentang-lahan dan pertanian, karena wujud
estetikanya atau karena produksi buahnya (misalny apel). Kayu dari pohon menjadi
bahan bangunan yang penting.
Benefits of Trees in Urban Areas
1.
2.
3.
4.
5.
6.
7.
Save Energy
Improve air quality
Extend life of paved surfaces
Increase traffic safety
Increase real estate values
Increase sociological benefits
Protect our water resources
Pepohonan membersihkan udara yang
kita hirup.
Partikel debu, CO, SO2, dan polutanpolutan lain akan diserap oleh tanaman
sehingga kita bisa menghirup udara yang
lebih baik kualitasnya.
All water is part of this cycle
Pepohonan Meningkatkan kualitas air tanah. Pepohonan
mengurangi aliran permukaan (run-off), karena akarnya menyerap air
yang jatuh ke tanah. Lebih banyak air yang terserap ke dalam tanah
artinya lebih banyak kesempatan untuk memperbaiki kualitas dan
kuantitas air tanah. Hal ini juga mengurangi tercemarnya air tanah
oleh bahan kimia yang ada di permukaan tanah.
AIR HUJAN DAN SIKLUS HIODROLOGI
• Urbanization dramatically alters the hydrologic cycle
– Increases runoff
– Increases flooding frequency
– Decreases infiltration and groundwater recharge
• Nationwide impervious surfaces have increased by 20%
in the past 20 years
More Trees Means Less Runoff
Some Statistics
1. Fayetteville, Arkansas: increasing
tree canopy from 27-40% reduced
their storm water runoff by 31%
2. South Miami residential study
found that a 21% existing tree
canopy reduces the storm water
runoff by 15%
Arkansas stormwater runoff reduction
valued at $43 million in capital
improvement savings (represents $2/
cubic ft cast to contain storm water
runoff).
For every 5% of tree cover added to a community,
storm water is reduced by approximately 2%
BAGAIMANA POHON MEMPENGARUHI AIR HUJAN?
•
•
•
Above ground effects:
– Interception, evaporation and absorption of precipitation
Ground surface effects:
– Temporary storage
Below ground effects:
– Infiltration, permeation and filtration
BAGAIMANA POHON MEMPENGARUHI AIR HUJAN?
EFEK POHON PADA LINGKUNGAN MIKRO DI ATAS
TANAH
•
•
Intercept rainwater on leaves, branches and trunks – slowing its
movement
Evaporation of some of this intercepted precipitation of the tree surfaces
1. The delay of precipitation onto the ground can
dampen the peak of runoff amounts from storms
which are most intense at their outset, before the
storage capacity of the tree canopy is reached.
2. The amounts of the effects on runoff are primarily
dependent on season (for deciduous trees), on the
leaf area index of a tree and on its density of twigs
and branches.
3. The evaporation rate is also crucial in influencing
the above-ground effects. This rate is determined
by air temperature, humidity and the intensity of
solar radiation. With a large amount of leaf-surface
area exposed to the sun and wind, water loss from
the leaves is high.
4. By slowing the storm water flow, the flow of water
is spread over a greater amount of time (time of
concentration) and the impact of a storm on the
facilities built to handle it at any one time is smaller.
5. Stemflow is a relatively small percentage of total
precipitation
6. Absorption of a small portion of rainwater into
leaves or stems
EFEK POHOIN
TERHADAP LINGKUNGAN BAWAH TANAH
•
Organic material from leaf litter and other tree detritus
tends to increase infiltration rates by increasing pore
spaces in soil
• Organic material also increases the moisture-holding
capacity of these sites
• Root mats of trees also tend to break up most soils
further improving infiltration and moisture-holding
capacity
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EFEK POHOIN
TERHADAP LINGKUNGAN BAWAH TANAH
•
•
•
Deep roots tend to improve the rates of percolation of water from
upper soil horizons into lower substrates
Trees take up water through their roots that is eventually
transpired onto leaf surfaces and evaporated
Tree roots act as natural pollution filters (biofilters) using
nitrogen, phosphorus and potassium
14
EPA’s Tree Canopy Target Goals
• Set to protect a community’s green
infrastructure and maximize the
environmental benefits
• For metropolitan areas east of the
Mississippi
–
–
–
–
Average tree cover for all land use
Suburban residential
Urban residential
Central business districts
40%
50%
25%
15%
FAKTOR KOMPLIKASI
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•
•
Presence of soil compaction
Presence of soil textural discontinuity
– Has the site been disturbed in the past?
Management of the ground surface
– Is litter layer removed?
– Is soil surface exposed in winter?
– How much of the surface is like a natural forest? (number
and size of trees)
PERGERAKAN AIR DALAM TANAH
•
•
•
Forces affecting the energy of soil water
– Matric force (absorption and capillary)
– Gravity
– Osmotic forces
Field Capacity is the amount of water held in the soil after
gravitational water had drained away
Movement of water is the soil is controlled :
– Gravitational forces if saturated
– Matric forces if unsaturated
FAKTOR TANAH MEMPENGARUHI
INFILTRASI
•
•
•
•
Infiltration is the mode of entry of all water into the soil
Rate of infiltration determined:
– Initial water content
– Surface permeability
– Internal characteristics of the soil
Intensity and duration of rainfall
Temperature of soil and water
FAKTOR TANAH MEMPENGARUHI
INFILTRASI
• Microrelief under trees provides catchment basins during
heavy rains
• Removal of litter layer reduces the infiltration rate
• Forest soils have a high percentage of macropores
• The frost type found in forest soils promotes infiltration yearlong
Soil compaction reduces
the infiltration rate
FOTO SMNO 2008
PENTINGNYA LAPISAN SERESAH
DI PERMUKAAN TANAH
•
•
•
•
•
•
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Absorbs several times its own weight
Breaks the impact of raindrops
Prevents agitation of the mineral soil
Discourages formation of surface crusts
Increases soil biotic activity
Increases incorporation of organics
Slows down lateral movement of water
The litter layer absorbs several times its own
weight of water, breaks the impact of raindrops,
prevents agitation of the mineral soil particles and
discourages the formations of surface crusts. It
also leads to an increase in the organic matter
content of the top mineral layer and creates a
habitat for many of the soil fauna to feed and hide
in which in turn increases the porosity of the soil.
The variety, numbers and activity of soil
organisms generally is much greater in forest
soils than in agricultural soils or in lawns. It also
slows down the lateral movement of surface water
permitting a longer period for infiltration.
Mempengaruhi pori-mikro dalam tanah the
Soil
•
•
•
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Develop in old root channels or from burrows and tunnels
made by insects, worms or other animals
Lead to better soil structure
Increases organic matter incorporation
Increases percolation rates and root penetration
Suharto, Edi (2006)
THE CAPACITY OF SOILWATER STORAGE ON LAND USE
SYSTEM AT LPP TAHURA RAJA LELO BENGKULU.
JIPI, 8 (1). pp. 44-49. ISSN 1411-0067
Objective of this study was to measure soil water storage
capacity on land use system at LPP TAHURA Raja Lelo
Bengkulu. Research was conducted from September 1999
to February 2000 in Laboratory of soil of Agriculture
Department, Gadjah Mada University.
The Research used sampling design and analysis the
physics and chemistry of soils. Land use system was
covered by tree crops which high of water storage capacity
of soils. Those covered by grasses and scrub will be less.
The variable of water storage capacity of soils are rain fall
interception by vegetation of land cover, soil depth of root
interception, the balanced of soil particle distribution of
clays and sands, and the distribution of soil micro pore. Soil
water drainage was determined by amount of organic
matter in top soils.
Therefore, forest and estate land use system covered by
tree crops is an effective conventional landscape for soil
and water conservation.
Diunduh dari: http://repository.unib.ac.id/42/
.
Source and fate of water added to a soil
system.
The proportion of the soil occupied by water and air is referred to
as the pore volume. The pore volume is generally constant for a
given soil layer but may be altered by tillage and compaction. The
ratio of air to water stored in the pores changes as water is added
to or lost from the soil. Water is added by rainfall or irrigation.
Water is lost through surface runoff, evaporation (direct loss from
the soil to the atmosphere), transpiration (losses from plant
tissue), and either percolation (seepage into lower layers) or
drainage.
PENGGUNAAN AIR TANAH DAN PENGISIANNYA DARI
PERMUKAAN
There is a substantial amount of ground water recharge from
surface water and ground water used to irrigate agricultural
crops. Some of the irrigation water flowing in unlined ditches
and some of the water that is applied to irrigate crops
infiltrates into the soil, percolates through the root zone and
recharges the ground water basins
AIR TANAH = Ground water
Ground water occupies the zone of saturation. Ground water moves
downward through the soil by percolation and then toward a stream
channel or large body of water as seepage. The water table
separates the zone of saturation from the zone of aeration.
The water table fluctuates with moisture conditions, during wet
times the water table will rise as more pore spaces are occupied with
water. Ground water is found in aquifers, bodies of earth material
that have the ability to hold and transmit water. Aquifers can be
either unconfined or confined. Unconfined (open) aquifers are
"connected" to the surface above.
AQUIFERS REPLENISH THEIR SUPPLY OF
WATER VERY SLOWLY.
The rate of ground water flow depends on the
permeability of the aquifer and the hydraulic gradient.
Permeability is affected by the size and connectivity of
pore spaces. Larger, better connected pore spaces
creates highly permeable earth material. The hydraulic
gradient is the difference in elevation between two
points on the water table divided by the horizontal
distance between them.
The rate of ground water flow is expressed by the
equation:
Ground water flow rate = permeability X hydraulic
gradient
Groundwater flow rates are usually quite slow.
Average ground water flow rate of 15 m per day is
common. Highly permeable materials like gravels can
have flow velocities of 125 m per day.
DIUNDUH DARI:
www.uwsp.edu/geo/faculty/ritter/geog101/textb...
Ground water in an aquifer is under pressure called
hydrostatic pressure. Hydrostatic pressure in a confined
aquifer pushes water upward when a well is drilled into the
aquifer.
The height to which the water rises is called the peizometeric
surface. If the hydrostatic pressure is great enough to push
the peizometeric surface above the elevation of the surface,
water readily flows out as an artesian well.
Following an infiltration event, in which the entire soil profile
becomes saturated with water (indicated by a solid vertical line
corresponding to a water saturation of 1.0), water will drain from the
soil profile primarily under the influence of gravity (i.e., the pressure
gradient is negligible). Assuming that no additional water enters the
system, the soil water saturation profile at static equilibrium (dashed
line) will decrease from a value of 1.0 in the saturated zone
(groundwater and capillary fringe) to a value corresponding to field
capacity below the root zone. In effect, the soil water profile is
analogous to a soil water retention (pressure-saturation) curve.
Hence, the solid and dashed lines represent the limits in water
content (saturation) between which soil water percolation occurs in
soils overlying an unconfined aquifer.
www.informaworld.com/smpp/95829679-70617050/c...
KONDISI ALAMIAH PENGISIAN AIR TANAH
Water is recharged to the ground-water system by
percolation of water from precipitation and then flows to the
stream through the ground-water system.
DIUNDUH DARI: ga.water.usgs.gov/edu/earthgwdecline.html
PENURUNAN TINGGI MUKA AIR TANAH
Water pumped from the ground-water system causes the
water table to lower and alters the direction of ground-water
movement. Some water that flowed to the stream no longer
does so and some water may be drawn in from the stream
into the ground-water system, thereby reducing the amount
of streamflow.
.
30
KUALITAS AIR TANAH
Contaminants introduced at the land surface may infiltrate to
the water table and flow towards a point of discharge, either
the well or the stream. (Not shown, but also important, is the
potential movement of contaminants from the stream into the
ground-water system.)
EFEK AIR TANAH TERHADAP LINGKUNGAN
Water-level declines may affect the environment for plants
and animals.
For example, plants in the riparian zone that grew because of
the close proximity of the water table to the land surface may
not survive as the depth to water increases.
The environment for fish and other aquatic species also may
be altered as the stream level drops.
DIUNDUH DARI: www.forestry.ubc.ca/.../forwady/forwady.htm
Forests and the Hydrologic Cycle
The surface water in a stream, lake, or wetland is most
commonly precipitation that has run off the land or
flowed through topsoils to subsequently enter the
waterbody. If a surficial aquifer is present and
hydraulically connected to a surface-water body, the
aquifer can sustain surface flow by releasing water to it.
In general, a heavy rainfall causes a temporary and
relatively rapid increase in streamflow due to surface
runoff. This increased flow is followed by a relatively
slow decline back to baseflow, which is the amount of
streamflow derived largely or entirely from groundwater.
During long dry spells, streams with a baseflow
component will keep flowing, whereas streams relying
totally on precipitation will cease flowing.
Generally speaking, a natural, expansive forest
environment can enhance and sustain relationships in
the water cycle because there are less human
modifications to interfere with its components. A
forested watershed helps moderate storm flows by
increasing infiltration and reducing overland runoff.
Further, a forest helps sustain streamflow by reducing
evaporation (e.g., owing to slightly lower temperatures in
shaded areas). Forests can help increase recharge to
aquifers by allowing more precipitation to infiltrate the
soil, as opposed to rapidly running off the land to a
downslope area.
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Groundwater –Surface Water Flows
35
POHON DAN AIR HUJAN
•
•
•
Trees have a relatively greater effect on smaller storm
runoff amounts than on large storm events
Surface and below-ground effects on runoff are much
more significant than the above-ground effects
All of the effects on runoff are greatest when urban trees
are large and well-established on undisturbed sites
DIUNDUH DARI:
www.cropscience.org.au/.../1399_shahbazkhan.htm
DIUNDUH DARI:
www.ene.gov.on.ca/envision/gp/4329e_1.htm
38
DIUNDUH DARI:
www.aucklandcity.govt.nz/.../hgiapp15.asp
Typical root systems are made up of a combination of four
types of roots:
major lateral roots
sinker roots
woody feeder roots
non-woody feeder roots.
DIAGRAM FUNGSI POHON
DIUNDUH DARI: www.dof.virginia.gov/urban/landscapemanual.shtml
Menanam Pohon di Lahan Datar
Lahan yang datar yang umumnya ditanami biji-bijian, sayuran, dan padi
dapat dikombinasikan dengan berbagai macam tanaman pohon.
Tanaman pohon akan meningkatkan jumlah produksi dan keragaman
tanaman. Tanaman pohon sedikit memerlukan perawatan dan akan tetap
bermanfaat walaupun di musim kemarau.
Tanaman pepohonan kecil seperti jeruk, pisang, pepaya, cengkeh, dan
kacang hijau dapat ditanam bersama dengan tanaman biji-bijian dan
sayuran. Pohon dapat memberikan naungan untuk tanaman musiman
yang lebih kecil. Pohon juga akan memberikan penghalang untuk
mempersulit gerak hama serangga saat berpindah dari tanaman satu ke
tanaman lainnya. Tanam pula legum, tanaman ini memiliki manfaat yang
sangat banyak.
Manfaat lain dari kombinasi pohon dengan tanaman biji-bijian dan
sayuran adalah tanaman kecil bisa dipanen lebih awal sementara
menunggu pohon yang besar tumbuh dan menghasilkan.
Diunduh dari:
.
DIUNDUH DARI: www.forestry.ubc.ca/.../forwady/forwady.htm
www.icsu-scope.org/.../scope51/chapter06.html
A model illustrating fluxes of sulphur in a forest ecosystem
Schematic illustration of the biogeochemical processes of importance in
long-term research of a watershed (Swank, 1986).
DIUNDUH DARI:
www.aracruz.com.br/show.do?menu=true&id=943...
Diunduh dari:
Diunduh dari: sofia.usgs.gov/publications/posters/challenge/
EFFECT OF ORGANIC AMENDMENTS ON SOIL WATER
STORAGE IN THE AEOLIAN SANDY LAND OF
NORTHEAST CHINA
Wenju Liang , Xia Wu ; Shixiu Zhang ; Yuehua Xing ; Ren
Wang
Electrical and Control Engineering (ICECE), 2011
International Conference on. Date of Conference: 16-18
Sept. 2011
Organic amendments such as crop residues and animal
manures play an important role in improving soil quality.
The objective of this research was to determine the effect
of corn straw retention and chicken manure on soil water
storage in the aeolian sandy land of Northwest Liaoning
province, China.
After four-year observation, the results showed that corn
straw in combination with chemical fertilizer (SR) treatment
significantly increased soil water content in the plow layer,
decreased soil bulk density in the plow pan, and obviously
enhanced plant available water storage capacity in the
plow pan. The chicken manure in combination with
chemical fertilizer (CM) treatment significantly increased
soil water content and organic matter content in the plow
layer. Our experiment indicates that corn straw retention
combined with chemical fertilizers may improve soil water
storage capacity in the short-term study.
Diunduh dari:
SIKLUS DAN NERACA AIR
51
Soil water storage and groundwater behaviour in a catenary
sequence beneath forest in central Amazonia:
I. Comparisons between plateau, slope and valley floor
M. G. Hodnett1, I. Vendrame2, A. De O. Marques Filho3, M. D. Oyama4, and
J. Tomasella
Hydrol. Earth Syst. Sci., 1, 265-277, 1997
Soil water storage was monitored in three landscape elements in the
forest (plateau, slope and valley floor) over a 3 year period to identify
differences in sub-surface hydrological response.
Under the plateau and slope, the changes of storage were very similar
and there was no indication of surface runoff on the slope. The mean
maximum seasonal storage change was 156 mm in the 2 m profile but it
was clear that, in the dry season, the forest was able to take up water
from below 3.6 m. Soil water availability was low.
Soil water storage changes in the valley were dominated by the behaviour
of a shallow water table which, in normal years, varied between 0.1 m
below the surface at the end of the wet season and 0.8 m at the end of
the dry season.
Soil water storage changes were small because root uptake was largely
replenished by groundwater flow towards the stream. The groundwater
behaviour is controlled mainly by the deep drainage from beneath the
plateau and slope areas.
The groundwater gradient beneath the slope indicated that recharge
beneath the plateau and slope commences only after the soil water
deficits from the previous dry season have been replenished. Following a
wet season with little recharge, the water table fell, ceasing to influence
the valley soil water storage, and the stream dried up. The plateau and
slope, a zone of very high porosity between 0.4 and 1.1 m, underlain by a
less conductive layer, is a probable route for interflow during, and for a
few hours after, heavy and prolonged rainfall.
Diunduh dari:
http://www.hydrol-earth-syst-sci.net/1/265/1997/hess-1-265-
STEM FLOW, THROUGHFALL, AND CANOPY
INTERCEPTION OF RAINFALL BY CITRUS TREE
CANOPIES
Y.C. Li, A.K. Alva, D.V. Calvert and M. Zhang.
HortScience October 1997 vol. 32 no. 6 1059-1160
It is generally believed that the interception of rain by the citrus
tree canopy can substantially decrease the throughfall under the
canopy as compared to that along the dripline or outside the
canopy (incident rainfall). Therefore, the position of placement of
soil-applied agrichemicals in relation to the tree canopy may be
an important consideration to minimize their leaching during rain
events.
In this study, the distributions of rainfall under the tree canopies of
three citrus cultivars, `Marsh' grapefruit (Citrus paradisi Macf.),
`Hamlin' orange (Citrus sinensis L. Osbeck), and `Temple' orange
(Citrus hybrid), were evaluated at four directions (north, south,
east, west), two positions (dripline and under the canopy), and
stem flow.
There was not a significant canopy effect on rainfall amounts from
stem flow or dripline, compared with outside canopy, for any citrus
cultivar or storm event. However, throughfall varied significantly
among the four cardinal directions under the canopy of all three
citrus cultivars and was highly related to the wind direction.
Among the three citrus cultivars evaluated in this study,
throughfall, stem flow, and canopy interception accounted for
89.5% to 92.7%, 0.5% to 4.7%, and 5.8% to 9.3% of the incident
rainfall, respectively.
Diunduh dari:
http://hortsci.ashspublications.org/content/32/6/1059.abstract .
Four-Way Collaboration
The Water Balance Model includes a tree canopy module so that the
rainfall interception benefits of trees in the urban environment can
be quantified. To populate the module with local data, a four-way
collaboration has been established under the umbrella of the InterGovernmental Partnership (IGP) that developed the Water Balance
Model. The Greater Vancouver Regional District and Ministry of
Community Services are providing funding, and the University of
British Columbia and District of North Vancouver are making in-kind
contributions in carrying out the applied research project. The
District of North Vancouver is acting on behalf of the IGP in leading
this on-the-ground initiative.
54
AIR HUJAN LOLOS-TAJUK
Tree canopy interception is the
process of storing precipitation
temporally in the canopy and releasing
it slowly to the ground and back to the
atmosphere.
It is an important component of the
water balance, easily accounting for up
to 35% of gross annual precipitation.
Removing trees will in general
decrease interception and thus
increase annual runoff and rainwater
runoff.
Vegetation also reduces rainfall
intensity due to the temporal storage
effect.
The influence of canopy traits on throughfall and
stemflow in five tropical trees growing in a
Panamanian plantation
Andrew Park and Jessie Lee Cameron
Forest Ecology and Management 255 (2008) 1915-1925
Tree canopies partition rainfall into temporary canopy storage, throughfall and
stemflow. Knowledge of this partitioning process is needed to
predict the hydrological effects of the large areas of tree plantations that are
being established in the tropics.
In this study, we compared throughfall, stemflow and interception in four
Neotropical and one exotic tree species growing in selection trials in the
Republic of Panama. We sought to answer four questions: (1) Are there
interspecific differences in total throughfall and stemflow, and throughfall and
stemflow for a range of rainfall depths?, (2) How do crown traits influence
interspecific differences in throughfall?, (3) Does the spatial heterogeneity of
throughfall differ among species? and (4) How do species affect litter biomass
and other variables that influence rainfall erosivity? Rainfall depth mediated
interspecific differences in throughfall and stemflow, the relative importance
of crown traits in the interception process, and spatial heterogeneity of
throughfall.
Total throughfall was between 10.9 and 16.2% less in Acacia mangium than
Gliricidia sepium, Guazuma ulmifolia, Ochroma pyramidale or Pachira quinata.
Increasing rainfall also changed relative quantities of throughfall and stemflow
among species. For example, throughfall was similar in Gliricidia and Acacia
for small rain events, but increased more rapidly in Gliricidia with increasing
rainfall depth. Interspecific differences in throughfall were driven, in part, by
canopy traits. Leaf area index (LAI), crown depth and crown openness all
affected throughfall from smaller storms, but live crown length was the only
significant predictor of throughfall in storms that were deeper than 20 mm. The
spatial heterogeneity of throughfall beneath individual tree canopies
increased with rainfall depth, but was always lower in Gliricidia than in Acacia,
Ochroma, or Pachira. High litter biomass and cover in Acacia and Ochroma
relative to other species would be likely to buffer the erosive effects of
raindrop impacts. These complex interactions between rainfall and species
traits may affect local hydrology, and may need to be explicitly considered in
reforestation projects in the seasonal tropics.
Diunduh dari: http://sipddr.si.edu/jspui/bitstream/10088/12103/1/stri_Park_and_Cameron_2008.pdf .
Interception loss, throughfall and stemflow chemistry
in pine and oak forests in northeastern Mexico
Israel Cantú Silva and Humberto González Rodríguez
Tree Physiol (2001) 21 (12-13): 1009-1013.
Interception loss, gross precipitation, throughfall and stemflow solution
chemistry beneath pine (Pinus pseudostrobus Lindl.), oak (Quercus sp.)
and pine–oak natural forest canopies in northeastern Mexico were
measured. Coefficients of variation for throughfall were 12% in pine and
oak canopies and 17% in the mixed pine–oak canopy. The variability of
stemflow averaged 66, 126 and 73% for pine, oak and the mixed pine–
oak canopies, respectively. Linear regression analysis of net versus gross
precipitation for the three canopies showed highly significant correlations
(r = 0.974–0.984). Total precipitation during the experimental period was
974 mm and estimated interception loss was 19.2, 13.6 and 23% for the
pine, oak and pine–oak canopies, respectively. Stemflow did not occur
following rainfall events of less than 4 mm and, in all canopies, stemflow
represented a minimal proportion of gross precipitation (0.60, 0.50 and
0.03% for pine, oak and pine–oak, respectively). Throughfall pH in pine
(6.2), oak (6.3) and pine–oak (6.3) canopies was significantly more acidic
than gross precipitation (6.6). Stemflow pH ranged from 3.7 (pine) to 6.0
(oak). The pine–oak canopy registered the highest throughfall and
stemflow electrical conductivities, 104 and 188 μS cm−1, respectively. Net
nutrient leaching of K, Mg, Na, Fe, Mn and Zn was significantly higher
from the pine–oak canopy than from the pure pine and oak canopies.
Mean depositions of Ca and Cu in throughfall behaved similarly among
the three types of canopies. A greater proportion of Zn in gross
precipitation was absorbed by the oak canopy than by the pine and pine–
oak canopies. Enrichment factors beneath the pine–oak canopy relative to
gross precipitation varied from 1.2 to 3.2 for macro-nutrients (Ca, K, Mg
and Na) and from 1.4 to 3.1 for micro-nutrients (Cu, Fe, Mn and Zn).
Stemflow depositions of Ca, K, Mg and Cu were higher in the pine–oak
canopy, whereas stemflow depositions of Na, Fe, Mn and Zn were higher
in the pine canopy.
Diunduh dari: http://treephys.oxfordjournals.org/content/21/12-13/1009.abstract .
Spatial Distributions of Throughfall beneath Canopies of
Understory Trees in a Mature Chamaecyparis obtusa
Stand.
TANAKA NOBUAKI, KURAJI KOICHIRO, SUZUKI MASAKAZU, OTA
TAKEHIKO
Bulletin of the Tokyo University Forests
VOL. NO.113;PAGE.133-153(2005)
Spatial distributions of throughfall beneath canopies of understory trees
in a mature Chamaecyparis obtusa stand were observed by grid-type
throughfall collectors. Throughfall amount beneath the canopies of
understory trees tended to be smaller than that observed at grids covered
only by canopy of Chamaecyparis obtusa. However, dripping points,
where throughfall exceeded gross rainfall, often appeared under canopies
of Aucuba japonica and Daphniphyllum macropodum, the species with
relatively large leaves, and never appeared under canopies of Quercus
myrsinifolia and Callicarpa mollis, the species with smaller leaves. With
respect to frequency of appearances of dripping points, we found that the
dripping points appeared more frequently in large storms than in small
storms. However, no dripping point was found in two relatively large
storms among nine observations, which seems to be exceptional. The
pattern of the distributions of dripping point over a grid-type collector had
a tendency to be fixed in most of the storms.
The size of one dripping point found in this forest was a circular area with
diameter of approximately 14cm. As an example of applying the result of
this study to estimations of mean throughfall of this forest or its error
ranges, a relationship between area of collecting throughfall and possible
errors in measuring throughfall was shown by supposing to measure
throughfall in the area of a grid-type collector with some virtual throughfall
collectors.
Diunduh dari:
http://sciencelinks.jp/j-
Loshali, D. C. ; Singh, R. P. (1992)
PARTITIONING OF RAINFALL BY THREE CENTRAL
HIMALAYAN FORESTS
Forest Ecology and Management, 53 (1-4). pp. 99-105. ISSN 03781127
Throughfall, interception losses and surface run-off studies during
the monsoon season (June through September) in three different
forests of Central Himalaya are described.
The tree canopy covers of the stands were 80.0-91.5%. Canopy
throughfall (throughfall directly beneath the canopy) made up
76.5% and canopy interception loss was 23.5% of the total rainfall
(1965.8 mm) during the 1985 and 1986 monsoons. Values of
throughfall and interception losses computed for entire forested
stands (stand throughfall and stand interception) accounted for
79.6% and 20.2% of the total rainfall.
The minimum canopy throughfall (74.9%) was recorded in chir
pine and maximum (78.6%) in mixed banj oak-tilonj oak forest.
Stand throughfall was maximum (80.7%) in mixed banj oak-chir
pine forest and minimum (77.5%) in chir pine forest. Stand
interception was higher in chir pine compared with mixed banj
oak-chir pine and banj oak-tilonj oak forests.
The highest value of surface run-off was recorded in chir pine
forest which had the lowest litter interception (8.3%). Canopy
throughfall and surface run-off were positively related (P < 0.01)
to bulk precipitation.
The low proportion of surface run-off (0.46-0.53%) is a
characteristic and a special feature of the forest ecosystems of
the Central Himalaya.
Diunduh dari:
http://repository.ias.ac.in/73033/ .
MENANAM POHON UNTUK
MENABUNG AIR-HUJAN
Diabstraksikan: smno.psdl.ppsub.2013