scholarly journals Rainfall Partitioning in Chinese Pine (Pinus tabuliformis Carr.) Stands at Three Different Ages

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 243
Author(s):  
Lingling Dong ◽  
Hairong Han ◽  
Fengfeng Kang ◽  
Xiaoqin Cheng ◽  
Jinlong Zhao ◽  
...  
Keyword(s):  
Rainfall Intensity ◽  
Northern China ◽  
Rainfall Amount ◽  
Pine Forest ◽  
The Other ◽  
Stand Age ◽  
Canopy Interception ◽  
Chinese Pine ◽  
Other Hand ◽  
Chinese Pine Forest

Chinese pine (Pinus tabuliformis Carr.) is the main forest species in northern China, with the potential to dramatically affect biotic and abiotic aspects of ecosystems in this region. To discover the rainfall partitioning patterns of different growth periods of Chinese pine forest, we studied the throughfall (Tf), stemflow (Sf) and canopy interception (I) in three stand ages (40-, 50-, 60-year-old) in Liaoheyuan Natural Reserve of Hebei Province during the growing seasons of 2013 and 2014, and analyzed effect of rainfall amount, rainfall intensity, and canopy structure on rainfall partitioning in Chinese pine forest. The results showed that throughfall decreased with the stand age, accounting for 78.8%, 74.1% and 66.7% of gross rainfall in 40-, 50- and 60-year-old Chinese pine forests, respectively. Canopy interception, on the other hand, increased with the stand age (20.4%, 24.8%, and 32.8%, respectively), while the pattern in stemflow was less clear (0.8%, 1.1%, and 0.6%, respectively). As rainfall intensity increased, the Tf and Sf increased and I declined. Additionally, our results showed that leaf area index (LAI) and the diameter at breast height (DBH) increased with age in Chinese pine stands, probably explaining the similar increase in canopy interception (I). On the other hand, the mean leaf angle, openness, gap fraction all decreased with the stand age. Stepwise regression analysis showed that the rainfall amount and LAI were the major determinants influencing the rainfall partition. Our study highlights the importance of stand age in shaping different forest canopy structures, and shows how age-related factors influence canopy rainfall partitioning. This study also significantly adds to our understanding the mechanisms of the hydrological cycle in coniferous forest ecosystems in northern China.

Micromonospora maoerensis sp. nov., isolated from a Chinese pine forest soil

2013 ◽  
Vol 105 (3) ◽  
pp. 451-459 ◽  
Author(s):  
Chuang Li ◽  
Chongxi Liu ◽  
Junwei Zhao ◽  
Yuejing Zhang ◽  
Ruixia Gao ◽  
...  
Keyword(s):  
Forest Soil ◽  
Pine Forest ◽  
Chinese Pine ◽  
Pine Forest Soil ◽  
Chinese Pine Forest

scholarly journals Combined effects of nitrogen addition and organic matter manipulation on soil respiration in a Chinese pine forest

2016 ◽  
Vol 23 (22) ◽  
pp. 22701-22710 ◽  
Author(s):  
Jinsong Wang ◽  
L. Wu ◽  
Chunyu Zhang ◽  
Xiuhai Zhao ◽  
Wensheng Bu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Respiration ◽  
Nitrogen Addition ◽  
Pine Forest ◽  
Combined Effects ◽  
Chinese Pine ◽  
Chinese Pine Forest

scholarly journals Determination of the number of sapwood annual rings in oak in the region of southern Moravia

2012 ◽  
Vol 52 (No. 3) ◽  
pp. 141-146 ◽  
Author(s):  
M. Rybníček ◽  
H. Vavrčík ◽  
R. Hubený
Keyword(s):  
Water Regime ◽  
The Other ◽  
Stand Age ◽  
Annual Rings ◽  
Crucial Importance ◽  
Other Hand ◽  
Site Water ◽  
Southern Moravia ◽  
Incomplete Sample

The paper deals with the determination of the number of sapwood annual rings in oak (Quercus sp.) in relation to altitude, locality and stand age. Several different groups of samples were used from two localities of southern Moravia. The results of the study demonstrate the effects of site water regime and age on the growth of sapwood annual rings. On the other hand, the effect of altitude was not proved. The information can be of crucial importance for the dendrochronological dating of an incomplete sample for particular regions where sapwood is partly or totally missing.

Patterns of canopy interception and throughfall along a topographic sequence for black spruce dominated forest ecosystems in northwestern Ontario

2003 ◽  
Vol 33 (6) ◽  
pp. 1046-1060 ◽  
Author(s):  
Dave M Morris ◽  
Alan G Gordon ◽  
Andrew M Gordon
Keyword(s):  
Black Spruce ◽  
Inorganic Nitrogen ◽  
The Other ◽  
Organic N ◽  
Nutrient Concentrations ◽  
Canopy Interception ◽  
Area Index ◽  
Northwestern Ontario ◽  
Other Hand ◽  
Study Sites

A 3-year (1993–1995) study was conducted to describe both the spatial (within- and between-site) and temporal (monthly) patterns associated with canopy interception, throughfall, and net forest water along a black spruce (Picea mariana (Mill.) BSP) topo-sequence situated in northwestern Ontario. This site array included (1) an upland, well-drained, mineral soil site; (2) a poorly drained, midslope, wet mineral site; and (3) a treed wetland on organic (peat) soil. Bulk precipitation (BP) and throughfall (TF) were collected, on an event basis (63 events, over 4800 samples analyzed), using standard collecting devices and analyzed for total Kjeldahl nitrogen (TKN), ammonium (NH4+), nitrate (NO3–), total phosphorus (TP), potassium (K), calcium (Ca), and magnesium (Mg). Comparison of BP and TF data suggested that an enrichment of K (190%), Mg (115%), and Ca (70%) occurred during canopy interactions. On the other hand, inorganic nitrogen (NH4+: –73%; NO3–: –47%), and to a lesser extent TP (–35%), rates declined. TKN, however, remained the same, suggesting that inorganic N reductions were offset by organic N inputs. Downward shifts in pH were also detected for TF (4.45–4.48), as compared with the pH of BP (4.52–4.80). Although all study sites received similar rainfall amounts, the more productive sites (i.e., carrying greater foliar mass, higher leaf area index) had lower TF volumes (i.e., higher interception rates) but higher macronutrient returns to the forest floor. This increase in macronutrient deposition was directly related to substantial increases in nutrient concentrations, which, in turn, suggested a greater degree of canopy interaction and (or) leaching on these sites. Throughfall pH, however, was not significantly different across the three study sites. With respect to temporal patterns, the major cations (K+, Ca2+, Mg2+) demonstrated an increasing trend in concentration levels in TF as the season progressed to a maximum in October. TKN and TP concentrations, on the other hand, maintained relatively stable levels throughout the summer, peaking in September, but dropping substantially in October as metabolic processes slowed and the supply of these nutrients to the foliage was reduced. Even with the increase in base cation concentration, throughfall pH shifted downward to 4.3 or below by late fall.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

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