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1.
Modelling the wind damage probability in forests in Southwestern Germany for the 1999 winter storm ‘Lothar’ 总被引:1,自引:0,他引:1
Dirk Schindler Karin Grebhan Axel Albrecht Jochen Schönborn 《International journal of biometeorology》2009,53(6):543-554
The wind damage probability (P
DAM) in the forests in the federal state of Baden-Wuerttemberg (Southwestern Germany) was calculated using weights of evidence
(WofE) methodology and a logistic regression model (LRM) after the winter storm ‘Lothar’ in December 1999. A geographic information
system (GIS) was used for the area-wide spatial prediction and mapping of P
DAM. The combination of the six evidential themes forest type, soil type, geology, soil moisture, soil acidification, and the
‘Lothar’ maximum gust field predicted wind damage best and was used to map P
DAM in a 50 × 50 m resolution grid. GIS software was utilised to produce probability maps, which allowed the identification of
areas of low, moderate, and high P
DAM across the study area. The highest P
DAM values were calculated for coniferous forest growing on acidic, fresh to moist soils on bunter sandstone formations—provided
that ‘Lothar’ maximum gust speed exceeded 35 m s−1 in the areas in question. One of the most significant benefits associated with the results of this study is that, for the
first time, there is a GIS-based area-wide quantification of P
DAM in the forests in Southwestern Germany. In combination with the experience and expert knowledge of local foresters, the probability
maps produced can be used as an important tool for decision support with respect to future silvicultural activities aimed
at reducing wind damage. One limitation of the P
DAM-predictions is that they are based on only one major storm event. At the moment it is not possible to relate storm event
intensity to the amount of wind damage in forests due to the lack of comprehensive long-term tree and stand damage data across
the study area. 相似文献
2.
J. M. Soriano E. M. Vera-Ruiz S. Vilanova J. Martínez-Calvo G. Llácer M. L. Badenes C. Romero 《Tree Genetics & Genomes》2008,4(3):391-402
Sharka disease, caused by the plum pox virus (PPV), is one of the major limiting factors for stone fruit crops in Europe and
America. In particular, apricot is severely affected suffering significant fruit losses. Thus, PPV resistance is a trait of
great interest for the apricot breeding programs currently in progress. In this work, two apricot maps, earlier constructed
with the F1 ‘Goldrich × Currot’ (G×C) and the F2 ‘Lito × Lito’-98 (L×L-98) populations, have been improved including 43 and 37 new simple sequence repeat (SSR) loci, respectively,
to facilitate PPV resistance trait mapping. Screening of PPV resistance on the segregating populations classified seedling
phenotypes into resistant or susceptible. A non-parametric mapping method, based on the Kruskal–Wallis (KW) rank sum test,
was initially used to score marker–trait association, and results were confirmed by interval mapping. Contrary to the putative
digenic model inferred from the phenotypic segregations, all significant markers for the KW statistic (P < 0.005) mapped in a unique region of ~21.0 and ~20.3 cM located on the upper part of the G1 linkage group in ‘G×C’ and ‘L×L-98’
maps, respectively. According to the data, PPV resistance is suggested to be controlled by at least one major dominant locus.
The association between three SSRs distributed within this region and the PPV resistance was tested in two additional populations
(‘Goldrich × Canino’ and ‘Lito × Lito’-00) and breeding program parents. The marker ssrPaCITA5 showed the highest KW value
(P < 0.005) in all cases, pointing out its usefulness in marker-assisted selection.
Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
3.
U. Kumar A. K. Joshi S. Kumar R. Chand M. S. R?der 《Molecular breeding : new strategies in plant improvement》2010,26(3):477-491
Spot blotch caused by Bipolaris sorokiniana is a destructive disease of wheat in warm and humid wheat growing regions of the world. To identify quantitative trait loci
(QTLs) for spot blotch resistance, two mapping populations were developed by making the crosses between common susceptible
cultivar ‘Sonalika’ with the resistant breeding lines ‘Ning 8201’ and ‘Chirya 3’. Single seed descent derived F6, F7, F8 lines of the first cross ‘Ning 8201’ × ‘Sonalika’ were evaluated for resistance to spot blotch in three blocks in each of
the 3 years. After screening of 388 pairs of simple sequence repeat primers between the two parents, 119 polymorphic markers
were used to genotype the mapping population. Four QTLs were identified on the chromosomes 2AS, 2BS, 5BL and 7DS and explained
62.9% of phenotypic variation in a simultaneous fit. The QTL on chromosome 2A was detected only in 1 year and explained 22.7%
of phenotypic variation. In the second cross (‘Chirya 3’ × ‘Sonalika’), F7 and F8 population were evaluated in three blocks in each of the 2 years. In this population, five QTLs were identified on chromosomes
2BS, 2DS, 3BS, 7BS and 7DS. The QTLs identified in the ‘Chirya 3’ × ‘Sonalika’ population explained 43.4% of phenotypic variation
in a simultaneous fit. The alleles for reduced disease severity in both the populations were derived from the respective resistant
parent. The QTLs QSb.bhu-2B and QSb.bhu-7D from both populations were placed in the same deletion bins, 2BS1-0.53-0.75 and 7DS5-0.36-0.61, respectively. The closely
linked markers Xgwm148 to the QTL on chromosome 2B and Xgwm111 to the QTL on chromosome 7D are potentially diagnostic markers for spot blotch resistance. 相似文献
4.
D. R. Bowling W. J. Massman S. M. Schaeffer S. P. Burns R. K. Monson M. W. Williams 《Biogeochemistry》2009,95(1):37-59
Considerable research has recently been devoted to understanding biogeochemical processes under winter snow cover, leading
to enhanced appreciation of the importance of many winter ecological processes. In this study, a comprehensive investigation
of the stable carbon isotope composition (δ13C) of CO2 within a high-elevation subalpine forest snowpack was conducted. Our goals were to study the δ13C of biological soil respiration under snow in winter, and to assess the relative importance of diffusion and advection (ventilation
by wind) for gas transport within snow. In agreement with other studies, we found evidence of an active microbial community
under a roughly 1-m deep snowpack during winter and into spring as it melted. Under-snow CO2 mole fractions were observed up to 3,500 μmol mol−1, and δ13C of CO2 varied from ~−22 to ~−8‰. The δ13C of soil respiration calculated from mixing relationships was −26 to −24‰, and although it varied in time, it was generally
close to that of the bulk organic horizon (−26.0‰). Subnivean CO2 and δ13C were quite dynamic in response to changes in soil temperature, liquid water availability, and wind events. No clear biologically-induced
isotopic changes were observed during periods when microbial activity and root/rhizosphere activity were expected to vary,
although such changes cannot be eliminated. There was clear evidence of isotopic enrichment associated with diffusive transport
as predicted by theory, but simple diffusive enrichment (4.4‰) was not observed. Instead, ventilation of the snowpack by sustained
wind events in the forest canopy led to changes in the diffusively-enriched gas profile. The isotopic influence of diffusion
on gases in the snowpack and litter was greatest at greater depths, due to the decreased relative contribution of advection
at depth. There were highly significant correlations between the apparent isotopic content of respiration from the soil with
wind speed and pressure. In summary, physical factors influencing gas transport substantially modified and potentially obscured
biological factors in their effects on δ13C of CO2 within this subalpine forest snowpack. 相似文献
5.
Roger A. Eigenberg Tami M. Brown-Brandl John A. Nienaber 《International journal of biometeorology》2009,53(6):501-507
Shade structures are often considered as one method of reducing stress in feedlot cattle. Selection of a suitable shade material
can be difficult without data that quantify material effectiveness for stress reduction. A summer study was conducted during
2007 using instrumented shade structures in conjunction with meteorological measurements to estimate relative effectiveness
of various shade materials. Shade structures were 3.6 m by 6.0 m by 3.0 m high at the peak and 2.0 m high at the sides. Polyethylene
shade cloth was used in three of the comparisons and consisted of effective coverings of 100%, 60% with a silver reflective
coating, and 60% black material with no reflective coating. Additionally, one of the structures was fitted with a poly snow
fence with an effective shade of about 30%. Each shade structure contained a solar radiation meter and a black globe thermometer
to measure radiant energy received under the shade material. Additionally, meteorological data were collected as a non-shaded
treatment and included temperature, humidity, wind speed, and solar radiation. Data analyses was conducted using a physiological
model based on temperature, humidity, solar radiation and wind speed; a second model using black globe temperatures, relative
humidity, and wind speed was used as well. Analyses of the data revealed that time spent in the highest stress category was
reduced by all shade materials. Moreover, significant differences (P < 0.05) existed between all shade materials (compared to no-shade) for hourly summaries during peak daylight hours and for
‘full sun’ days. 相似文献
6.
Roger A. Eigenberg Tami M. Brown-Brandl John A. Nienaber 《International journal of biometeorology》2010,54(6):601-607
Shade structures are often considered as one method of reducing stress in feedlot cattle. Selection of a suitable shade material
can be difficult without data that quantify material effectiveness for stress reduction. A summer study was conducted during
2007 using instrumented shade structures in conjunction with meteorological measurements to estimate relative effectiveness
of various shade materials. Shade structures were 3.6 m by 6.0 m by 3.0 m high at the peak and 2.0 m high at the sides. Polyethylene
shade cloth was used in three of the comparisons and consisted of effective coverings of 100%, 60% with a silver reflective
coating, and 60% black material with no reflective coating. Additionally, one of the structures was fitted with a poly snow
fence with an effective shade of about 30%. Each shade structure contained a solar radiation meter and a black globe thermometer
to measure radiant energy received under the shade material. Additionally, meteorological data were collected as a non-shaded
treatment and included temperature, humidity, wind speed, and solar radiation. Data analyses was conducted using a physiological
model based on temperature, humidity, solar radiation and wind speed; a second model using black globe temperatures, relative
humidity, and wind speed was used as well. Analyses of the data revealed that time spent in the highest stress category was
reduced by all shade materials. Moreover, significant differences (P < 0.05) existed between all shade materials (compared to no-shade) for hourly summaries during peak daylight hours and for
‘full sun’ days. 相似文献
7.
To investigate the influence of selenium on body weights and the immune organ indexes in ducklings administrated with aflatoxin
B1 (AFB1), 90 7-day-old ducklings were randomly divided into three groups (groups I–III). Group I was used as a blank control. Group
II was administered with AFB1 (0.1 mg/kg body weight). Group III was administered with AFB1 (0.1 mg/kg body weight) plus sodium selenite (1 mg/kg body weight). All treatments were given once daily for 21 days. It
showed that the ducklings’ bursa of fabricius, thymus indexes, and body weights in group II significantly decreased when compared
with group I (P < 0.01). Furthermore, the spleen indexes significantly decreased (P < 0.01). However, the ducklings’ bursa of fabricius and thymus indexes, body weights in group III ducklings significantly
increased when compared with group II (P < 0.01). In addition, the spleen indexes significantly decreased (P < 0.01). These results revealed that AFB1 significantly affect ducklings’ growth and immune organs development. However, selenium significantly ameliorated the negative
effects induced by AFB1. 相似文献
8.
Shade material evaluation using a cattle response model and meteorological instrumentation 总被引:1,自引:0,他引:1
Roger A. Eigenberg Tami M. Brown-Brandl John A. Nienaber 《International journal of biometeorology》2010,54(5):509-515
Shade structures are often considered as one method of reducing stress in feedlot cattle. Selection of a suitable shade material
can be difficult without data that quantify material effectiveness for stress reduction. A summer study was conducted during
2007 using instrumented shade structures in conjunction with meteorological measurements to estimate relative effectiveness
of various shade materials. Shade structures were 3.6 m × 6.0 m × 3.0 m high at the peak and 2.0 m high at the sides. Polyethylene
shade cloth was used in three of the comparisons and consisted of effective coverings of 100%, 60% with a silver reflective
coating, and 60% black material with no reflective coating. Additionally, one of the structures was fitted with a poly snow
fence with an effective shade of about 30%. Each shade structure contained a solar radiation meter and a black globe thermometer
to measure radiant energy received under the shade material. Additionally, meteorological data were collected as a non-shaded
treatment and included temperature, humidity, wind speed, and solar radiation. Data analyses was conducted using a physiological
model based on temperature, humidity, solar radiation and wind speed; a second model using black globe temperatures, relative
humidity, and wind speed was used as well. Analyses of the data revealed that time spent in the highest stress category was
reduced by all shade materials. Moreover, significant differences (P < 0.05) existed between all shade materials (compared to no-shade) for hourly summaries during peak daylight hours and for
‘full sun’ days. 相似文献
9.
Sheila F. Christopher Hideaki Shibata Megumi Ozawa Yasunori Nakagawa Myron J. Mitchell 《Biogeochemistry》2008,88(1):15-30
Climate change models predict that the snowpacks of temperate forests will develop later and be shallower resulting in a higher
propensity for soil freezing. In the northern most island of Japan, Hokkaido, snowpack depth decreases from west to east.
This snowpack depth gradient provided a unique opportunity to test the effects of variable snowpack and soil freezing on N
biogeochemistry. The Shibecha Northern Catchment in Shibecha Experimental Forest, eastern Hokkaido had deciduous trees and
a mean annual snowpack of 0.7 m while the M3 catchment in Uryu Experimental Forest, western Hokkaido had mixed deciduous and
coniferous tree species and a mean annual snowpack of 2.0 m. We conducted a field study (October 2004–April 2005) to determine
if differences in Shibecha and Uryu soil extractable N, N mineralization, and nitrification were controlled by the variability
in soil freezing during winter or tree species composition that affected the quality of the forest floor. The mixed deciduous
and coniferous trees forming the Uryu forest floor had a higher C:N ratio (25.0 vs. 22.4 at Shibecha), higher lignin:N ratio
(15 vs. 8.8), and higher lignin concentrations (0.28 vs. 0.18 g lignin g−1). These differences in forest floor quality contributed to higher net N mineralization and nitrification in Shibecha compared
to Uryu. In Shibecha, soil remained frozen for the entire study. For Uryu, except for an early period with cold temperatures
and no snow, the soil generally remained unfrozen. As a result of the early winter cold period and soil freezing, extractable
soil NH4+ did not change but NO3− increased. Reciprocal 0–5 cm mineral soil transplants made between Shibecha and Uryu and incubated during winter at 0, 5,
and 30 cm suggested that soil freezing resulted in greater net N mineralization yet lower nitrification regardless of the
soil origin. The effect of soil freezing should be considered when evaluating differences in N dynamics between temperate
ecosystems having a propensity for soil freezing. 相似文献
10.
Zhang L Sun YN Li YM Lin LX Ye Y Yan YQ Chen ZP 《Biological trace element research》2011,143(3):1629-1639
The thyroid functions of breastfed infants, as well as (indirectly) the development of their central nervous system, are dependent
on the iodine status of the lactating mother. Purkinje cell protein-2 is a cell-specific marker of the cerebellum Purkinje
cell and is a suitable indicator for observing the postnatal development of the cerebellum after birth. We measured the Purkinje
cell protein-2 mRNA and protein levels in the rat cerebellum in the critical postnatal (14 days after birth) and maturation
periods (28 days after birth) to determine the effect of different nutritional iodine levels on cerebellum growth in the offspring
during lactation. We found that severe iodine deficiency resulted in thyroid dysfunction in lactating rats and their offspring
on both 14 and 28 days, showing maternal total T4 16.7 ± 12.0 vs 36.4 ± 15.0, P < 0.05 (14 days) and 22.6 ± 18.7 vs 53.4 ± 9.4, P < 0.01 (28 days), and neonatal total T4 10.6 ± 2.3 vs 16.4 ± 4.7, P < 0.01(14 days) and 12.8 ± 2.9 vs 16.7 ± 3.4, P < 0.05 (28 days), respectively. The Purkinje cell protein-2 mRNA and its protein levels in offspring rats were significantly
reduced that showed Purkinje cell protein-2 mRNA 1.12 ± 0.04 vs 2.25 ± 0.53, P < 0.05 (14 days) and 1.74 ± 0.94 vs 8.69 ± 2.71, P < 0.01 (28 days). However, mild iodine deficiency and excessive iodine maintained almost normal thyroid function in maternal
and neonatal rats and normal Purkinje cell protein-2 mRNA and protein levels in offspring’s cerebellum. We conclude that severe
iodine deficiency could significantly reduce Purkinje cell protein-2 mRNA and its protein levels, indicating that the cerebellum
development was retarded, but mild iodine deficiency and excessive iodine could maintain them at an approximately normal level
by the mother’s and offspring’s compensations, especially by the mother’s mammary glands. 相似文献
11.
12.
J. B. Gaughan T. L. Mader S. M. Holt M. L. Sullivan G. L. Hahn 《International journal of biometeorology》2010,54(6):617-627
Cattle production plays a significant role in terms of world food production. Nearly 82% of the world’s 1.2 billion cattle
can be found in developing countries. An increasing demand for meat in developing countries has seen an increase in intensification
of animal industries, and a move to cross-bred animals. Heat tolerance is considered to be one of the most important adaptive
aspects for cattle, and the lack of thermally-tolerant breeds is a major constraint on cattle production in many countries.
There is a need to not only identify heat tolerant breeds, but also heat tolerant animals within a non-tolerant breed. Identification
of heat tolerant animals is not easy under field conditions. In this study, panting score (0 to 4.5 scale where 0 = no stress
and 4.5 = extreme stress) and the heat load index (HLI) [HLIBG<25°C = 10.66 + 0.28 × rh + 1.30 × BG – WS; and, HLI BG> 25°C = 8.62 + 0.38 × rh + 1.55 × BG – 0.5 × WS + e(2.4 – WS), where BG = black globe temperature (oC), rh = relative humidity (decimal form), WS = wind speed (m/s) and e is the base of the natural logarithm] were used to
assess the heat tolerance of 17 genotypes (12,757 steers) within 13 Australian feedlots over three summers. The cattle were
assessed under natural climatic conditions in which HLI ranged from thermonuetral (HLI < 70) to extreme (HLI > 96; black globe
temperature = 40.2°C, relative humidity = 64%, wind speed = 1.58 m/s). When HLI > 96 a greater number (P < 0.001) of pure bred Bos taurus and crosses of Bos taurus cattle had a panting score ≥ 2 compared to Brahman cattle, and Brahman-cross cattle. The heat tolerance of the assessed breeds
was verified using panting scores and the HLI. Heat tolerance of cattle can be assessed under field conditions by using panting
score and HLI. 相似文献
13.
Hilde Nybom Artur Mikiciński Larisa Garkava-Gustavsson Jasna Sehic Mariusz Lewandowski Piotr Sobiczewski 《Trees - Structure and Function》2012,26(1):199-213
Fire blight (Erwinia amylovora) causes serious damage to pome fruit orchards, and identification of germplasm with heritable disease resistance is therefore
crucial. Two dominant SCAR (sequence characterised amplified region) marker alleles (AE10-375 and GE-8019), flanking a previously
identified QTL (quantitative trait locus) for resistance to fire blight on ‘Fiesta’ linkage group 7 in apple cultivars related
to ‘Cox’s Orange Pippin’, were screened on 205 apple cultivars. Both marker alleles were present in 22% of the cultivars,
indicating presence of the QTL allele for tolerance, and both were lacking in 25%, indicating homozygosity for absence of
the QTL tolerance allele. However, 33% had only the marker allele AE10-375, while 20% had only GE-8019, suggesting that some
cultivars with the dominant alleles for both of the flanking markers can carry these on separate chromosomes and may lack
the QTL allele for tolerance. In 2009 and 2010, terminal shoots of greenhouse-grown grafted trees of 21 cultivars (only 20
in 2010) were inoculated with Erwinia amylovora. ‘Idared’ (susceptible) and ‘Enterprise’ (tolerant) were included as controls. Disease severity for each cultivar was expressed
as percentage of necrosis in relation to entire length of shoot, and the ranking of cultivars in 2009 and 2010 was compared
with a Spearman rank correlation test, P < 0.01. A relationship between presence of both flanking marker alleles for tolerance and level of fire blight tolerance
was confirmed with a Mann–Whitney U-test, P < 0.01 in 2009, and P < 0.05 in 2010. A PCO (principal coordinate) analysis based on band profiles obtained with 12 SSR (simple sequence repeat)
loci produced three loose clusters, two of which contained known offspring of ‘Cox’s Orange Pippin’, and one with cultivars
that were either unrelated or had an unknown origin. Cases where DNA markers did not predict level of fire blight damage as
expected, were, however, as common among descendants of ‘Cox’s Orange Pippin’ as among apparently unrelated cultivars. Obviously
the ‘Fiesta’ LG 7 QTL has some predictive value, both for known ‘Cox’ relatives and others, but more efficient markers would
be desirable for marker-assisted selection. 相似文献
14.
Summary Differences in the productivity of establishedP. radiata plantations on pasture and forest soils were found to be reproducible withP. radiata seedlings in a glasshouse environment. The growth of seedlings on pasture soil exceeded that of seedlings on native forest
soil (the ‘primary pasture effect’). After a history of pine on both native and pasture soils a residual effect of pasture
on seedling growth was evident (the ‘secondary pasture effect’). However, the effect of a history of pine plantation (the
‘pine effect’) was to decrease the productivity of both native and pasture soil as assessed by seedling growth. These effects
were not related to changes due to land management in mycorrhizal infection or in soil structure. The analysis of seedling
growth leads to the conclusion that soil fertility, particularly the availability of nitrogen and phosphorus, has changed. 相似文献
15.
J. Perry Gustafson Xue-Feng Ma Viktor Korzun John W. Snape 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(4):793-800
A consensus map of rye (Secale cereale L.) was constructed using JoinMap 2.0 based on mapping data from five different mapping populations, including ‘UC90’ × ‘E-line’,
‘P87’ × ‘P105’, ‘I0.1-line’ × ‘I0.1-line’, ‘E-line’ × ‘R-line’, and ‘Ds2’ × ‘RxL10’. The integration of the five mapping populations resulted in a 779-cM map
containing 501 markers with the number of markers per chromosome ranging from 57 on 1R to 86 on 4R. The linkage sizes ranged
from 71.5 cM on 2R to 148.7 cM on 4R. A comparison of the individual maps to the consensus map revealed that the linear locus
order was generally in good agreement between the various populations, but the 4R orientations were not consistent among the
five individual maps. The 4R short arm and long arm assignments were switched between the two population maps involving the
‘E-line’ parent and the other three individual maps. Map comparisons also indicated that marker order variations exist among
the five individual maps. However, the chromosome 5R showed very little marker order variation among the five maps. The consensus
map not only integrated the linkage data from different maps, but also greatly increased the map resolution, thus, facilitating
molecular breeding activities involving rye and triticale. 相似文献
16.
Sophie Y. Dillen Véronique Storme Nicolas Marron Catherine Bastien Sabrina Neyrinck Marijke Steenackers Reinhart Ceulemans Wout Boerjan 《Tree Genetics & Genomes》2009,5(1):147-164
Interspecific hybrids of Populus species are known for their superior growth. In this study, we examined the effect of the genetic background and contrasting
environmental conditions on growth and searched for quantitative trait loci (QTL) affecting growth traits. To this end, two
hybrid poplar families resulting from controlled crosses, Populus deltoides ‘S9-2’ × P. nigra ‘Ghoy’ (D × N, 180 F1) and P. deltoides ‘S9-2’ × P. trichocarpa ‘V24’ (D × T, 182 F1), were grown at two contrasting sites, Northern Italy and Central France. At the end of the second growing season, tree dimensions
(stem height, circumference, and volume) were assessed. The performances of both families significantly differed within and
between sites. Tree volume was significantly larger at the Italian site as compared to the French site. Genotype by environment
interactions were significant but low for both families and for all growth traits. Tight correlations among the individual
growth traits indicated that there may be a common genetic mechanism with pleiotropic effects on these growth traits. In line
with previous studies, linkage groups I, VII, IX, X, XVI, XVII, and XIX appeared to have genomic regions with the largest
effects on growth traits. This study revealed that (1) both families have high potential for selection of superior poplar
hybrids due to the pronounced heterosis (hybrid vigor) and the large genetic variability in terms of growth and (2) the choice
of site is crucial for poplar cultivation.
Dillen and Storme contributed equally to the work.
An erratum to this article can be found at 相似文献
17.
A comparison of water and carbon dioxide exchange at a windy alpine tundra and subalpine forest site near Niwot Ridge,Colorado 总被引:1,自引:1,他引:0
Peter D. Blanken Mark W. Williams Sean P. Burns Russell K. Monson John Knowles Kurt Chowanski Todd Ackerman 《Biogeochemistry》2009,95(1):61-76
Eddy covariance measurements of the surface energy balance and carbon dioxide exchange above high-elevation (3,480 m above
sea level) alpine tundra located near Niwot Ridge, Colorado, were compared to simultaneous measurements made over an adjacent
subalpine forest over two summers and one winter, from June 9, 2007 to July 3, 2008. The surface energy balance closure at
the alpine site averaged 71 and 91%, winter and summer, respectively, due to the high wind speeds, short turbulent flux footprint,
and relatively flat ridge-top location of the measurement site. Throughout the year, the alpine site was cooler with higher
relative humidity, and had a higher horizontal wind speed, especially in winter, compared to the forest site. Wind direction
was persistently downslope at the alpine site (summer and winter, day and night), whereas upslope winds were common at the
forest site during summer daytime periods. The latent and sensible heat fluxes were consistently larger in magnitude at the
forest site, with the largest differences during summer. The horizontal advective flux of CO2 at the alpine site averaged 6% of the net ecosystem exchange (NEE) during summer nights (5% during summer daytime), and was small in relation to the high wind speeds, relatively flat site,
and weak sources of CO2 upwind of the site. The magnitudes and diurnal behavior of the alpine NEE calculated using three methods; eddy-covariance, friction velocity filter, and with advection and storage calculations, gave
similar results. The period of net CO2 uptake (negative NEE) was 100 days at the alpine site with a net uptake of 16 g C m−2, compared to 208 days at the forest site with a net uptake of 108 g C m−2, with initiation of net uptake coinciding with air temperatures reaching +10°C. Winter respiration loss at the alpine site
was 164 g C m−2 over 271 days, compared to 52 g C m−2 over 175 days at the forest site, with the initiation of net loss coinciding with air temperatures reaching −10°C at each
site. 相似文献
18.
Natasha A. Kenny Jon S. Warland Robert D. Brown Terry G. Gillespie 《International journal of biometeorology》2009,53(5):429-441
This study assessed the performance of the COMFA outdoor thermal comfort model on subjects performing moderate to vigorous
physical activity. Field tests were conducted on 27 subjects performing 30 min of steady-state activity (walking, running,
and cycling) in an outdoor environment. The predicted COMFA budgets were compared to the actual thermal sensation (ATS) votes
provided by participants during each 5-min interval. The results revealed a normal distribution in the subjects’ ATS votes,
with 82% of votes received in categories 0 (neutral) to +2 (warm). The ATS votes were significantly dependent upon sex, air
temperature, short and long-wave radiation, wind speed, and metabolic activity rate. There was a significant positive correlation
between the ATS and predicted budgets (Spearman’s rho = 0.574, P < 0.01). However, the predicted budgets did not display a normal distribution, and the model produced erroneous estimates
of the heat and moisture exchange between the human body and the ambient environment in 6% of the cases. 相似文献
19.
Lughaidh Ó Néill Tijmen Veldhuizen Addy de Jongh John Rochford 《European Journal of Wildlife Research》2009,55(4):363-370
We examined the spatial structure and socio-biology of a native wild population of Eurasian otters (Lutra lutra) on mesotrophic rivers in a mild temperate climate. Radio-tracking of 20 individuals revealed exclusive intra-sexual adult
home-ranges. Adult female home-ranges (7.5 km, SD = 1.5 km, n = 7) were inversely related to river width (, F
6 = 13.5, P = 0.014) and so appeared to be based on food resources. The aquatic area within adult male home-ranges (30.2 ha, SD = 9.5 ha,
n = 5) was greater than that within adult female’s (16.8 ha, SD = 7.0 ha) (t
10 = 2.437, P = 0.035), though this result is inconclusive because some males were tracked on oligotrophic rivers. One adult male expanded
its range from 10.2 km to 19.3 km within 5 days of the death of the neighbouring male, suggesting that male home-ranges were
heavily influenced by conspecifics. 相似文献
20.
Guomo Zhou Shunyao Zhuang Qiufang Xu Hua Qin Minghung Wong Zhihong Cao 《The Botanical review》2011,77(3):296-303
Area of bamboo forest (Phyllostachys praecox) has rapidly increased in southern China during the last 20 years due to its high economic value. Aims of this study were
to analyse the temporal and spatial variations of soil organic matter (SOM) in heavily winter mulched bamboo stands and to
estimate potential for carbon sequestration. Total of 60 soil profiles with 0–15 years of bamboo plantation were sampled from
three towns in Lin’an County. Results showed that with increased plantation years, SOM decreased slightly at the beginning
(1–5 years), and then rose up steadily. Based on the average of the three locations, the highest SOM content of 75.82 g/kg
was the surface layer (0–10 cm) of the 15 years. As plantation year increased, the variation of SOM in the surface layer (0–10 cm)
was represented by a parabolic shape, and in the second layer (10–20 cm), it was a similar mode, but less vigorous. Soil organic
carbon (SOC) storage significantly increased during 5 to 15 years after it reached full production, and the calculated annual
SOC increment in 0–40 cm soil profile was about 6.3 t C/ha/year. Therefore, extended Phyllostachys praecox forests can be considered as one option for countering CO2 emissions and regional climate change. 相似文献