高人帮忙翻译一段英文急!IthasbeenestimatedthatabouthalfofallspeciesexhibitingCAMareepiphytes(WinterandSmith1996;Zotz2004).InastudyconductedbyGriffithsandSmith(1983),sevenoutof17obligateepiphytespeciesinth

Question

高人帮忙翻译一段英文 急!
It has been estimated that about half of all species
exhibiting CAM are epiphytes (Winter and Smith 1996;
Zotz 2004). In a study conducted by Griffiths and Smith
(1983), seven out of 17 obligate epiphyte species in the
genus Tillandsia exhibited obligate C3 photosynthesis, as
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determined by d C values between -23 and -35%. The
other ten Tillandsia species were deemed obligate CAM,
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with d C values of -10 to -21%. Values more negative
than -14%, however, indicate the potential for daytime
CO2 uptake and fixation by Rubisco during CAM phases 1
13
and2.Otherpublishedd CvaluesforspeciesofTillandsia
show that this genus spans the range of values expected for
CAM and C3 plants, including a number of potentially
intermediate species (Medina 1974; Medina and Troughton
1974; Griffiths and Smith 1983).
The isotopic composition of bulk leaf tissue has com-
monly been used to determine photosynthetic pathways
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(Winter et al. 1983; Silvera et al. 2005). The d C of bulk
leaf tissue is a time-integrated measure, describing relative
photosynthetic pathway utilization and CO2 concentration
at the site of carboxylation over relatively long time scales.
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The d C of leaf sugars, however, provides an indication ofpathways used for C fixation on the day the leaf was col-
lected (Brugnoli et al. 1988). We utilized these long- and
short-term measures of C fixation to investigate photo-
syntheticvariationbetweenseasonsandamongforesttypes
with contrasting microclimate. We expected that the mode
of C assimilation is flexible, leading to: (1) less negative
13
d C of bulk leaf tissues in drier habitats, indicating a
greater relative proportion of CO2 fixation through the
13
CAM pathway; and (2) less negative d C of sugars in the
dry season than in the wet season, indicating greater uti-
lization of CAM.

Answer 1

It has been estimated that about half of all species据估计,约有一半的物种
exhibiting CAM are epiphytes (Winter and Smith 1996;参展CAM的是附生植物（冬季和史密斯1996年;
Zotz 2004).措茨2004年）.In a study conducted by Griffiths and Smith在由格里菲斯和史密斯进行的一项研究
(1983),seven out of 17 obligate epiphyte species in the （1983年）,7附生植物物种的17责成列于
genus Tillandsia exhibited obligate C3 photosynthesis,as铁兰属展出责成体C3光合作用,作为
13 13
determined by d C values between -23 and -35%.决定由D C值-23和-35％之间.The该
other ten Tillandsia species were deemed obligate CAM,铁兰等10种被认为有义务计算机辅助制造,
13 13
with d C values of -10 to -21%.与d C值-10到-21％.Values more negative更多的负面价值
than -14%,however,indicate the potential for daytime超过-14％,但是,显示白天的潜力
CO2 uptake and fixation by Rubisco during CAM phases 1二氧化碳吸收和固定在Rubisco的CAM的阶段1
13 13
and2.Otherpublishedd CvaluesforspeciesofTillandsia and2.Otherpublishedd CvaluesforspeciesofTillandsia
show that this genus spans the range of values expected for结果表明,该属跨越了预期值的范围
CAM and C3 plants,including a number of potentially CAM和C3植物,包括潜在的数目
intermediate species (Medina 1974; Medina and Troughton中间物种（1974年麦地那;梅迪纳和特劳
1974; Griffiths and Smith 1983).1974年,格里菲斯和Smith 1983）.
The isotopic composition of bulk leaf tissue has com-散叶组织的同位素构成发生了COM的
monly been used to determine photosynthetic pathways monly被用来确定光合作用途径
13 13
(Winter et al.1983; Silvera et al.2005).（冬等人.1983年;锡尔弗拉等.2005年）.The d C of bulk在D散装ç
leaf tissue is a time-integrated measure,describing relative叶组织是一个时间的综合措施,说明相对
photosynthetic pathway utilization and CO2 concentration光合利用率和二氧化碳浓度途径
at the site of carboxylation over relatively long time scales.在现场的羧在相对长的时间尺度.
13 13
The d C of leaf sugars,however,provides an indication ofpathways used for C fixation on the day the leaf was col-叶糖的D ć,但是,提供了一个固定的C ofpathways用于日常的叶显示山口,
lected (Brugnoli et al.1988).lected（布鲁尼奥利等.1988年）.We utilized these long- and我们利用这些长期和
short-term measures of C fixation to investigate photo-碳固定的短期措施,调查照片
syntheticvariationbetweenseasonsandamongforesttypes syntheticvariationbetweenseasonsandamongforesttypes
with contrasting microclimate.与小气候对比.We expected that the mode我们预计该模式
of C assimilation is flexible,leading to:(1) less negative灵活的C同化,导致：（1）负少
13 13
d C of bulk leaf tissues in drier habitats,indicating a Ð栖息在较干燥的散装叶组织ć,这表明
greater relative proportion of CO2 fixation through the更大的相对比例固定CO2通过
13 13
CAM pathway; and (2) less negative d C of sugars in the CAM的途径;（二）负D C以较少的糖
dry season than in the wet season,indicating greater uti-旱季比雨季,显示更大的尿路感染,
lization of CAM.化中的CAM研究.