在德国植物营养和土壤科学研究所的温室中,用盆栽试验研究了3种不同的养分处理下(所有养分+硫肥、所有养分但无硫肥、空白对照(什么都不添加))大针茅(Stipa grandis L.)和糙隐子草(Cleistogenes squarrosa L.)对养分资源的竞争在形态学上的反应.竞争试验设计为替代序列设计,即每盆的植物密度为4株,大针茅的植株数从4→0,相反,糙隐子草的密度则从0→4.试验所用的土壤为内蒙古典型草原沙质栗钙土,2001年5月20日播种,待种籽发芽出苗后的第二天进行间苗.然后,每间隔10 d分别对两种草的叶层高度、叶片数、分孽数进行测定;并于试验的第80天,度量糙隐子草新近展开的顶部叶片的叶绿素含量,之后齐地面刈割地上部分测地上生物量,同时将试验盆浸泡在蒸馏水中,用60目的网筛轻轻冲洗根系,用滤纸吸干水分,称鲜重,以便测定根长、根半径和根表面积等;然后用无离子水冲洗根系,在65℃下烘48 h称重,过0.5mm筛粉碎装瓶备分析用.每个处理重复3次.结果表明,所有处理的大针茅和糙隐子草形态特征不存在竞争关系,即彼此比例的消长对对方无显著性的影响,且大针茅的根茎形态特征随两者比例的变化而变化不显著,在空白对照处理中糙隐子草也有类似的现象.然而,当供给养分时(无论是否同时添加硫肥),糙隐子草的比例大小显著影响其形态特征,即存在密度制约原理,且硫的供给与糙隐子草的比例间存在互作现象.养分添加显著增加了大针茅地上部分的生长利发育,但对根系的生长影响很小,且硫对其地上地下均无显著性的影响.而养分添加不仅增加了糙隐子草地上部分的生长发育,而且增加了根系的生长,硫的缺乏阻碍了糙隐子草地上地下的生长和发育.养分供给显著降低了糙隐子草的根茎比,但没有影响大针茅的根茎比.硫对糙隐子草根茎比的影响随糙隐子草比例的变化而变化,在其比例为100%和75%时,供硫显著降低了其根茎比.在所有养分处理中,25%比例的糙隐子草的根茎比显著小于100%比例的糙隐子草根茎比.供给其他养分而不供硫时,糙隐子草叶片的绿度显著淡于其它两种处理;且在养分供应(无论是否供硫)25%比例的糙隐子草叶片绿度显著深于100%比例的糙隐子草叶片绿度.该研究表明,大针茅与糙隐子草的形态之间似乎不存在竞争关系;由于所有处理大针茅种群生产力较低,其种间竞争很小,但糙隐子草种间竞争明显.养分的缺乏主要限制了大针茅地上部分的生长和发育,对地下部分影响较小,且对硫供给的状况反应不敏感.而养分供给对糙隐子草地上地下均有显著的影响,且硫的缺乏阻碍了糙隐子草的生长发育.土壤贫瘠时,由于糙隐子草种群生产力低,植物间竞争较小,相反,对养分资源的竞争加剧.对养分的竞争刺激了根系的生长,使更多的光合产物分配到根中.其他养分的供给,提高了糙隐子草的生产力,因而加剧了硫的缺乏,而在低养分状况下(不供给任何养分)则缓解了硫的缺乏症状.
在德國植物營養和土壤科學研究所的溫室中,用盆栽試驗研究瞭3種不同的養分處理下(所有養分+硫肥、所有養分但無硫肥、空白對照(什麽都不添加))大針茅(Stipa grandis L.)和糙隱子草(Cleistogenes squarrosa L.)對養分資源的競爭在形態學上的反應.競爭試驗設計為替代序列設計,即每盆的植物密度為4株,大針茅的植株數從4→0,相反,糙隱子草的密度則從0→4.試驗所用的土壤為內矇古典型草原沙質慄鈣土,2001年5月20日播種,待種籽髮芽齣苗後的第二天進行間苗.然後,每間隔10 d分彆對兩種草的葉層高度、葉片數、分孽數進行測定;併于試驗的第80天,度量糙隱子草新近展開的頂部葉片的葉綠素含量,之後齊地麵刈割地上部分測地上生物量,同時將試驗盆浸泡在蒸餾水中,用60目的網篩輕輕遲洗根繫,用濾紙吸榦水分,稱鮮重,以便測定根長、根半徑和根錶麵積等;然後用無離子水遲洗根繫,在65℃下烘48 h稱重,過0.5mm篩粉碎裝瓶備分析用.每箇處理重複3次.結果錶明,所有處理的大針茅和糙隱子草形態特徵不存在競爭關繫,即彼此比例的消長對對方無顯著性的影響,且大針茅的根莖形態特徵隨兩者比例的變化而變化不顯著,在空白對照處理中糙隱子草也有類似的現象.然而,噹供給養分時(無論是否同時添加硫肥),糙隱子草的比例大小顯著影響其形態特徵,即存在密度製約原理,且硫的供給與糙隱子草的比例間存在互作現象.養分添加顯著增加瞭大針茅地上部分的生長利髮育,但對根繫的生長影響很小,且硫對其地上地下均無顯著性的影響.而養分添加不僅增加瞭糙隱子草地上部分的生長髮育,而且增加瞭根繫的生長,硫的缺乏阻礙瞭糙隱子草地上地下的生長和髮育.養分供給顯著降低瞭糙隱子草的根莖比,但沒有影響大針茅的根莖比.硫對糙隱子草根莖比的影響隨糙隱子草比例的變化而變化,在其比例為100%和75%時,供硫顯著降低瞭其根莖比.在所有養分處理中,25%比例的糙隱子草的根莖比顯著小于100%比例的糙隱子草根莖比.供給其他養分而不供硫時,糙隱子草葉片的綠度顯著淡于其它兩種處理;且在養分供應(無論是否供硫)25%比例的糙隱子草葉片綠度顯著深于100%比例的糙隱子草葉片綠度.該研究錶明,大針茅與糙隱子草的形態之間似乎不存在競爭關繫;由于所有處理大針茅種群生產力較低,其種間競爭很小,但糙隱子草種間競爭明顯.養分的缺乏主要限製瞭大針茅地上部分的生長和髮育,對地下部分影響較小,且對硫供給的狀況反應不敏感.而養分供給對糙隱子草地上地下均有顯著的影響,且硫的缺乏阻礙瞭糙隱子草的生長髮育.土壤貧瘠時,由于糙隱子草種群生產力低,植物間競爭較小,相反,對養分資源的競爭加劇.對養分的競爭刺激瞭根繫的生長,使更多的光閤產物分配到根中.其他養分的供給,提高瞭糙隱子草的生產力,因而加劇瞭硫的缺乏,而在低養分狀況下(不供給任何養分)則緩解瞭硫的缺乏癥狀.
재덕국식물영양화토양과학연구소적온실중,용분재시험연구료3충불동적양분처리하(소유양분+류비、소유양분단무류비、공백대조(십요도불첨가))대침모(Stipa grandis L.)화조은자초(Cleistogenes squarrosa L.)대양분자원적경쟁재형태학상적반응.경쟁시험설계위체대서렬설계,즉매분적식물밀도위4주,대침모적식주수종4→0,상반,조은자초적밀도칙종0→4.시험소용적토양위내몽고전형초원사질률개토,2001년5월20일파충,대충자발아출묘후적제이천진행간묘.연후,매간격10 d분별대량충초적협층고도、협편수、분얼수진행측정;병우시험적제80천,도량조은자초신근전개적정부협편적협록소함량,지후제지면예할지상부분측지상생물량,동시장시험분침포재증류수중,용60목적망사경경충세근계,용려지흡간수분,칭선중,이편측정근장、근반경화근표면적등;연후용무리자수충세근계,재65℃하홍48 h칭중,과0.5mm사분쇄장병비분석용.매개처리중복3차.결과표명,소유처리적대침모화조은자초형태특정불존재경쟁관계,즉피차비례적소장대대방무현저성적영향,차대침모적근경형태특정수량자비례적변화이변화불현저,재공백대조처리중조은자초야유유사적현상.연이,당공급양분시(무론시부동시첨가류비),조은자초적비례대소현저영향기형태특정,즉존재밀도제약원리,차류적공급여조은자초적비례간존재호작현상.양분첨가현저증가료대침모지상부분적생장리발육,단대근계적생장영향흔소,차류대기지상지하균무현저성적영향.이양분첨가불부증가료조은자초지상부분적생장발육,이차증가료근계적생장,류적결핍조애료조은자초지상지하적생장화발육.양분공급현저강저료조은자초적근경비,단몰유영향대침모적근경비.류대조은자초근경비적영향수조은자초비례적변화이변화,재기비례위100%화75%시,공류현저강저료기근경비.재소유양분처리중,25%비례적조은자초적근경비현저소우100%비례적조은자초근경비.공급기타양분이불공류시,조은자초협편적록도현저담우기타량충처리;차재양분공응(무론시부공류)25%비례적조은자초협편록도현저심우100%비례적조은자초협편록도.해연구표명,대침모여조은자초적형태지간사호불존재경쟁관계;유우소유처리대침모충군생산력교저,기충간경쟁흔소,단조은자초충간경쟁명현.양분적결핍주요한제료대침모지상부분적생장화발육,대지하부분영향교소,차대류공급적상황반응불민감.이양분공급대조은자초지상지하균유현저적영향,차류적결핍조애료조은자초적생장발육.토양빈척시,유우조은자초충군생산력저,식물간경쟁교소,상반,대양분자원적경쟁가극.대양분적경쟁자격료근계적생장,사경다적광합산물분배도근중.기타양분적공급,제고료조은자초적생산력,인이가극료류적결핍,이재저양분상황하(불공급임하양분)칙완해료류적결핍증상.
Effects of nutrients (compounds of macro- and micro-elements) supply without sulfur (T1)and with sulfur (T2) on the competition between Stipa grandis L. (C3) and Cleistogenes squarrosa L. (C4)were examined using a replacement series design in a greenhouse experiment over a period of 80 d. Blank treatment (nothing applied) (To) was conducted simultaneously. it seems to be no inter-competition between S. grandis and C. squarrosa in all treatments. There was also no intra-competition for S. grandis in all treatments, and for C. squarrosa under T0 treatment because of low productivity. However, the intra-competition of aboveground of C squarrosa was significant when nutrients were supplied regardless of sulfur (S) application. The interaction on dry weight of C. squarrosa per pot between S supply and proportion of C. squarrosa was observed. Under the treatments of T1 and T2 the shoot growth of S. grandis increased significantly compared with To treatment, but there was no significant difference between T1 and T2 treatments, indicating S had no effect on it. Root morphologies of S. grandis was not sensitive to nutrients added. Nutrients supply (T1 and T2 treatments) not only increased significantly the shoot growth of C. squarrosa, but also increased significantly its root growth. Sulfur increased significantly growth of the shoot and root of C. squarrosa. Nutrients supply decreased significantly ratio of root to shoot dry matter (RRS) of C. squarrosa regardless of S application, but the RRS of S. grandis was not affected by nutrients applied. Sulfur also decreased significantly the RRS of C. squarrosa in 100% and 75% proportions of C.squarrosa. The RRS of C. squarrosa was greater significantly in the 100% proportion than that in the 25% proportion of C. squarrosa for all treatments. Therefore, photosynthesis is more allocated to root in infertility soils than in fertility soils and the competition for nutrient resources stimulates root production.The degree of leaf greenness of C. squarrosa in T1 treatment was less significantly than that in To and T2 treatments, and it was greater significantly in the 25% proportion than in the 100% proportion of C.squarrosa under T1 and T2 treatments, indicating that nutrients supply increase chlorophyll content in plant and may accentuate S deficiency or low plant productivity alleviate S deficiency.
