CAJ | 학술논문

以青藏高原典型高寒草甸为例,研究了施肥对植物群落生产力和物种多样性的影响.本文报道了这个实验的初步结果,就施肥对草地生产力和物种多样性的影响进行了分析,结果如下:(1)施肥提高生产力.施肥第1年和第2年,植物群落生产力显著增加;施肥第3年,生产力是施肥前的2倍多;(2)施肥使物种多样性降低.施肥第1年物种丰富度变化不显著;第2年施肥梯度上物种多样性差异显著;第3年最高施肥水平物种丰富度为对照的1/4;(3)施肥使草地质量提高.因为草地质量和生物量以及优良牧草比例直接相关,施肥使地上生物量明显增加,毒杂草比例降低,禾草比例增加,所以草地质量提高,说明施肥对改良草地有显著作用;(4)群落结构发生了明显的变化,施肥水平高时群落结构接近于生态位优先占领假说.随着施肥水平增加,各个物种重要值的最大值从0.107,0.183,0.585一直增加到0.775.不施肥时有10个物种地上生物量超过最大单种生物量的一半,最高施肥时只有一个.(5)对6个优势种进行的分析表明,只有垂穗鹅观草的生物量随着施肥水平的增加持续增加,其它物种都是减少的趋势.说明垂穗鹅观草的急剧增加可能是导致物种丰富度降低的原因.
이청장고원전형고한초전위례,연구료시비대식물군락생산력화물충다양성적영향.본문보도료저개실험적초보결과,취시비대초지생산력화물충다양성적영향진행료분석,결과여하:(1)시비제고생산력.시비제1년화제2년,식물군락생산력현저증가;시비제3년,생산력시시비전적2배다;(2)시비사물충다양성강저.시비제1년물충봉부도변화불현저;제2년시비제도상물충다양성차이현저;제3년최고시비수평물충봉부도위대조적1/4;(3)시비사초지질량제고.인위초지질량화생물량이급우량목초비례직접상관,시비사지상생물량명현증가,독잡초비례강저,화초비례증가,소이초지질량제고,설명시비대개량초지유현저작용;(4)군락결구발생료명현적변화,시비수평고시군락결구접근우생태위우선점령가설.수착시비수평증가,각개물충중요치적최대치종0.107,0.183,0.585일직증가도0.775.불시비시유10개물충지상생물량초과최대단충생물량적일반,최고시비시지유일개.(5)대6개우세충진행적분석표명,지유수수아관초적생물량수착시비수평적증가지속증가,기타물충도시감소적추세.설명수수아관초적급극증가가능시도치물충봉부도강저적원인.
A two-year (2000, 2001) fertilizing experiment in an alpine meadow of east Qinghai-Tibet Plateau showed that the plant species diversity decreased significantly while the aboveground net primary production increased significantly along the 4 levels of fertilization created using (NH4)2HPO4. The plant community structure changed- the number of species that weighed more than half of the greatest one changed from 10 to 1 along the fertilization levels, with the biggest relative importance varing from 0.107,0.183, 0.585 to 0.775. We grouped the species into 5 groups: graminoids, sedges, legumes, forbs, poison forbs, and found that graminoids increased significantly with fertilization while other groups all decreased.At the highest fertilization level, graminoids increased from 33% to more than 94% but other groups all decreased to less than 1%, except the forbs group, which was 3%. Since the grassland was grazed in winter and early spring, which removed the litter, the litter did not affect the experimental results. So fertilization may affect biodiversity without increasing litter.