生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2014年
1期
73-79
,共7页
指示生物%营养类群%外来物种%根际%生态效应
指示生物%營養類群%外來物種%根際%生態效應
지시생물%영양류군%외래물충%근제%생태효응
biological indicator%trophic level%exotic species%rhizosphere%ecological effects
相思树和桉树等树种因其生长迅速、耐性好以及适合制作纸浆等特点，近年来在华南地区大面积种植，带来了巨大的经济利益，但是相思树和桉树如何影响林下土壤生物多样性和土壤肥力还不清楚，科学评价其林下土壤健康水平十分必要。土壤线虫的种类和数量十分丰富，在土壤食物网各营养级中占据重要位置，对土壤环境变化反应敏感，作为土壤健康的指示生物被广泛应用。本文以幼龄厚荚相思 Acacia crassicapa和尾叶桉 Eucalyptus urophylla人工林为研究对象，于干季和湿季分别对2个林分根区和非根区土壤线虫进行研究，探讨土壤线虫这种指示生物的数量、各营养类群比例和多样性的变化规律，以及它们和环境因子的关系。主要结果表明：（1）厚荚相思土壤线虫总数为每公斤干土6741条，显著高于尾叶桉线虫总数的28.3%。厚荚相思人工林土壤食细菌线虫的百分比相比尾叶桉人工林高6.3%，且差异显著。（2）土壤线虫的群落组成变化具有明显的季节波动，湿季土壤食细菌线虫比例上升，而植物寄生线虫的比例下降，多样性指数由干季的0.87减小到0.75，统计差异均达到了显著水平。（3）根区比非根区显著提高了线虫数量的89.1%，这是由根区积累更多的有机碳和总氮引起的。总之，厚荚相思人工林为土壤自由生活线虫提供了优良环境，且在幼龄期没有表现出土壤酸化，生态效应优于尾叶桉人工林，在华南地区人工林营林过程中可适当增加厚荚相思林分面积。
相思樹和桉樹等樹種因其生長迅速、耐性好以及適閤製作紙漿等特點，近年來在華南地區大麵積種植，帶來瞭巨大的經濟利益，但是相思樹和桉樹如何影響林下土壤生物多樣性和土壤肥力還不清楚，科學評價其林下土壤健康水平十分必要。土壤線蟲的種類和數量十分豐富，在土壤食物網各營養級中佔據重要位置，對土壤環境變化反應敏感，作為土壤健康的指示生物被廣汎應用。本文以幼齡厚莢相思 Acacia crassicapa和尾葉桉 Eucalyptus urophylla人工林為研究對象，于榦季和濕季分彆對2箇林分根區和非根區土壤線蟲進行研究，探討土壤線蟲這種指示生物的數量、各營養類群比例和多樣性的變化規律，以及它們和環境因子的關繫。主要結果錶明：（1）厚莢相思土壤線蟲總數為每公斤榦土6741條，顯著高于尾葉桉線蟲總數的28.3%。厚莢相思人工林土壤食細菌線蟲的百分比相比尾葉桉人工林高6.3%，且差異顯著。（2）土壤線蟲的群落組成變化具有明顯的季節波動，濕季土壤食細菌線蟲比例上升，而植物寄生線蟲的比例下降，多樣性指數由榦季的0.87減小到0.75，統計差異均達到瞭顯著水平。（3）根區比非根區顯著提高瞭線蟲數量的89.1%，這是由根區積纍更多的有機碳和總氮引起的。總之，厚莢相思人工林為土壤自由生活線蟲提供瞭優良環境，且在幼齡期沒有錶現齣土壤痠化，生態效應優于尾葉桉人工林，在華南地區人工林營林過程中可適噹增加厚莢相思林分麵積。
상사수화안수등수충인기생장신속、내성호이급괄합제작지장등특점，근년래재화남지구대면적충식，대래료거대적경제이익，단시상사수화안수여하영향림하토양생물다양성화토양비력환불청초，과학평개기림하토양건강수평십분필요。토양선충적충류화수량십분봉부，재토양식물망각영양급중점거중요위치，대토양배경변화반응민감，작위토양건강적지시생물피엄범응용。본문이유령후협상사 Acacia crassicapa화미협안 Eucalyptus urophylla인공림위연구대상，우간계화습계분별대2개림분근구화비근구토양선충진행연구，탐토토양선충저충지시생물적수량、각영양류군비례화다양성적변화규률，이급타문화배경인자적관계。주요결과표명：（1）후협상사토양선충총수위매공근간토6741조，현저고우미협안선충총수적28.3%。후협상사인공림토양식세균선충적백분비상비미협안인공림고6.3%，차차이현저。（2）토양선충적군락조성변화구유명현적계절파동，습계토양식세균선충비례상승，이식물기생선충적비례하강，다양성지수유간계적0.87감소도0.75，통계차이균체도료현저수평。（3）근구비비근구현저제고료선충수량적89.1%，저시유근구적루경다적유궤탄화총담인기적。총지，후협상사인공림위토양자유생활선충제공료우량배경，차재유령기몰유표현출토양산화，생태효응우우미협안인공림，재화남지구인공림영림과정중가괄당증가후협상사림분면적。
Wide areas of Acacia crassicapa and Eucalyptus urophylla were planted in South China recently due to their rapid growth, strong tolerance and suitability for paper pulp. However, it is still not clear how these two tree species impact soil biodiversity and fertility. It is necessary to evaluate their soil health condition scientifically. The number and variety of soil nematodes are abundant. Soil nematodes occupy the key positions in trophic levels of soil food web and are sensitive to environmental changes. As indicator of soil health, nematodes are used in ecology widely. In this study, soil nematodes were investigated in young Acacia crassicapa and Eucalyptus urophylla plantations with different seasons and sampling positions, to analyze the patterns of soil nematode individuals, community composition and diversity index, as well as relationships with environmental factors. The main results showed that:(1) Total nematode individuals in Acacia crassicapa plantation were 674.1/100 g dry soil, more 28.3%than Eucalyptus urophylla plantation significantly. Percentages of bacterivores in Acacia crassicapa plantation were more 6.3%than Eucalyptus urophylla significantly. (2) Community composition of soil nematodes varied with the season. The percentage of bacterivores increased, whereas the percentage of plant parasites decreased in wet season. Diversity index decreased from 0.87 in dry season to 0.75 in wet season. Statistic differences were all significant. (3) Nematode density in rhizosphere was more 89.1%than non-rhizosphere which attributed to accumulated organic carbon and nitrogen in rhizosphere. In conclusion, Acacia crassicapa plantation provide optimal environment for soil free living nematodes, whereas soil acidification do not happen in young forest period. For ecological effects of Acacia crassicapa plantation are superior to Eucalyptus urophylla, planting areas of Acacia crassicapa may be expanded in South China in future.
