浙江大学学报(农业与生命科学版)
浙江大學學報(農業與生命科學版)
절강대학학보(농업여생명과학판)
Journal of Zhejiang University (Agriculture & Life Sciences)
2015年
6期
723-731
,共9页
赵伟%杨明秀%陈林%王磊%宋乃平%杨新国
趙偉%楊明秀%陳林%王磊%宋迺平%楊新國
조위%양명수%진림%왕뢰%송내평%양신국
荒漠草原%人工柠条林%林龄%季节动态%草本层植被
荒漠草原%人工檸條林%林齡%季節動態%草本層植被
황막초원%인공저조림%림령%계절동태%초본층식피
desert steppe%artificial Caragana intermedia shrublands%age of shrublands%seasonal dynamics%herbaceous layer vegetation
为系统认识柠条林草本层植被的物种组成特征及其动态变化规律,把握灌草结构及人工林系统的演变趋势,采用空间换时间的方法,以天然草地为对照,搭建一个由不同林龄样地构成的研究序列,并开展灌丛内外植被季节性动态的跟踪监测与分析.结果表明:1)对照草地和柠条林地草本层物种共计25种,分属于8个科23个属.16 a柠条林物种数最多(16种),随着林龄的增大,物种数逐渐减少,中亚白草和隐子草等多年生禾草开始出现,但是优势种以一年生短命植物为主.物种多样性指数则随林龄增长呈先增长后下降的趋势.2)草本层植被盖度、生物量与物种数的季节动态主要受降水、气温变化的影响,但是灌丛的存在显著延滞了草本层植被经历春季干旱后的生长恢复速度,并以25 a柠条林的生长节律变化最为突出.3)林龄显著改变了灌丛内外草本层植被盖度以及灌丛内草本层植被生物量的季节动态,林龄与季节因子间存在显著的交互作用.综上所述,荒漠草原人工柠条林草本层植被的结构与动态是林龄、季节以及空间异质性等因子交互作用下的产物,伴随人工柠条林的衰败,群落存在逐步向地带性植被演替的趋势,但是在以一年生短命植物为主要优势物种情况下,系统稳定性的维持和演替方向还存在诸多的不确定性.
為繫統認識檸條林草本層植被的物種組成特徵及其動態變化規律,把握灌草結構及人工林繫統的縯變趨勢,採用空間換時間的方法,以天然草地為對照,搭建一箇由不同林齡樣地構成的研究序列,併開展灌叢內外植被季節性動態的跟蹤鑑測與分析.結果錶明:1)對照草地和檸條林地草本層物種共計25種,分屬于8箇科23箇屬.16 a檸條林物種數最多(16種),隨著林齡的增大,物種數逐漸減少,中亞白草和隱子草等多年生禾草開始齣現,但是優勢種以一年生短命植物為主.物種多樣性指數則隨林齡增長呈先增長後下降的趨勢.2)草本層植被蓋度、生物量與物種數的季節動態主要受降水、氣溫變化的影響,但是灌叢的存在顯著延滯瞭草本層植被經歷春季榦旱後的生長恢複速度,併以25 a檸條林的生長節律變化最為突齣.3)林齡顯著改變瞭灌叢內外草本層植被蓋度以及灌叢內草本層植被生物量的季節動態,林齡與季節因子間存在顯著的交互作用.綜上所述,荒漠草原人工檸條林草本層植被的結構與動態是林齡、季節以及空間異質性等因子交互作用下的產物,伴隨人工檸條林的衰敗,群落存在逐步嚮地帶性植被縯替的趨勢,但是在以一年生短命植物為主要優勢物種情況下,繫統穩定性的維持和縯替方嚮還存在諸多的不確定性.
위계통인식저조림초본층식피적물충조성특정급기동태변화규률,파악관초결구급인공림계통적연변추세,채용공간환시간적방법,이천연초지위대조,탑건일개유불동림령양지구성적연구서렬,병개전관총내외식피계절성동태적근종감측여분석.결과표명:1)대조초지화저조임지초본층물충공계25충,분속우8개과23개속.16 a저조림물충수최다(16충),수착림령적증대,물충수축점감소,중아백초화은자초등다년생화초개시출현,단시우세충이일년생단명식물위주.물충다양성지수칙수림령증장정선증장후하강적추세.2)초본층식피개도、생물량여물충수적계절동태주요수강수、기온변화적영향,단시관총적존재현저연체료초본층식피경력춘계간한후적생장회복속도,병이25 a저조림적생장절률변화최위돌출.3)림령현저개변료관총내외초본층식피개도이급관총내초본층식피생물량적계절동태,림령여계절인자간존재현저적교호작용.종상소술,황막초원인공저조림초본층식피적결구여동태시림령、계절이급공간이질성등인자교호작용하적산물,반수인공저조림적쇠패,군락존재축보향지대성식피연체적추세,단시재이일년생단명식물위주요우세물충정황하,계통은정성적유지화연체방향환존재제다적불학정성.
Summary Caragana intermedia is a leguminous shrub plant , which is planted in desert steppe area on a large scale , which can also be used as forage grass , with very important ecological and economic value . However , a series of shrub and grass resource competition problem emerged with the aging of C . intermedia shrublands . The growth of zonal perennial vegetation often subjected to great constraints , and self‐degradation of C . intermedia shrublands was also developed to different degrees . The reasonable collocation relations of shrub and grass were one of the key elements to maintain ecology and production services of C . intermedia shrublands in desert steppe . The objective of this study is to understand composition characteristics of herbaceous plant species and its dynamic change rules around the C . intermedia shrublands , and to reveal the structure of shrub and grass and the evolution trend of C . intermedia shrubland system . Taking natural grassland as a control , spatiotemporal substitution methods were used , and a research sequence constituted of different ages of C . intermedia shrubland plots was erected to carry out tracking , monitoring and analysis of vegetation seasonal dynamics at interior and exterior of the shrubs . The results showed that : 1) The number of natural grassland (CK) and herbaceous plant species of C . intermedia shrublands were 25 species , belonging to 8 families and 23 genera . The highest species number was the 16 a C . intermedia shrublands ( 16 species) , and the number of species gradually decreased with aging of C . intermedia shrublands .Pennisetum centrasiaticum , Cleistogenes squarrosa and other perennial grasses began to appear , but the dominant species still was short‐lived annual plants . Species diversity indexes showed a decreasing trend after a steady increase with aging of C . intermedia shrublands . 2) The seasonal dynamics , coverage degree , aboveground biomass and species number of herbaceous layer vegetation were mainly affected by the change of precipitation and temperature , but the existence of C . intermedia shrubs delayed the grow th recovery rate of herbaceous layer vegetation after spring drought , and the highest relative volatility index was 25 a C . intermedia shrublands . 3) The coverage degree of herbaceous layer vegetation at the interior and exterior of the C . intermedia shrubs and the seasonal dynamics of aboveground biomass at the interior of the C . intermedia shrubs were significantly changed by the ages of C . intermedia shrubland , and a significant interaction between ages of C . intermedia shrublands and seasonal factors was observed . In conclusion , the structure and dynamics of herbaceous layer vegetation of C . intermedia shrublands in desert steppe is regulated by the ages of C . intermedia shrublands , season and spatial heterogeneity and so on . With the decay of C . intermedia shrublands , the community gradually grows towards zonal vegetation succession , but under the circumstance of short‐lived annual plants as dominant species , maintenance of system stability and succession direction still has many uncertainties .