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1.
生物土壤结皮对荒漠土壤种子库和种子萌发的影响   总被引:6,自引:0,他引:6  
研究了腾格里沙漠东南缘在不同自然条件(风、温度、水分)下,人工固沙植被区(24龄、41龄、50龄)和相邻天然植被区的两种生物土壤结皮对荒漠土壤种子库和种子萌发的影响。结果表明,荒漠土壤种子库在苔藓结皮上的储量显著高于藻类结皮。随着生物土壤结皮的发育,种子萌发量在苔藓结皮上增加,在藻类结皮上减少。生物土壤结皮层的含水量对种子萌发有显著的影响(p〈0.05),植物种子在湿润处理的生物土壤结皮上的萌发量高于干燥处理的生物土壤结皮上的种子萌发量。生物土壤结皮表层温度和亚表层温度对荒漠植物种子萌发无显著影响(p〉0.05),但总体而言,对于苔藓结皮,植物种子在较高温度下的萌发量略高于在较低温度下的萌发量,而对于藻类结皮,植物种子在较低温度下的萌发量略高。  相似文献   

2.
土壤种子库对漫溢区受损植被更新的贡献   总被引:1,自引:0,他引:1  
在塔里木河下游选择两个典型漫溢区,在野外进行了土壤种子库萌发试验,并与河水漫溢区的幼苗库进行比较,以确定土壤种子库对受损植被更新的贡献度.结果表明:两个漫溢区土壤种子库物种数均为12种,生活型组成以多年生草本和灌木为主;种子库密度分别为282.5和173.2粒·m-2,表层土壤(0~2 cm)种子密度分别占总密度的76.9%和71.0%.土壤种子库对实生幼苗的物种组成和密度具有显著影响,两个漫溢区实生幼苗数量分别有84.7%和99.4%来源于土壤种子库.两个漫溢区土壤种子库与实生幼苗库物种相似性系数分别为0.72和0.63;实生幼苗密度与种子库密度具有很好的正相关性,说明土壤种子库对植被更新具有重要贡献.  相似文献   

3.
李翠  王庆海  陈超  温海峰 《生态科学》2019,38(3):133-142
为明确蔡家河湿地土壤种子库特征及其与地上植被和土壤因子的关系, 采用野外调查取样和室内萌发实验相结合的方法, 对芦苇群落, 野艾蒿群落和林下杂草群落3种不同植被类型的土壤种子库密度, 物种组成, 地上植被以及土壤理化性质进行了调查研究。结果表明: 蔡家河湿地3种植被类型的土壤种子库密度分别为(7725±1286) 粒•m-2, (2535±556) 粒•m-2和(5085±984) 粒•m-2; 物种数量分别为36种, 28种和39种。3种植被类型土壤种子库的物种丰富度以及多样性均高于地上植被, 并且3种植被类型间土壤种子库物种组成的相似性高于地上植被, 说明土壤种子库比地上植被具有更高的稳定性。芦苇群落的种子库密度, 物种多样性指数以及土壤种子库和地上植被物种组成的相似性均高于野艾蒿群落和林下杂草群落。土壤含水量与土壤有机质是影响土壤种子库物种组成的主要土壤因子, 在土壤水分以及有机质含量高的芦苇群落中含有大量湿生植物种子, 但在水分和有机质含量低的野艾蒿和林下杂草群落未发现柳叶菜(Epilobium hirsutum)、马先蒿(Pedicularis resupinata)、问荆(Equisetum arvense)等湿生植物的种子。因此, 蔡家河湿地土壤种子库已出现一定程度的退化, 芦苇群落土壤种子库可用作退化湿地植被恢复的种源, 在植被恢复时要满足种子萌发对土壤水分和有机质的需求。  相似文献   

4.
5.
对种子休眠的自然释放及其作用因素的研究, 是了解种子休眠生态学、种群适应机制的重要途径。以内蒙古阿拉善干旱荒漠区的3种主要植物牛枝子(Lespedeza potaninii)、唐古特白刺(Nitraria tangutorum)和骆驼蒿(Peganum nigellastrum)为材料, 研究了种子在野外埋藏18个月期间和4个埋深条件下的休眠释放特性和土壤种子库。3种植物种子在野外埋藏时(采收后5 ℃冷藏6个月)的休眠率分别为98%、95%和3%。结果显示, 埋藏过程中, 3种植物种子的休眠释放表现出不同的变化特性。对牛枝子而言, 置于地表(0 cm)的种子比埋藏于土中的种子的休眠释放快, 埋藏期末, 埋深0、2、5和10 cm的种子的休眠率分别为64%、87%、86%和82%。唐古特白刺种子埋藏6个月后, 各埋深的休眠已完全释放, 释放速率随埋深增加而加快。骆驼蒿种子具有典型的季节性休眠循环特性, 休眠率各年度最高点出现在10月份, 释放速率随埋深增加呈减慢趋势。埋藏期末不同埋深条件下, 牛枝子、唐古特白刺和骆驼蒿种子的平均田间萌发率分别为11%、12%和8%; 平均室内萌发率分别为3%、74%和42%; 而平均死种子率分别为3%、15%和10%。根据Thompson和Grime (1979)的土壤种子库分类体系, 供试的3种植物都属于持久土壤种子库类型。  相似文献   

6.
A decade-long examination was made of recruitment and establishment in a tidal freshwater high marsh along the Delaware River. Over the 10 yr of the study, seed bank, field seedlings, and vegetation showed variable patterns and significant year-to-year fluctuations. Patterns of each species were unique, perhaps the result of specific germination and/or establishment requirements and seedling morphology. For a given species there was little correlation among seed bank, seedling, and vegetation patterns, and germination success did not guarantee establishment. Species diversity showed significant year-to-year fluctuation, but there was no trend, and perennials did not change in importance during the 10-yr period. Because four annual species (Bidens laevis, Cuscuta gronovii, Impatiens capensis, and Polygonum arifolium) composed over 90% of the seed bank and field seedlings, and 58-89% ( = 70 ± 4) of the cover, community dynamics were dependent on seedling recruitment. For a given species life history stages (seed bank, field seedlings, and vegetation) were not predictable over the temporal scale of a decade. It is predicted, however, that if hydrology remains unchanged, the same suite of species will persist. The importance of the parasite Cuscuta gronovii is noteworthy.  相似文献   

7.
The persistent soil seed bank (viable seeds >1 year) and standing vegetation were investigated in the upper alpine belt (3250 m) in the Andes of central Chile, 33° S. Nine species (eight in standing vegetation) were found in a total persistent seed bank of 899 seeds m−2. Seven additional species were represented by physically intact, non-viable seeds. Over 90% of the persistent seed bank was concentrated in Montiopsis sericea (Portulacaceae), Pozoa coriacea (Umbelliferae), Phacelia secunda (Hydrophyllaceae) and Oxalis compacta (Oxalidaceae). Examination of the seed/cover ratio revealed different propensities for persistent seed bank formation among species, and annuals formed persistent seed banks more frequently than perennial species. Abundance in the standing vegetation had predictive value for abundance in the persistent seed bank only when non-persistent seed bank species in the standing vegetation were discarded from the analysis. At the local scale, species diversity in the persistent seed bank and standing vegetation were correlated, but compositional similarity was low. Secondary down-slope dispersal promoted by frost heaving in combination with runoff, and life-form correlates are discussed as possible factors accounting for poor correspondence between the persistent seed bank and the standing vegetation at a local scale. The high Andean seed bank is similar to or larger than that reported for two Arctic tundra sites, but smaller than for a northern hemisphere subalpine site. If seed bank size is considered in relation to plant cover, the Andean seed bank greatly exceeds that of one Arctic site. Our study constitutes the first demonstration of a sizable persistent seed bank at an alpine site in the South American Andes and in southern hemisphere temperate mountains in general. Received: 26 May 1998 / Accepted: 21 November 1998  相似文献   

8.
9.
This study investigates a soil–water–vegetation system in a drying-out alkaline sodic wetland altered by climate change and artificial drainage by evaluating the habitat pattern and the physical and chemical attributes of the upper soil. The spatial and temporal alteration of the vegetation was monitored by detailed coenological investigations and habitat mapping during a 13-year period (2002–2014) to analyse the succession trend of the habitat in the changing environment. The spatial structures of the physical and chemical attributes of the soil were surveyed by topsoil sampling along a regular network to detect the desalinization process and to reveal the discrepancies between the soil attributes and the typical habitats because anomalies between the habitat and its optimal soil properties can project a possible vegetation change in a dynamically changing sodic ecosystem. The micro-topography was investigated to detect the effect of the elevation difference on the hydrologic conditions, soil and vegetation attributes. Statistical analyses were performed to describe the characteristic pedological processes and the spatial structures of the soil parameters. An overlapping analysis was conducted to compare the soil, vegetation pattern and topography to explore the relationships in the altering soil–water–vegetation system.Rapid alterations of the habitats, species composition, and soil desalinization processes were clearly recognised. The rate of change reflects degradation beyond the natural dynamics of vegetation processes. The desalinization process was extremely rapid due to the sandy sediment. The significant changes in the vegetation and soil pattern led to the loss of diversity in the short term; annual salt pioneer swards and Puccinellia swards became highly threatened. The main driving factors in the desalinization process are water shortage caused by artificial drainage and climate change, furthermore extreme high precipitation which intensifies leaching. The degradation process can be mitigated by adequate water management because habitats have a high naturalness reflecting good regeneration potential.  相似文献   

10.
In order to predict the long-term consequences of climate change, it is necessary to link future environmental changes to mechanisms that control plant population processes. This information can then be incorporated into strategies to more accurately model climate change impacts on species or to estimate future extinction risks. We examined the impact of increased temperatures on the longevity and dynamics of the persistent soil seed banks of eight ephemeral species from arid Australia. We found that the predicted global temperature increases under climate change will be reflected in increased soil temperatures, and that seeds in the soil seed bank will be exposed to long durations of high temperatures over the summer months. Three of the eight species studied had significantly greater levels of germination after exposure to predicted increased soil temperatures. Another species displayed a dramatic decrease in seed viability after such exposure. The capacity of such species to use the seed bank to bet hedge against rainfall events that cause germination but are insufficient to allow plant maturation, is compromised by increased germinability and subsequent loss or reduction of seed bank persistence. These predicted changes in the dynamics of soil seed banks increase the risk of local extinctions of these species, while the composition of the community may be altered by changes in species abundance. Our results show that the risk spreading mechanism provided by persistent seed banks could be compromised by the mechanistic impact of forecast temperature increases in arid habitats, and highlight the need to understand mechanisms that control population dynamics when attempting to address likely future impacts of climate change on biodiversity.  相似文献   

11.
Questions: How does urbanisation influence soil mineral nitrogen stocks (nitrate and ammonium stocks) and what are the consequences of these modifications on the functional diversity of the herbaceous vegetation (vascular plants) and the seed bank? Location: Nine study sites were located on an urbanisation gradient in the city of Rennes, France. Methods: Three urbanisation levels were defined: urban areas (high grey/green ratio), suburban (medium grey/green ratio) and periurban (low grey/green ratio). For each urbanisation level, nitrates and ammonium stocks were quantified; the herbaceous vegetation was surveyed as well as the soil seed bank (using the seedling emergence method). Results: Nitrate concentration increased with urbanisation (the nitrate level in urban plots was twice the concentration in periurban ones) whereas the ammonium level was higher in periurban areas than in urban areas. In urban plots, the vegetation and the seed bank were more nitrophilous, whereas the nitrogen requirement was lower for periurban species. The relationship between the seed bank and the above‐ground vegetation was not significant. Conclusions: The higher nitrate concentration in the urban area appeared to be related to higher concentrations of atmospheric pollutants found in this area and lower ammonium levels may be related to the higher temperature in urban areas (leading to higher nitrification rates). The shift in the composition of the seed bank and vegetation appeared to be a consequence of higher nitrate stocks. The dissimilarity between the seed bank and vegetation may be caused by enhanced emergence of nitrophilous species in urban areas.  相似文献   

12.
张起鹏  王建  赵成章  张志刚  冯婉婉  王珂 《生态学报》2017,37(14):4619-4626
以祁连山高寒干旱退化草地披针叶黄华(Thermopsis lanceolate)群落为研究对象,采取野外调查取样和室内分析相结合的方法,对群落土壤种子库与地上植被的关系进行了对比研究。结果表明:地上植被物种共调查出15种,土壤种子库检测出植物18种,地上植被阿尔泰针茅(S.krylovii)、赖草(A.dasystachys)和扁穗冰草等可食草以及不食草披针叶黄华和阿尔泰狗哇花(H.altaicus)优势度明显,其它物种不明显;土壤种子库与地上植被物种组成的相似性程度较低;土壤种子库与地上植被中可食草的物种数多于不食草,土壤种子库的物种数均不小于地上植被中的物种数,地上植被中存在而未在土壤种子库中检测到的可食草物种有阿尔泰针茅和赖草,土壤种子库中存在而地上植被中未被发现的物种有早熟禾(P.annua)、灰绿藜(C.glaucum)、碱韭(A.polyrhizum)、酸模(R.patientia)、独行菜(L.apetalum)和秦艽(G.macrophylla);原生禾草物种在可食草功能群中生物量所占比例较低,毒杂草物种生物量所占比例增加显著,而土壤种子库的数量百分含量较低;可食草与不食草的生物量在植被梯度下的变化呈显著负相关(r=-0.940,P=0.018),而土壤种子库密度变化无相关性;可食草生物量变化与其土壤种子库密度变化不相关,不食草生物量变化与其土壤种子库密度的增加呈显著正相关(r=0.902,P=0.036)。  相似文献   

13.
Population declines of once‐abundant species have often preceded understanding of their roles within ecosystems. Consequently, important drivers of environmental change may remain undiagnosed because we simply do not know how species that are now rare or extinct shaped ecosystems in the past. Australia's desert rodents are thought to have little numerical impact on seed fate and vegetation recruitment when compared with ants or with desert rodents on other continents. However most research on granivory by Australian desert rodents has occurred in areas where rodents were rare or functionally extinct. Here we ask if the paradigm that rodents are relatively un‐important granivores in Australian deserts is an artefact of their historical decline. In the Strzelecki Desert, the endangered rodent, Notomys fuscus is rare where introduced mesopredators are abundant but common where dingoes (an apex predator) suppress mesopredator populations. We used foraging trays to compare rates of seed removal for a common shrub (Dodonaea viscosa angustissima hopbush) between areas where N. fuscus, hopbush shrubs and their seedlings were rare and common and found that seed removal was consistently higher where rodents were common and hopbush rare. By excluding ants and rodents from foraging trays we show that ants removed more seeds than rodents where rodents were rare but rodents removed far more seeds than ants where rodents were common. By manipulating rodents’ access to the soil seed‐bank we show that hopbush seeds persisted in greater numbers where rodents were excluded than where they had access. Our results support the hypothesis that granivory by rodents may once have been a far more important process influencing the fate of seeds and shaping plant communities in arid Australia and suggest that dingo extirpation has cascading effects on shrub seeds. Our study highlights that functional extinction of rodents may be an under‐appreciated driver of vegetation change.  相似文献   

14.
1. Vernal pools and rock pools (gnammas) in the Southwest Australian Floristic Region are forms of temporary wetlands that are under threat. Some of their aquatic macrophytes are rare and/or endemic, and there is a need to develop off‐site seed banks to assure their conservation. Here, we report results of the first comprehensive study of the seed germination, dormancy and seed storage behaviour of nine indigenous macrophyte species. 2. Seeds of Glossostigma drummondii, Myriophyllum balladoniense, M. lapidicola, M. petreaum and Triglochin linearis were non‐dormant, whereas those of Damasonium minus, Glossostigma sp. (currently undescribed), G. trichodes and Myriophyllum crispatum were dormant. Non‐dormant seeds germinated over a range of temperatures (5–20 °C) but temperatures at which highest germination occurred were species specific. All species demonstrated a germination preference for the light. Warm stratification substantially increased germination of dormant Glossostigma trichodes seeds and all dormancy‐breaking treatments partially overcame dormancy in Glossostigma spp. 3. Seeds possessed orthodox storage behaviour (tolerating drying to 5% moisture content and storage at ?18 °C) and are thus amenable to seed banking as a means of ex situ conservation. 4. It appears that seeds of most species are able to germinate upon inundation as long as they are situated at the soil surface. Thus, species are opportunistic and respond to the first rains of the season providing prompt ecological cuing in an environment vulnerable to rapid drying events. Maintaining the integrity of the soil crust may be an important first step for on‐site conservation if seeds are in the superficial layers.  相似文献   

15.
Abstract Analysis was performed of the richness and abundance of woody species, forbs, and annual grasses in the easily germinating soil seed bank (henceforth seed bank) in a mediterranean shrubland of central Chile. The effects of successional development after fire and by microsite type (underneath or outside shrubs) on the density of seeds in the soil, and the relationship of species abundance in the seed bank with its abundance in the above‐ground vegetation was examined. A total of 64 plant species were recorded in the seed bank, of which 44 were annual or biannual. Eight species were woody and another eight were perennial herbs. Four could not be identified to species level. The highest richness of established herbaceous species was recorded in late spring, with 31 species. The regeneration of the herbaceous vegetation was driven by the annual production of seeds and by a reserve of short‐lived propagules in the soil. Density of all germinating seeds was significantly higher during late spring and late summer. Density of grass seeds was greater during late spring, while that of all other species was greater during late summer. Annual grass seeds accumulated in higher proportion at exposed microsites rather than under woody canopy, and in young (< 5 years old) and intermediate‐age patches (10–20 years old) rather than in mature vegetation (30–50 years old). The abundance of established woody and herb species was uncorrelated with that of the seed bank.  相似文献   

16.
荒漠草原土壤种子库对草地管理方式的响应   总被引:1,自引:0,他引:1  
沈艳  刘彩凤  马红彬  赵菲  谢应忠 《生态学报》2015,35(14):4725-4732
以宁夏中部不同封育年限(封育1a、3a、5a和7a)、不同放牧方式(中等强度自由放牧、中等强度4区轮牧)、补播改良(2006年补播沙打旺Astragalus adsurgens和紫花苜蓿Alfalfa stiva)及未封育等管理方式下的荒漠草原为研究对象,采用空间梯度代替时间梯度法,于2012年3月下旬用样线法采集土壤样品,采用温室萌发法,统计土壤种子库物种组成和种子数,研究了不同草地管理方式下的种子库与地上植被相似性、多样性等特征。结果表明:1)宁夏荒漠草原土壤种子库中共出现14种植物,分属6科14属,除牛枝子(Lespedeza potanimii)为半灌木外其余均为草本植物。多年生植物占土壤种子库植物总数的65.3%,一年生植物占土壤种子库植物总数的35.7%;多年生植物种子数量随封育年限增加而表现为下降趋势,封育1a和未封育草地最多;2)不同管理方式下土壤种子库和地上植被的共有物种数为2—6种,封育时间延长导致土壤种子库物种与地上植被相似性下降,土壤种子库和地上植被共有物种数有减少趋势,自由放牧降低了土壤种子库和地上植被的共有物种数,补播恢复的草地土壤种子库中未出现补播物种;3)种子库物种多样性与管理方式无明显的相关性;种子库物种多样性指数4区轮牧草地最高,封育7a草地最低,物种丰富度指数封育1a草地最高,均匀度指数自由放牧草地最高,补播草地最低。若荒漠草原仅依靠土壤种子库恢复自然植被,则不建议封育时间过久,需间以适当的干扰(放牧);补播外来种未对荒漠草原土壤种子库产生贡献,反而对乡土种产生了一定限制。  相似文献   

17.
Abstract. Hawaiian ecosystems are prone to invasion by alien plant species. I compared the seed rain, seed bank, and vegetation of a native Hawaiian forest to examine the potential role that seed ecology plays in allowing alien species to invade native forest. Absolute cover of seed plants in the forest was 126 %, annual seed rain was 5 713 seeds m-2 yr-1, and the mean density of seedlings emerging from the seed bank averaged across four seasons was 1 020/m2. The endemic tree Metrosideros polymorpha was the most abundant species in the vegetation, seed rain and winter seed bank. Overall, native seed plants comprised 95 % of the relative cover in the vegetation and 99 % of the seeds in the seed rain, but alien species comprised 67 % of the seeds in the seed bank. Alien species tended to form persistent seed banks while native species formed transient or pseudo-persistent seed banks. Dominance of the seed bank by alien species with persistent seed banks suggests that aliens are favorably placed to increase in abundance in the vegetation if the forest is disturbed.  相似文献   

18.

Background and Aims

Differences in dormancy and germination requirements have been documented in heteromorphic seeds of many species, but it is unknown how this difference contributes to maintenance and regeneration of populations. The primary aim of this study was to compare the seed bank dynamics, including dormancy cycling, of the two seed morphs (black and brown) of the cold desert halophyte Suaeda corniculata and, if differences were found, to determine their influence on regeneration of the species.

Method

Seeds of the two seed morphs were buried, exhumed and tested monthly for 24 months over a range of temperatures and salinities, and germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were also investigated for the two morphs.

Key Results

Black seeds had an annual dormancy/non-dormancy cycle, while brown seeds, which were non-dormant at maturity, remained non-dormant. Black seeds also exhibited an annual cycle in sensitivity of germination to salinity. Seedlings derived from black seeds emerged in July and August and those from brown seeds in May. Seedlings were recruited from 2·6 % of the black seeds and from 2·8 % of the brown seeds in the soil, and only 0·5 % and 0·4 % of the total number of black and brown seeds in the soil, respectively, gave rise to seedlings that survived to produce seeds. Salinity and water stress induced dormancy in black seeds and decreased viability of brown seeds. Brown seeds formed only a transient soil seed bank and black seeds a persistent seed bank.

Conclusions

The presence of a dormancy cycle in black but not in brown seeds of S. corniculata and differences in germination requirements of the two morphs cause them to differ in their germination dynamics. The study contributes to our limited knowledge of dormancy cycling and seed bank formation in species producing heteromorphic seeds.  相似文献   

19.
Seed densities, estimated from germinations under glasshouse conditions, were determined for fire-treated and control soils sampled from north and south facing stands of mixedAdenostoma fasciculatum-Ceanothus greggii chaparral that last burned 10, 17, 36, 62 and 86 years before 1987. A total of 53 species was recorded. Total germinable seed density was not influenced by aspect nor by an experimental fire treatment, however, densities varied significantly, but not predictably, over the time since fire sequence. Species diversity was significantly lower in the 86 year old stand, but neither diversity or richness was influenced by the fire treatment. Soils from north facing slopes supported a higher species diversity overall, and seed densities of six species were significantly higher on north than on south slopes.We identify two functional groups in the seed bank on the basis of the direct effects of fire on seed densities: a fire-dependent group, comprising 6 species and about 21% of the total seed bank, in which germinable densities increased after the fire treatment, and a fire-independent group, made up of 11 species and almost two-thirds of the seed bank. The fire-independent group is further separated into two: a shrub-centred sub-group (Crassula erecta, Filago californica, Pterostegia drymarioides, Streptanthus heterophyllus andCryptantha intermedia) maintained larger seed banks in older stands and was associated with shrub cover; and an opportunistic sub-group (Camissonia hirtella, Gnaphalium chilense, Mimulus pilosus andSenecio vulgaris) tended to have larger seed banks in younger stands and was associated with canopy gaps.Overall, the soil seed assemblage from this mixed chaparral does not appear to be tightly coupled to fire-generated opportunities for recruitment. The reason for this is that the fire-dependent group represents only 6 species. In addition, among the fire-independent species, the shrub-centred group of 5 annuals made up almost 40% of total soil seed density. This group shows ecological and taxonomic affinities with desert annuals.  相似文献   

20.
Precipitation variability and heatwaves are expected to intensify over much of inland Australia under most projected climate change scenarios. This will undoubtedly have impacts on the biota of Australian dryland systems. However, accurate modelling of these impacts is presently impeded by a lack of empirical research on drought/heatwave effects on native arid flora and fauna. During the 2018–2021 Australian drought, many parts of the continent's inland experienced their hottest, driest period on record. Here, we present the results of a field survey in 2021 involving indigenous rangers, scientists and national parks staff who assessed plant dieback during this drought at Ulur u-Kata Tjut a National Park (UKTNP), central Australia. Spatially randomized quadrat sampling of eight common and culturally important plants indicated the following plant death rates across UKTNP (in order of drought susceptibility): desert myrtle (Aluta maisonneuvei subsp. maisonneuvei) (91%), yellow flame grevillea (Grevillea eriostachya) (79%), Maitland's wattle (Acacia maitlandii) (67%), waxy wattle (A. melleodora) (65%), soft spinifex grass (Triodia pungens) (53%), mulga (A. aneura) (42%), desert oak (Allocasuarina decaisneana) (22%) and quandong (Santalum acuminatum) (0%). The sampling also detected that seedling recruitment was absent or minimal for all plants except soft spinifex, while a generalized linear mixed model (GLMM) indicated two-way interactions among species, plant size and stand density as important predictors of drought survival of adult plants. A substantial loss of biodiversity has occurred at UKTNP during the recent drought, with likely drivers of widespread plant mortality being extreme multi-year rainfall deficit (2019 recorded the lowest-ever annual rainfall at UKTNP [27 mm]) and record high summer temperatures (December 2019 recorded the highest-ever temperature [47.1°C]). Our findings indicate that widespread plant death and extensive vegetation restructuring will occur across arid Australia if the severity and frequency of droughts increase under climate change.  相似文献   

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