Riparian vegetation‐environment relationships: complimentarity of gradients versus patch hierarchy approaches

Abstract. Two prominent conceptual frameworks, environmental gradients and patch hierarchies, are used in combination to describe vegetation patterns along a riparian corridor in a semi‐arid South African system. We adopt both approaches, since riparian corridors are characterized by both strong environmental gradients above, away from and along the river, as well as a mosaic of patches in the geomorphology at multiple hierarchical scales. Constrained and unconstrained ordinations were used to determine the variability in vegetation pattern accounted for by the gradient and the geomorphic patch hierarchy data sets. The gradient data set consisted of vertical, lateral and longitudinal dimensions of the macro‐channel, while the patch hierarchy data set consisted of substratum type, morphological unit and channel type. Elevation up the macro‐channel bank, of the gradient data set, explained the main variation in vegetation pattern, and alluded to overriding processes of flooding frequency and water availability as determinants of vegetation pattern. Along the fluvially dynamic macro‐channel floor (lower elevation range), patchiness at the scale of the morphological unit best explained vegetation pattern. This relationship with morphological units suggests that the formation of well developed alluvial bars, and the degree of bedrock influence are important processes. The nested hierarchical framework used provided a good basis for identifying scale specific pattern in a relational manner. In systems characterized by strong environmental gradients as well as a patch mosaic at different spatial and temporal scales, the combined use of both perspectives to develop a fuller understanding of vegetation pattern is imperative and is encouraged.     

河岸无脊椎动物多样性维持机制研究进展

河岸是河流与陆地之间重要的生态界面,生物多样性丰富,但受到人为活动的严重威胁。无脊椎动物在河岸生物多样性中占有重要地位,发挥着非常重要的生态功能,也是水生生态系统和陆地生态系统之间物质和能量联系的重要纽带。尽管已有很多学者对河岸无脊椎动物群落进行了研究,但缺乏对河岸无脊椎动物多样性维持机制的总结。本文结合洪水和干旱、营养物质、微生境多样性、河岸植被、微气候梯度、食物资源以及河流空间梯度等影响因素,初步讨论和归纳了河岸无脊椎动物多样性的维持机制。周期性洪水和干旱引发了无脊椎动物的繁殖和迁移等行为,增加了河岸无脊椎动物群落周转率,为无脊椎动物创造了理想的条件。充足的营养物质使河岸具有较高的初级生产力,支撑了较高的无脊椎动物多样性。较高的微生境多样性为无脊椎动物提供了多样的生态位空间,孕育了特殊的河岸无脊椎动物种类。复杂的河岸植物群落不但是河岸无脊椎动物的食物来源之一,也为河岸无脊椎动物提供了多样的生态位空间和重要的避难场所。微气候环境的空间分异提供了复杂多样的生境条件,为水生无脊椎动物和陆生无脊椎动物种类在河岸共存创造了条件。跨越界面的资源补给增加了河岸无脊椎动物的食物可利用率,为河岸无脊椎动物提供了特殊的食物来源。这些因素在空间上呈现出明显的纵向梯度和侧向梯度,从更大尺度上为河岸无脊椎动物的多样化提供了条件。因此,探讨河岸无脊椎动物多样性的维持机制对于河岸生物多样性保护以及河流生态系统综合管理具有重要的指导意义。     

Montane plant communities of Fynbos Biome

The vegetation of the mountains of the Fynbos Biome is classified and described, mostly on the basis of vegetation structure and higher taxa. Various gradients can be recognized. A gradient in soil conditions runs from coarse textured, nutrient-poor soils in non-grassy fynbos (Mountain Fynbos) through grassy fynbos and grassy non-fynbos (Eastern Fynbos and Grasslands & Grassy Shrubland) to finer textured and less nutrient-poor soils in the non-fynbos Karroid & Renoster Shrubland. Another gradient of significance can be likened to the tropical gradient running from the dry conditions of hot semi-deserts to savannas or grasslands to woodlands. At the dry extreme an open shrubland occurs (Karroid & Renoster Shrubland, Asteraceous Fynbos), at intermediate positions a herbland occurs (Restioid Fynbos) and at the wet extreme another type of shrubland occurs (Ericaceous Fynbos). This kind of moisture gradient occurs on individual mountains with the xeric end being at the base of the north slopes, and the mesic end being on the upper south aspects. Soil characteristics are closely linked to this gradient; the better developed soils being found on the south aspects. Another moisture gradient is apparent in the vegetation. This gradient runs from the mesic southern coastal mountains to the north west where summer droughts are extremely severe although total rainfall may be similar.Nomenclature follows that used in the Government Herbarium, Stellenbosch.I thank William Bond, Richard Cowling, John Rushworth, Eddy van der Maarel and Marinus Werger for critical comments and discussion.     

Low bird diversity in the Fynbos plant diversity hotspot: Quaternary legacies in the current distributions of passerine birds

The Fynbos Biome or Cape Floristic Region is well‐known for its plant diversity. This diversity does not seem to carry over at higher trophic levels, and in particular in birds. Here, we analyzed the passerine bird assemblages of the Fynbos Biome at the quarter degree resolution with occupancy models and citizen science data. Multivariate analysis of distribution summary metrics revealed a gradient of specialist to generalist species, in which range‐restricted, specialist species responded positively to increases in number of competing species and included ancient lineages. Wide‐ranging, generalist species exhibited stronger affinities for the arid Karoo Biomes than for the other neighboring biome (Albany Thicket) and for the other mesic biomes in South Africa. Both results are explained by the Quaternary legacy hypothesis: the combined effects of habitat filtering, isolation by distance, and limited in situ diversification, acting throughout the Quaternary, and caused by the contrasting winter‐rainfall regime of the region and the low phylogenetic diversity and original adaptations of the plant assemblages.     

Spatial and temporal patterns of species richness in a riparian landscape

Aim To test for control of vascular plant species richness in the riparian corridor by exploring three contrasting (although not mutually exclusive) hypotheses: (1) longitudinal patterns in riparian plant species richness are governed by local, river‐related processes independent of the regional species richness, (2) riparian plant species richness is controlled by dispersal along the river (longitudinal control), and (3) the variation in riparian plant species richness mirrors variation in regional richness (lateral control). Location The riparian zones of the free‐flowing Vindel River and its surrounding river valley, northern Sweden. Methods We used data from three surveys, undertaken at 10‐year intervals, of riparian reaches (200‐m stretches of riverbank) spanning the entire river. In addition, we surveyed species richness of vascular plants in the uplands adjacent to the river in 3.75‐km² large plots along the same regional gradient. We explored the relationship between riparian and upland flora, and various environmental variables. We also evaluated temporal variation in downstream patterns of the riparian flora. Results Our results suggest that local species richness in boreal rivers is mainly a result of local, river‐related processes and dispersal along the corridor. The strongest correlation between species richness and the environment was a negative one between species number and soil pH, but pH varied within a narrow range. We did not find evidence for a correlation between species richness on regional and local scales. We found that the local patterns of species richness for naturally occurring vascular plants were temporally variable, probably in response to large‐scale disturbance caused by extreme floods. Most previous studies have found a unimodal pattern of species richness with peaks in the middle reaches of a river. In contrast, on two of three occasions corresponding to major flooding events, we found that the distribution of species richness of naturally occurring vascular plants resembled that of regional diversity: a monotonic decrease from headwater to coast. We also found high floristic similarity between the riparian corridor and the surrounding landscape. Main conclusions These results suggest that local processes control patterns of riparian species richness, but that species composition is also highly dependent on the regional species pool. We argue that inter‐annual variation in flood disturbance is probably the most important factor producing temporal variability of longitudinal species richness patterns.     

Life form spectra in the Hantam-Tanqua-Roggeveld, South Africa

The Hantam-Tanqua-Roggeveld subregion is situated in an area where the Fynbos, Succulent Karoo and Nama Karoo biomes meet. Life form spectra were compiled at a species richness and vegetation cover level in order to determine the affinities of the vegetation of the subregion with respect to its Succulent Karoo, Fynbos and Nama Karoo Biome status. A percentage succulence was also calculated for both species richness and cover. Comparisons of life form spectra and succulence were made across the eight vegetation associations found in the area and across three broad vegetation groups, i.e., Mountain Renosterveld, Winter Rainfall Karoo and Tanqua Karoo. Mountain Renosterveld vegetation was characterised by high chamaephyte, cryptophyte and therophyte species contributions. Compared to the other broad vegetation groups, the Mountain Renosterveld group showed phanerophyte contributions at the vegetation cover level to be highest, but the degree of succulence was low. Winter Rainfall Karoo vegetation was co-dominated by high levels of chamaephyte, cryptophyte and therophyte species with chamaephytes dominating the vegetation cover. Succulent contributions to species richness and cover values were higher than for Mountain Renosterveld vegetation. Tanqua Karoo vegetation was dominated by chamaephyte species or co-dominated by chamaephyte and cryptophyte species with therophyte species contributions lowest of all vegetation groups. Contributions by succulent species to richness and vegetation cover were high in the Tanqua Karoo. Life form spectra of the Mountain Renosterveld associations compared poorly to other sites in the Fynbos Biome. However, the low level of succulence in the Mountain Renosterveld associations also precludes its inclusion into the Succulent Karoo Biome. The large contribution of succulent species at a species and vegetation cover level in Winter Rainfall Karoo and Tanqua Karoo associations confirms that these two groups belong to the Succulent Karoo Biome. Affinities to the Nama Karoo Biome were indicated by the low level of succulence at a vegetation cover level in one of the Winter Rainfall Karoo associations (Roggeveld Karoo).     

九龙江源头山地河流河岸带植物区系研究

在野外调查、标本采集和综合分析国内有关山地河流河岸带植被研究的基础上,探讨山地河流河岸带植物区系特征。调查表明：九龙江源头山地河流共有维管植物145科390属574种,其中蕨类植物29科54属80种,裸子植物6科8属10种,被子植物110科328属484种。综合分析表明,山地河流（以九龙江源头河段为例）河岸带植被具有如下典型特征：（1）植物区系组成丰富,优势科、属明显,单型属、单种属和少种属,单种科、少种科比例大;（2）植物区系起源古老,珍稀、孑遗植物众多;（3）区系地理成分复杂,联系广泛,能充分反映区域气候、地形地貌和人为活动等自然和人为干扰条件。表明山地河流河岸带在区域生物多样性保护中具有极其重要的价值。     

Environment‐driven changes in diversity of riparian plant communities along a mountain river

The study of changes in species richness and composition along rivers has focused on large spatial scales. It has been ignored that in different sections of the river (high mountain area, middle zone, and mouth of the river) the specific environmental conditions can generate different longitudinal patterns of the species richness and composition. In this study, we determine whether species richness and composition of the riparian plant communities change along a mountain river and whether these changes are related to environmental variables. We expect an increase in species richness and turnover along the river, that the upstream communities would be a subset of the downstream communities, and that such would be related to edaphic and hydrologic conditions. To test this, we sampled three strata of the riparian vegetation (upper: individuals with <1 cm of ND, middle: individuals with >1 cm of ND, low: individuals with >1 m tall) in a set of 15 sites that we place along a mountain river. Additionally, we recorded topographic, hydrological, morphological, and soil variables. We performed correlation analyzes to determine whether changes in species richness and turnover were related to increased distance to the origin of the river. Also, we obtained the nestedness and evaluated the importance of environmental variables with GLM, LASSO regression, and CCA. With the increase in distance, the species richness decreases in the upper stratum, but not in the middle and the low stratum (although the highest values were observed near the origin of the river), the turnover increase in all strata and the upstream communities were not a subset of the downstream communities. The changes in species richness and composition were related to topographic (altitude), hydrological (flow), and edaphic (conductivity and pH) variables. Our results indicate that at small spatial scales the patterns of richness and composition differ from what has been found at larger spatial scales and that these patterns are associated with environmental changes in the strong altitude gradients of mountain rivers.     

Geomorphic predictors of riparian vegetation in small mountain watersheds

Aims Hydrogeomorphic processes operating at watershed, process zone and site scales influence the distribution of riparian vegetation. However, most studies examining the relationships between hydrogeomorphic processes and riparian vegetation are conducted at site scales. We quantified the relative importance of watershed, process zone and site geomorphic characteristics for predicting riparian plant community types and plant species abundances in four small mountain watersheds in central Nevada, USA.Methods We mapped riparian vegetation types and identified process zones (based on dominant geomorphic process and valley fill material) within the watersheds. We sampled sites in each combination of vegetation type and process zone (n = 184 sites) and collected data on watershed scale factors, valley and stream geomorphic characteristics and on plant cover of each geomorphic surface. Plant community types were defined by cluster and indicator species analyses of plant cover data, and related to geomorphic variables using ordination analysis (nonmetric multidimensional scaling). Linear mixed effects models were used to predict abundances of indicator species.Important findings Variables describing position in the watershed (elevation, contributing area) that are related to gradients of temperature, moisture and stream discharge were of primary importance in predicting plant community types. Variables describing local geomorphic setting (valley width, stream gradient, channel sediments, geomorphic surface height) were of secondary importance, but accurately described the geomorphic setting of indicator species. The process zone classification did not include position in the watershed or channel characteristics and only predicted plant community types with unique geomorphic settings. In small mountain watersheds, predicting riparian vegetation distribution requires explicit consideration of scale and geomorphic context within and among watersheds in addition to site variables.     

Contrasting patterns and mechanisms of spatial turnover for native and exotic freshwater fish in Europe

Aim We compare the distribution patterns of native and exotic freshwater fish in Europe, and test whether the same mechanisms (environmental filtering and/or dispersal limitation) govern patterns of decrease in similarity of native and exotic species composition over geographical distance (spatial species turnover). Locations Major river basins of Europe. Methods Data related to geography, habitat diversity, regional climate and species composition of native and exotic freshwater fish were collated for 26 major European river basins. We explored the degree of nestedness in native and exotic species composition, and quantified compositional similarity between river basins according to the beta‐sim (independent of richness gradient) and Jaccard (dependent of richness gradient) indices of similarity. Multiple regression on distance matrices and variation‐partitioning approaches were used to quantify the relative roles of environmental filtering and dispersal limitation in shaping patterns of decreasing compositional similarity over geographical distance. Results Native and exotic species exhibited significant nested patterns of species composition, indicating that differences in fish species composition between river basins are primarily the result of species loss, rather than species replacement. Both native and exotic compositional similarity decreased significantly with increasing geographical distance between river basins. However, gradual changes in species composition with geographical distance were found only for exotic species. In addition, exotic species displayed a higher rate of similarity decay (higher species turnover rate) with geographical distance, compared with native species. Lastly, the majority of explained variation in exotic compositional similarity was uniquely related to geography, whereas native compositional similarity was either uniquely explained by geography or jointly explained by environment and geography. Main conclusions Our study suggests that large‐scale patterns of spatial turnover for exotic freshwater fish in Europe are generated by human‐mediated dispersal limitation, whereas patterns of spatial turnover for native fish result from both dispersal limitation relative to historical events (isolation by mountain ranges, glacial history) and environmental filtering.     

Patterns of plant species and community diversity at different organization levels in a forested riparian landscape

Abstract. Integrated synusial phytosociology combined with traditional measures of diversity is used to describe the structure of vascular vegetation diversity along the forested riparian landscape of the upper Oise valley (Belgium and France). The two dimensions (longitudinal and lateral) of the geomorphological complex are examined at four scales: synusia, phytocoenosis, tesela and catena. The results support the following hypotheses: (1) the environmental gradients observed, particularly the lateral ones, are very complex; (2) there is a clear lack of coupling between the tree, shrub and herb layers, which indicates a differential response to the underlying influence of environmental controls; (3) moderate flooding‐induced disturbance enhances herb species richness; (4) stressful environments support a low plant species diversity but a high synusial richness; (5) natural factors (substrate, climate, disturbance) are more important at the synusia and phytocoenose scales, but (6) anthropogenic disturbances, mainly through forest and river management, are more important at the landscape level. By considering plant communities as structural‐dynamic entities of ecosystems in a landscape context, integrated synusial phytosociology provides a basis for decomposing a complex system since the different hierarchical levels are both nested and thus strongly relational and process‐based.     

Woody riparian plant distributions in western Oregon,USA: comparing landscape and local scale factors

We studied riparian forests along mountain streams in four large watersheds of western Oregon and far northern California, USA, to better understand the multiscale controls on woody riparian vegetation in a geographically complex region. In each of the four-study watersheds, we sampled woody riparian vegetation in161-ha sampling reaches that straddled the stream channel. Within each hectare, we sampled riparian vegetation and local environmental factors in 40 m² sampling plots arrayed along topographic transects. We also surveyed natural disturbance gaps in 6 ha in each watershed to explore the effects of fine scale disturbance on species distributions. We compared species composition across our study watersheds and used Nonmetric Multidimensional Scaling (NMS) and chi-squared analyses to compare the relative importance of landscape scale climate variables and local topographic and disturbance variables in explaining species distributions at sampling plot and hectare scales. We noted substantial turnover in the riparian flora across the region, with greatest numbers of unique species in watersheds at the ends of the regional gradient. In NMS ordinations at both scales, variation in woody riparian species composition showed strongest correlations with climatic variables and Rubus spectabilis cover, but the latter was only an important factor in the two northern watersheds. At the smaller scale, topographic variables were also important. Chi-squared analyses confirmed that more species showed landscape scale habitat preferences (watershed associations) than associations with topographic position (94.7% vs. 42.7% of species tested) or gap versus forest setting (94.7% vs. 24.6% of species tested). The woody riparian flora of western Oregon shows important biogeographic variation; species distributions showed strong associations with climatic variables, which were the primary correlates of compositional change between riparian sites at both scales analyzed. Additional local variation in composition was explained by measures of topography and disturbance.     

Environmental determinants of woody and herbaceous riparian vegetation patterns in a semi-arid mediterranean basin

What environmental variables determine riparian vegetation patterns? Are there differences between woody and herbaceous species? To answer these questions, we first explored the composition and richness patterns of both riparian woody and herbaceous species in a semi-arid mediterranean basin. Then, we assessed the environmental factors (climate, geology, topography, hydrogeomorphology and land use) that best explain these patterns. We used the following methodological approaches: clustering analyses, distance-based linear models, generalised linear models and hierarchical partitioning procedures. Valley shape, drought duration, river habitat heterogeneity, water conductivity and agricultural land use were the most important variables explaining variation in species composition for both groups. Woody riparian richness was mainly influenced by flow conditions and valley shape, whereas herbaceous one was more dependent on substrate features. Thus, although some differences in the importance of individual variables were observed, we found a notable congruence in the composition and species richness of both groups and also in the main types of variables explaining these patterns (hydrogeomorphology and land use, especially agriculture). Our results show that both communities could be treated in a holistic way, since they respond similarly to the strong natural and anthropogenic environmental gradients present in mediterranean basins.     

Geographical and ecological differentiation in Greek Fagus forest vegetation

Question: Which are the gradients of floristic differentiation in Greek beech (Fagus sylvatica) forests? Which is the role of geographical and ecological factors in this differentiation? Location: Beech forests of the plant geographical regions Northeast, North Central and East Central Greece. Methods: A total of 1404 published and unpublished phytoso‐ciological relevés were used in the analyses. TWINSPAN and DCA were applied to classify and ordinate the relevés. Altitude, Indicator Values of relevés and their X and Y coordinates were used in a posteriori interpretation of the ordination axes. Kendall's correlation coefficients were calculated between DCA relevé scores and explanatory variables. Multiple linear regression was used to partition the variation explained by the first two DCA axes, between the geographical and the ecological variables. Results: Classification resulted in 14 vegetation units defined by species composition. Two types of gradients, ecological and geographical, were revealed by the DCA of all releves. The partition of the variation accounted for by the first and second DCA axis was attributed mainly to ecological and geographical variables, respectively. Conclusions: Beech forests of northeast and Central Greece show phytogeographical differences, while ecologically similar vegetation units occur in both regions. A west‐east gradient is revealed in Greek beech forest vegetation. The extent of the study area, its position along regional gradients and the comprehensiveness of the data set that is analysed determine the types of the gradients which can be revealed in a vegetation study.     

Modelling the distribution of Aspalathus linearis (Rooibos tea): implications of climate change for livelihoods dependent on both cultivation and harvesting from the wild

Aspalathus linearis (Burm. f.) R. Dahlgren (rooibos) is endemic to the Fynbos Biome of South Africa, which is an internationally recognized biodiversity hot spot. Rooibos is both an invaluable wild resource and commercially cultivated crop in suitable areas. Climate change predictions for the region indicate a significant warming scenario coupled with a decline in winter rainfall. First estimates of possible consequences for biodiversity point to species extinctions of 23% in the long term in the Fynbos Biome. Bioclimatic modelling using the maximum entropy method was used to develop an estimate of the realized niche of wild rooibos and the current geographic distribution of areas suitable for commercially production. The distribution modelling provided a good match to the known distribution and production area of A. linearis. An ensemble of global climate models that assume the A2 emissions scenario of high energy requirements was applied to develop possible scenarios of range/suitability shift under future climate conditions. When these were extrapolated to a future climate (2041–2070) both wild and cultivated tea exhibited substantial range contraction with some range shifts southeastwards and upslope. Most of the areas where range expansion was indicated are located in existing conservation areas or include conservation worthy vegetation. These findings will be critical in directing conservation efforts as well as developing strategies for farmers to cope with and adapt to climate change.     

Importance of scale,land‐use,and stream network properties for riparian plant communities along an urban gradient

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Insect species richness tracking plant species richness in a diverse flora: gall-insects in the Cape Floristic Region, South Africa

The Cape Floristic Region (CFR) is one of the most plant-species-rich regions in the world. It is also a warm temperate region and hypothetically should have high gall-insect species richness, making it interesting to investigate the relationship between the insects of the region and the rich flora. The relationship between gall-insect species richness (GSR) and plant richness was investigated for the Fynbos and for representatives of vegetation of the whole CFR. Samples (of up to 600 plants per transect for Fynbos) of woody shrubs were investigated for the presence of galls. The species richness of these insects was quantified, as well as plant species richness for each transect. GSR for Fynbos was compared to global figures for GSR. Fynbos harboured significantly more gall-insect species than other CFR vegetation types. GSR was positively correlated with CFR plant richness. GSR also closely tracked plant richness in Fynbos. GSR was not significantly influenced by other variables (elevation and aspect), suggesting that plant richness per se was an important factor in generating GSR. Fynbos GSR is comparable to other sclerophyllous regions of high GSR globally, corroborating that this vegetation type is conducive to gall-insect diversification. There is likely to be a high percentage of gall-insect endemism in the Fynbos, as might be expected from the high host fidelity of this insect group. Received: 22 September 1997 / Accepted: 16 February 1998     

基于坡面水文连通性的黄河下游河岸缓冲带植被格局优化

河岸缓冲带作为河流-陆地之间重要的生态过渡区,恢复以及优化其退化的植被系统对防止水土流失、改善生态环境及实现该区域生态系统的可持续发展具有重要的现实意义.本文基于植被格局情景模拟和汇流路径长度指数,分析不同植被盖度和坡度下坡面水文连通性对植被格局的响应,探讨黄河下游河岸缓冲带水土保持效应的最优植被格局.结果表明: 坡中格局-粗粒度-集群分布的植被配置方式所产生的汇流路径长度最小、水文连通性最弱,是抑制坡面产流汇流效果最优的植被格局类型.对于最优植被格局,其汇流路径长度随坡长的增加而增加,坡长越长,坡度的作用越明显,水文连通性在各坡度之间的差异越显著;汇流路径长度随植被盖度增加而减小,低盖度时各坡度之间的汇流路径长度差异明显,当盖度达到45%时,各坡度之间的汇流路径长度趋于一致、水文连通性差异较小.实证坡面汇流路径长度随植被盖度增加其降低趋势无规律性,而最优植被格局汇流路径长度随植被盖度增加均呈现出一致的先急剧后平缓下降趋势.在设置的5°～20°坡度范围内,最优植被格局在一定程度上改变了盖度变化过程中不同坡度之间汇流路径长度的差异,突显了河岸缓冲带植被格局对水文连通性的影响.     

Impact of graminoid cover on postfire growth of nonsprouting Protea seedlings in the eastern Fynbos Biome of South Africa

Large tracts of lowland and foothill landscape in the bimodal rainfall, eastern Fynbos Biome of South Africa lack an overstorey of nonsprouting, serotinous Proteaceae (proteoids). Scattered stands of proteoids in the grassy fynbos that dominate these landscapes suggest that proteoids have the potential to be more widespread. Here, we assessed whether interactions between the resprouting graminoid (predominantly C4 grasses) understorey and the proteoid overstorey could explain the sparseness of proteoids in grassy fynbos. We quantified postfire seedling growth and graminoid cover for three proteoid (Protea) species in beneath‐proteoid canopy and open microsites at sixteen locations in the eastern Fynbos Biome. Contrary to studies undertaken in proteoid fynbos west of our study area, we found no consistent differences between graminoid cover and growth of proteoid seedlings in beneath‐canopy and open microsites. Nor did we find consistent negative relationships between graminoid cover and seedling growth. We conclude that graminoid–proteoid interactions do not explain the sparseness of proteoids in the eastern Fynbos Biome.