Performance Of Clonal Plants Research Articles

Clonal fragmentation drives performance deterioration of epiphytic and lithophytic ferns in a karst forest

Clonal plants can regenerate after being fragmented by natural or artificial disturbances, which may be attributed to physiological integration. Both lithophytes and epiphytes are important ecotypes of clonal plants. However, few studies have compared the responses of lithophytes and epiphytes to clonal fragmentation. Focusing on this issue could help us to understand the regeneration potential of clonal plants in different habitats, and to know more about the environmental adaptation of the two ecotypes. Two clonal ferns Pyrrosia nummulariifolia (Sw.) Ching and Lemmaphyllum microphyllum C. Presl, living in two ecotypes (lithophytes and epiphytes) of a tropical karst forest, were tested for the survival, biomass, the maximum quantum yield of photosystem Ⅱ (Fv/Fm), and leaf length of clonal plants in response to clonal fragmentation. Fragmentation had a significantly negative effect on the survival rate and biomass of clonal plants. However, ecotypes showed few effects on the performance of both clonal ferns in response to the fragmentation of different levels, suggesting that both epiphytes and lithophytes were equally susceptible to clonal fragmentation, probably because they were equivalently living in harsh and heterogeneous habitats. Further, decreasing clonal fragmentation and increasing ramet developmental age had positive effects on ramet survival, biomass, stress resistance, and leaf length. The effects of fragmentation level depended on ramet age. The results reveal that fragmentation has negative effects on the performance of clonal plants, especially juveniles and small ones. For better management of karst forests, disturbances should be avoided as much as possible to allow the growth and regeneration of clonal plants.

Difference in capacity of physiological integration between two ecotypes of Leymus chinensis underlies their different performance

Background and aims Physiological integration can enhance the performance of clonal plants, but whether this differs between ecotypes and whether such difference is underlying their distribution have scarcely been addressed. We aimed to determine whether physiological integration differs between ecotypes and whether an ecotype with a wider distribution shows a greater capacity of physiological integration.

Arbuscular mycorrhizal fungi reduce effects of physiological integration in Trifolium repens.

One of the special properties of clonal plants is the capacity for physiological integration, which can increase plant performance through mechanisms such as resource sharing and co-ordinated phenotypic plasticity when plants grow in microsites with contrasting resource availabilities. However, many clonal plants are colonized by arbuscular mycorrhizal fungi (AMF). Since AMF are likely to reduce contrasts in effective resource levels, they could also reduce these effects of clonal integration on plasticity and performance in heterogeneous environments. To test this hypothesis, pairs of connected and disconnected ramets of the stoloniferous herb Trifolium repens were grown. One ramet in a pair was given high light and low nutrients while the other ramet was given high nutrients and low light. The pairs were inoculated with zero, one or five species of AMF. Pairs of ramets grown without AMF developed division of labour and benefited from resource sharing, as indicated by effects of connection on allocation to roots, accumulation of mass, and ramet production. Inoculation with five species of AMF significantly reduced these effects of connection, both by inhibiting them in ramets given high nutrients and inducing them in ramets given high light. Inoculation with one species of AMF also reduced some effects of connection, but generally to a lesser degree. The results show that AMF can significantly modify the effects of clonal integration on the plasticity and performance of clonal plants in heterogeneous environments. In particular, AMF may partly replace the effects and benefits of clonal integration in low-nutrient habitats, possibly more so where species richness of AMF is high. This provides the first test of interaction between colonization by AMF and physiological integration in a clonal plant, and a new example of how biotic and abiotic factors could interact to determine the ecological importance of clonal growth.

Architectural and growth traits differ in effects on performance of clonal plants: an analysis using a field-parameterized simulation model

Individual traits are often assumed to be linked in a straightforward manner to plant performance and processes such as population growth, competition and community dynamics. However, because no trait functions in isolation in an organism, the effect of any one trait is likely to be at least somewhat contingent on other trait values. Thus, to the extent that the suite of trait values differs among species, the magnitude and even direction of correlation between values of any particular trait and performance is likely to differ among species. Working with a group of clonal plant species, we assessed the degree of this contingency and therefore the extent to which the assumption of simple and general linkages between traits and performance is valid. To do this, we parameterized a highly calibrated, spatially explicit, individual-based model of clonal plant population dynamics and then manipulated one trait at a time in the context of realistic values of other traits for each species. The model includes traits describing growth, resource allocation, response to competition, as well as architectural traits that determine spatial spread. The model was parameterized from a short-term (3 month) experiment and then validated with a separate, longer term (two year) experiment for six clonal wetland sedges, Carex lasiocarpa, Carex sterilis, Carex stricta, Cladium mariscoides, Scirpus acutus and Scirpus americanus. These plants all co-occur in fens in southeastern Michigan and represent a spectrum of clonal growth forms from strong clumpers to runners with long rhizomes. Varying growth, allocation and competition traits produced the largest and most uniform responses in population growth among species, while variation in architectural traits produced responses that were smaller and more variable among species. This is likely due to the fact that growth and competition traits directly affect mean ramet size and number of ramets, which are direct components of population biomass. In contrast, architectural and allocation traits determine spatial distribution of biomass; in the long run, this also affects population size, but its net effect is more likely to be mediated by other traits. Such differences in how traits affect plant performance are likely to have implications for interspecific interactions and community structure, as well as on the interpretation and usefulness of single trait optimality models.

Architectural and growth traits differ in effects on performance of clonal plants: an analysis using a field‐parameterized simulation model

Individual traits are often assumed to be linked in a straightforward manner to plant performance and processes such as population growth, competition and community dynamics. However, because no trait functions in isolation in an organism, the effect of any one trait is likely to be at least somewhat contingent on other trait values. Thus, to the extent that the suite of trait values differs among species, the magnitude and even direction of correlation between values of any particular trait and performance is likely to differ among species. Working with a group of clonal plant species, we assessed the degree of this contingency and therefore the extent to which the assumption of simple and general linkages between traits and performance is valid. To do this, we parameterized a highly calibrated, spatially explicit, individual‐based model of clonal plant population dynamics and then manipulated one trait at a time in the context of realistic values of other traits for each species. The model includes traits describing growth, resource allocation, response to competition, as well as architectural traits that determine spatial spread. The model was parameterized from a short‐term (3 month) experiment and then validated with a separate, longer term (two year) experiment for six clonal wetland sedges, Carex lasiocarpa, Carex sterilis, Carex stricta, Cladium mariscoides, Scirpus acutus and Scirpus americanus. These plants all co‐occur in fens in southeastern Michigan and represent a spectrum of clonal growth forms from strong clumpers to runners with long rhizomes.Varying growth, allocation and competition traits produced the largest and most uniform responses in population growth among species, while variation in architectural traits produced responses that were smaller and more variable among species. This is likely due to the fact that growth and competition traits directly affect mean ramet size and number of ramets, which are direct components of population biomass. In contrast, architectural and allocation traits determine spatial distribution of biomass; in the long run, this also affects population size, but its net effect is more likely to be mediated by other traits. Such differences in how traits affect plant performance are likely to have implications for interspecific interactions and community structure, as well as on the interpretation and usefulness of single trait optimality models.

Differential effects of clonal integration on performance in the stoloniferous herb Duchesnea indica, as growing at two sites with different altitude

Clonal integration may be adaptive and enhance the genet performance of clonal plants. Degree of clonal integration may differ between different environments . Here, a container experiment was used to determine how clonal integration affected the performance of the stoloniferous herb Duchesnea indica at two sites with different altitude along the transitional zone between the Qinghai-Tibet plateau and the Sichuan basin of Southwest China. In the experiment, the stolon between partially shaded two ramets experienced severing and intact treatments.We predicted that clonal integration would increase performance of whole clonal fragments and their shaded clonal parts at both sites. In both arctic and alpine environments, clonal plants may form highly integrated plant units (group of ramets).We predicted again that the reduction due to stolon severing in performance of whole clonal fragments and their shaded clonal parts would be greater at the site with high altitude than one with low altitude. The results indicated that the benefit for the shaded clonal parts and whole clonal fragments due to clonal integration was only observed at the site with high altitude. The results suggest that the performance of Duchesnea indica tends to be more responsive to the stolon severing at the site with high altitude than one with low altitude and support the second prediction. In addition, the effects of conditions of the sites and clonal integration on local morphological traits of ramets may be adaptive, five morphological traits of ramet-level (length of petiole, mean stolon internode length, specific petiole weight, specific stolon internode weight and specific leaf area) were investigated. Altogether, the results suggest that clonal integration might help D. indica plants to successfully inhabit the high-altitude habitat of the Qinghai-Tibet plateau of Southwest China, providing new evidences for the notion that clonal integration is an adaptive trait in stressful environments.

Clonal integration of the stoloniferous herb Fragaria vesca from different altitudes in Southwest China

In plants, species with clonal growth are able to directly transfer resources between potentially independent parts of the same genetic composition. As long as clonal parts remain connected, this heterogeneity among clonal parts may be alleviated by the exchange of resources. In Southwest China there is a transitional zone between Qinghai-Tibet plateau (relatively high altitudes) and Sichuan basin (relatively low altitudes), where the higher the altitude is, the more severe the habitat conditions are for growth of plants. The impact of clonal integration on plant performance may vary among species and habitats. So it was hypothesized that the impact of clonal integration on performance of clonal plants from high altitude could be greater than those from low altitude. The hypothesis was tested in a field container experiment in which clonal fragments of the stoloniferous herb Fragaria vesca from two populations located at different altitudes (1800 m a.s.l. and 3944 m a.s.l.) were grown in West China Sub-alpine Botanical Garden, the Chinese Academy of Sciences in Dujiangyan, Sichuan Province, China. The results indicate that under heterogeneous light environment, clonal integration between interconnected ramets occurred for F. vesca from the two populations located at different altitudes. The effects of clonal integration on biomass, total length of stolons and numer of ramets were not different between the two populations which originated from different altitudes. However, the effects of clonal integration on performance of whole clonal fragments, such as biomass and number of ramets, seemed to be greater for plants from 3944 m a.s.l. than from 1800 m a.s.l‥ So, clonal integration may not only be adaptive for F. vesca to successfully inhabit its habitats, but may also be more ecologically important for the clonal plants to grow in higher-altitude habitats. In addition, some morphological traits were studied in the experiment. The results have been discussed in the context of adaptation in clonal plants to environmental heterogeneity

Clonal plants—What is their role in succession?

Fifteen successional seres from man-made habitats in central Europe were compared and the occurrence of clonal species assessed on the basis of cover data. The effects of soil moisture and nitrogen (expressed using Ellenberg indicator values) on the performance of clonal plants were also considered. Clonal species formed the dominant component of vegetation cover in the majority of the seres studied. In moist sites, their dominance was more pronounced and the peak in their relative cover occurred earlier in succession. The relative importance of species with guerilla type growth tended to increase with time in most seres and after 10 years these were mostly more important than those exhibiting phalanx type growth. The prevalence of guerilla species after 10 years was more obvious in moist seres. Clonal species were able to become dominant regardless of soil conditions, whereas the dominance of non-clonal species tended to be restricted to very wet and nutrient-poor sites. Clonal plant species appeared to maintain their dominance for a longer period than non-clonal plants.