Physiological integration can increase competitive ability in clonal plants if competition is patchy

Oecologia ◽  
2021 ◽  
Author(s):  
Pu Wang ◽  
Peter Alpert ◽  
Fei-Hai Yu
2021 ◽  
Author(s):  
Wei Xue ◽  
Lin Huang ◽  
Wei-Jia Sheng ◽  
Jia-Tao Zhu ◽  
Shu-Qi Li ◽  
...  

Abstract AimSoil abiotic and biotic conditions are often spatially variable, challenging plants with a heterogeneous environment consisting of favorable and unfavorable patches of soil. Many stoloniferous clonal plants can escape from unfavorable patches by elongating stolon internodes, but aggregate in favorable ones through shortening stolon internodes. However, whether these plants can use their stolons to respond to plant-soil feedbacks (PSFs) is largely unknown. MethodsIn the conditioning phase, we grew either Hydrocotyle vulgaris or Glechoma longituba clonal plants separately in mesocosms to condition bulk soil. In the feedback phase, we grew connected mother and daughter ramets of each species in soil inoculated with the unsterilized or sterilized soil conditioned by conspecifics. We grew the plants for 12 weeks and measured the growth of the mother and daughter ramets separately. ResultsThe daughter ramets of H. vulgaris produced more biomass but shorter stolon internodes when grown in soil with sterilized inocula than with unsterilized inocula. However, no difference was found between the daughter ramets of G. longituba grown in soil with unsterilized and sterilized inocula. For both species, no significant difference was found between the mother ramet or between the daughter ramets when the mother ramet was grown in soil with sterilized and unsterilized inocula. ConclusionsThe daughter ramets rather than the mother ramet of H. vulgaris experienced negative biotic PSFs. However, PSF had no effects on the daughter or mother ramet of G. longituba. Moreover, physiological integration or plasticity in stolon internode lengths cannot help H. vulgaris alleviate the negative PSFs.


Author(s):  
Jushan Liu ◽  
Chen Chen ◽  
Yao Pan ◽  
Yang Zhang ◽  
Ying Gao

Clonal plants in grasslands are special species with physiological integration which can enhance their ability to tolerate herbivory stress especially in heterogeneous environments. However, little is known about how grazing intensity affects the trade-off between the benefits and costs of physiological integration, and the mechanism by which physiological integration improves compensatory growth in response to herbivory stress. We examined the effects of simulated grazing intensity on compensatory growth and physiological integration in a clonal species Leymus chinensis with a greenhouse experiment. This experiment was conducted in a factorial design involving nutrient heterogeneity (high-high, high-low, low-high, low-low), simulated grazing by clipping (0%, 25%, 50% or 75% shoot removal) and rhizome connection (intact versus severed) treatments. Compensatory indexes at 25% and 50% clipping levels were higher than that at 75% clipping level except in low-low nutrient treatments. Physiological integration decreased and increased compensatory indexes when the target-ramets worked as exporter and importer, respectively. Generally, clipping increased both benefits and costs of physiological integration, but its net benefits (benefits minus costs) changed with clipping intensity. Physiological integration optimized compensatory growth at light and moderate clipping intensity, and its net benefits determined the high capacity of compensatory growth. Grassland managements such as grazing or mowing at light and moderate intensity would maximize the profit of physiological integration and improve grassland sustainability.


2019 ◽  
Vol 12 (6) ◽  
pp. 972-981 ◽  
Author(s):  
Sergio R Roiloa ◽  
Peter Alpert ◽  
Rodolfo Barreiro

Abstract Aims Clonal growth is associated with invasiveness in introduced plant species, but few studies have compared invasive and noninvasive introduced clonal species to investigate which clonal traits may underlie invasiveness. To test the hypothesis that greater capacity to increase clonal growth via physiological integration of connected ramets increases invasiveness in clonal plants, we compared the effects of severing connections on accumulation of mass in the two species of the creeping, succulent, perennial, herbaceous genus Carpobrotus that have been introduced on sand dunes along the Pacific Coast of northern California, the highly invasive species Carpobrotus edulis and the co-occurring, noninvasive species Carpobrotus chilensis. Methods Pairs of ramets from four mixed populations of the species from California were grown in a common garden for 3 months with and without severing the stem connecting the ramets. To simulate the effect of clones on soils in natural populations, the older ramet was grown in sand amended with potting compost and the younger in sand alone. Important Findings Severance decreased net growth in mass by ~60% in C. edulis and ~100% in C. chilensis, due mainly to the negative effect of severance on the shoot mass of the younger ramet within a pair. Contrary to the hypothesis, this suggests that physiological integration increases growth more in the less invasive species. However, severance also decreased allocation of mass to roots in the older ramet and increased it in the younger ramet in a pair, and the effect on the younger ramet was about twice as great in C. edulis as in C. chilensis. This indicates that the more invasive species shows greater phenotypic plasticity in response to physiological integration, in particular greater capacity for division of labor. This could contribute to greater long-term growth and suggests that the division of labor may be a trait that underlies the association between clonal growth and invasiveness in plants.


2020 ◽  
Author(s):  
Jianyong Wang ◽  
Tongtong Xu ◽  
Yue Wang ◽  
Guangyin Li ◽  
Iram Abdullah ◽  
...  

Diversity ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 47
Author(s):  
Sergio R. Roiloa ◽  
Fei-Hai Yu ◽  
Rodolfo Barreiro

Management of invasive alien species is a high priority for biodiversity conservation. Here, we studied the effects of glyphosate application, at 0.06 g/m2 concentration, on physiologically integrated basal and apical ramets of the invasive clonal plant Carpobrotus edulis. Physiological integration allows the transport of resources and other substances between connected ramets in clonal plants. We found a significant reduction of growth and photochemical efficiency both in basal and apical ramets of C. edulis after glyphosate application. Interestingly, we also observed a significant growth reduction in untreated basal ramets when they remained connected to apical ramets treated with glyphosate. This result was interpreted as a cost for basal ramets due to supporting severely stressed apical ramets. Therefore, local application of glyphosate to apical ramets of C. edulis can negatively affect not only their own growth, but also the growth of their interconnected, untreated basal ramets. Our results suggest that glyphosate effectiveness can be maintained when applied only to one part of the clone so that the amount of herbicide used in eradication programs can be greatly reduced, which can minimize the negative impact of chemical herbicides on ecosystems.


2020 ◽  
Vol 127 (1) ◽  
pp. 123-133
Author(s):  
Michael Opoku Adomako ◽  
Peter Alpert ◽  
Dao-Lin Du ◽  
Fei-Hai Yu

Abstract Background and Aims Clonal plants dominate many plant communities, especially in aquatic systems, and clonality appears to promote invasiveness and to affect how diversity changes in response to disturbance and resource availability. Understanding how the special physiological and morphological properties of clonal growth lead to these ecological effects depends upon studying the long-term consequences of clonal growth properties across vegetative generations, but this has rarely been done. This study aimed to show how a key clonal property, physiological integration between connected ramets within clones, affects the response of clones to disturbance and resources in an aquatic, invasive, dominant species across multiple generations. Methods Single, parental ramets of the floating stoloniferous plant Pistia stratiotes were grown for 3 weeks, during which they produced two or three generations of offspring; connections between new ramets were cut or left intact. Individual offspring were then used as parents in a second 3-week iteration that crossed fragmentation with previous fragmentation in the first iteration. A third iteration yielded eight treatment combinations, zero to three rounds of fragmentation at different times in the past. The experiment was run once at a high and once at a low level of nutrients. Results In each iteration, fragmentation increased biomass of the parental ramet, decreased biomass of the offspring and increased number of offspring. These effects persisted and compounded from one iteration to another, though more recent fragmentation had stronger effects, and were stronger at the low than at the high nutrient level. Fragmentation did not affect net accumulation of mass by groups after one iteration but increased it after two iterations at low nutrients, and after three iterations at both nutrient levels. Conclusions Both the positive and negative effects of fragmentation on clonal performance can compound and persist over time and can be stronger when resource levels are lower. Even when fragmentation has no short-term net effect on clonal performance, it can have a longer-term effect. In some cases, fragmentation may increase total accumulation of mass by a clone. The results provide the first demonstration of how physiological integration in clonal plants can affect fitness across generations and suggest that increased disturbance may promote invasion of introduced clonal species via effects on integration, perhaps especially at lower nutrient levels.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1608
Author(s):  
Jian Guo ◽  
Haiyan Li ◽  
Yunfei Yang

Clonal plants usually reproduce asexually through vegetative propagation and sexually by producing seeds. Physiological integration, the translocation of essential resources between ramets, usually improves vegetative reproduction. However, how physiological integration affects sexual reproduction has been less studied in clonal grasses. Here, we chose Hierochloe glabra, a major early spring forage of the eastern Eurasian steppe, and conducted a series of field experiments, including sampling reproductive ramets connected by tillering nodes to different numbers of vegetative ramets and 15N leaf labeling of ramet pairs at the seed-filling stage. In the natural populations of H. glabra, vegetative ramets were taller, had more and larger leaves, and greater biomass than reproductive ramets. Except for reproductive ramet biomass, sexual reproductive characteristics significantly increased with an increase in the number and biomass of vegetative ramets connected to tillering nodes. 15N labeling showed that vegetative ramets supplied nutrients to reproductive ramets through tillering nodes. Overall, our results indicate that significant differences in morphological characteristics and biomass allocation underlie resources translocation from vegetative ramets towards reproductive ramets. Physiological integration between different functional ramets can increase sexual reproductive performance, which will be beneficial to population persistence in H. glabra.


2015 ◽  
Vol 140 (3) ◽  
pp. 288-294 ◽  
Author(s):  
Erick Amombo ◽  
Longxing Hu ◽  
Jibiao Fan ◽  
Zhengrong Hu ◽  
Jinmin Fu

Clonal plants can consist of connected individual ramets that enhance resource sharing through physiological integration. This integration enables the whole clone to tolerate environmental stresses. The objective of this research was to investigate the effects of physical ramet connections on the integration of antioxidant enzymes in clonal common bermudagrass (Cynodon dactylon) growing under heterogeneously distributed water; i.e., nonuniform distribution of water due to 20% polyethylene glycol (PEG 6000) treatment on some ramets and not others. The bottom, middle, upper and three fragments of clonal common bermudagrass were subjected to 20% PEG 6000 with water potential of −1.8 MPa to induce heterogeneous and homogeneous drought stress. The control was not treated with 20% PEG 6000. Within the heterogeneous treatment, water stressed clonal fragments generally had higher leaf and root antioxidant enzyme activities with respect to superoxide dismutase, catalase, peroxidase (except for root peroxidase). There was no difference in antioxidant enzyme activity within the connected clonal ramets for homogeneous treatment; i.e., three connected ramets treated with 20% PEG 6000. Osmotically stressed clonal fragments under heterogeneous environments had a lower level of malonaldehyde (MDA) compared with those in homogeneous regimes. The antioxidant enzyme integration was affected by directionality and water availability contrast. This was indicated by significant decline in MDA levels within the heterogeneous treatments as compared with homogeneous treatment, which suggested reduced lipid peroxidation. These results suggested that ramet connections facilitate integration of antioxidant enzymes within clonal plants growing in heterogeneously available water. Enzymes were integrated from clonal fragments growing in water sufficient environment to those in water stressed regimes. This enhanced reactive oxygen species scavenging capacity of the entire clone hence improved drought tolerance.


2018 ◽  
Vol 13 (1) ◽  
pp. 422-430
Author(s):  
Liang Xu ◽  
Xiao Wu ◽  
Dan Xiang

AbstractResource sharing between the connected ramets of clonal plants through physiological integration can increase the tolerance of plants to environmental stress. However, the role of physiological integration in the translocation of heavy-metal pollutants between different habitats receives little attention, especially in the aquatic-terrestrial ecotones. An amphibious clonal plant Alternanthera philoxeroides was used to simulate plant expansion from unpolluted soil to a chromium (Cr)-polluted water environment. Basal older ramets growing in unpolluted soil were connected or disconnected with apical younger ramets of the same fragments in polluted environments at different Cr concentrations. Harvested basal ramets were also used for decomposition tests for the loss of residual mass and release of Cr to soil. With increasing Cr concentration there was reduction in biomass of the apical ramets, especially those separated from the basal parts. Cr was detected in the basal ramets with connection to apical parts. The decomposition of plant litter from the basal ramets connected with polluted apical parts might release retained Cr to unpolluted soil. The amount and chemical forms of Cr in the plant litter changed over time. It is concluded that Cr could be transferred from polluted aquatic to unpolluted terrestrial habitats through amphibious clonal plants.


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