The effect of allometric partitioning on herbivory tolerance in four species in South China.

Zhe‐Xuan Fan,Bao‐Ming Chen,Hui‐Xuan Liao,Shao‐Lin Peng,Guo‐Hao Zhou

doi:10.1002/ece3.5651

Zhe‐Xuan Fan, Bao‐Ming Chen + Show 3 more

Open Access

https://doi.org/10.1002/ece3.5651

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Abstract

Herbivory tolerance can offset the negative effects of herbivory on plants and plays an important role in both immigration and population establishment. Biomass reallocation is an important potential mechanism of herbivory tolerance. To understand how biomass allocation affects plant herbivory tolerance, it is necessary to distinguish the biomass allocations resulting from environmental gradients or plant growth. There is generally a tight balance between the amounts of biomass invested in different organs, which must be analyzed by means of an allometric model. The allometric exponent is not affected by individual growth and can reflect the changes in biomass allocation patterns of different parts. Therefore, the allometric exponent was chosen to study the relationship between biomass allocation pattern and herbivory tolerance. We selected four species (Wedelia chinensis, Wedelia trilobata, Merremia hederacea, and Mikania micrantha), two of which are invasive species and two of which are accompanying native species, and established three herbivory levels (0%, 25% and 50%) to compare differences in allometry. The biomass allocation in stems was negatively correlated with herbivory tolerance, while that in leaves was positively correlated with herbivory tolerance. Furthermore, the stability of the allometric exponent was related to tolerance, indicating that plants with the ability to maintain their biomass allocation patterns are more tolerant than those without this ability, and the tendency to allocate biomass to leaves rather than to stems or roots helps increase this tolerance. The allometric exponent was used to remove the effects of individual development on allocation pattern, allowing the relationship between biomass allocation and herbivory tolerance to be more accurately explored. This research used an allometric model to fit the nonlinear process of biomass partitioning during the growth and development of plants and provides a new understanding of the relationship between biomass allocation and herbivory tolerance.

Highlights

Herbivory typically has a negative effect on plant fitness, and plants are pressured to increase levels of defence (Strauss & Agrawal, 1999)
Tolerance is related to biomass allocation pattern, but plants have a remarkable capacity to coordinate the growth of their organs, such that there is generally a tight balance between the amounts of bio‐ mass invested in different organs, which requires analysis by means of an allometric model
The allometric scaling relationship is related to the herbivory tolerance score, and there is no correlation between the partitioning ratio and herbivory tolerance (Figure 3)

Summary

| INTRODUCTION

Herbivory typically has a negative effect on plant fitness, and plants are pressured to increase levels of defence (Strauss & Agrawal, 1999). Tolerance is related to biomass allocation pattern, but plants have a remarkable capacity to coordinate the growth of their organs, such that there is generally a tight balance between the amounts of bio‐ mass invested in different organs, which requires analysis by means of an allometric model. Research on the relationship between bio‐ mass allocation and herbivory tolerance has mainly focused on two aspects: (a) how biomass allocation patterns influence herbivory tol‐ erance and (b) how the capacity to alter biomass allocation patterns in response to herbivores influences herbivory tolerance. We used an allometric model to distinguish the roles of body size and different patterns in the allocation response to the environment, which fur‐ thers our understanding of the herbivory tolerance of plants. An allometric model was used to study the relationship between biomass allocation patterns and herbivory tolerance. The study focused on two aspects: whether partitioning pattern influences tolerance and whether vari‐ ation in biomass partitioning influences tolerance

| MATERIALS AND METHODS

| DISCUSSION

Findings

CONFLICT OF INTEREST