A trade-off between primary and secondary seed dispersal by wind

The distribution and abundance of plants across the world depends in part on their ability to move, which is commonly characterized by a dispersal kernel. For seeds, the total dispersal kernel (TDK) describes the combined influence of all primary, secondary and higher-order dispersal vectors on the overall dispersal kernel for a plant individual, population, species or community. Understanding the role of each vector within the TDK, and their combined influence on the TDK, is critically important for being able to predict plant responses to a changing biotic or abiotic environment. In addition, fully characterizing the TDK by including all vectors may affect predictions of population spread. Here, we review existing research on the TDK and discuss advances in empirical, conceptual modelling and statistical approaches that will facilitate broader application. The concept is simple, but few examples of well-characterized TDKs exist. We find that significant empirical challenges exist, as many studies do not account for all dispersal vectors (e.g. gravity, higher-order dispersal vectors), inadequately measure or estimate long-distance dispersal resulting from multiple vectors and/or neglect spatial heterogeneity and context dependence. Existing mathematical and conceptual modelling approaches and statistical methods allow fitting individual dispersal kernels and combining them to form a TDK; these will perform best if robust prior information is available. We recommend a modelling cycle to parameterize TDKs, where empirical data inform models, which in turn inform additional data collection. Finally, we recommend that the TDK concept be extended to account for not only where seeds land, but also how that location affects the likelihood of establishing and producing a reproductive adult, i.e. the total effective dispersal kernel.

show abstract

“…2003). For example, in wind-dispersed species, tumble dispersal (Zhu et al . 2019) or human-mediated dispersal (Wichmann et al .…”

Section: Introductionmentioning

confidence: 99%

The total dispersal kernel: a review and future directions

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The positive association of D1 and D2 among pods with different shapes may contradict the context‐dependent trade‐off between primary and secondary dispersal (Zhu et al, 2019), although we did not test the wind loading and the ratio of vertical to horizontal seed projection as Zhu et al (Zhu et al, 2019) did. However, our data still indicate an apparent influence of context on secondary wind dispersal.…”

Section: Discussionmentioning

confidence: 91%

“…The dispersal analysis revealed a trend of longer D2 and D1 for the dehiscent‐flat and dehiscent‐twisted pods than for the indehiscent flat pods, suggesting a positive correlation between the primary and secondary wind dispersal distances due to similar wind loadings (Zhu, Liu, Xin, Liu, & Schurr, 2019). However, D2 increased exponentially with wind speed and exhibited slightly different increasing trends among pods with different shapes, especially on sandy ground (Figure 4), suggesting different effects of wind speed on heterocarpy for different ground substrates.…”

Section: Discussionmentioning

confidence: 99%

Heterocarpy diversifies diaspore propagation of the desert shrub Ammopiptanthus mongolicus

Yang

Rong

Gao

et al. 2020

Plant Species Biology

View full text Add to dashboard Cite

In the desert, plant diaspore spreading usually relies on both external vectors, such as wind, and internal factors, such as diaspore shape. Ammopiptanthus mongolicus is a heterocarpous shrub species in the cold desert in northwest China. Mature pods may have dehisced or not yet dehisced when abscising, and the dehiscent pods may be twisted or flattened. The propagation distances of diaspores might vary due to differences in their buoyancies in upward air and ground friction according to pod shape. The wind tunnel experiments were conducted to measure the horizontal displacement upon fruit dropping (D1) and the wind‐blown distance traveled by a fallen pod (D2) of A. mongolicus. A generalized linear mixed model and generalized linear model were used to test the effects of pod shape, release height, wind speed and ground substrate type on the spread distance of pods. D1 is jointly determined by the effects of release height and pod shape. Wind speed, pod shape and ground substrate type together affect D2. A twisted pod has higher dispersibility than a flat pod, and dehiscent pods spread further than indehiscent ones. The positive correlation of D1 and D2 indicates that the difference in pod shape additively broadens the range of seed‐spreading distance. Differential seed‐spreading properties could be adaptively advantageous to disperse the risks associated with diasporic dissemination compared with the maintenance of a single optimal dissemination characteristic. Thus, heterodiaspory is an advantageous adaptive characteristic for seed spreading in the windy, arid and harsh desert environment.

show abstract

“…Also, diaspores with a large projected area were more easily caught than those with a small area (Table 3). Terminal velocity of diaspores is important in predicting primary wind dispersal capacity (Greene, 1980;Nathan et al, 2011;Zhu et al, 2015;Zhu et al, 2019), but the probability of diaspore interception by a plant canopy is associated more with projected area than with terminal velocity. Shape index of diaspores has been reported to be a factor affecting wind dispersal ability (Casseau et al, 2015;Planchuelo et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

Shrub canopy interception of diaspores dispersed by wind

Qin

Liu

et al. 2020

Seed Sci. Res.

Self Cite

View full text Add to dashboard Cite

Interception by plant canopies during wind dispersal can affect the final destination of diaspores. However, how the interaction of wind speed, canopy type and diaspore attributes affects interception of diaspores by the plant canopy has rarely been studied. We investigated canopy interception for 29 species with different diaspore attributes, six canopy types and six wind speeds in controlled experiments in a wind tunnel. Shrub canopy interception of diaspores were controlled by wind speed and diaspore attributes, but the latter had a greater influence on canopy interception than the former. At low wind speed, diaspore wing loading had a large influence on canopy interception, whereas at high wind speed, diaspore projection area had a large influence. The chance of canopy interception at a particular wind speed was additionally affected by the type of canopy. This study increases our knowledge of the dispersal process, corrects the previous understanding of diaspore dispersal potential and improves the theoretical basis for predicting spatial pattern and dynamics of plant populations.

show abstract

A trade-off between primary and secondary seed dispersal by wind

Cited by 19 publications

References 45 publications

The total dispersal kernel: a review and future directions

The total dispersal kernel: a review and future directions

Heterocarpy diversifies diaspore propagation of the desert shrub Ammopiptanthus mongolicus

Shrub canopy interception of diaspores dispersed by wind

Contact Info

Product

Resources

About