Biology and anthropology of plant invasions - Invasive Plants: Ecological and Agricultural Aspects - page 210

Phenotypic life history traits
Given an opportunity in a locality, the second condition necessary for plant
invasion is the presence of propagules of a particular species possessing life his-
tory traits suitable to exploit that space. A life history perspective provides some
advantages in understanding how invasion occurs in a community. Plants expe-
rience the same general life history processes (birth, dispersal, recruitment, veg-
etative and seed reproductive growth). This life cycle can be described by the
underlying plant morphological structures, developmental processes and whole
plant activities that occur during each of these phases (Tab. 2). The time a plant
performs these developmental processes and activities, relative to that of its
neighbors, determines its success in the invasion process: timing is everything.
If a particular invading plant is at the right place, at the right time, it is the traits
that it expresses at those times that make it a winner or a loser relative to its
neighbor. A plant's life cycle is a Markov Chain process in which the state of
the plant at any one time is a direct consequence of its state in the previous time
period [6]. Failure at any time in the life history ends the invasion process.
Phenotypes and traits inevitably fill opportunity spaces in disturbed localities.
Selection favors individual phenotypes and traits that preferentially take advan-
tage of these opportunities at the expense of their neighbors (Tab. 3). Selected

Table 2. Plant morphological structures, developmental (physiological, morphogenic) processes and
whole plant phenotypic activities during the plant life history processes of birth, dispersal, recruit-
ment, vegetative growth and seed reproductive growth

Life history Plant morphological Developmental Whole plant

process structure (physiological, mor- activity-phenotype

phogenic) process

Birth Seed or vegetative • fertilization • seed and bud formation

bud (parental)

• zygote
• embryogenesis
• bud morphogenesis
• dormancy induction

Dispersal Seed or vegetative • dormancy maintenance • spatial dispersal

bud (independent

• spatial foraging (ortet)

ramet; parental ortet)

• seed or bud pool formation
(dispersal in time)

Recruitment Seedling or bud shoot • germination or bud • establishment

(juvenile)

growth
• emergence from soil
• first leaf greening

Vegetative Vegetative plant • growth • interactions with

growth (adult) neighbors

• meristem morphogenesis

• senescence of some tissues

Seed repro- Flowering plant • flower formation • pollen dispersal

ductive (adult)

• senescence

growth

• meristem morphogenesis