Seed dispersal In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

syndromes are morphological characters of

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s correlated to particular seed dispersal agents.Clobert, J., Le Galliard, J.F., Cote, J., Meylan, S. & Massot, M. (2009). Informed dispersal, heterogeneity in animal dispersal syndromes and the dynamics of spatially structured populations. Ecology Letters, 12, 197-209.Griz, L.M.S. & Machado, I.C.S. (2001). Fruiting phenology and seed dispersal syndromes in caatinga, a tropical dry forest in the northeast of Brazil. Journal of Tropical Ecology, 17, 303-321.Link, A. & Stevenson, P.R. (2004). Fruit dispersal syndromes in animal disseminated plants at Tinigua National Park, Colombia. Revista Chilena de Historia Natural, 77, 319-334.Tamboia, T., Cipollini, M.L. & Levey, D.J. (1996). An Evaluation of Vertebrates Seed Dispersal Syndromes in Four Species of Black Nightshade. Oecologia, 107(4), 522-532. Dispersal is the event by which individuals move from the site of their

parent A parent is a caregiver of the offspring in their own species. In humans, a parent is the caretaker of a child (where "child" refers to offspring, not necessarily age). A ''biological parent'' is a person whose gamete resulted in a child, a male t ...

s to establish in a new area.Herrera, C. M. & Pellmyr, O. (2002).Plant Animal Interactions: An Evolutionary Approach. USA: Blackwell Science Ltd A seed disperser is the vector by which a seed moves from its parent to the resting place where the individual will establish, for instance an

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

. Similar to the term syndrome, a

diaspore Diaspore , also known as diasporite, empholite, kayserite, or tanatarite, is an aluminium oxide hydroxide mineral, α-AlO(OH), crystallizing in the orthorhombic system and isomorphous with goethite. It occurs sometimes as flattened crystals, bu ...

is a morphological functional unit of a seed for dispersal purposes. Characteristics for seed dispersal syndromes are commonly

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

colour, mass, and persistence. These syndrome characteristics are often associated with the fruit that carries the seeds. Fruits are packages for seeds, composed of nutritious tissues to feed animals. However, fruit pulp is not commonly used as a seed dispersal syndrome because pulp

nutrition Nutrition is the biochemical and physiological process by which an organism uses food to support its life. It provides organisms with nutrients, which can be metabolized to create energy and chemical structures. Failure to obtain sufficient n ...

al value does not enhance seed dispersal success. Animals interact with these fruits because they are a common

food source Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...

for them. Although, not all seed dispersal syndromes have fruits because not all seeds are dispersed by animals. Suitable biological and environmental conditions of dispersal syndromes are needed for seed dispersal and invasion success such as

temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...

and

moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapo ...

. Seed dispersal syndromes are parallel to

pollination syndrome Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic (wind and water) or biotic, such as birds, bees, flies, and so forth through a process c ...

s, which are defined as floral characteristics that attract organisms as

pollinator A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains. Insects are the maj ...

s. They are considered parallels because they are both plant-animal interactions, which increase the reproductive success of a plant. However, seed dispersal syndromes are more common in

gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, ''Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμνό� ...

s, while pollination syndromes are found in

angiosperms Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

. Seeds disperse to increase the reproductive success of the plant. The farther away a seed is from a parent, the better its chances of survival and

germination Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, fer ...

. Therefore, a plant should select certain traits to increase dispersal by a vector (i.e.

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

) to increase the reproductive success of the plant.

Evolution

Seeds have evolved traits to reward animals to enhance their dispersal abilities. Differing

foraging Foraging is searching for wild food resources. It affects an animal's Fitness (biology), fitness because it plays an important role in an animal's ability to survive and reproduce. Optimal foraging theory, Foraging theory is a branch of behaviora ...

behaviours of animals can lead to selection of dispersal traits and spatial variation Castro, S., Ferrero, V., Loureiro, J., Espadaler, X., Silveira, P. & Navarro, L. (2010). Dispersal mechanisms of the narrow endemic Polygala vayredae: dispersal syndromes and spatio-temporal variations in ant dispersal assemblages. Plant Ecology, 207, 359-372. such as increase in seed size for

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

dispersal, which can limit

seed production Seed companies produce and sell seeds for flowers, fruits and vegetables to commercial growers and amateur gardeners. The production of seed is a multibillion-dollar business, which uses growing facilities and growing locations worldwide. While m ...

.Fischer, K.E. & Chapman, C.A. (1993). Frugivores and Fruit Syndromes: Differences in Patterns at the Genus and Species Level. Oikos, 66(3), 472-482. Seed production is limited by some seed syndromes because of their cost to the plant. Therefore, seed dispersal syndromes will evolve in a plant when the trait benefit outweighs the cost. The seed dispersers themselves play an essential role in syndrome evolution.Butler, D.W., Green, R.J., Lamb, D., McDonald, W.J.F. & Forster, P.I. (2007). Biogeography of seed-dispersal syndromes, life-forms and seed sizes among woody rain-forest plants in Australia’s subtropics. Journal of Biogeography, 34, 1736-1750. For example, birds put strong

selection pressure Any cause that reduces or increases reproductive success in a portion of a population potentially exerts evolutionary pressure, selective pressure or selection pressure, driving natural selection. It is a quantitative description of the amount of ...

on seeds for colour of fruits because of their enhanced vision. Illustrations of such colour evolution include green colour being produced because its

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

abilities are less costly Lomascolo, S.B., Speranza, P. & Kimball, R.T. (2008). Correlated evolution of fig size and color supports the dispersal syndromes hypothesis. Oecologia, 158, 783-796. while red colour emerges as a byproduct for protection from

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

s. For visible characteristic differences to develop between dispersers and non-dispersers a few conditions need to be met 1. Specialization must increase dispersal success whether morphological, physiological or behavioural 2. Energy investment for dispersal will be taken from energy investment of other traits 3. Dispersal traits will benefit the dispersers over non-dispersers.

Phenotypic In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological proper ...

(visible characteristics) differences in non-dispersers and dispersers can be caused by external factors, kin

competition Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indivi ...

, intraspecific competition and

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

quality.

History

In 1930, Ridley wrote an important book called The dispersal of plants throughout the world, which goes into detail about each form of dispersal; dispersal by wind, water, animals, birds, reptiles and fish,

adhesion Adhesion is the tendency of dissimilar particles or surfaces to cling to one another ( cohesion refers to the tendency of similar or identical particles/surfaces to cling to one another). The forces that cause adhesion and cohesion can be ...

, and people. He details the morphology and traits for each dispersal method, which are later described as seed dispersal syndromes. This began the idea of seed trait selection being associated with a form of seed dispersal. Then in 1969 van der Pijl identified seed dispersal syndromes based on each mechanism of seed dispersal in his book Principles of Dispersal in Higher Plants. He is the pinnacle of seed dispersal syndromes and is cited by many scientists who study seed dispersal syndromes. He describes the morphology of interactions between fruits and

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s, and classifies dispersal in invertebrates, fish, reptiles, birds, mammals, ants, wind, water and the plant itself. Janson in 1983 continued the study on seed dispersal syndromes and classified seed dispersal syndromes of fruit by size, colour and

husk Husk (or hull) in botany is the outer shell or coating of a seed. In the United States, the term husk often refers to the leafy outer covering of an ear of maize (corn) as it grows on the plant. Literally, a husk or hull includes the protective ...

or no husks in species of

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

vian

tropical forest Tropical forests (a.k.a. jungle) are forested landscapes in tropical regions: ''i.e.'' land areas approximately bounded by the tropic of Cancer and Capricorn, but possibly affected by other factors such as prevailing winds. Some tropical fores ...

. He went in depth about the interaction between plants that have adapted to seed dispersal by birds and mammals. Willson, Irvine & Walsh in 1989 added more factors to the study of seed dispersal syndromes and looked at differing fleshy fruits and their correlation to moisture and differing ecological factors. They looked at bird-dispersal and mammal-dispersal and how the fruits differed in dispersal syndromes such as colour and size. These scientists began the theory and ideas behind seed dispersal syndromes that are crucial to the

evolution Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...

of reproduction in plants.

Types and functions

Dispersal syndromes have been previously classified by: size, colour, weight, protection, flesh type, number of seeds, weight and start time of ripening.Du, Y., Mi, X., Liu, X., Chen, L. & Ma, K. (2009). Seed dispersal phenology and dispersal syndromes in a subtropical broad-leaved forest of China. Forest Ecology and Management, 258, 1147-1152. Syndromes are often associated with the type of dispersal and

morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines *Morphology (archaeology), study of the shapes or forms of artifacts *Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...

. Also

chemical composition A chemical composition specifies the identity, arrangement, and ratio of the elements making up a compound. Chemical formulas can be used to describe the relative amounts of elements present in a compound. For example, the chemical formula for ...

can influence the disperser’s fruit choice. The following are types of seed dispersal and their syndromes.

Anemochory

Anemochory In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

is defined as seed dispersal by wind. Common dispersal syndromes of anemochory are wing structures and brown or dull coloured seeds without further rewards. Van der Pijl named seeds for anemochory flyers, rollers, or throwers to represent the seed dispersal syndromes and their behaviour. Flyers are typically categorized as dust diaspores, balloons, plumed or winged. Dust diaspores are small flat structures on seeds that appear to be the transition to wing diaspores, balloons are inflated seed characteristics and plumes are hairs or elongation seed characteristics. Wings have evolved to increase dispersal distance to promote gene flow. Anemochory is commonly found in open habitats,Armesto, J.J. & Rozzi, R. (1989). Seed Dispersal Syndromes in the Rain Forest of Chiloe: Evidence for the importance of Biotic Dispersal in a Temperate Rain Forest. Journal Biogeography, 16(3), 219-226. canopy trees, and dry season

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

forests. Wind dispersers mature in the dry season for optimum high long-distance dispersal to increase success of germination.

Barochory

Barochory is seed dispersal by

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

alone in which a plant's seeds fall beneath the parent plant. These seeds commonly have heavy seed dispersal syndromes.van de Pijl, L. (1969). Principles of dispersal in higher plants. Springer, Berlin Heidelberg, New York. However, heavy seeds may not be a form of seed dispersal syndrome, but a random seed characteristic that has no dispersal purpose. It has been thought that barochory does not develop a seed dispersal syndrome because it does not select for characters to enhance dispersal. It is questionable whether barochory is dispersal at all.

Hydrochory

Hydrochory In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

is seed dispersal by water. Seeds can disperse by rain or ice or be submerged in water. Seeds dispersed by water need to have the ability to float and resist water damage. They often have hairs to assist with enlargement and floating. More features that cause floating are air space, lightweight tissues and corky tissues. Hydrochory syndromes are most common in

aquatic plant Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that ...

Zoochory

Zoochory In Spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, ...

is the dispersal of seeds by animals and can be further divided into three classes. # Endozoochory is seed dispersal by animal ingestion and defecation of a seed. In a mutualistic behavior, the animal is rewarded with nutritious fruit while harmlessly dispersing the seed or seeds, thereby increasing their fitness and chances for survival. # Synzoochory is dispersal of diaspores by the

mouth In animal anatomy, the mouth, also known as the oral cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on ...

parts of animals, and # Epizoochory is the accidental dispersal by animals. Differing characteristics of zoochory syndromes include coloured fruits, scented fruits, and different textures for different animals. Endozoochory syndrome characteristics will develop based on

palatability Palatability (or palatableness) is the hedonic reward (i.e., pleasure) provided by foods or fluids that are agreeable to the "palate", which often varies relative to the homeostatic satisfaction of nutritional, water, or energy needs. The palatabil ...

of the fruit by an organism. For example, mammals are attracted to

scent An odor (American English) or odour (Commonwealth English; see spelling differences) is caused by one or more volatilized chemical compounds that are generally found in low concentrations that humans and animals can perceive via their sense ...

of a seed and birds are attracted to colour. Endozoochory syndromes have evolved to be ingested by animals and later bypassed in a new environment so the seed can germinate.Herrera, C. M. & Pellmyr, O. (2002). Plant Animal Interactions: An Evolutionary Approach. USA: Blackwell Science Ltd. Synzoochory should possess hard skins to protect seeds from damage of mouthparts; for example, sharp beaks on animals such as birds or

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

s. Epizoochory commonly has burrs or spines to transport seeds on the outside of animals. These syndromes are highly associated with animals that have

fur Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an insulating blanket t ...

, while burrs would be lacking on seeds that are dispersed by reptiles because of their smooth skin. It is believed that not all animals that interact with plant fruits are dispersers because some animals do not increase the successful dispersal of seeds but consume and destroy them. Therefore, some animals are dispersers and some are consumers.

Mammalochory

Mammalochory is specifically the seed dispersal by mammals. The dispersal syndromes for mammalochory include large fleshy fruit, green or dull coloured fruits, and husked or unhusked. The seeds tend to have more protection to prevent mechanical destruction. Mammals rely on smell more than vision for foraging, which causes the seeds they disperse to be more scented compared to bird-dispersed seeds. Animal-dispersed seeds ripen in rainy season when foraging activity is high, resulting in fleshy diaspores. Mammals consume fruits whole or in smaller pieces, which explains the larger seed syndromes. Mammalochory syndromes can increase the reproductive success of the plant compared to seed dispersal syndromes of a plant associated with barochory for example. An example of seed dispersal syndromes associated with mammals that increases reproductive success would be seed-consuming

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

s that increase germination by burial of seeds.Hollander, J.L. & Vander Wall, S.B. (2009). Dispersal syndromes in North American Ephedra. ''International Journal of Plant Sciences'', 170(3), 323-330.

Ornithochory

Ornithochory is seed dispersal by birds. Common syndrome characteristics include small fleshy fruits with bright colours and without husks. Ornithochory is common in temperate zones and oceanic islands because of absence of native mammals. Birds have heightened colour vision and swallow seeds and fruits whole, explaining the small and coloured characteristics of dispersal syndromes. Birds have a weak

sense of smell The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it ...

, therefore ornithochory syndromes would specialize more in colour than scent, in comparison to mammalochory. Ornithochory can increase the reproductive success of a plant because a bird’s

digestive tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organs of the digestive system, in humans a ...

increases seed germination after it has been bypassed and dispersed by the bird.

Myrmecochory

Myrmecochory Myrmecochory ( (sometimes myrmechory); from grc, μύρμηξ, mýrmēks ("ant") and ''khoreíā'' ("circular dance") is seed dispersal by ants, an ecologically significant ant–plant interaction with worldwide distribution. Most myrmeco ...

is seed dispersal by

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

s. Myrmecochory is considered an ant-plant mutualistic relationship. The common syndrome traits for myrmecochory are elaiosomes, and are often hard and difficult to damage. Elaiosomes are structures that attract ants because they are high in

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...

content, providing important

nutrient A nutrient is a substance used by an organism to survive, grow, and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi, and protists. Nutrients can be incorporated into cells for metabolic purposes or excret ...

s for the ant. Without ants, seed dispersal becomes barochory and dispersal success declines. It is debated if ants are good dispersers and if plants would select for ant dispersal. Ants do clearly interact with seeds, however ants cannot travel very long distances. Therefore, would a plant select for a bird over an ant when birds can disperse seeds much farther than ants, increasing a plant's reproductive success.

Problems in seed dispersal syndromes

Some scientists are skeptical whether seed dispersal syndromes actually exist because their parallel, pollination syndromes, are often disputed in

scientific literature : ''For a broader class of literature, see Academic publishing.'' Scientific literature comprises scholarly publications that report original empirical and theoretical work in the natural and social sciences. Within an academic field, scient ...

. Seed dispersal syndromes do not seem to have much disagreement among scientists. It is unclear whether this is due to lack of research or interest in seed dispersal syndromes, or that scientists agree with the idea of seed dispersal syndromes. It also may be that seed dispersal syndromes are harder to test because once seeds disperse they are difficult to collect and study. Jordano (1995) states that the evolution of fruit traits for seed dispersal success is only dependent on diameter. This is one scientist’s perspective but does not appear to be the common consensus among scientists. Colour and olfaction are other common seed dispersal syndromes tested and discussed in scientific literature, with equivocal results. One possible reason is that adaptive variation in fruit colours could be scale dependent, occurring only on broad taxonomic scales rather than within assemblages of either bird-dispersed or mammal-dispersed fruit species. One limitation to seed dispersal syndromes mentioned is the limited definitions of syndrome characteristics such as odour or texture. It is possible that there has not been enough research to test these characteristics or they do not play a role in seed dispersal syndromes. The differences in seed dispersal syndromes appear to be weak, but do exist. There needs to be consideration for the possibility that these syndromes evolved not to benefit seed dispersal but possibility to combat other

selective pressure Any cause that reduces or increases reproductive success in a portion of a population potentially exerts evolutionary pressure, selective pressure or selection pressure, driving natural selection. It is a quantitative description of the amount of ...

s. For example, syndromes may have developed to combat

predation Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

or environmental hazards. Predation could produce a

secondary metabolite Secondary metabolites, also called specialised metabolites, toxins, secondary products, or natural products, are organic compounds produced by any lifeform, e.g. bacteria, fungi, animals, or plants, which are not directly involved in the norm ...

syndrome. Secondary metabolites are compounds that are not used for the primary function of a plant and are normally used as

defense mechanisms In psychoanalytic theory, a defence mechanism (American English: defense mechanism), is an Unconscious mind, unconscious psychological operation that functions to protect a person from anxiety-producing thoughts and feelings related to interna ...

.Futuyma, D. J. & Agrawal, A. A. (2009). Macroevolution and the biological diversity of plants and herbivores. Proceedings of the National Academy of Sciences of the United States of America, 106(43), 18054-18061.

Further research

Seed dispersal syndromes have not been studied in complete breadth for every seed dispersal method. Therefore, further research should be conducted to fill the gaps of knowledge about dispersal syndromes. The following are problems areas or directions research can continue on the study of seed dispersal syndromes. There is a lack of understanding of morphology in correlation to behavioural traits of dispersers. Research in this area would assist in the understanding of why particular dispersers are selected by plants to enhance reproductive success. Also, understanding movement strategies of factors affecting departure to settlement is important in determining whether seed dispersal syndromes are only affect by plant selection for a disperser. There are few studies concerning phenotype-dependent dispersal and how it affects spatial structures of populations. Distance of dispersal is not researched in enough detail to correlate to a seed dispersal syndrome. More experimental field studies on plant-animal interactions regarding seed dispersal need to be conducted for a thorough understanding of seed dispersal syndromes. There is limited knowledge about the presence of elaisomes and ant behaviour affecting seed dispersal, and how ant-plant interactions evolved under various plant traits. Understanding these interactions would help clarify if myrmecochory did evolve seed dispersal syndromes. Micro and macroevolutionary processes are needed to determine the effects of biological dispersal of seeds. There cannot be inferences about seed dispersal syndromes without robust phylogenies and evolutionary studies. There is also a gap in the understanding of genetic consequences of zoochory. Using

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...

could help clarify if these syndromes were formed at random or if they correspond to evolution of seed dispersal. It is unclear if these seed dispersal syndromes evolved for specialization between plants and animals to increase seed dispersal success or if these syndromes are simply formed from generalist plant-animal interactions. Understanding these relationships would clarify the confusion about seed dispersal syndromes and if they are true examples of evolution increasing plant reproductive success or if they have developed without selective pressures.

References

{{Reflist Mutualism (biology) Seeds Syndromes in plants