Research Report | SR132 ORIGIN, BIOGEOGRAPHICAL MIGRATIONS AND DIVERSIFICATIONS OF TURFGRASSES James B Beard1 Executive Summary Whether a turfgrass species is characterized as Primitive ancestral grasses are now proposed native or naturalized to North America has been to have appeared during the Late Cretaceous based on world-wide simplistic observations between 65 and 96 mya (million years ago) in focused on where the greatest genetic diversity Gondwanan Africa. The ancestral Pooideae are occurred, termed center-of-origin. Research infor- estimated to have migrated to the steppes of mation as to dating and locations of subsequent Laurasian Eurasia during the Eocene ~ 38 to migration and diversification has been minimal 47 mya. Taxonomic divergence of the base C3 due to a lack of needed research technologies. Pooideae group appears to have been initiated in Intercontinental migration of grasses has been Europe ~ 26 to 33.5 mya. The base C4 Pooideae assumed to have been unlikely due to oceanic apparently arose in Africa ~ 30 to 33 mya, followed separation. Recent development of paleobotanical by migration to West Gondwana South America studies using ultrastructural electron microscopic and to East Gondwana India and Australia. techniques and stable carbon isotope dating instrumentation and research procedures, plus Diversification led to the emergence of an ancient molecular phylogenetic research and cladistic Poeae group known as the fine-leaf fescues biogeographic analysis of large data sets are (Festuca) in central-Europe during the mid- clarifying our understanding of migration patterns Miocene ~ 13 mya. Subsequent migration occurred and dating of multiple secondary centers-of-origin via the mountains of central and eastern Asia, for grasses. across the Bering Land Bridge into North America, southward via the western mountains, over the Pre-anthropological intercontinental migration of Panamanian Land Bridge, and across the Andes grasses is now being documented as more sig- to Patagonia. This occurred between ~ 3.8 and 10 nificant than previously assumed. Global heating/ mya, which is before the anthropological effects cooling phases and shifts in sea level appear to of humans. Clearly, the fine-leaf fescues are native have facilitated oceanic island hopping. At varying to North America, migrating eastward after the times, these bridge migrations may have involved ice age glacial melt ~ 1 mya. Similar investigations the northern Europe to North America route with other turfgrasses may clarify the migration via Greenland, Bering Bridge between Asia and routing and diversification dating of other turf- North America, southeast Asia to Australia via grass species. Thus, the current status of turfgrass New Guinea, South America to North America via species in terms of native or anthropological Caribbean and later via Panama Bridge, and Africa- naturalization is presented in this paper and sum- Europe via the Gibraltar Straits. Also, the potential marized in the following table. for transoceanic migrations is being reconsidered. 1 Professor Emeritus, Texas A&M University and International Sports Turf Institute, College Station, Texas, 77840; e-mail isti@ neo.tamu.edu. This electronic version is being published by the Michigan State University Press in a book titled Turfgrass His- tory and Literature. Copyright 2012, James B Beard. Origin, Biogeographical Migrations and Diversifications of Turfgrasses 1 Summary of native and naturalized categories of 24 turfgrasses found in North America, based on current knowledge. Native/Naturalized Categories Grass Genus and Species Turfgrasses Common Name Native, based on biogeo- Festuca rubra red fescues graphical, phenotypic, and phylogenetic studies. Festuca trachyphylla hard fescue Festuca ovina sheep fescue Native, based on phenotypic Axonopus compressus broadleaf carpetgrass and genetic assessments.* Axonopus fissifolius common carepetgrass Bouteloua curtipendula side-oats gramagrass Bouteloua gracilis blue gramagrass Buchloe dactyloides American buffalograss Stenotaphrum secundatum St. Augustinegrass Possible native, based on Agrostis capillaris colonial bentgrass phenotypic assessments and allied species biogeographical, Agrostis stolonifera creeping bentgrass phylogenetic studies.* Agrostis canina velvet bentgrass Poa pratensis Kentucky bluegrass Possible naturalized, following Eremochloa ophiuroides centipedegrass anthropological introduction.* Lolium multiflorum annual ryegrass Lolium perenne perennial ryegrass Paspalum vaginatum seashore paspalum Poa trivialis rough bluegrass Schedonorus arundinaceus tall fescue Zoysia japonica Japanese zoysiagrass Zoysia matrella ssp. matrella manila zoysiagrass Zoysia pacifica mascarene zoysiagrass Undocumented, needs Cynodon dactylon ssp. dactylon dactylon bermudagrass research Poa annua annual bluegrass *Needs further biogeographical and phylogenetic research to confirm. 2 Origin, Biogeographical Migrations and Diversifications of Turfgrasses Introduction Understanding the relatively recent research in persisted in recent times if human disturbance had grass species evolution and development has not occurred. Disturbed environments can have dictated revision of how native and naturalized long-term or short-term effects on plant com- turfgrass species are viewed, especially in North munity composition depending on the degree and America. The supporting research for this updat- duration of the disturbance event. Disturbance can ing is reviewed herein.2 be a natural aspect of plant ecosystems as caused by drought, fire, disease, insect, glaciation, heat Native Turfgrass Species. Webster’s Third stress, freeze stress, volcanic smoke, soil deposi- New International Dictionary defines native as tion, soil salt level, animal pressures, etc. Defining something indigenous to a particular locality. a native plant based on a fixed point in time, such Indigenous is defined as native and as originating as pre-Holocene, pre-Neolithic, or pre-European or developing or produced naturally in a particular colonial, is unrealistic as it assumes no non-human land or region or environment. The emotive as- disturbances would have occurred subsequently. sociated terminologies relative to native that have It also fails to acknowledge humans as a compo- been used include naturalized, alien, exotic and nent of the ecosystem. Historically, the species non-native. Criteria for classifying native spe- composition of most plant communities has been cies that have been utilized or proposed include a continuous, dynamic process of transitional historical, geographical, economical, behavioral, diversification and recovery. It is likely the natural sociological and/or political considerations. The distribution of plant communities still would latter four involve value judgments based on an be different even if human intervention had not arbitrary frame time that results in controversy occurred. Similarly, species move geographically due to the diversity of human preferences and in response to environmental changes caused both needs (53). Thus, the native aspects of turfgrasses naturally and by human disturbances. Thus native addressed herein will rely on time and geographic sites should not be viewed as fixed geographical dimensions documented by sound, hard science. areas that existed prior to human activity. Also, There are proponents who consider the plant spe- the premise stated by some individuals that native cies present in America when Europeans arrived as turfgrasses inherently possess lower cultural the natives that have persisted from time imme- requirements, resource inputs, and/or water use morial free from human disturbances. However, rates, plus better human benefits than non-native recent research indicates there are woodland areas species is not valid (53). that have developed subsequent to anthropologi- Application of the native terminology for grasses cal disturbance during the late-Holocene at least has varied over the past century, and previously 4,000 years ago (80). These mound-building, early- emphasized the effects of tectonic processes American populations were active in domesticated that resulted in assumed geographic barriers crop propagation involving intensive land use by such as oceanic separation of continents. Some fire to remove forested areas. Such anthropological grass taxonomy and flora books include a geo- impacts on plant species disturbance and reinva- graphic description that proposes a continent(s) sion by intermediate succession species have been or region(s) where each species is native. In the recently documented for regions in southeastern early 1900s there were North American texts on and in north east central North America (33, 80), grass taxonomy that referred to grass species, such and others probably will be found. as the Agrostis, Festuca and Poa, as natives. Then by One can only speculate as to the grass species the mid-1900s most grass taxonomic, flora and that would have been naturally introduced and other texts listed such species as native to Eurasia. 2Assistance of Michigan State University Library personnel in the Turfgrass Information Center is acknowledged, including literature acquisition by Peter Cookingham and Michael Schury, and artwork by Aaron Tomak. Also, critical reviews of the section by Jeff V. Krans, Emeritus, Mississippi State University, William A. Meyer, Rutgers University, Robert B. Shaw, Texas A&M University, and Robert C. Shearman, Emeritus, University of Nebraska, are appreciated. Origin, Biogeographical