4
or fern acacia), S. greggii (= A . greggii, catclaw acacia), S. roemeriana (= A. roemeriana, Romer’s acacia), and others (Correll and Johnston 1979; Van Auken and
Bush 1985 ; Jurena and Van Auken 1998 ; Powell 1998 ; Seigler and Ebinger 2005 ;
Seigler et al. 2007 ).
There are three species of Prosopis in southwestern parts of Asia and all across
central Africa (Fig. 1.1 ) (Simpson 1977 ), with 35 species in South America and nine
species from North America. The two major species of Prosopis in North America
( P. velutina and P. glandulosa ) occur mostly in the arid and semiarid regions of the
southwestern United States and northern parts of Mexico (Fig. 1.1 ). Prosopis velutina is present in southeastern California, southern Arizona, and northwestern
Mexico. Prosopis glandulosa is more widespread and is reported from southern
Kansas, southwestern Oklahoma, central and western Texas, northern Mexico,
eastern and southern New Mexico, eastern and southern Arizona, southwestern
California, and Baja California (Correll and Johnston 1970 ; Simpson 1977 ).
We originally planned to include the old genus Acacia s. l. in this book, and we
will include it briefl y in the next chapter, to put our work in prospective in relation
to the former and current genus Acacia s. l. The genera with species that we have
worked with are Senegalia and Vachellia which, for the most part, we will concentrate on here. However, Prosopis will be included as appropriate.
Members of the old genus Acacia ( s. l. ) are found in the same general area as
Prosopis but more widespread, mostly temperate, tropical and subtropical, arid and
semiarid C 4 grasslands, savannas, and woodlands in both the Old and New World
(Fig. 1.2 ). However, Prosopis is not reported from southeast Asia or Australia. The
Acacias are usually found below 1,000 m, but some have been reported up to
2,100 m (Dharani 2006 ).
In the following chapters we will suggest that the invasion or encroachment of
woody legumes into grasslands is the start of secondary succession in these grasslands
(Begon et al. 2006 ). We propose to present and discuss why we think this is the case. We
will also show the structure of some of these savanna and woodland communities and
demonstrate the factors that seem to control or determine the growth of the main species
in these communities. In addition, we will examine the importance of competition
between the grasses and the legumes and the distribution of species in the communities.
Other topics of importance that will be examined include global climate change and
how management of these communities should commence. Are these grasslands,
woody legume savannas, and woodlands ecologically stable communities? Could they
be restored or should they be restored is also a topic. Then, we will pull all of these factors together in a discussion and projection of what we think will happen in the future.
References
Allred BW, Fuhlendorf SD, Smeins FE, Taylor CA (2012) Herbivore species and grazing intensity
regulate community composition and an encroaching woody plant in semi-arid rangeland.
Basic Appl Ecol 13:149–158
Anderson RC (2006) Evolution and origin of the Central Grasslands of North America: climate,
fi re and mammalian grazers. J Torrey Bot Soc 133:626–647
1 Introduction
or fern acacia), S. greggii (= A . greggii, catclaw acacia), S. roemeriana (= A. roemeriana, Romer’s acacia), and others (Correll and Johnston 1979; Van Auken and
Bush 1985 ; Jurena and Van Auken 1998 ; Powell 1998 ; Seigler and Ebinger 2005 ;
Seigler et al. 2007 ).
There are three species of Prosopis in southwestern parts of Asia and all across
central Africa (Fig. 1.1 ) (Simpson 1977 ), with 35 species in South America and nine
species from North America. The two major species of Prosopis in North America
( P. velutina and P. glandulosa ) occur mostly in the arid and semiarid regions of the
southwestern United States and northern parts of Mexico (Fig. 1.1 ). Prosopis velutina is present in southeastern California, southern Arizona, and northwestern
Mexico. Prosopis glandulosa is more widespread and is reported from southern
Kansas, southwestern Oklahoma, central and western Texas, northern Mexico,
eastern and southern New Mexico, eastern and southern Arizona, southwestern
California, and Baja California (Correll and Johnston 1970 ; Simpson 1977 ).
We originally planned to include the old genus Acacia s. l. in this book, and we
will include it briefl y in the next chapter, to put our work in prospective in relation
to the former and current genus Acacia s. l. The genera with species that we have
worked with are Senegalia and Vachellia which, for the most part, we will concentrate on here. However, Prosopis will be included as appropriate.
Members of the old genus Acacia ( s. l. ) are found in the same general area as
Prosopis but more widespread, mostly temperate, tropical and subtropical, arid and
semiarid C 4 grasslands, savannas, and woodlands in both the Old and New World
(Fig. 1.2 ). However, Prosopis is not reported from southeast Asia or Australia. The
Acacias are usually found below 1,000 m, but some have been reported up to
2,100 m (Dharani 2006 ).
In the following chapters we will suggest that the invasion or encroachment of
woody legumes into grasslands is the start of secondary succession in these grasslands
(Begon et al. 2006 ). We propose to present and discuss why we think this is the case. We
will also show the structure of some of these savanna and woodland communities and
demonstrate the factors that seem to control or determine the growth of the main species
in these communities. In addition, we will examine the importance of competition
between the grasses and the legumes and the distribution of species in the communities.
Other topics of importance that will be examined include global climate change and
how management of these communities should commence. Are these grasslands,
woody legume savannas, and woodlands ecologically stable communities? Could they
be restored or should they be restored is also a topic. Then, we will pull all of these factors together in a discussion and projection of what we think will happen in the future.
References
Allred BW, Fuhlendorf SD, Smeins FE, Taylor CA (2012) Herbivore species and grazing intensity
regulate community composition and an encroaching woody plant in semi-arid rangeland.
Basic Appl Ecol 13:149–158
Anderson RC (2006) Evolution and origin of the Central Grasslands of North America: climate,
fi re and mammalian grazers. J Torrey Bot Soc 133:626–647
1 Introduction