vegetation dynamics (succession and climax) in relation to plant community management

Society for Conservation Biology

Vegetation Dynamics (Succession and Climax) in Relation to Plant Community ManagementAuthor(s): William A. NieringSource: Conservation Biology, Vol. 1, No. 4 (Dec., 1987), pp. 287-295Published by: Wiley for Society for Conservation BiologyStable URL: http://www.jstor.org/stable/2386014 .

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Essay

Vegetation Dynamics (Succession and Climax) in Relation to Plant Community Management WILLIAM A. NIERING Department of Botany Connecticut College New London, Connecticut 06320

Abstract: An understanding of vegetation dynamics is basic to the manipulation of plant communities. Tra- ditional succession/climax concepts can often hinder rather than aid in sound vegetation management In interpreting vegetation change, a diverse set of factors is often operative. Certain of these-initial floristic composition and the tolerance, facilitation, and inhibition models-are specifically related to the basic processes involved in vegetation or biotic change and to specific management problems. For example, certain shrublands within forested regions can exhibit remarkable resistance to tree invasion, a phenomenon especially relevant in managing rights-of-way, naturalistic landscape areas, and wildlife habitats and in maintaining landscape diversity. Fire and herbicides are also important management tools in the restoration and perpetuation of certain community types. Be- cause natural disturbances are critical in maintaining landscape diversity, the incorporation of natural areas should be a part of every land-use management plan. Because wetlands are pulsed systems, succession and climax concepts are often of limited usefulness, that is, wetland vegetation belting is often erroneously interpreted as succession. Considering the diverse interpre- tations of these traditional concepts, a new paradigm is needed. To give a more holistic view of biotic or ecosystem change, the appellations vegetational or biotic development are proposed to replace succession, and steady state and relative stability are offered as more realistic terms than climax.

Paper submitted September 10, 1986; revised manuscript accepted June30, 1987.

Resumen: En al entendimiento de las dinamicas vegetacionales es basico para el manejo de las comunidades vegetales. Los conceptos tradicionales sobre sucesion y cli'max, en ocasiones, pueden impedir y no ayudar al manejo acertado de la vegetacion. Frecuen- temente, al interpretar cambios vegetacionales operan una serie de factores diversos. Algunos de estos, tales como la Composicion Floristica Initial y los Modelos de Tolerancia, Facilitacion e Inhibicion, estdn especi- ficamente relacionados tanto con los procesos basicos involucrados en cambios bioticos o vegetacionales, como con problemas especifi'cos de manejo. Por ejemplo, ciertas areas arbustivas dentro regiones forestales pueden exhibir resistencia extraordinaria a la invasion por arboles; dichofenomeno es especialmente im- portante tanto en el manejo de prioridades de pasaje, paisajes naturalesy habitats de vida silvestre, como en el mantenimiento de la diversidadpaisajista. El Fuego y los herbicidas tambien son instrumentos impor- tantes de manejo en la restauracion y perpetuacion de ciertos tipos de comunidades. Debido a que disturbios naturales son criticos en al mantenimiento de la di- versidad paisajf'stica, la incorporacion de areas naturales debe serparte de todo plan de manejopara el uso de la tierra. Debido a que las humedades son sistemas con pulsaciones, los conceptos de sucesion y cli'max son muchas veces de uso limitado, por ejemplo, lafor- macion de cinturones de vegetacion en los humedales es muchas veces interpretado falsamente como sucesion. Considerando las diversas interpretaciones de estos conceptos tradicionales, un nuevo paradigma es necesario. En el intento de dar una perpectiva mas integral del cambio biotico o del ecosistema, las de- nominaciones desarrollo vegetacional o desarrollo bi- 6tico son propuestas para remplazar el termino de sucesion y estado estable y estabilidad relativa como terminos mas realistas que el de cli'max.

287

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288 Vegetation Dynamics and Vegetation Management Niering

Plant community dynamics and vegetation management are intricately interrelated, and an understanding of the basic processes involved in vegetation change is essential for the sound manipulation of plant communities.

Since natural ecosystems have been, or are being, in- creasingly modified by human activities, restoring and preserving landscape diversity are now major aspects of applied ecology. Along utility, highway, and railroad rights-of-way, millions of acres of vegetation are being manipulated. In wildlife management, large acreages are being managed to maintain a diversity of vegetation types and thereby favor certain animal populations. In wetland ecology, restoration and mitigation require a proper understanding of wetland vegetation dynamics. Two basic concepts, succession and climax, are inte- grally involved in vegetation management, yet they can hinder rather than assist in sound management if they are not fully understood. Although most ecologists have revised their views concerning these concepts since their inception over a half century ago, there is still considerable debate concerning the actual processes and mechanisms involved (Drury & Nisbet 1973; Horn 1976; Pickett 1976; Golley 1977; MacMahon 1980; McIntosh 1980, 1981; Walker 1981; West 1981; Zedler 1981; Shugart 1984).

The purpose of this paper is to review these concepts and then relate them to the dynamics of vegetational change in natural and manipulated terrestrial and wetland ecosystems. Several decades of field experience in manipulating plant communities in relation to rights- of-way, aesthetic landscaping, and fire management at the Connecticut Arboretum at Connecticut College will be cited as relevant.

Some Factors Involved in Vegetational Change Vegetation is here defined as the holistically integrated complex of plant communities within a given area. Suc- cession has been employed to denote a sequence of vegetation or biotic changes over time which may lead to a relatively steady state (climax). It initially, in Clem- ents's (1916) usage, implied an autogenic process referred to as relay floristics, in which one stage prepared the way for the next. Egler (1954) introduced another factor-initial floristic composition (IFC)-especially related to postagricultural vegetation development (secondary succession), in which certain species (i.e., shrubs and trees) that appear later in the process may already be present at the time of abandonment or become established soon thereafter (Niering & Goodwin 1974). This process is also operative in Alaskan flood- plain colonization in which both pioneer (willow, pop- lar, alder) and late-forest (spruce) species were all present within the first five years of silt bar formation with spruce continuing to establish later (Walter et al. 1986). In fact, removal of forest litter also favored es-

tablishment of all tree species. If IFC is an important factor, there is no causative dependence of one stage on the next, as implied in relay floristics, but rather the unfolding of the multispecies development is based on differential tolerances and life histories of the compo- nent species. A knowledge of which process is most important is especially critical to the vegetation manager. For example, if one is attempting to favor shrub- land within forested regions for wildlife or aesthetic purposes, it is essential to know whether the shrubs are serving as nurse plants for tree seedlings or actually inhibiting tree establishment.

More recently Connell and Slatyer (1977) have sug- gested three possible models-facilitation, tolerance, and inhibition-that may be operative in the process of biotic or vegetational change. The tolerance model pro- poses that vegetational change favors those species that are most efficient in exploiting the available resources. For example, in old field development, seedlings of late- forest trees that invade or are already present on the site continue to develop regardless of the presence of earlier pioneer species. This model incorporates Egler's IFC and also Clements's ideas that shade-tolerant species outcompete intolerant forms. It also parallels Tilman's (1985) views that light and nitrogen are important factors in mediating change in species populations. Glea- son's (1926) individualistic concept is also relevant here, in that the genetic characteristics of each species limit its range of ecological tolerance and therefore every environment has its own biotic potential. Gleason could explain all successions and communities as essentially chance dispersal and ecesis of individuals.

The facilitation model is the traditional relay floristics process for which there is a minimum of evidence at the community level, although nurse plants can be important in certain tropical, desert, and wetland ecosystems. For example, in the Sonoran Desert, palo verde (Cer- cidium microphyllum) may provide an especially suit- able habitat for the establishment of saguaro (Carnegiea gigantea) seedlings and other plants (Niering et al. 1963, Steenbergh & Lowe 1969, Turner et al. 1969). On the island of Oahu, the naturalized guava (Psidium cat- tleianum) serves as a nurse plant for many native trees (Egler 1939).

In the inhibition or "finders keepers" model there is no necessary sequence of species superiority but rather chance and coincidence by which the species that initially colonize the site tend to occupy it against other possible invaders. This model emphasizes the early oc- cupation of the site over later competitive interactions in which allelopathy may also be involved. It incorporates Egler's IFC factor, which is not only relevant to terrestrial systems but also to marine environments (Lubchenco & Menge 1978, Sousa 1979).

MacMahon (1981) concluded that the six steps proposed by Clements to describe succession-nudation




Niering Vegetation Dynamics and Vegetation Management 289

migration, ecesis, interaction, competition, and the reaction involved-are essentially correct if the driving forces are on the individual species rather than the su- perorganism, again reflecting Gleason's views.

As a corollary to succession, climax must also be placed in its proper perspective, since, in the traditional sense, succession leads to climax. The concept has evolved from Clements's monoclimax to Tansley's poly- climax to Whittaker's multiple climax pattern. Others insist on the continuum concept, later referred to as gradient, in which discrete communities are often diffi- cult to recognize. However, if one considers a community as a relative continuum between two discontinua (Egler 1977), both concepts are valid. The climax is probably the most contested concept in ecology. More than three decades ago Oosting (1956), in his classic text, indicated that there might be some value in drop- ping the use of the term. The following observations by Egler (1947) are also relevant in this regard:

Plant succession is deservedly one of the very credit- able developments of students of American vegetation. In this study of Oahu, however, the writer prefers to use the term vegetation change, so as to embrace any and all kinds of temporal alterations within and between communities. The term Succession, in the minds of some, appears to denote a succession of step-like meta- morphoses from one association to another. Further- more, the retrogressive-progressive argument makes it necessary for one to know whether he is "coming" or "going," a stand which the writer cannot always take for Oahu, and which others usually settle more by faith than by empirical knowledge.

The Climax, and God, have certain things in common for certain botanical atheists. To paraphrase Julian Hux- ley, the writer does not believe in the climax, because he thinks the idea has ceased to be a useful hypothesis.

In studying the sand dune vegetation in eastern Aus- tralia, Walker et al. (1981) conclude, "The axiomatic assumption of a self-perpetuating forest [climax] seems both biologically and geomorphically untenable."

In an excellent critique Patterson (1986) challenged the Society of American Foresters to drop usage of the terms climax and climax forest from its Terminology of Forest Science, Technology, Practice and Products. He also noted that succession is often misused in re- gards to the aging of forest stands.

Some wetland ecologists also have their reservations about these concepts as applied to wetland ecosystems. Mitsch and Gosselink (1986) indicate that both allogenic and autogenic factors act to change wetlands and that the idea of a regional climax is inappropriate. In considering population interactions among emergents, van der Valk (1981, 1982) advocates the Gleasonian model that emphasizes specific life history traits in relation to changing water regimes. In the northern peatlands, Sjors (1959, 1961) indicated that the use of climax should be avoided, and Heinselman (1970) found "no consistent trend toward mesophytism, terrestrial-

ization or even uniformity.... The concept of succession has little relevance in bog development." Since wetlands are pulsed hydrologically and exhibit distinctive soil characteristics, it is logical to question the application of these concepts.

In an attempt to guide the vegetation manager, I have developed a flexible and somewhat holistic flowchart (Fig. 1) that incorporates some of Clements's original processes as modified by MacMahon (1981). With emphasis on the interactions of individual species, it also incorporates some of the mechanisms involved in Con- nell and Slatyer's three models and IFC. Here vegetational or biotic change at the community or ecosystem level can lead to a relatively stable or constantly changing system depending upon the frequency and scope of disturbance (White 1979, Pickett & White 1985). This is by no means intended to include all the factors that may be involved; it is merely to serve as a guide for those concerned with ecosystem dynamics. One should not seek to apply a given model but rather test these as well as others that may be operative, since vegetational or biotic change is usually multifactorial.

Maintaining Landscape Diversity

Terrestrial Systems

Although ecosystem manipulation is regarded as a means of maintaining landscape diversity, it should be pointed out that natural areas - unmanipulated tracts of lands set aside for scientific, educational, and aesthetic purposes - should also be a part of any long-term landscape management strategy designed to preserve landscape diversity (Niering 1982). Two natural areas at the Connecticut Arboretum are an integral part of our long-range land-use management plan (Niering & Good- win 1962). Although certain vegetation types within a natural area may appear somewhat static during the short term, they are highly dynamic when considered over decades or centuries (Butcher et al. 1981, Hemond et al. 1983). Wind, disease, fire, and other natural disturbances are constantly playing a role in their development. For example, natural fires in the boreal forest region of northern Minnesota prior to the entry of the white man kept the forests in a constant state of flux (Heinselman 1971) and resulted in a mosaic of intolerant forest types (aspen and birch). Thus the predicted climax (spruce-fir) was not the dominant vegetation un- der pristine conditions. Fire is now widely used as a management tool in maintaining diversity (Niering 1981). For example, in California the replacement of the giant sequoia (Sequoidendron giganteum) by white fir (Abies concolor) and incense cedar (Calocedrus decur- rens) is being arrested by prescribed burning (Kilgore 1972). In the Southeast evergreen forest region, pine forests are favored over oak by controlled burning, and

Conservation Biology Vo)lume 1, No 4, December 1987




--->- DISTURBANCE

Natural Man-induced

Fire Fire Disease Disease Animals Animals Drought Pollution Wind Past land use Frost action

MIGRATION| INITIAL FLORISTIC COMPOSITION Vegetative reproduction

Seed bank (residual) Seed (current) Mode of dispersal Proximity of propagule source

FACILITATION MODEL 4

ECESIS

Dependent on life history of TOLERANCE species and local site con- MODELERANCE \ \ditions (i.e., bare substrate, MODEL \ \ \ windthrows, logs, moss mats)

Nurse plants

INHIBITION MODEL COMPETITION

Biotic Abiotic

Plant/plant Light Herbivores Nutrients Allelopathy Moisture

CONSTANT I RELATIVELY ,CHANGE STEADY STATE

Constantly shifting Mosaic of relatively mosaic of populations stable communities at community or at regional landscape regional landscape level. \\

_A__ level. REACTION

Differential species survival and exclusion.

Figure 1. Some processes, mechanisms, and interacting factors involved in vegetation or ecosystem development. Basic processes (boxed) tend to form a cyclic pattern, whereas some of the various mechanisms identified, such as initial floristic composition (IFC) and inhibition, tolerance, and facilitation models, are shown where possibly relevant. IFC is involved in the tolerance and inhibition models. Some of the various factors or processes are indicated where relevant. In some situations a relatively steady state community develops. In other situations there is a constantly shifting mosaic of populations. This is an attempt to replace the more generally used concepts of succession and climax with a more holistic view of biotic or ecosystem development.





midwestern grasslands are burned to maintain prairie vegetation. Moreover, the current "let burn" policy of the U.S. Forest Service in the more remote national forests is a sound management strategy to achieve landscape diversity.

In the Northeast there is considerable evidence that natural grasslands existed within the deciduous forest region, especially on edaphically favorable sites. The Hempstead Plains, originally a 50-square-mile Andro- pogon grassland on western Long Island, New York (Harper 1911, 1912; Cain et al. 1937), is an example. Other such grasslands have also been described by Dwight (1969) in his early travels through New York and New England. Since 1968, fire has been successfully used on postagricultural landscapes in the Connecticut Arboretum to perpetuate little bluestem (Andropogon scoparius) grasslands and also to create open, park-like oak forests (Niering et al. 1970) somewhat similar to those favored by Indian-set or lightning-caused fires prior to European settlement (Day 1953, Russell 1983).

After nearly two decades of burning, the Arboretum fields (manuscript in preparation) are now floristically similar to the Hempstead Plains and to the now lost pine plains in North Haven, Connecticut, and related areas near Albany, New York. The mid- and tall grass prairies of the Midwest have a significant geographical affinity to the eastern forests despite their difference in physiog- nomy (Egler 1977) and extend the concept developed by Transeau (1905) concerning the prairie extension into the eastern deciduous forest. Thus with the rein- troduction of fire we are essentially perpetuating an eastern prairie vegetation and also re-creating an element of an ecosystem that was once more widespread in the Northeast. This highlights a worldwide trend in restoring fire to those ecosystems where it was once a primary element and, in the process, favoring a distinctive set of plant communities and their associated fauna.

In forest management, clear-cutting often initiates a dramatic set of vegetational changes until the system recovers (Bormann et al. 1968, Bormann & Likens 1979). In the northern hardwoods forest of New En- gland, pin cherry (Prunus pensylvanica) serves as an important pioneer, intercepting nutrients and therefore preventing their loss from the watershed (Marks 1974). Although this tree has been considered a "weed" species, following disturbance it is capable of rapid establishment (IFC) from the seed bank in the forest litter. Forest managers should be aware of this phenomenon since it may also be operative in other forest communities. Unnecessary destruction of pioneer species following disturbance, such as spraying the ground cover to favor tree regeneration, should be carefully evaluated at the ecosystem level. In the case of the cherry, it will eventually be replaced by late forest hardwoods, yet the stage is set for its return following another perturbation whether by natural or man-induced disturbance. This

emphasizes that, although the individualistic species population approach is often valid in terms of vegetational change, at the community level there has evolved a considerable degree of integration, which is consistent with Odum's (1969) ecosystem development paradigm.

During the colonial period, forest clearing for agricul- ture in New England was an even more drastic perturbation than forestry clear-cutting, often resulting in severe erosion (Cronon 1983). With agricultural abandonment there developed a distinctive set of postagricultural communities with considerable ecological diversity. However, since they are primarily shade- intolerant communities, the question arises as to how these anthropogenic vegetation types can be perpetu- ated. According to the traditional concept of succession, these types are doomed within forested regions, since they are capable of being shaded by taller tree growth. However, if the inhibition model and IFC are operative, certain of these shrub communities can be maintained with a minimum of management. In Greenwich, Con- necticut, a fortuitously established nannyberry (Vibur- num lentago) thicket has remained relatively stable for 55 years (Niering & Egler 1955, Niering et al. 1986). Within postagricultural thickets where trees may be associated with shrubs, this does not necessarily mean that the trees are invading the shrubs but rather that the two life forms became established concomitantly (IFC) by chance early in the development. Each life form ex- presses its physiognomic dominance at different times. Therefore, when one selectively eliminates associated trees from such dense clonal shrub thickets as huckleberry (Gaylusaccia baccata) and greenbrier (Smilax rotundifolia), an ecological setting is created where tree seedling establishment is less probable. In southern New England such shrub communities have exhibited a relative stability for several decades. Changes in vegetation at the Connecticut Arboretum since 1967, and at Aton Forest in northwestern Connecticut since 1946 (Egler 1975), are not consistent with Clementsian relay floristics of all stages from bare soil to a self- perpetuating community. However, it should be ac- knowledged that lateral shading from peripherally established trees can eventually fragment such shrublands unless these trees are removed.

Certain perennial herbaceous species associated with postagricultural landscapes can also exhibit considerable stability (Grime 1979). For example, little bluestem, red fescue (Festuca rubra), a turf-forming graminoid, and goldenrods (Solidago spp.) can often form such dense stands that woody seedling invasion is greatly decreased or arrested. After 15 years a fescue grassland has developed remarkable stability and even replaced little bluestem in southeastern Connecticut. Although fire, as previously mentioned, and mowing may favor certain of these perennial communities, the selective use of herbicides or even manual removal of

Conservation Biology Volume 1, No 4, December 1987




woody regeneration can also favor such communities until a dense cover develops. These semi-wooded, postagricultural communities are invaluable as wildlife habitats, since many wildlife species prefer the edge habitat created by such management.

This manipulation of postagricultural communities by the selective removal of certain less desirable trees is also applicable to wildlife and rights-of-way (Egler & Foote 1975) vegetational management and to the art of naturalistic landscaping (Kenfield 1966). In the North- east there is a rich spectrum of old field species with spectacular autumn foliage (huckleberry and highbush blueberry [Vaccinium corymbosum], or flowering characteristics (flowering dogwood [Cornus florida]) that can be favored in a semi-open, naturalistic setting. A demonstration area established in the early 1950s in the Arboretum (Niering & Goodwin 1963, 1975) is still aes- thetically appealing and relatively easy to maintain, free of unwanted tree growth, emphasizing the importance of the IFC concept. Also a transmission right-of-way demonstration area crossing the Arboretum has been managed since the early 1950s with the objective of creating relatively stable upland and wetland shrublands (Niering & Goodwin 1974). Over 40 species of shrubs have been favored by the selective removal of tree growth. Currently Northeast Utilities employs this selective approach as a general management policy for rights-of-way because the resulting shrub communities are stable and valuable for wildlife (Dreyer & Niering 1986). The problem of woody ground cover interfering with tree regeneration following clear-cutting has been long known in forest management. Therefore, this concept of shrub stability should be carefully evaluated in a variety of geographical regions.

Crest communities (vegetation typical of rock out- crop sites in forested regions) and wetlands offer two environmental extremes, and both often exhibit vegetation belting that may be mistaken for succession. If interpreted as succession, certain vegetation types might disappear; however, if this belting pattern is controlled by a complex set of allogenic factors, then these zones may be relatively stable. On rock outcrops lichens are not necessarily followed by mosses, with herbaceous and woody species as an autogenic set of belts replacing one another. In Connecticut, and probably elsewhere, lichens on convex or sloping rocks and talus slopes have been relatively stable since the end of the glacial era 10,000 years ago. Our permanent lichen plots in the Arboretum show constant change among the various kinds of lichens with a cyclic pattern rather than an orderly or predictable progression (Coleman 1975). This is not to imply that some facets of autogenic development cannot occur in rock island depressions or microsites where soil depth and moisture can control the distribution of certain annuals (Sharitz & McCor- mick 1973). Winterringer and Vestal (1956) concluded

that there was great instability on rocky sites and no conventional sequence of stages, but rather several so- called steady states. Drought, erosion, and frost action are obvious recurring hazards. These crest sites may represent an integral part of certain natural areas and thus add a further element of diversity. The idea that such sites inevitably become engulfed and replaced by the surrounding forest is usually unfounded in many forested areas. In the Northeast they have remained suf- ficiently open to provide refuge for certain field species such as red cedar and little bluestem.

Wetland Systems In certain kinds of wetlands, especially lakes, bogs, and tidal marshes, spatial belting is often mistaken for temporal succession. Several studies have shown that these belts merely oscillate over time depending upon changes in water level owing to climatic or edaphic factors, including beaver activity. In Cedar Creek bog (Minnesota) the edge of the so-called advancing mat was at the same point after 33 years, although the char- acter of the belts themselves had changed over this period (Buell et al. 1968). Yet here within a shorter period (1934-44) Lindeman (1941) found that the sedge mat was advancing at the rate of 1 meter per decade. In Beckley bog (northwestern Connecticut) Egler (per- sonal communication, 1977) found the trees in five belts: 1) outer marginal red maple, 2) white pine, 3) large spruce, 4) intermediate spruce and larch, and 5) dwarf spruce closest to the open water-all with about 90 rings. To imply that wetland development will eventually end with an upland community can be dogmati- cally misleading and often erroneous (Nichols 1915, Walker 1970). In his pothole wetland studies, van der Valk ( 1981) replaced the autogenic succession concept with Gleason's emphasis on species differences. Yet this does not imply that certain species such as tussock sedge (Carex stricta) cannot play a facilitating role in Northeast marsh to swamp development in which tree seedlings of red maple (Acer rubrum) become established on such elevated microsites. To the wetland manager a recognition of the complexity of wetland developmental processes involving autogenic and/or allogenic factors in relation to hydrology is essential (Nier- ing 1987). Although efforts to restore degraded wetlands are basically sound, the concept of mitigation that allows a viable wetland to be destroyed while an attempt is made to create a new one has questionable ecological validity, because re-creation of the multifunc- tional roles of many wetlands such as bogs and swamps (forest wetlands) is not yet a reality (Golet 1986, Larson & Neill 1986).

Tidal wetlands may also exhibit distinctive belting patterns. In the Northeast, marsh development bayward involves an intertidal salt water cordgrass (Spartina al-





terniflora) belt that may be replaced by salt meadow cordgrass (Spartina patens) owing to both autogenic and/or allogenic factors. However, on the high marsh there are endless combinations (Chapman 1940) that can develop over 200 to 1000 years or more according to our peat core studies (Niering et al. 1977). A multi- plicity of factors controls this ever-changing, unpredict- able high marsh pattern (Niering & Warren 1980). In the Northeast, tidal restriction of valley marshes has resulted in a dramatic shift from Spartina- to Phragmites- dominated marshes (Roman et al. 1984). Management of such wetlands involves restoring tidal flushing to 20 to 30 ppt or even the removal of Phragmites and plant- ing of Spartina alterniflora within the intertidal zone. Interest in both fresh and saline wetland restoration is rapidly increasing and will require a future understanding of tidal wetland dynamics. Restoration of intertidal S. alterniflora, a species restricted to the zone flooded by every tide, has been relatively successful. However, re- creation of the more complex high marsh community is still in the future (Shisler & Charrette 1984).

Conclusion It is evident that a thorough understanding of vegetation dynamics is critical for sound vegetation management and the maintenance of landscape diversity. The role of landscape ecology in this regard is to focus attention on hierarchy theory that considers vegetation patterns at different scales. It appears that our degree of predict- ability decreases as the scale decreases to specific sites where most management strategies are formulated (Ur- ban et al. 1987). Therefore, a new paradigm is needed in relation to vegetation development and community stability. The use of such terms as vegetational or biotic development could relieve ecologists of the confusing term succession. In addition, the terms steady state or relative stability for climax would also crack the mind- set of yesteryear and permit a more flexible way of look- ing at a physiognomic, historically conditioned mosaic of relatively stable cover types on a diversity of sites within any given vegetation zone or biotic system.

Literature Cited Bormann, F. H., and G. E. Likens. 1979. Pattern and process in a forested ecosystem: disturbance, development and the steady state based on the Hubbard Brook ecosystem study. Springer-Verlag, New York, New York, USA.

Bormann, F. H., G. E. Likens, D. W. Fisher, and R. S. Pierce. 1968. Nutrient loss accelerated by clear-cutting of a forest ecosystem. Science 159:882-884.

Buell, M. F., H. F. Buell, and W. A. Reiners. 1968. Radial mat growth on Cedar Creek Bog, Minnesota. Ecology 49:1198- 1199.

Butcher, G. S., W. A. Niering, W. J. Barry, and R. H. Goodwin. 1981. Equilibrium biogeography and the size of nature pre- serves: an avian case study. Oecologia 49:29-37.

Cain, S. A., M. Nelson, and W. McLean. 1937. Andropogonetum Hempsteadii: a Long Island grassland vegetation type. Ameri- can Midland Naturalist 18:324-350.

Chapman, V.J. 1940. Succession on the New England salt marshes. Ecology 21:279-282.

Clements, F. E. 1916. Plant succession: an analysis of the development of vegetation. Pub. No. 242. Carnegie Institute, Washington, D.C., USA.

Coleman, Wendy. 1975. A study of rock dynamics in the Bolleswood Natural Area of the Connecticut Arboretum. Un- published independent study. Connecticut College, New Lon- don, Connecticut, USA.

Connell, J. H., and R. 0. Slatyer. 1977. Mechanisms of succession in natural communities and their role in community stability and organization. American Naturalist 111:1 1 19-1144.

Cronon, William. 1983. Changes in the land: Indians, colonists, and the ecology of New England. Hill & Wang, New York, New York, USA.

Day, G. M. 1953. The Indian as an ecological factor in the northeast forest. Ecology 34:329-346.

Dreyer, G. D., and W. A. Niering. 1986. Evaluation of two her- bicide techniques on electric transmission rights-of-way: development of relatively stable shrublands. Environmental Man- agement 10:1 13-1 18.

Drury, W. H., and I. C. T. Nisbet. 1973. Succession. Journal of the Arnold Arboretum 54:331-368.

Dwight, Timothy. 1969. Travels in New England and New York [1822], 4 volumes. Barbara Miller Solomon, editor. Belknap Press of Harvard University Press, Cambridge, Massa- chusetts, USA.

Egler, F. E., 1939. Vegetation zones of Oahu, Hawaii. Empire Forestry Journal 18:44-57.

.1947. Arid southwest Oahu vegetation, Hawaii. Eco- logical Monographs 17:383-435.

. 1954. Vegetation science concept. I. Initial floristic composition-a factor in old-field vegetation development. Vegetatio 4:412-417.

.1975. The home lawn: botanical absurdity. Connecti- cut Arboretum Bulletin 8:3-8.

.1977. The nature of vegetation, its management and mismanagement: an introduction to vegetation science. Aton Forest, Norfolk, Connecticut, USA.

Egler, F. E. and S. R. Foote. 1975. The plight of the rightofway domain: victim of vandalism. 2 volumes. Futura Media Ser- vices, Mt. Kisco, New York, USA.

Gleason, H. A. 1926. The individualistic concept of the plant association. Bulletin of the Torrey Botanical Club 53:7-26.





Golet, F. C. 1986. Critical issues in wetland mitigation: a scientific perspective. National Wetlands Newsletter 8(5):3-6.

Golley, F. B., editor. 1977. Ecological succession. (Benchmark papers in ecology, 5). Dowden, Hutchinson & Ross, Strouds- burg, Pennsylvania, USA.

Grime, J. P. 1979. Plant strategies and vegetation processes. John Wiley & Sons, New York, New York, USA.

Harper, R. B. 1911. The Hempstead plains: a natural prairie on Long Island. Bulletin of the American Geographical Society 43:351-360.

. 1912. The Hempstead plains of Long Island. Torreya 12:277-287.

Heinselman, M. L. 1970. Landscape evolution, peatland types, and the environment in the Lake Agassiz peatlands natural area, Minnesota. Ecological Monographs 40:235-261.

. 1971. The natural role of fire in northern conifer forests. Pages 61-72 in Fire in the northern environment. Pacific Northwest Forest Range Experiment Station, U.S.D.A. Forest Service, Portland, Oregon, USA.

Hemond, H. F., W. A. Niering, and R. H. Goodwin. 1983. Two decades of vegetation change in the Connecticut Arboretum Natural Area. Bull. Torrey Botanical Club 110:184-194.

Horn, H. S. 1976. Succession. Pages 187-190 in R. M. May, editor. Theoretical ecology. W. B. Saunders, Philadelphia, Pennsylvania, USA.

Kenfield, G. W. 1966. The wild gardener in the wild landscape: the art of naturalistic landscaping. Hafner Publishing, New York, New York, USA.

Kilgore, B. M. 1972. The role of fire in giant sequoia-mixed conifer forest. Pages 1-38 in Proceedings of the American Association for the Advancement of Science Symposium, 1971.

Larson, J. S., and C. Neill, editors. 1986. Mitigating freshwater wetland alterations in the glaciated northeastern United States: an assessment of the science base. Proceedings of workshop. Pub. No. 87-1. Sept. 29-30, 1986, Environmental Institute, University of Massachusetts at Amherst, USA.

Lindeman, R.I. 1941. The developmental history of Cedar Creek Bog, Minnesota, American Midland Naturalist 25:101- 112.

Lubchenco, J., and B.A. Menge. 1978. Community development in a low rocky intertidal zone. Ecological Monographs 48:67-94.

McIntosh, R. P. 1980. The relationship between succession and the recovery process in ecosystems. Pages 11-62 in J. Cairns, Jr., editor. The recovery process in damaged ecosystems. Ann Arbor Science Publishers, Ann Arbor, Michigan, USA.

1981. Succession and ecological theory. Pages 10-23 in D. C. West, H. H. Shugart, and D. B. Botkin, editors. Forest

succession: concepts and application. Springer-Verlag, New York, New York, USA.

MacMahon, J. A. 1980. Ecosystems over time: succession and other types of change. Pages 27-58 in R. H. Waring, editor. Forests: fresh perspectives from ecosystem analysis. Proceed- ings of the 40th Annual Biology Colloquium. Oregon State University Press, Corvallis, Oregon, USA.

. 1981. Successional processes: comparisons among bi- omes with special reference to probable roles of and influ- ences on animals. Pages 277-304 in D. C. West, H. H. Shugart, and D. B. Botkin, editors. Forest succession: concepts and application. Springer-Verlag, New York, New York, USA.

Marks, P. L. 1974. The role of pin cherry (Prunus pensylvanica L.) in the maintenance of stability in northern hardwood ecosystems. Ecological Monographs 44:73-88.

Mitsch, W.J., and J. G. Gosselink. 1986. Wetlands. Van Nos- trand Reinhold, New York, New York, USA.

Nichols, G. E. 1915. The vegetation of Connecticut. IV. Plant societies in wetlands. Bulletin of the Torrey Botanical Club 42:169-217.

Niering, W. A. 1981. The role of fire management in altering ecosystems. Pages 489-510 in Proceedings of Fire Regimes and Ecosystem Properties conference, Dec. 11-15,1978. Gen- eral Technical Report No. WO-26. U.S.D.A. Forest Service, Ho- nolulu, Hawaii, USA.

. 1982. The research and conservation programs. The Connecticut Arboretum: its first fifty years. Connecticut Arbo- retum Bulletin 28:32-43.

Niering, W. A. 1987. Wetlands hydrology and vegetation dynamics. National Wetlands Newsletter 9:9-11.

Niering, W. A., G. D. Dreyer, F. E. Egler, and J. P. Anderson, Jr. 1986. Stability of a Viburnum lentago shrub community after 30 years. Bulletin of the Torrey Botanical Club 113:23-27.

Niering, W.A., and F. E. Egler. 1955. A shrub community of Viburnum lentago stable for twenty-five years. Ecology 36:356-360.

Niering, W. A., and R. H. Goodwin. 1962. Ecological studies in the Connecticut Arboretum natural area. I. Introduction and a survey of vegetation types. Ecology 43:41-54.

. 1963. Creating new landscapes with herbicides: a homeowner's guide. Connecticut Arboretum Bulletin 14:1-30.

Niering, W. A., and R. H. Goodwin. 1974. Creation of relatively stable shrublands with herbicides: arresting "succession" on rights-of-way and pastureland. Ecology 55:784-795.

.1975. Energy conservation on the home grounds-the role of naturalistic landscaping. Connecticut Arboretum Bul- letin 21:1-28.

Niering, W. A., and R. S. Warren. 1980. Vegetation patterns and processes in New England salt marshes. BioScience 30:301- 307.

Niering, W. A., R. S. Warren, and C. G. Weymouth. 1977. Our dynamic tidal marshes: vegetation changes as revealed by peat analysis. Connecticut Arboretum Bulletin 22:1-12.





Niering, W.A., R. H. Whittaker, and C. H. Lowe. 1963. The saguaro: a population in relation to environment. Science 142:15-23.

Odum, E. P. 1969. The strategy of ecosystem development. Science 164:262-270.

Oosting, H.J. 1956. The study of plant communities, 2d ed. W. H. Freeman & Co., San Francisco, California, USA.

Patterson, W. A., III. 1986. A "new ecology"-implications of modern forest management. "Let's strike 'climax' from forest terminology." Journal of Forestry 84:73.

Pickett, S. T. A. 1976. Succession: an evolutionary interpreta- tion. American Naturalist 110:107-109.

Pickett, S. T. A., and P. S. White, editors. 1985. The ecology of natural disturbance and patch dynamics. Academic Press, New York, New York, USA.

Roman, C. T., W. A. Niering, and R. S. Warren. 1984. Salt marsh vegetation change in response to tidal restriction. Environ- mental Management 8:141-150.

Russell, E. W. B. 1983. Indian-set fires in the forests of the northeastern United States. Ecology 64:78-88.

Sharitz, R. R., and J. F. McCormick. 1973. Population dynamics of two competing annual plant species. Ecology 54:723-739.

Shisler, J. K, and D.J. Charette. 1984. Evaluation of artificial salt marshes in New Jersey. New Jersey Agricultural Experi- ment Station Publication No. P-40502-01-84.

Shugart, H. H. 1984. A theory of forest dynamics: the ecological implications of forest succession models. Springer-Verlag, New York, New York, USA.

Sj6rs, H. 1959. On the relation between vegetation and elec- trolytes in North Swedish mire waters. Oikos 2:241-258.

. 1961. Surface patterns in boreal peatland. Endeavor 20:217-224.

Sousa, W. P. 1979. Experimental investigations of disturbance and ecological succession in a rocky intertidal algal community. Ecological Monographs 49:227-254.

Steenbergh, W. F., and C. H. Lowe. 1969. Critical factors during the first years of life of the saguaro (Cereus giganteus) at Saguaro National Monument, Arizona. Ecology 5:825-834.

Tilman, D. 1985. The resource-ratio hypothesis of plant succession. American Naturalist 125:827-852.

Transeau, E. N. 1905. Forest centers of eastern North America. American Naturalist 39:875-889.

Turner, R. M., S. M. Alcorn, and G. Olin. 1969. Mortality of transplanted saguaro seedlings. Ecology 5:835-844.

Urban, D. L., R. V. O'Neill, and H. H. Shugart. 1987. Landscape ecology. BioScience 37:119-127.

van der Valk, A. G. 1981. Succession in wetlands: a Gleasonian approach. Ecology 62:688-696.

. 1982. Succession in temperate North American wetlands. Pages 169-179 in B. Gopal, R. E. Turner, R. G. Wetzel, and D. F. Whigham, editors. Wetlands: ecology and management. National Institute of Ecology and International Scientific Publications, Jaipur, India.

Walker, D. 1970. Direction and rate in some British post- glacial hydroseres. Pages 117-139 in D. Walker and R. G. West, editors. The vegetation history of the British Isles. Cam- bridge University Press, Cambridge, England.

Walker, B. H. 1981. Is succession a viable concept in African savanna ecosystems? Pages 431-447 in D. C. West, H. H. Shugart, and D. B. Botkin, editors. Forest succession: concepts and application. Springer-Verlag, New York, New York, USA.

Walker, J., C. H. Thompson, I. F. Fergus, and B. R. Tunstall. 1981. Plant succession and soil development in coastal sand dunes of subtropical eastern Australia. Pages 107-131 in D. C. West, H. H. Shugart, and D. B. Botkin, editors. Forest succession: concepts and application. Springer-Verlag, New York, New York, USA.

Walker, L. R., J. C. Zasada, and F. S. Chapin III. 1986. The role of life history process in primary succession on an Alaskan flood- plain. Ecology 67:1243-1253.

West, D. C., H. H. Shugart, and D. B. Botkin, editors. 1981. For- est succession: concepts and application. Springer-Verlag, New York, New York, USA.

White, P. S. 1979. Pattern, process, and natural disturbance in vegetation. Botanical Review 45:229-299.

Winterringer, G. D., and A. G. Vestal. 1956. Rock ledge vegetation in southern Illinois. Ecological Monographs 26:105- 128.

Zedler, P. H. 1981. Vegetation change in chaparral and desert communities in San Diego County, California. Pages 431-447 in D. C. West, H. H. Shugart, and D. B. Botkin, editors. Forest succession: concepts and application. Springer-Verlag, New York, New York, USA.

Conservation Biology Volume 1, No 4, December 1987



vegetation dynamics (succession and climax) in relation to plant community management

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