Plant community dynamics in a semi-arid ecosystem in relation to nutrient addition following a major disturbance

Abstract

Effects of annual additions of mineral N and P (100 kg ha -1) on plant species composition and annual aboveground net primary production (ANPP) were investigated during the first three years following disturbance in a semi-arid ecosystem. Additions of N reduced richness of perennial plant species during years 2 and 3, while P reduced the number of perennial species only in year 3. From year 1 to year 2, annual and biennial species richness declined in all treatments while ANPP of annual species increased greatly. Added N increased ANPP of annual species while it decreased ANPP of most perennial species relative to the unfertilized control treatment. Community similarities were higher for the control and native vegetation than for other pairs of treatments using both species presence and plant production data. Nitrogen additions have retarded but not completely arrested secondary succession in this system.

Above- and belowground dynamics of plant community succession following abandonment of farmland on the Loess Plateau, China

“…Many researchers have observed that plant community characteristics were usually relatively lower in species richness and plant density in the earlier stages of succession following farmland abandonment (Keever 1983, Carpenter et al 1990, El-Sheikh 2005, and our study further supports that finding. For example, we found a relatively lower species richness, plant density, FRLD, and FRAD (Table 1, Fig 4 a,b).…”

Above- and belowground responses to nitrogen addition in a Chihuahuan Desert grassland

“…Although present, N limitation only occurred during periods of above-average precipitation, adding further support to the claim that semiarid systems are primarily water limited and secondarily N limited (Gutierrez et al 1988;Carpenter et al 1990;Gutierrez 1992;Brooks 2003;Allen et al 2009;. Although apparent aboveground, N fertilization did not increase belowground production nor did it drive directional changes in plant community diversity, composition or dynamics.…”

“…Although N additions did not have large impacts on species abundances at our site, N fertilization has altered community dynamics in other desert systems. Other semiarid fertilization studies indicate decreases in species richness, a switch from C 4 to C 3 species, or influences that scale directly with amount of precipitation (Carpenter et al 1990;Zeng et al 2010;Hall et al 2011). Site-specific differences may account for the differing results, as the degree of aridity and community composition varied between sites and may impact how plants respond to precipitation and N addition.…”

“…N fertilization in other semiarid systems has lead to both decreases (Carpenter et al 1990) and increases (Ettershank et al 1978) in ANPP of perennial species and, even within the same grassland, C 4 grasses can show variable responses to N addition (Báez et al 2007;Collins et al 2010). Experimental N fertilization of 3.2-10 g N m -2 year -1 in Mojave, Sonoran and Chihuahuan desert communities increased ANPP, especially by quickly responding annual plants during years of average to above average precipitation (Gutierrez and Whitford 1987;Gutierrez et al 1988;Brooks 2003;Allen et al 2009;).…”

Plant succession on abandoned fields after 25 years of shifting cultivation in Assuit, Egypt

“…However, most of this literature focuses on temperate and tropical regions, thus largely neglecting arid and semi-arid areas. The main ideas in these studies relate to the effects of grazing, land use history, and nutrients on secondary succession dynamics (Puerto et al, 1977;Carpenter et al, 1990;Bin-Shaher, 1991;McLendon and Redente, 1991;Backeus et al, 1994;Miroshichenko, 1995;Bonet, 2004). The work undertaken by Karpiscak and Grosz (1979) is among the rare researches concentrating on secondary succession of abandoned fields in arid areas.…”