Species Richness–productivity Patterns Differ Between N-, P-, and K-Limited Wetlands

Abstract

We evaluated whether the kind of nutrient limitation (N, P, or K) may affect species richness-productivity patterns and subsequently may explain variation in species richness and in richness of threatened species. We present a data set from previous studies in wetlands in Poland, Belgium, and The Netherlands and examine species richness-productivity patterns for vascular plants in all 150 sites together as well as for N-, P-, and Klimited sites separately. The kind of nutrient limitation was assessed by N:P, N:K, and K: P ratios in the vegetation. Critical values for these ratios were derived from a literature review of fertilization experiments. The kind of nutrient limitation influenced species richness-productivity patterns in our 150 sites through large differences in productivity. P (co)limitation occurred only at low productivity, K (co)-limitation up to intermediate productivity, and N limitation along the entire productivity gradient. There was a decreasing trend in species richness with increasing productivity for K (co)-limited sites, whereas for both the N-limited sites and P (co)-limited sites a sort of ''filled hump-shaped curve'' was observed. The species richness-productivity relationship for threatened species was restricted to a much narrower productivity range than that for all species. Richness of threatened species was higher in P (co)-limited sites than in N-limited sites, suggesting that increased P availabilities in wetlands may be particularly important in causing disappearance of threatened species in western Europe. The role of nutrient limitation in species richnessproductivity relationships not only reveals mechanisms that may explain variation in species richness and occurrence of threatened species, but it also may be important for nature management practice.

Influence of fire history and soil properties on plant species richness and functional diversity in a neotropical savanna

“…Because different plant species are adapted to the availability of distinct nutrients in the soil, the type and number of limiting resources can affect species composition and richness (Critchley et al 2002;Venterink et al 2003;Harpole & Tilman 2007). Disturbances also affect species richness and composition, as well as altering the influence that species traits have on plant establishment and development (Haddad et al 2008).…”

Understanding the Long Term Ecosystem Stability of a Fen Mire by Analyzing Subsurface Geology, Eco-Hydrology and Nutrient Stoichiometry – Case Study of the Rospuda Valley (NE Poland)

“…Fen vegetation in the upper basin (B) has a higher N:P ratio, suggesting N/P co-limitation (Güsewell and Koerselman 2002;Wassen et al 2005), whereas N-limitation was found in the lower basin (A). Neither in the upper nor in the lower basin Klimitation occurred (Olde Venterink et al 2003). Floristic differences between small sedge-brown moss vegetation in the two basins correspond to the main division of rich fen vegetation in NE Poland described by Pawlikowski et al (2013).…”

“…Their amount in fen pore water is controlled in first instance by (hydrology-dependent) peat mineralisation rates (Olde Venterink et al 2003) and external input, e.g. from floodwater or anthropogenic deposition (Olde Venterink et al 2003, 2009). Secondly, the availability of P can be reduced due to precipitation by calcium (Ca) ions or iron (Fe) hydroxides, the latter mechanisms being enhanced by higher redox potential .…”

Biomass production of the last remaining fen with Saxifraga hirculus in Switzerland is controlled by nitrogen availability

“…A second subsample was extracted with 0.5 M HCl and analysed on K concentrations, using atomic absorption spectrometry (Hunt 1982) (SPECTRAA 240 FS,Varian AG,Zug,Switzerland). We used the critical values of Olde Venterink et al (2003) to determine the type of nutrient limitation, i.e. : N-limitation if N:P < 14.5 and N:K < 2.1; P-or N&P co-limitation if N:P > 14.5 and K:P > 3.4; K-or N&K colimitation if N:K > 2.1 and K:P < 3.4.…”

“…Olde Venterink et al (2003) and Wassen et al (2005) analysed the occurrence of endangered species at a large number of sites in herbaceous grasslands and wetlands along a N-deposition gradient in Eurasia (The Netherlands, Belgium, Poland, Siberia). They observed that many endangered species persisted better at sites where P was growth-limiting than at sites where N was limiting, and concluded that P enrichment has been at least as important as N enrichment for species loss in these ecosystems.…”