Geographical and environmental gradients of lianas and vines in China

Abstract

Aim Climbing plants are characterized by long, wide vessel elements, which may be vulnerable to cold-or drought-induced embolism. However, the difference in vulnerability between lianas (woody climbing plants) and vines (herbaceous climbing plants) has not yet been reported. Here we hypothesize that both lianas and vines are more sensitive to variations in water and temperature than are self-supporting plants.Consequently, the proportions of lianas and vines in flora are expected to decline significantly along geographical and environmental gradients. Location China.Methods A unique dataset describing 82 floras in China was examined. The proportion of lianas in the flora (LPF) and the proportion of vines in the flora (VPF) were calculated independently. The proportion of the climbing plants in total spermatophyte flora (CPF) was also calculated. LPF and VPF were compared along latitudinal, mean annual rainfall (Rain), and mean January temperature (T1) gradients. Local linear regression analyses showed the changing tendencies of LPF and VPF. Prediction models of LPF using geographical and environmental factors were studied in some subranges. Results(1) LPF was highest in the tropics (13.8% on average), decreased linearly with increasing latitude within the latitude < 42°N subrange, and reached < 1% north of 42°N in China. VPF fluctuated slightly from tropical (4.7%), to subtropical (4.2%) to warm temperate (4.5%) regions, but declined significantly in temperate (3.2%) and dry (1.5%) zones in China. (2) LPF decreased significantly with decreasing rainfall, and decreased significantly with decreasing T1 in areas where T1 > -10°C. In contrast, VPF tended to be constant in areas where T1 > -5°C or Rain > 1000 mm, and declined under extreme water or temperature stresses. (3) Predictions of LPF using Rain and T1 in areas where T1 > -10°C, and using latitude and altitude within the latitude < 42°N subrange were both reliable. According to the geographical model for LPF and a constant VPF, tropical Asian forests would have a LPF as high as 25.4% and the highest CPF would be c. 30%. ConclusionsWe conclude that liana diversity is more sensitive to temperature and water availability than that of vines and other plants. Geographical and environmental gradients affected LPF but not VPF. Shorter life spans and underground nutrient storage may be effective strategies adopted by vines to avoid drought and cold stresses.

Diversity and community composition of euglossine bee assemblages (Hymenoptera: Apidae) in western Amazonia

“…Species richness and individual numbers per site were strongly correlated, and the regression analyses recovered very similar suites of environmental variables. The latitudinal decline of species richness and it's relationship to climatic factors parallel the situation in many other plant and animal groups (Wiens et al 2006;Hawkins and De Vries 2009;Hu et al 2010). The causes for this decline are still unknown, and may involve either the carrying capacity of ecosystems as determined by water availability and temperature (Hawkins et al 2003), or historical and evolutionary causes (Wiens and Donoghue 2004).…”

The differential responses of lianas and vines to rainfall gradients in distribution and abundance in Qinling Mountains, China

“…Vines and lianas responded differently to water availability. Lianas are considered to be more vulnerable to drought than vines and other plant forms because the wide and long vessels easily become nonconductive due to drought-induced embolism (Salleo and Lo Gullo 1986;Ewers et al 1990Ewers et al , 1991Hu et al 2010). Although the below ground storage tissues of climbers may help them withstand diurnal drought, these may not be effective during extended drought (Rundel and Franklin 1991).…”

“…Hu et al (2010) investigated the changes of lianas and vines along the macro rainfall gradients across China and found that the proportion of lianas in the flora increased significantly with increasing rainfall (100-2,500 mm). In comparison, vine growth remained constant when rainfall exceeded 700 mm, but increased significantly with increasing rainfall when rainfall was less than 700 mm.…”

“…Cold intolerance is a strong control on the global distribution of lianas (Gentry 1991;Jimenez-Castillo et al 2007;Hu et al 2010). The freezing weather will also induce embolisms in the wide and vessel elements of lianas, which limit the distribution of climbing plants under extreme temperature conditions (Ewers et al 1991;Schnitzer 2005).…”

“…Therefore, comparative studies of lianas and vines may have important ecological implications. Hu et al (2010) examined the percentage of climbers in the total flora across China along major macro-geographical and environmental gradients and found that lianas and vines changed differently with respect to latitude, rainfall, and temperature. To test whether there are different responses in abundance and richness to rainfall gradients between lianas and vines, a survey of lianas and vines was specifically conducted along the rainfall gradient in the Qinling Mountains of China.…”