Elevational diversity of terrestrial rainforest herbs: when the whole is less than the sum of its parts

We studied the species richness of herbaceous terrestrial plant species along an elevational gradient at 250-2425m a.s.l. in evergreen tropical forest in Central Sulawesi, Indonesia. We recorded 302 species belonging to 51 families. Ferns and lycophytes contributed 62% of the species, followed by monocots with 24% and dicots with 14%. Overall herb species richness did not show any particular relation with elevation, while the richness of ferns increased significantly with elevation, monocots did not show a pattern, and dicots showed a hump-shaped pattern with maximum richness at 1800m. These patterns in turn were only partly reflected in the patterns of the individual plant families making up each group. The independence of different taxa was also reflected in their relationships to environmental factors (temperature, precipitation, and area): although, each single family was related to one or several factors, at the group level and at the overall level these trends were lost. These results show that interpreting diversity at higher taxonomic level may overlook important information at the family level and raises the biologically intriguing question whether overall patterns of diversity result from a random accumulation of group-specific patterns or if there is some interaction between groups (e.g., via competition and niche-pre-emption

Responses of terrestrial herb assemblages to weeding and fertilization in cacao agroforests in Indonesia

Terrestrial herbs are important ecological components in tropical agroforests, but little is known about how they are affected by agricultural management. In cacao agroforests of Central Sulawesi, Indonesia, we studied the change in herb species richness, cover, and biomass over 3years in 86 subplots subjected to high and low weeding frequency as well as fertilized and non-fertilized treatments. We recorded 111 species with rapid changes in species composition between the 3years. Species richness increased sharply in the 2nd year, presumably as a result of changes in the management with the experimental regimes, and decreased in the 3rd, probably due to competitive exclusion. Species richness, cover, and biomass were all significantly higher in the infrequently weeded plots than in the frequently weeded ones, but there were only slight responses to the fertilization treatment. An indicator species analysis recovered 45 species that were typical for a given year and a further eight that were typical for certain treatments, but these species showed no clear patterns relative to their ecology or biogeography. We conclude that the herb assemblages in cacao agroforests are quite resilient against weeding, but that the cover of species shifts rapidly in response to managemen

Influence of spatial and environmental variables on rattan palm (Arecaceae) assemblage composition in Central Sulawesi, Indonesia

Rattan palms are dominant elements of Southeast Asian rainforests and of high economic importance, yet little is known about the ecological factors determining the spatial distribution of species and assemblages. We studied rattan palm assemblages at two sites at different elevations in Lore Lindu National Park, Sulawesi, Indonesia (Pono: 958–1,266 m; Bariri: 1,390–1,507 m). At each site, we established a transect of 1.29 km consisting of 65 study plots of 10 × 10 m2 each, regularly spaced 20 m from each other. In total, we recorded 5,081 rattan individuals belonging to 22 species, with 1,367 individuals of 16 species at Pono and 3,714 individuals of 8 species at Bariri. Variance partitioning explained 29–49 % of community variation at Pono and 40–72 % at Bariri, with most variation jointly explained by spatial and environmental variables. Within the environmental influence, soil factors dominated over local topographical ones. RDA ordination allowed the discrimination of four species groups at Pono and three groups at Bariri. These groups were related to soil and less clearly to topographic variables. Our study is the first documentation of the importance of soil parameters in determining the spatial distribution of rattan palms. Interestingly, juvenile palms (1 m tall), calling for further studies on the demography of rattan palms

A transcontinental comparison of the diversity and composition of tropical forest understory herb assemblages

Although tropical forests are renowned for their high plant diversity, to date there has been no global quantitative evaluation of the local species richness of terrestrial forest herbs in tropical forests. In this paper, richness and composition of terrestrial herb assemblages is compared in tropical forests of America, Africa and South East Asia. We established 86 non-continuous transects of 445m each. Herb species richness was analysed and compared to six environmental parameters using minimal adequate regression models and simultaneous autoregressive models. At the global scale, we found a close relationship between herb species richness and temperature parameters, with no differences between continents. The subdivision into three main taxonomic groups (ferns, monocots, dicots) showed that each group has distinct relations to environmental factors and differences in richness between continents. Most of the 72 families found have pantropical distributions but 12, 11, and 16 families were significantly over-represented in America, Africa, and Asia, respectively. Although total species richness was closely related to climatic factors, ferns, monocots and dicots were represented by distinct sets of families with varying species richness on each continent. Which species are found at a given site may thus reflect group-specific evolutionary and historical factor

A transcontinental comparison of the diversity and composition of tropical forest understory herb assemblages

Although tropical forests are renowned for their high plant diversity, to date there has been no global quantitative evaluation of the local species richness of terrestrial forest herbs in tropical forests. In this paper, richness and composition of terrestrial herb assemblages is compared in tropical forests of America, Africa and South East Asia. We established 86 non-continuous transects of 445 m each. Herb species richness was analysed and compared to six environmental parameters using minimal adequate regression models and simultaneous autoregressive models. At the global scale, we found a close relationship between herb species richness and temperature parameters, with no differences between continents. The subdivision into three main taxonomic groups (ferns, monocots, dicots) showed that each group has distinct relations to environmental factors and differences in richness between continents. Most of the 72 families found have pantropical distributions but 12, 11, and 16 families were significantly over-represented in America, Africa, and Asia, respectively. Although total species richness was closely related to climatic factors, ferns, monocots and dicots were represented by distinct sets of families with varying species richness on each continent. Which species are found at a given site may thus reflect group-specific evolutionary and historical factors

Lindsea linduensis D. Cicuzza & M. Kessler 2012, sp. nov.

Lindsea linduensis D.Cicuzza & M.Kessler, sp. nov. (Fig. 1). Type: — INDONESIA. Sulawesi: Central Sulawesi, at the border of the Lore Lindu National Park, Nokilalaki Mountain, Kulawi valley, 1200 m, 01°14'30.483" S, 120°09'19.828" E, 16 March 2008, Cicuzza 891 (holotype Z!, isotypes UC!, BO!, CEB!, GOET!). Differs from Lindsaea repens var. sessilis by having 2-pinnate fronds (versus 1-pinnate), longer petioles (10–17 cm versus 1–5 cm), and more widely spaced ultimate segments (> 5 mm apart versus 5 mm apart versus <4 mm). Following the keys of Kramer (1971), Lindsaea linduensis falls into group G (subg. Odontoloma Kunth). The specimen of L. linduensis keys out to the couplet containing L. rigida and L. regularis. From these, Lindsaea linduensis differs by having less strongly creeping rhizomes, fewer pinna pairs (1 in L. linduensis, 1–7 in L. rigida, 3–9 in L. regularis), and more sori per pinnule (7–8 in L. linduensis, 1–4 in L. rigida, 3–5 in L. regularis).Published as part of Cicuzza, Daniele & Kessler, Michael, 2012, Lindsaea linduensis (Lindsaeaceae, Polypodiales), a new fern species from Sulawesi, Indonesia, pp. 36-40 in Phytotaxa 65 (1) on pages 37-39, DOI: 10.11646/phytotaxa.65.1.4, http://zenodo.org/record/506209

Soil, Topography and Forest Structure Shape the Abundance, Richness and Composition of Fern Species in the Fragmented Tropical Landscape of Xishuangbanna, Yunnan, China

Understanding how forest fragment size, topography, forest structure, and soil properties affect plant diversity remains a crucial question in conservation biology, with ferns often being understudied. To address this knowledge gap, we surveyed the abundance, species richness, and composition of ferns in a tropical landscape in south China using 75 sites in 42 forest fragments. We then used a multi-model inference approach to assess whether fern abundance, richness, and composition were better explained by (a) fragment size, (b) topography (slope, aspect), (c) forest structure (tree basal area, light availability), or (d) soil properties (pH, Carbon, Nitrogen, Phosphorous, Calcium, Magnesium, water availability, and proportion of clay, silt, and sand). We also conducted a nestedness analysis to examine whether the composition of the fern communities in smaller fragments (0.4&ndash;1 km&sup2;) differed or represented a subset of the communities found in larger fragments (e.g., &gt;10 km&sup2;). We found that (a) fern abundance was mostly influenced by soil properties, slope, and aspect, (b) fern species richness by soil properties and slope, and (c) fern species composition by forest structure, specifically, tree basal area. We also found that fern species composition was not nested in the landscape, suggesting that smaller forest fragments had different communities from larger fragments. Our results suggest also that soil properties play an important role in maintaining fern abundance and diversity and therefore protecting soil can help conserve ferns in fragmented landscapes

Lindsaea linduensis (Lindsaeaceae, Polypodiales), a new fern species from Sulawesi, Indoensia

Cicuzza, Daniele, Kessler, Michael (2012): Lindsaea linduensis (Lindsaeaceae, Polypodiales), a new fern species from Sulawesi, Indonesia. Phytotaxa 65 (1): 36-40, DOI: 10.11646/phytotaxa.65.1.4, URL: http://biotaxa.org/Phytotaxa/article/view/phytotaxa.65.1.