Discovery of coprolites in an Early Permian fern mesophyll

Plants and arthropods interact with each other and constitute an important part of the modern terrestrial ecosystem (Schoonhoven et al., 2005). Historically, fossil records of plant-arthropod interactions have been well documented in Paleozoic terrestrial ecosystems, which were evidenced by large coprolites containing various plant fragments (e.g., Salter et al., 2012), small larvae and coprolites remained in plant organs (e.g., Feng et al., 2017), and diverse functional feeding groups discovered on plant stems, rachises, roots, leaves and fertile organs (e.g., Liu et al., 2020).

Functional Feeding Groups of Macrofauna and Detritus Decomposition along a Gradient of Glacial Meltwater Influence in Tropical High-Andean Streams

Tropical Andean glaciers are retreating rapidly, with possible consequences for trophic structure and ecosystem processes in high Andean meltwater streams. Here, we measured the environmental characteristics, quantified pools of particulate organic matter (POM) and periphyton (Chl. a), sampled benthic macroinvertebrates, determined functional feeding groups (FFG), and performed mesh bag decomposition experiments with Calamagrostis grass detritus at 17 stream sites along a gradient of glacial influence (GI) with 0–23% glacier cover in the catchment at 4050–4200 m a.s.l. in the Andes of Ecuador. POM was unrelated to GI while Chl. a. showed a weak (non-significant) negative relationship to GI. The macrofauna abundance decreased while taxon richness and the number of FFGs per site showed a hump-shaped relationship with increasing GI. Taxa with an opportunistic and generalist feeding mode generally dominated benthic assemblages and were related to high GI levels and low Chl. a. Only shredders were negatively related to GI, but unrelated to POM. Decomposition rates were comparable to those found in temperate alpine streams, and for both fine (0.0010–0.0065; median 0.0028 d−1) and coarse (0.0019–0.0088; median 0.0048 d−1) mesh bags, peaked at intermediate GI values, while the difference between bag types was small and almost constant along the GI gradient. This indicates an overall minor effect of macroinvertebrate shredders compared to that of microbes, in particular at high GI. It also suggests that the relatively high average temperature of these high-altitude equatorial streams (7–10 °C) does not produce higher decomposition rates than those in comparable but colder streams at temperate latitudes. The results suggest that, at the lower end of glacier cover, tropical glacier loss will not change the dominant microbial role in detritus decomposition, but that part of the physical abrasion could be partially replaced by biological shredding.

Abundance- and biomass-based metrics of functional composition of macroinvertebrate as surrogates of ecosystem attributes in Afrotropical streams

The composition of macroinvertebrate functional feeding groups (FFGs) has been used as surrogates of ecosystem attributes in aquatic ecosystems but studies that utilize such knowledge are still limited in the tropics. This study investigated the suitability of abundance- vs. biomass-based metrics of macroinvertebrate FFGs as surrogates of ecosystems attributes of the Sosiani-Kipkaren River in western Kenya. Macroinvertebrates were sampled in wet and dry seasons, classified into five FFGs and used to derive five metrics that are surrogates of ecosystem attributes; 1) a balance between autotrophy and heterotrophy, 2) linkage between riparian inputs of coarse particulate organic matter (CPOM) and fine particulate organic matter (FPOM), 3) top-down predator control, 4) geomorphic channel stability, and 5) relative dominance of fine particulate organic matter (FPOM) in transport compared to FPOM deposited in the sediments. Taxon richness, abundance and biomass of shredders were higher in forested sites, scrapers were numerically dominant in mid-order streams, whereas collectors dominated agricultural and urban sites. Abundance-based metrics were better predictors of ecosystem attributes and displayed a greater response to changes in stream size than biomass-based metrics. Moreover, there was incongruence between abundance- and biomass-based indicators for P/R and CPOM/ FPOM. Catchment land use did not influence metric performance, suggesting that reach scale influences played a predominant role in structuring communities and determining ecosystem functioning. Although the use of FFGs as indicators of ecosystem integrity and functioning in this river show promise, the lack of agreement between abundance- and biomass-based measures suggests that more studies are needed to refine the metrics used.

Changes of community structure and functional feeding groups of benthic macrofauna after mangrove afforestation in a subtropical intertidal zone, China

Afforestation is a primary response to the loss and degradation of mangroves worldwide. The successful restoration of mangrove ecosystems is in part indicated by the rebuilding of macrobenthic community. However, the community dynamic of benthic macrofauna after mangrove afforestation was poorly known. Here, three quarterly surveys (2006–2007, 2014–2015, 2019–2020) of the benthic macrofauna and sediment grain size were conducted in a mix-planted mangrove stand (Kandelia obovata + Sonneratia apetala) in Xiamen Tong'an Bay, China. Our results showed that the community structure of benthic macrofauna differed significantly after mangrove afforestation. These differences were accompanied by the declines in the species number, abundance, biomass, and diversity (H'), as well as the fining of sediments. We also found that the epifauna and infauna exhibited different adaptabilities to mangrove vegetation. Additionally, shifts in the composition of the functional feeding groups were observed, indicating the modification of trophic structure after mangrove afforestation. We recommend that future mangrove afforestation programs call for a guide to coordinate habitats for different taxa.

Spatial Variations in the Distribution of Benthic Macroinvertebrate Functional Feeding Groups in Tropical Rivers

Functional feeding group (FFG) is an approach that classifies macroinvertebrates based on their utilization of organic matter food resources. Across streams and rivers, variations in the distribution of FFGs reflect the unequal distribution of food resources, which are affected by varying environmental conditions and disturbances to the ecosystem. In the tropics, the distribution of FFGs does not follow the pattern observed in temperate streams. This study aims to (1) determine the FFGs present in selected Philippine tropical streams, (2) assess the variations in FFG distributions and how the distributions vary across space, and (3) evaluate how FFG distributions are affected by certain environmental factors and habitat structure. Benthic macroinvertebrates were collected in 2010 from five sites and assigned to their primary FFG based on published literature. Across study sites, the macroinvertebrates collected were classified into gathering collectors (total n = 4,640), scrapers (n = 1,670), filtering collectors (n = 1,545), predators (n = 632), and shredders (n = 270). Within and between sites, these FFGs varied significantly. Variations explained the upstream-downstream and north-south variations in the mean of FFG abundance in width and depth of the stream, discharge, temperature, pH, riparian vegetation, and habitat stability and variability. This study reveals that the FFG approach is a useful bioassessment tool in tropical aquatic systems. However, there is still a need for verification of the findings in other streams and seasons.

Variations in Benthic Macroinvertebrate Communities and Biological Quality in the Aguarico and Coca River Basins in the Ecuadorian Amazon

Adequate environmental management in tropical aquatic ecosystems is imperative. Given the lack of knowledge about functional diversity and bioassessment programs, management is missing the needed evidence on pollution and its effect on biodiversity and functional ecology. Therefore, we investigated the composition and distribution of the macroinvertebrate community along two rivers. Specifically, 15 locations were sampled in the Coca and Aguarico Rivers (Ecuadorian Amazon) and the macroinvertebrates were used to indicate water quality (WQ), expressed as the Biological Monitoring Working Party Colombia (BMWP-Col) classes. Results indicate that elevation, pH, temperature, width, and water depth played an important role in the taxa and functional feeding groups (FFG) composition. The results show that diversity of taxa and FFG were generally scarce but were more abundant in good quality sites. Collector-gathers (CG) were, in general, dominant and were particularly abundant at low WQ and downstream sites. Scrapers (SC) were the second most abundant group, dominating mostly at good WQ and upstream sites. Predators (PR) were homogeneously distributed among the sites, without clear dominance, and their abundance was slightly higher in sites with medium-low WQ and downstream sites. Lastly, both shredders (SH) and collector-filterers (CF) were almost absent and were more abundant in good quality sites. The findings of this research can be used as baseline information in the studied region since a dam was constructed two years after the sampling campaign, which has been operating since. Furthermore, the results can be used to fill the knowledge gaps related to the bioassessments of other similar systems, particularly for a tropical rainforest.

Florivory of Early Cretaceous flowers by functionally diverse insects: implications for early angiosperm pollination

Florivory (flower consumption) occurs worldwide in modern angiosperms, associated with pollen and nectar consumption. However, florivory remains unrecorded from fossil flowers since their Early Cretaceous appearance. We test hypotheses that earliest angiosperms were pollinated by a diverse insect fauna by evaluating 7858 plants from eight localities of the latest Albian Dakota Formation from midcontinental North America, in which 645 specimens (8.2%) were flowers or inflorescences. Well-preserved specimens were categorized into 32 morphotypes, nine of which displayed 207 instances of damage from 11 insect damage types (DTs) by four functional-feeding groups of hole feeding, margin feeding, surface feeding and piercing-and-sucking. We assessed the same DTs inflicted by known florivores on modern flowers that also are their pollinators, and associated insect mouthpart types causing such damage. The diverse, Dakota florivore–pollinator community showed a local pattern at Braun's Ranch of flower morphotypes 4 and 5 having piercing-and-sucking as dominant and margin feeding as minor interactions, whereas Dakotanthus cordiformis at Rose Creek I and II had an opposite pattern. We found no evidence for nectar robbing. These data support the rapid emergence of early angiosperms of florivore and associated pollinator guilds expressed at both the local and regional community levels.