The importance of climate in determining biodiversity patterns has been well documented. However, the relationship between climate and rates of genetic evolution remains controversial. Latitude and elevation have been associated with rates of change in genetic markers such as cytochrome b . What is not known, however, is the strength of such associations and whether patterns found among these genes apply across entire genomes. Here, using bumblebee genetic data from seven subgenera of Bombus , we demonstrate that all species occupying warmer elevations have undergone faster genome-wide evolution than those in the same subgenera occupying cooler elevations. Our findings point to a critical biogeographic role in the relative rates of whole species evolution, potentially influencing global biodiversity patterns.
Global patterns in ecology need to be identified and interpreted if macroecological processes are to be fully understood. Facilitating effects on seedlings such as that of nurse plants and competitive effects such as allelopathy have been well recognized but the importance of plants acting as killers through physical damage by the litterfall they produce has received relatively little attention. Here I examine latitudinal patterns of physical disturbance to seedlings (microdisturbance) due to litterfall and discuss the macroecological implications in light of current research. Analyses of results from published studies show that both the risk of litterfall disturbance, as measured using artificial model seedlings, and the proportion of seedling mortalities due to litterfall decrease significantly with increasing latitude. Patterns of microdisturbance appear to be driven by the dynamic interaction between macro-litterfall, safe sites with protective overhead vegetation, topography, and animal activity. However, we are informed on this subject by few studies. There is evidence, again from a limited number of studies, for considerable spatial heterogeneity in microdisturbance intensity and for seedling resilience to litterfall damage to differ substantially among species. Therefore, differential survival among microsites may produce regeneration niche diversity. However, more focused studies are required across a range of forest types and latitudes before these results can be generalized. Therefore, there is fertile ground for researchers to use comparable multifactorial methods to investigate the implications of microdisturbance at macro-ecological scales.
Non-technical summaryAs green spaces, lawns are often thought to capture carbon from the atmosphere. However, once mowing, fertlising, and irrigation are taken into account, we show that they become carbon sources, at least in the long run. Converting unused urban and rural lawn and grassland to treescapes can make a substantial contribution to reducing greenhouse gas emissions and increasing carbon absorption from the atmosphere. However, it is imperative for governing bodies to put in place appropriate policies and incentives in order to achieve this.Technical summaryMown grass or lawn is a ubiquitous form of vegetation in human dominated landscapes and it is often claimed to perform an ecosystem service by sequestering soil carbon. If lawn maintenance is included, however, we show that lawns become net carbon emitters. We estimate that globally, if one third of mown grass in cities was returned to treescapes, 310 to 1,630 million tonnes of carbon could be absorbed from the atmosphere, and up to 43 tonnes of carbon equivalent per hectare of emissions could be avoided over a two-decade time span. We therefore propose that local and central governments introduce policies to incentivise and/or regulate the conversion of underutilised grass into treescapes.
The upsurge in the development of RPAS technology for low altitude remote sensing and miniaturized sensors for enhanced imaging, have led to an increase in marine ecological applications. However, the ubiquity of RPAS with sensors in the visible electromagnetic spectrum may be limiting the applications of fine-scale mapping, monitoring, and identification of biogenic marine habitats along temperate intertidal rocky reefs. Here we used a low-cost RPAS coupled with a multispectral sensor (MicaSense® RedEdge™) and object-based image analysis (OBIA) workflow to produce very high-resolution maps of biogenic oyster reefs in Waitemata Harbour, Auckland, New Zealand. The results show that having spectral bands beyond the visible electromagnetic spectrum gradually enhances feature detection on the imagery and increases the potential to delineate targeted features within a heterogeneous marine ecosystem. Using a rule-based classification technique to extract target features, based on their spectral characteristics following segmentation, yielded an overall accuracy of 83.9% and a kappa coefficient of 69.8%.Spectral resolution improved for habitat mapping of oyster reefs with additional spectral bands. Highspatial scale monitoring and mapping of turbid exposed intertidal rocky reefs presents unique challenges, but these challenges can be mitigated by targeting flights during ideal meteorological and oceanographic conditions with RPAS.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.