Treesearch

Vegetation response to climate change can be characterized as long-term trends, but with periodic oscillations. Revealing vegetation response trends, with oscillations, is essential for formulating climate change mitigation and adaptation planning, as well as adopting ecological protection and restoration measures. Here, the long-term trend and periodic oscillations in vegetation changes were explored through a measure of gross primary production (GPP), an indicator of vegetation photosynthesis, using data of both high spatial resolution (1 km2) and a long-term of nearly 4 decades, from...

The alpine grasslands of the Qinghai-Tibetan Plateau play an important role in multiple ecosystem functions, all of which are key in regulating regional climate influences and providing pristine headwaters for millions of people downstream from this basin. Alpine grasslands act as a carbon sink, storing carbon dioxide and keeping heat-trapping greenhouse gases out of the atmosphere, but it is not clear how this will change in a warming climate in the future. In this paper, the net ecosystem productivity (NEP) of alpine grasslands in Qinghai province, on the Qinghai-Tibetan Plateau, was...

Plant survival depends on a balance between carbon supply and demand. When carbon supply becomes limited, plants buffer demand by using stored carbohydrates (sugar and starch). During drought, NSCs (non-structural carbohydrates) may accumulate if growth stops before photosynthesis. This expectation is pervasive, yet few studies have combined simultaneous measurements of drought, photosynthesis, growth, and carbon storage to test this. Using a field experiment with mature trees in a semi-arid woodland, we show that growth and photosynthesis slow in parallel as ψpd declines, preventing...

Land managers rely heavily on herbicides to mitigate exotic plant invasions but the nontarget effects of herbicides on treated plant, animal, and soil communities are often overlooked. Biological soil crusts (biocrusts) are important components of ecosystems yet the effects of different herbicides on biocrusts are rarely considered. We tested the impact of three widely used herbicides, indaziflam, imazapic, aminocyclopyrachlor, and chlorsulfuron, two of which were applied with or without a surfactant, on biocrusts dominated by mosses or lichens in intermountain grasslands. We found that...

The Paraclius arcuatus species-group is reviewed and includes the following seven species: P. angusticauda Van Duzee, 1933, P. angustipennis Van Duzee, 1929, P. arcuatus (Loew, 1861), P. brooksi sp. nov., P. elongatus Van Duzee, 1930, P. pumilio Loew, 1872, and P. xibun sp. nov. Paraclius angustipennis, P. arcuatus and P. pumilio are redescribed based on photographs of types and additional specimens. Paraclius femoratus Aldrich, 1901 is synonymized with P. arcuatus, syn. nov. and Paraclius magnicornis Van Duzee, 1927 is regarded as a junior synonym of P. pumilio, syn. nov. An identification...

Categorization of soil organic carbon (SOC) into different functional subpools according to their recalcitrance and protective mechanisms helps better understand ecosystems organic carbon (OC) dynamics, and various attempts have been made to explore the suitable experimental fractionation method for such purpose. However, most previous studies neglected the influences of environmental factors on the effectiveness of varying fractionation methods. Density fractionation has shown great promise in elucidating SOC immobilization mechanisms. Here, we compared three varying types of density...

This article is a Commentary on Marshall et al. (2023), 239: 2166-2179. Both eddy covariance (EC) and ground-based (biometric) estimates of carbon (C) stocks and fluxes are used to understand current stocks and fluxes of C, their future trajectories, and responses to changing climates. EC measures C fluxes by quantifying the covariance between fluctuations in vertical wind velocity and CO2 concentrations (Baldocchi, 2003). EC measurements are continuous over a large area (c. 0.5km2 ), nondestructive, use a more standardized methodology, and are made at hundreds of locations across different...

Visibility analyses, used in many disciplines, rely on viewshed algorithms that map locations visible to an observer based on a given surface model. Mapping continuous visibility over broad extents is uncommon due to extreme computational expense. This study introduces a novel method for spatially-exhaustive visibility mapping using airborne lidar and random forests that requires only a sparse sample of viewsheds. In 24 topographically and vegetatively diverse landscapes across the contiguous US, 1000 random point viewsheds were generated at four different observation radii (125 m, 250 m,...

Understanding interactions between environmental stress and genetic variation is crucial to predict the adaptive capacity of species to climate change. Leaf temperature is both a driver and a responsive indicator of plant physiological response to thermal stress, and methods to monitor it are needed. Foliar temperatures vary across leaf to canopy scales and are influenced by genetic factors, challenging efforts to map and model this critical variable. Thermal imagery collected using unoccupied aerial systems (UAS) offers an innovative way to measure thermal variation in plants across...

The past 100 years of empirical research in ecology have generated tremendous knowledge about the component interactions that structure ecological communities. Yet, we still lack the ability to reassemble these puzzle pieces to predict community responses to perturbations, a challenge that grows increasingly urgent given rapid global change. We summarize key advances in community ecology that have set the stage for modeling ecological systems and briefly review the evolution of ecological modeling efforts to identify critical hurdles to progress. We find that while Robert May demonstrated...