Treesearch

Peatlands are important players in climate change–biosphere feedbacks via long-termnet carbon (C) accumulation in soil organic matter and as potential net C sources including the potent greenhouse gas methane (CH4). Interactions of climate, site-hydrology, plant community, and groundwater chemical factors influence peatland development and functioning, including C dioxide (CO2) and CH4 fluxes, but the role of microbial community composition is not well understood. To assess microbial functional and taxonomic dissimilarities, we used high throughput sequencing of the small subunit ribosomal...

Most plant diversity in temperate deciduous forests is found in the ground layer, but nearly all studies comparing plant community assembly using taxonomic, trait, and phylogenetic diversity indices are limited to woody plants. To examine the relationship between short-term ground-layer plant community assembly and disturbance severity, we leveraged a silvicultural experiment that applied a combination of harvest and site preparation treatments in a northern hardwood forest in Michigan, USA. We predicted that after two growing seasons, plant communities would be less sensitive to harvest...

Many tropical mountain peatlands in the Andes are formed by cushion plants. These unique cushion plant peatlands are intensively utilized for grazing and are also influenced by climate change, both of which alter hydrologic conditions. Little is known about the natural hydroperiods and greenhouse gas fluxes of these peatlands or the consequences of hydrologic alteration for these fluxes. Therefore, our objectives were to assess how carbon dioxide (CO2) and methane (CH4) fluxes varied across a hydrological gradient caused by ditching and evaluate how shortterm carbon cycling responds after...

The Fisher (Pekania pennanti) is a mesocarnivore of conservation concern in the Pacific coastal region of North America with a diverse but poorly understood diet. From 1995 to 2001, we collected 297 scats from 11 radio-collared females and 83 scats from 8 radio-collared males, and used frequency of occurrence (percentage of scats containing a particular food item) to investigate their diets. Mammals were the most frequently occurring food item in the diets of both female and male Fishers (84.8 and 77.1 % of scats, respectively); however, the prevalence of small (≤166 g) mammalian prey was...

This research expands the applicability of the Feasible Goals (FGoal) Pareto frontier multiple criteria method to display the Edgeworth–Pareto hull using interactive decision maps (IDMs). Emphasis is placed upon the development of a communication architecture to display the Pareto frontiers, which includes a client device, a web server, and a dedicated computation server implemented with sockets. A standalone application on the latter processes client-server requests and responses to display updated information on the client. Specifically, the dedicated computation server is responsible...

Multiple restoration actions have been implemented in response to declining salmon populations. Among these is the addition of salmon carcasses or artificial nutrients to mimic marine-derived nutrients historically provided by large spawning runs of salmon. A key assumption in this approach is that increased nutrients will catalyze salmon population growth. Although effects on aquatic ecosystems have been observed during treatments, it is unclear whether permanent population increases for salmon will occur. To test this assumption and address associated uncertainties, we linked a food web...

The mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), is a major tree-killing bark beetle that attacks primarily ponderosa pine, Pinus ponderosa Lawson & C. Lawson, and lodgepole pine, Pinus contorta Douglas ex Loudon (Pinaceae), among other pines, across the western coniferous forests of North America (Negron and Fettig 2014). A continental-scale outbreak of MPB occurred from the late 1990s through the mid- to late 2010s, ranging from the southern Rockies north to British Columbia (Jarvis and Kulakowski 2015; Negron and Fettig 2014). In...

Asymmetric warming was bound to have a major impact on terrestrial ecosystems in arid regions during global warming. Further study was necessary to reveal the spatiotemporal patterns of asymmetric warming in Xinjiang; this study analyzed the climate and normalized difference vegetation index (NDVI) data (2000–2020). The change trends of the day and nighttime warming (DNW), seasonal warming, and the diurnal temperature range in northern Xinjiang (S1) and southern Xinjiang (S2) were determined. The findings indicated that the DNW rate showed a significant (p < 0.05) upward trend, especially...

Forest vegetation management can improve planted seedling survival and growth and is thus widely used in plantation silviculture. In some jurisdictions, mechanical release using brushsaws has replaced the traditional use of chemical herbicides for forest vegetation management purposes. However, its associated costs and the increasing difficulty of finding qualified labor represent a challenge. The browsing of competition by large herbivores may represent an alternative to mechanical release when planted seedlings are resistant to browsing. Here, we compare the efficacy of moose browsing...