scholarly journals Water availability limits tree productivity, carbon stocks, and carbon residence time in mature forests across the western US

2017 ◽  
Vol 14 (2) ◽  
pp. 365-378 ◽  
Author(s):  
Logan T. Berner ◽  
Beverly E. Law ◽  
Tara W. Hudiburg
Keyword(s):  
Residence Time ◽  
Water Availability ◽  
Net Primary Productivity ◽  
Terrestrial Ecosystems ◽  
Structure And Function ◽  
Data Sets ◽  
Climate Data ◽  
Moisture Index ◽  
Western Us ◽  
And Function

Abstract. Water availability constrains the structure and function of terrestrial ecosystems and is projected to change in many parts of the world over the coming century. We quantified the response of tree net primary productivity (NPP), live biomass (BIO), and mean carbon residence time (CRT = BIO / NPP) to spatial variation in water availability in the western US. We used forest inventory measurements from 1953 mature stands (> 100 years) in Washington, Oregon, and California (WAORCA) along with satellite and climate data sets covering the western US. We summarized forest structure and function in both domains along a 400 cm yr−1 hydrologic gradient, quantified with a climate moisture index (CMI) based on the difference between precipitation and reference evapotranspiration summed over the water year (October–September) and then averaged annually from 1985 to 2014 (CMIwy). Median NPP, BIO, and CRT computed at 10 cm yr−1 intervals along the CMIwy gradient increased monotonically with increasing CMIwy across both WAORCA (rs = 0.93–0.96, p < 0.001) and the western US (rs = 0.93–0.99, p < 0.001). Field measurements from WAORCA showed that median NPP increased from 2.2 to 5.6 Mg C ha−1 yr−1 between the driest and wettest 5 % of sites, while BIO increased from 26 to 281 Mg C ha−1 and CRT increased from 11 to 49 years. The satellite data sets revealed similar changes over the western US, though these data sets tended to plateau in the wettest areas, suggesting that additional efforts are needed to better quantify NPP and BIO from satellites in high-productivity, high-biomass forests. Our results illustrate that long-term average water availability is a key environmental constraint on tree productivity, carbon storage, and carbon residence time in mature forests across the western US, underscoring the need to assess potential ecosystem response to projected warming and drying over the coming century.

scholarly journals Water availability limits tree productivity, carbon stocks, and carbon residence time in mature forests across the western United States

2016 ◽  
Author(s):  
Logan T. Berner ◽  
Beverly E. Law ◽  
Tara W. Hudiburg
Keyword(s):  
Residence Time ◽  
Water Availability ◽  
Net Primary Productivity ◽  
Terrestrial Ecosystems ◽  
Data Sets ◽  
Climate Data ◽  
Moisture Index ◽  
Western Us ◽  
The Difference ◽  
And Function

Abstract. Much of the western US is projected to become warmer and drier over the coming century, underscoring the need to understand how climate influences terrestrial ecosystems in this region. We quantified the response of tree net primary productivity (NPP), live biomass (BIO), and mean carbon residence time (CRT = BIO/NPP) to spatial variation in climatic water availability in the western US. We used forest inventory measurements from 1,953 mature stands (≥ 100 years) in Washington, Oregon, and California (WAORCA) along with satellite and climate data sets covering the western US. We summarized forest structure and function in both domains along a 400 cm yr−1 hydrologic gradient, quantified with a climate moisture index based on the difference between precipitation and reference evapotranspiration summed from October-September (i.e., water-year) and then averaged annually from 1985–2014 (CMIwy). Median NPP, BIO, and CRT computed at 10 cm yr−1 intervals along the CMIwy gradient increased monotonically with increasing CMIwy across both WAORCA (rs = 0.93–0.96, p 

Distribution of arbuscular mycorrhizae in relation to microsites on primary successional substrates on Mount St. Helens

2007 ◽  
Vol 85 (10) ◽  
pp. 941-948 ◽  
Author(s):  
Jonathan H. Titus ◽  
Sean Whitcomb ◽  
Hillary Joy Pitoniak
Keyword(s):  
Primary Succession ◽  
Arbuscular Mycorrhizae ◽  
Terrestrial Ecosystems ◽  
Structure And Function ◽  
Inoculum Potential ◽  
Plant Community Structure ◽  
Spore Trap ◽  
Mycorrhizal Inoculum Potential ◽  
And Function ◽  
Mount St Helens

Arbuscular mycorrhizae fungi (AMF) occur in most terrestrial ecosystems and are crucial to plant community structure and function. This study examined the distribution of AMF propagules, spores, and colonized plants across the Pumice Plain of Mount St. Helens 23 years after its eruption, documenting the changes since 1993. Propagules of AMF were detected by using the mycorrhizal inoculum potential assay in six microsite types across the Pumice Plain. Fifteen species of AMF were isolated from spore trap cultures, and spores were found in all of the microsites, although the distribution was aggregated. The vegetation of the Pumice Plain is currently composed primarily of facultatively mycotrophic species, which are predominantly associated with arbuscular mycorrhizae. Mycorrhizal colonization and propagule levels continue to increase as primary succession proceeds.

scholarly journals Global Overview of Ecosystem Services Provided by Riparian Vegetation

BioScience ◽  
2020 ◽  
Vol 70 (6) ◽  
pp. 501-514 ◽  
Author(s):  
Tenna Riis ◽  
Mary Kelly-Quinn ◽  
Francisca C Aguiar ◽  
Paraskevi Manolaki ◽  
Daniel Bruno ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Riparian Vegetation ◽  
Anthropogenic Activities ◽  
Terrestrial Ecosystems ◽  
Structure And Function ◽  
Global Perspective ◽  
Vegetation Types ◽  
Broad Concept ◽  
And Function ◽  
Structured Approach

Abstract Fluvial riparian vegetation (RV) links fluvial and terrestrial ecosystems. It is under significant pressure from anthropogenic activities, and, therefore, the management and restoration of RV are increasingly important worldwide. RV has been investigated from different perspectives, so knowledge on its structure and function is widely distributed. An important step forward is to convert existing knowledge into an overview easily accessible—for example, for use in decision-making and management. We aim to provide an overview of ecosystem services provided by RV by adopting a structured approach to identify the ecosystem services, describe their characteristics, and rank the importance of each service. We evaluate each service within four main riparian vegetation types adopting a global perspective to derive a broad concept. Subsequently, we introduce a guided framework for use in RV management based on our structured approach. We also identify knowledge gaps and evaluate the opportunities an ecosystem service approach offers to RV management.

scholarly journals Assessment on spatial extent of arid and semi-arid climatic zones of India using GIS

2021 ◽  
Vol 23 (2) ◽  
pp. 189-193
Author(s):  
NISHA SAHU ◽  
G. P. OBI REDDY ◽  
B. DASH ◽  
NIRMAL KUMAR ◽  
S. K. SINGH
Keyword(s):  
Crop Production ◽  
Global Climate ◽  
Climatic Conditions ◽  
Spatial Extent ◽  
Data Sets ◽  
Climate Data ◽  
Moisture Index ◽  
Climatic Zones ◽  
Temporal And Spatial ◽  
Semi Arid

In this study, a quantitative assessment of spatial extent of arid and semi-arid climatic zones of India was performed for the period from 1988 to 2018 using potential evapo-transpiration (PET) calculated by Modified Penman Method, estimated from global climate data sets. Climatic water balances computed for 625 stations across the country are used for classifying to bio-climate types based on moisture index and areas falling under arid climatic zones in India are delineated using ArcGIS 10.5. It was noticed a considerable changes in the country’s arid and semi-arid climatic zones between the two periods; 1992 and 2018. Overall, there has been a net percent change in hyper arid, typic arid and semi arid (dry) areas is 5.62, 1.62 and 7.17 percent, respectively. Dryness and wetness are increasing in different parts of the country. There is also change in rainfall, PET and moisture index over a period of time which is vital to determine aridity pattern of any region. Thus, results are of great significance for studying the assessment of temporal and spatial dry climatic water balance of India, which can help immensely in the management of water resources and sustainability of crop production under changing climatic conditions.

scholarly journals The influence of soil age on ecosystem structure and function across biomes

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Manuel Delgado-Baquerizo ◽  
Peter B. Reich ◽  
Richard D. Bardgett ◽  
David J. Eldridge ◽  
Hans Lambers ◽  
...  
Keyword(s):  
Meta Analysis ◽  
Land Use Changes ◽  
Terrestrial Ecosystems ◽  
Environmental Context ◽  
Structure And Function ◽  
Parent Material ◽  
Ecosystem Structure ◽  
Ecosystem Properties ◽  
Soil Age ◽  
And Function

Abstract The importance of soil age as an ecosystem driver across biomes remains largely unresolved. By combining a cross-biome global field survey, including data for 32 soil, plant, and microbial properties in 16 soil chronosequences, with a global meta-analysis, we show that soil age is a significant ecosystem driver, but only accounts for a relatively small proportion of the cross-biome variation in multiple ecosystem properties. Parent material, climate, vegetation and topography predict, collectively, 24 times more variation in ecosystem properties than soil age alone. Soil age is an important local-scale ecosystem driver; however, environmental context, rather than soil age, determines the rates and trajectories of ecosystem development in structure and function across biomes. Our work provides insights into the natural history of terrestrial ecosystems. We propose that, regardless of soil age, changes in the environmental context, such as those associated with global climatic and land-use changes, will have important long-term impacts on the structure and function of terrestrial ecosystems across biomes.

Structure and function of neural networks in the retina

1988 ◽  
Vol 46 ◽  
pp. 26-27
Author(s):  
Peter Sterling
Keyword(s):  
Ganglion Cells ◽  
Three Dimensional ◽  
Structure And Function ◽  
Synaptic Connections ◽  
Visual Axis ◽  
One Dimensional ◽  
Cat Retina ◽  
Ultrathin Sections ◽  
And Function ◽  
Insight Into

The synaptic connections in cat retina that link photoreceptors to ganglion cells have been analyzed quantitatively. Our approach has been to prepare serial, ultrathin sections and photograph en montage at low magnification (˜2000X) in the electron microscope. Six series, 100-300 sections long, have been prepared over the last decade. They derive from different cats but always from the same region of retina, about one degree from the center of the visual axis. The material has been analyzed by reconstructing adjacent neurons in each array and then identifying systematically the synaptic connections between arrays. Most reconstructions were done manually by tracing the outlines of processes in successive sections onto acetate sheets aligned on a cartoonist's jig. The tracings were then digitized, stacked by computer, and printed with the hidden lines removed. The results have provided rather than the usual one-dimensional account of pathways, a three-dimensional account of circuits. From this has emerged insight into the functional architecture.

Osseointegration interface of calcified bone and endosseous implants

1992 ◽  
Vol 50 (2) ◽  
pp. 1096-1097
Author(s):  
K.E. Krizan ◽  
J.E. Laffoon ◽  
M.J. Buckley
Keyword(s):  
Structure And Function ◽  
Titanium Implants ◽  
En Bloc ◽  
Endosseous Implants ◽  
Ultrastructural Studies ◽  
The Past ◽  
Cacodylate Buffer ◽  
One Year ◽  
And Function

With increase use of tissue-integrated prostheses in recent years it is a goal to understand what is happening at the interface between haversion bone and bulk metal. This study uses electron microscopy (EM) techniques to establish parameters for osseointegration (structure and function between bone and nonload-carrying implants) in an animal model. In the past the interface has been evaluated extensively with light microscopy methods. Today researchers are using the EM for ultrastructural studies of the bone tissue and implant responses to an in vivo environment. Under general anesthesia nine adult mongrel dogs received three Brånemark (Nobelpharma) 3.75 × 7 mm titanium implants surgical placed in their left zygomatic arch. After a one year healing period the animals were injected with a routine bone marker (oxytetracycline), euthanized and perfused via aortic cannulation with 3% glutaraldehyde in 0.1M cacodylate buffer pH 7.2. Implants were retrieved en bloc, harvest radiographs made (Fig. 1), and routinely embedded in plastic. Tissue and implants were cut into 300 micron thick wafers, longitudinally to the implant with an Isomet saw and diamond wafering blade [Beuhler] until the center of the implant was reached.

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