James W. Raich

• Ph.D.
• Professor Emeritus at Iowa State University

Dataset guide for: Raich_Kaiser_Dornbush_Martin_Valverde-Barrantes_2022.csv Column 1: Row, integer values 1-8039, used for returning file to original sorted state, Column 2: Location, text, name of study location Column 3: Date, date of measurement, mm/dd/yyyy Column 4: Vegetation, text, dominant vegetation of study location Column 5: Land cover t...

Soil respiration is a major source of atmospheric CO2. If it increases with warming, it will counteract efforts to minimize climate change. To improve understanding of environmental controls over soil CO2 emission, we applied generalized linear modeling to a large dataset of in situ measurements of short-term soil respiration rate, with associated...

Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soil-toatmosphere CO2 flux, commonly though imprecisely termed soil respiration (RS), is one of the largest car...

Humid tropical forests are major players in the global carbon cycle, despite evidence that cations (rock-derived, positively charged ions) can limit or co-limit net primary productivity (NPP). In mature forests, tight cation cycling, i.e., without leaching losses, could maintain cation stocks on site. That mechanism does not explain how regeneratin...

This data set provides measurements of soil carbon dioxide (CO2) emission rates, soil moisture, relative humidity (RH), temperature, and litterfall from six types of tree plantations at the La Selva Biological Station, Costa Rica. Soil CO2 flux and related measurements were made 1) hourly during 2­day diel field campaigns and 2) as single daytime m...

The principal objective of this study was to determine if there is consistent temporal variability in soil respiration from different forest plantations in a lowland tropical rainforest environment. Soil respiration was measured regularly over 2004 to 2010 in replicated plantations of 15-to 20-year-old evergreen tropical trees in lowland Costa Rica...

Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15-20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root system...

Estimations of fine-root storage and dynamics have been lacking in most ecological studies in tropical forests, deterring proper quantification of productivity in this biome. My thesis addresses this issue by exploring fine-root biomass and growth rates for five native species (Hyeronima alchorneoides, Pentaclethra macroloba, Virola koschnyi, Vochy...

Respiration drives life processes. Measurements of respiration rates provide objective assessments of the total metabolism of organisms, ecosystems, and the terrestrial biosphere. They also provide insight into material cycling processes: respiration, for instance, is a major source of atmospheric trace gases including CO2. The authors herein revie...

Background/Question/Methods Individual tree species differ in morphology, phenology, tissue chemistry, and resource use, and these differences can affect ecosystem carbon cycling. To what extent do tree species differ in respiration, photosynthesis, and carbon partitioning at the ecosystem level? We examined this question using experimental plant...

Fast-growing forests such as tropical secondary forests can accumulate large amounts of carbon (C), and thereby play an important role in the atmospheric CO(2) balance. Because nitrogen (N) cycling is inextricably linked with C cycling, the question becomes: Where does the N come from to match high rates of C accumulation? In unique experimental 16...

Understanding the temperature sensitivity of soil organic matter (SOM) decomposition is important to predict the response of soil carbon (C) dynamics to projected global warming. There is no consensus, however, as to whether or not the decomposition of recalcitrant soil C is as sensitive to temperature as is that of labile soil C. Soil C is stabili...

Background/Question/Methods Soil respiration is the largest terrestrial source of atmospheric CO2 but, in comparison to CO2 fixation by photosynthesis, our understanding of factors that control rates of CO2 production within soils is poor. As a result, our ability to model soil CO2 emissions across spatial and temporal scales is limited. We measu...

Close relationships among climatic factors and soil respiration (Rs) are commonly reported. However, variation in Rs across the landscape is compounded by site-specific differences that impede the development of spatially explicit models. Among factors that influence Rs, the effect of ecosystem age is poorly documented. We hypothesized that Rs incr...

Secondary forests and young forest plantations frequently have high rates of tree growth and NPP – higher even than mature forests in similar situations. The nutrients required to sustain this rapid growth are derived from the soil and by external inputs such as rainfall or, in the case of nitrogen, by biological N fixation. In our study of the eff...

In the moist tropical forest biome, which cycles carbon (C) rapidly and stores huge amounts of C, the impacts of individual species on C balances are not well known. In one of the earliest replicated experimental sites for investigating growth of native tropical trees, we examined traits of tree species in relation to their effects on forest C bala...

Although fine roots might account for 50% of the annual net primary productivity in moist tropical forests, there are relatively few studies of fine-root dynamics in this biome. We examined fine-root distributions, mass, growth and tissue N and C concentrations for six tree species established in 16-year-old plantations in the Caribbean lowlands of...

Prolific fine root growth coupled with small accumulations of dead fine roots indicate rapid rates of fine root production, mortality and decay in young tree plantations in lowland Costa Rica. However, published studies indicate that fine roots decay relatively slowly in tropical forests. To resolve this discrepancy, we used the intact-core techniq...

Denitrification within riparian buffers may trade reduced nonpoint source pollution of surface waters for increased greenhouse gas emissions resulting from denitrification-produced nitrous oxide (N2O). However, little is known about the N2O emission within conservation buffers established for water quality improvement or of the importance of short-...

Soil food webs influence organic matter mineralization and plant nutrient availability, but the potential for plants to capitalize on these processes by altering soil food webs has received little attention. We compared soil food webs beneath C3- and C4-grass plantings by measuring bacterial and fungal biomass and protozoan and nematode abundance r...

Carbon allocation plays a critical role in forest ecosystem carbon cycling. We reviewed existing literature and compiled annual carbon budgets for forest ecosystems to test a series of hypotheses addressing the patterns, plasticity, and limits of three components of allocation: biomass, the amount of material present; flux, the flow of carbon to a...

We resampled one of the earliest replicated experimental sites used to investigate the impacts of native tropical tree species on soil properties, to examine longer term effects to 1-m depth. The mono-dominant stands, established in abandoned pasture in 1988 at La Selva Biological Station, Costa Rica, contained six species, including one exotic, Pi...

The carbon-isotopic composition (delta13C) of soil-respired CO2 has been employed to evaluate soil carbon-cycling processes and the contribution of soil CO2 emissions to canopy and tropospheric air. These evaluations can be successful only when accurate isotope values of soil-respired CO2 are available. Here, we tested the robustness of delta13C va...

We quantified the effect of overstory species composition on forest floor dynamics in lowland Costa Rica. Aboveground litter production and forest floor mass were measured over 1 year in 16-year-old single-species plantations established in a randomized complete block design with four blocks. The tree species investigated (=experimental treatments)...

Although fine roots might account for 50% of the annual net primary productivity in moist tropical forests, there are relatively few studies of fine-root dynamics in this biome. We examined fine-root distributions, mass, growth and tissue N and C concentrations for six tree species established in 16-year-old plantations in the Caribbean lowlands of...

Carbon allocation plays a critical role in forest ecosystem carbon cycling. We reviewed existing literature and compiled annual carbon budgets for forest ecosystems to test a series of hypotheses addressing the patterns, plasticity, and limits of three components of allocation: biomass, the amount of material present; flux, the flow of carbon to a...

Soil respiration (RSOIL) is the second largest carbon flux between terrestrial systems and the atmosphere, with a magnitude 10 times greater than anthropogenic carbon dioxide production. Therefore, it is important that we understand, and be able to predict, how RSOIL responds to climate change. Although a positive, significant temperature effect on...

Evergreen broad-leaved tropical forests can have high rates of productivity and large accumulations of carbon in plant biomass and soils. They can therefore play an important role in the global carbon cycle, influencing atmospheric CO2 concentrations if climate warms. We applied meta-analyses to published data to evaluate the apparent effects of te...

Although soil respiration represents an important C transfer from terrestrial ecosystems to the atmosphere, the effects of environmental and biological factors on soil respiration rates are not adequately understood. This is due primarily to the variety of processes that produce CO, within the soil. Thus, separating the main CO2-producing processes...

Graphic output of Raich, Potter and Bhagwati (2002).

This study was conducted to determine biomass dynamics, carbon sequestration and plant nitrogen immobilization in multispecies riparian buffers, cool-season grass buffers and adjacent crop fields in central Iowa. The seven-year-old multispecies buffers were composed of poplar (Populus×euroamericana ‘Eugenei’) and switchgrass (Panicum virgatum L.)....

Dicranopteris linearis (Gleicheniaceae), a native fern common throughout the Old World tropics and Polynesia, forms dense thickets > 3m deep over large areas of open-canopy, oligotrophic, wet Hawaiian rainforests. Our objectives were to identify leaf- and whole plant-level traits that are key to its success and to determine its community-and ecosys...

Our understanding of fine-root decay processes is derived almost exclusively from litterbag studies. However, preparation of roots for litterbag studies and their sub- sequent decay within litterbags represent major departures from in situ conditions. We hypothesized that litterbag studies misrepresent fine-root decay and nutrient release rates dur...

Our understanding of fine-root decay processes is derived almost exclusively from litterbag studies. However, preparation of roots for litterbag studies and their subsequent decay within litterbags represent major departures from in situ conditions. We hypothesized that litterbag studies misrepresent fine-root decay and nutrient release rates durin...

We used a climate-driven regression model to develop spatially resolved estimates of soil-CO2 emissions from the terrestrial land surface for each month from January 1980 to December 1994, to evaluate the effects of interannual variations in climate on global soil-to-atmosphere CO2 fluxes. The mean annual global soil-CO2 flux over this 15-y period...

We used a climate-driven regression model to develop spatially resolved estimates of soil-CO2 emissions from the terrestrial land surface for each month from January 1980 to December 1994, to evaluate the effects of interannual variations in climate on global soil-to-atmosphere CO2 fluxes. The mean annual global soil-CO2 flux over this 15-y period...

We quantified rates of soil respiration among sites within an agricultural landscape in central Iowa, USA. The study was conducted in riparian cool-season grass buffers, in re-established multispecies (switchgrass + poplar) riparian buffers and in adjacent crop (maize and soybean) fields. The objectives were to determine the variability in soil res...

We used the Century model to evaluateenvironmental controls over ecosystem developmentduring the first 3500 y of primary succession onpahoehoe (i.e., relatively smooth, solid) lava flowsof wet, windward Mauna Loa, Hawaii. The Century modelis a generalized ecosystem model that simulatescarbon, nitrogen and phosphorus dynamics forplant-soil systems....

Soil respiration rates vary significantly among major plant biomes, suggesting that vegetation type influences the rate of soil respiration. However, correlations among climatic factors, vegetation distributions, and soil respiration rates make cause-effect arguments difficult. Vegetation may affect soil respiration by influencing soil microclimate...

By influencing belowground processes, streamside vegetation affects soil processes important to surface water quality. We conducted this study to compare root distributions and dynamics, and total soil respiration among six sites comprising an agricultural buffer system: poplar (Populus × euroamericana‘ Eugenei), switchgrass, cool-season pasture gr...

I measured aboveground productivity and soil respiration in three Hawaiian rain forests to compare carbon allocation patterns among natural forests varying in climatic, soil and vegetational characteristics. I hypothesized that total carbon allocation to roots (i.e., root production plus respiration) would increase with increasing aboveground detri...

1 Dicranopteris linearis (Gleicheniaceae), a native fern common throughout the Old World tropics and Polynesia, forms dense thickets > 3 m deep over large areas of open-canopy, oligotrophic, wet Hawaiian rainforests. Our objectives were to identify leaf- and whole plant-level traits that are key to its success and to determine its community- and ec...

We measured aboveground plant biomass, aboveground net primary productivity (ANPP), detritus accumulation, and nitrogen and phosphorus uptake by above- ground vegetation in six Metrosiderospolymorpha stands on the windward slopes of Manna Loa, Hawai'i, USA. Our objective was to quantify the effects of elevation (primarily temperature) on ecosystem...

We measured aboveground plant biomass, aboveground net primary productivity (ANPP), detritus accumulation, and nitrogen and phosphorus uptake by aboveground vegetation in six Metrosideros polymorpha stands on the windward slopes of Mauna Loa, Hawai‘i, USA. Our objective was to quantify the effects of elevation (primarily temperature) on ecosystem p...

Semimechanistic, empirically based statistical models were used to predict the spatial (0.5-degree grid cells) and temporal (monthly and annual) patterns of global carbon emissions form terrestrial soils. Emissions include the respiration of both soil organisms and plant roots. Geographically referenced data of mean monthly air temperature and prec...

We applied fertilizers in a 23complete factorial design to determine the effects of nutrient amendments on plant growth in Hawaiian montane forests growing on two different volcanic substrates: a and phoehoe lava. Both sites were about 140 years old and their overstories were nearly monospecific stands of Metrosideros polymorpha. Fertilizer applica...

We use semi-mechanistic, empirically based statistical models to predict the spatial and temporal patterns of global carbon dioxide emissions from terrestrial soils. Emissions include the respiration of both soil organisms and plant roots. At the global scale, rates of soil CO2 efflux correlate significantly with temperature and precipitation; they...

As a result of evaluations of volcanic hazards, most of the surface lava flows of Mauna Loa have been mapped and dated. Each of these flows represents a valuable resource for ecological studies—a single-age, single-substrate transect reaching from near the summit towards the sea, often spanning a range of nearly 20°C in mean annual temperature. The...

We tested the suitability of using root-ingrowth cores to identify nutrient limitations in a Metrosideros-dominated forest in Hawaii that previously was demonstrated to be nitrogen limited. Plastic mesh cylinders filled with a calcined-clay growing medium were treated with nitrogen, phosphorus, calcium and potassium, or distilled water, and were in...

In this paper we review results of research to summarize the state-of-knowledge of the past, present, and potential future roles of tropical forests in the global C cycle. In the pre-industrial period (ca. 1850), the flux from changes in tropical land use amounted to a small C source of about 0.06 Pg yr–1. By 1990, the C source had increased to 1.7...

Soil respiration is a major flux in the global carbon cycle. Seasonal variation in soil-CO[sub 2] efflux rates is often high, yet current global summaries are generally confined to annual estimates. We have developed an empirical model that resolves temporal (monthly) and spatial (0.51 latitude-longitude) patterns of soil CO[sub 2] emissions at the...

We compared published estimates of the net fine root production (FRP) in forest sites to litterfall and aboveground net primary production (ANPP) to test whether annual rates of fine root and aboveground production vary together at global scales. We also compared FRP estimates to theoretical upper limits as defined by our previously published relat...

We review measured rates of soil respiration from terrestrial and wetland ecosystems to define the annual global CO2 flux from soils, to identify uncertainties in the global flux estimate, and to investigate the influences of temperature, precipitation, and vegetation on soil respiration rates. The annual global CO2 flux from soils is estimated to...

We review measured rates of soil respiration from terrestrial and wetland ecosystems to define the annual global CO 2 flux from soils, to identify uncertainties in the global flux estimate, and to investigate the influences of temperature, precipitation, and vegetation on soil respiration rates. The annual global CO 2 flux from soils is estimated t...

ABSTRACT We review measured rates of soil respiration from terrestrial and wetland ecosystems to define the annual global CO 2 flux from soils , to identify uncertainties in the global flux estimate, and to investigate the influences of temperature, precipitation, and ...

We use a mechanistically based ecosystem simulation model to describe and analyze the spatial and temporal patterns of terrestrial net primary productivity (NPP) in South America. The Terrestrial Ecosystem Model (TEM) is designed to predict major carbon and nitrogen fluxes and pool sizes in terrestrial ecosystems at continental to global scales. In...

The 2 commonly used methods were assessed by directly comparing the sodalime method with a static chamber technique using gas chromatographic analysis of CO2-concentration changes during short-term incubations. A paired-chamber sampling design was applied in 11 different forest stands across a range of soil-CO2 efflux rates. No consistent differenc...

The germination of 43 tree species native to the lowland forests of Malaysia was monitored on forest soil in trays placed in closed-canopy forest, an artificial forest gap, and a large clearing. Germination varied significantly among habitats, with only seven species germinating well in all three sites. Seed germination of most species demonstrated...

Incoming photosynthetically active radiation was continuously monitored for almost one year in closed-canopy dipterocarp forest and in two forest gaps. Mean weekly photosynthetic photon flux densities (PPFD) in the forest and in the small and large gap sites averaged 1.9, 8.3, and 37 percent respectively of the PPFD in the open. There was no appare...

Carbon allocation to roots in forest ecosystems is estimated from published data on soil respiration and litterfall. On a global scale, rates of in situ respiration and aboveground litter production are highly and positively correlated, suggesting that above- and belowground production are controlled by the same factors. Over a gradient of litterfa...

The diversity of many tropical forest ecosystems is thought to depend, in part, on the variety of regeneration opportunities created by smallscale disturbances such as tree-fall gaps. The authors tallied all tree and shrub seedlings and saplings s 5 cm dbh in 39 hexagonal, 20-m2 plots in coastal hill dipterocarp forest of Penang, Malaysia. Ten plot...

Studies were conducted in coastal hill dipterocarp forest of Malaysia to determine: 1) effects of treefall gap size on forest microclimate, 2) the influence of gap size on tree seed germination, 3) the influence of light on the seedling growth of shade-tolerant and shade-intolerant species, and 4) which factors influenced the distribution of tree s...

Studies were conducted in coastal hill dipterocarp forest of peninsular Malaysia to determine: 1) effects of treefall gaps on forest microclimate, 2) the influence of gap size on tree seed germination, 3} the influence of light on the seedling growth of shade-tolerant and shade-intolerant species, and 4) what factors influence the distribution of t...

Soil-C02 efflux was measured from nine ecosystems, all on the same relatively fertile soil. The ecosystems ranged from 0.8 to 10 yr old and included a vegetation-free soil, monocultures of melina ( Gmelina arborea) and cassava (Manihot esculenta), and successional communities containing 80 to > 150 species. C02 effluxes were based on replicated (n...

Data obtained in the humid lowlands of Costa Rica suggest that a common understory palm, Asterogyne martiana, is a nutrient trap. It is hypothesized that Asterogyne palms increase their competitiveness in the mature forest understory by capturing nutrients cycling in precipitation and litterfall. The morphology of Asterogyne is such that litter and...

Soil-C02 efflux was measured from nine ecosystems, all on the same relatively fertile soil. The ecosystems ranged from 0.8 to 10 yr old and included a vegetation-free soil, monocultures of melina ( Gmelina arborea) and cassava (Manihot esculenta), and successional communities containing 80 to > 150 species. C02 effluxes were based on replicated (n...

To determine how the conversion of mature tropical forests to secondary forests affects the soil carbon budget, major soil carbon storages, inputs, and CO2 evolution from a tropical inceptisol were measured over a six-month period in both a mature lowland Tropical Premontane Wet Forest and a nearby secondary site located on the same soil type. Tota...

Impacts of felling, mulching, and burning on budgets of C, N, S, P, K, Ca, and Mg; rates of COâ evolution from the soil; soil seed storage; and plant growth were evaluated. The felled tropical evergreen forest was 8 to 9 yr old, interspersed with patches of 70-yr-old forest and had a leaf area index of 6 and aboveground biomass of 5.2 kg/m². Harve...

We used a climate-driven regression model to develop spatially resolved estimates of soil-COâ emissions from the terrestrial land surface for each month from January 1980 to December 1994, to evaluate the effects of interannual variations in climate on global soil-to-atmosphere COâ fluxes. The mean annual global soil-COâ flux over this 15-y period...