G. Geoff Wang

Clemson University | CU · School of Agricultural, Forest, and Environmental Sciences

Invasive plants can significantly impact the diversity of understory ground flora and forest regeneration in eastern North America. However, managing invasive plants has resulted in positive, negative, or neutral effects on key ecosystem components depending on treatment type, duration, and intensity. Management may also result in short-term contro...

Forest ecosystems store ~80% of the carbon in terrestrial ecosystems, but their long-term carbon sequestration depends partly on how plant biomass and soil carbon stocks will respond to global changes. Although the stimulation of plant growth by global change drivers has been widely observed, the response of soil carbon stock to global changes rema...

Forest gaps play an important role in species regeneration and forest succession. Gap size has a primary influence on tree species coexistence and community assembly along an elevation gradient. In this study, we evaluated the regeneration and coexistence of Abies faxoniana, Betula utilis, and Acer maximowiczii at different life history stages in v...

Halophytes play a crucial role in the ecological restoration of saline and alkaline land and hold promising benefits to food security in China. Although a variety of aspects of halophytes have been extensively addressed, there is still a lack of overall understanding of the leaf nitrogen (N) and phosphorus (P) stoichiometric characteristics, especi...

Background Three-North Afforestation Program (TNAP) in China is the largest ecological restoration project on Earth (ongoing from 1978 to 2050), harboring a huge area of newly planted forests, which provides a wealth of goods and ecosystem services that benefit society at levels ranging from region to East Asia. This project-induced carbon (C) sink...

Forest ecosystems store ca. 80% of the carbon (C) in terrestrial ecosystems 1–2 , but their long-term C sequestration partly depends on how plant biomass and soil C stocks will respond to global changes. Although the stimulation of plant growth by global change drivers such as nitrogen (N) deposition, elevated CO 2, and warming has been widely obse...

Aims: Changes in root system architecture (RSA) and soil depth affect the root decomposition rate. However, due to soil opacity, many variables of RSA have not been well studied or even measured. Methods: To investigate the effects of soil depth and the characteristics of RSA on the root decomposition rate, soil samples (Soil cores were collected i...

Rhizospheric arbuscular mycorrhizal fungi (AMF) are vital for the growth of navel oranges (Citrus sinensis Osbeck). However, the molecular diversity of AMF communities associated with navel oranges in the field is largely unknown. This study employed Illumina MiSeq sequencing to reveal the effects of cultivars and habitats on the rhizospheric AMF c...

Pinus massoniana is an important timber species with high ecological and economic value in southern China and a pioneer species for the reforestation of barren mountains. The structure and function of the existing Masson pine ecosystem have been seriously affected by worsening habitats under current climate change. Its suitable habitat is likely to...

In order to control the desertification, large-scale afforestation programs have been attempted worldwide. Among them, China initiated the world’s largest afforestation program, Three-North Afforestation Program (TNAP, 1978–2050), in which the afforestation in sandy land has been questioned during the first 40 years. In fact, the contribution of th...

Aims Changes in root structure and soil depth affect root decomposition. However, due to soil opacity, many variables of root structure have not been well studied and even measured. Methods To investigate the effects of soil depth and the characteristics of root structure on root decomposition, soil samples (In-situ soil core of 10cm diameter and...

Background Granivore-mediated seed dispersal is susceptible to changes in seed availability and silvicultural management, which alters synzoochorous interactions in the antagonism-mutualism continuum and affects the seed dispersal effectiveness (SDE), and eventually, the plant recruitment. We conducted a whole-year study of seed addition to quantif...

Key message The accuracy of gap age estimation can be improved from 5–6 to 2 years by analyzing the annual width and carbon isotope discrimination of the rings of gap-surrounding trees. Context Gap age has a direct link to the composition and structure of regeneration. However, the accuracy of gap age estimation is still limited. Aim We aim to im...

Acute and extreme weather events can cause considerable damage to the tissues of trees, including stem death and branch or leaf distortion, which may limit their survival and reproduction. In January 2016, a rare cold spell impacted the coastal forests of subtropical China. Using post-hoc assessments, we evaluated the morphological and physiologica...

AimsCanadian goldenrod (Solidago canadensis) invasion is degrading the coastal shelterbelt forests of subtropical China, but few studies have quantified the role of this invader in structuring understory plant diversity and soil properties.Methods Understory species richness, Margalef index, Pielow index, community stability index, soil organic car...

Planting broad-leaved trees with coniferous species typically influences the rhizosphere soil microorganisms of broad-leaved trees. However, how tree species mixture affects microbial community compositions and microbial nutrient limitation represented by soil extracellular enzyme stoichiometry (EES) remains poorly understood. We investigated the m...

The frequency and severity of extreme weather events, including hurricanes, are expected to increase in response to global change. Concurrently, southern U.S. forests will experience droughts that may facilitate a rise in wildfire. Wind damage can alter fuel dynamics and forest structure increasing susceptibility to wildfire, especially with drough...

Tree species mixing is a prevalent practice to improve soil quality in monoculture plantations and the rhizosphere soil organic carbon (SOC) dynamics of conifers will be affected by mixing the species with broad-leaved trees; however, the influence characteristics and underlying mechanism of mixing on rhizosphere SOC mineralization remain elusive....

Soil and climatic conditions are known to have close associations with plant morphological and stoichiometric traits at a regional scale along latitudinal gradients; however, how latitude drives biotic and abiotic factors affecting plant nutrient acquisition to accommodate environmental nutrient deficiency remains unclear. We quantified soil, root,...

The effects of abiotic and biotic factors on plant stoichiometry have been widely reported at the global scale. However, stand age has not always been considered and its effect on stoichiometry showed large uncertainties at the global scale. In this study, we examined the role of stand age in leaf N:P, and observed the general pattern of leaf N:P f...

The plant nutrient acquisition strategies are diverse, such as root nutrient acquisition and leaf nutrient resorption, playing important roles in driving soil processes, vegetation performance as well as ecosystem nutrient cycling. However, it is still in a debate whether there is a synergy or tradeoff between above- and below-ground nutrient acqui...

Gleditsia sinensis is a valuable tree species with important pharmaceutical uses. However, high soil NaCl concentration limits its growth in saline soil, including coastal areas. This study aimed to investigate the effects of arbuscular mycorrhizal fungi (AMF) on G. sinensis salinity tolerance and reveal its underlying physiological mechanism. A gr...

Litter decomposition and nutrient release are key processes for soil C and nutrient cycling. However, the relative importance of the effects of litter quality, fauna and decomposition site on litter decomposition remains poorly understood. Moreover, the macronutrient and micronutrient (C, N, P, K, Ca, Mg, Mn, Cu and Zn) release in the decomposition...

Question Longleaf pine (Pinus palustris) restoration is an important management objective throughout the southeastern U.S. Site preparation prior to planting longleaf pine seedlings is often required to overcome challenges to seedling establishment on hydric sites. We know site preparation improves growth and survival of planted longleaf pine on hy...

Background To restore secondary forests (major forest resources worldwide), it is essential to accelerate the natural regeneration of dominant trees by altering micro-environments. Forest gaps are products of various disturbances, ranging from natural storms or wildfires to anthropogenic events like logging and slashing-and-burning, and sprouts of...

Background Plant stoichiometry displayed flexible over age sequences in previous studies, but effect of stand age on stoichiometry showed large uncertainties for different plantations at the global scale. In this study, we want to obtain the general pattern of leaf N:P ratio for global plantations across age gradients through the compilation and an...

Key message Torreya grandis seedlings showed significant gender difference under drought stress and females had a better performance in the process of photosynthesis. Abstract Starting with saturated moisture content, the natural drought stress process was comprehensively investigated to clarify the possible sex differences of Torreya grandis and...

Nitrogen (N) addition has a pronounced impact on tree growth and forest function, but its effects on forest structure diversity are seldom studied. In this study, we measured leaf N and phosphorus (P) stoichiometry, and diameter at breast height (DBH) in both young (N limitation) and middle-aged (P limitation) Metasequoia glyptostroboides plantatio...

In managed orchards, fertilization brings out not only high productivity expectations but also severe environmental pollution. Because economic profit takes priority over environmental cost, increasing amounts of fertilizer have been used in mature subtropical Torreya grandis orchards. However, given the magnitude of global nitrogen deposition, it’...

Nutrient resorption is an important strategy for nutrient conservation, particularly under conditions of nutrient limitation. However, changes in nutrient resorption efficiency with stand development and the associated correlations with ecological stoichiometry and homeostasis are poorly understood. In the study, the authors measured carbon (C), ni...

The poor natural regeneration of Korean pine represents a substantial hurdle limiting the restoration of secondary forests to mixed broad-leaved Korean pine forests (MBKPFs). Active restoration based on direct seeding or planting seedlings is accordingly considered to be a prerequisite for promoting Korean pine recruitment in secondary forests. To...

Background: Gap size and environmental gradient have fundamental influence on the tree species coexistence and community assembly. We studied the regeneration and coexistence of three co-dominant tree species in three different gap size (large gap, 201-402 m²; medium gap, 101-200 m²; small gap, 38.8-100 m²) along an elevation gradient (between 3000...

Forest gaps play an important role in tree regeneration and forest restoration in modern silviculture. Many previous studies examined gap effects on seedling survival, growth, or both but lacked a systemic assessment incorporating morphological and physiological responses to varying environmental gradients along gap size and within-gap position, wh...

Forest fragmentation is increasing rapidly around the world, and edge effects caused by fragmented forests can influence ecosystem functions and ecological processes, including coarse woody debris (CWD) decomposition. Understanding the influencing mechanisms of edge effect on CWD decomposition is needed to assess the effects of forest fragmentation...

Deadwood contains a sizeable proportion of total forest C, and its decomposition transfers organic C to the atmosphere , other organisms and soils. Microbes have traditionally been thought to be the primary drivers of wood decomposition worldwide, but few studies have tested the relative importance of termites to this process. The aim of this study...

Forest gaps are essential small-scale disturbances in forest succession. However, little attention has been paid to the long-term effects of gap dynamics on woody species regeneration and succession. We selected 20 medium and 25 large gaps representing a range of age classes (0–10, 10–20, 20–30, 30–40, and 40–50 years) from remote-sensing images ob...

Establishing mixed-species plantations on the reclaimed coastal lands has become a new paradigm in forest management in China, because it increases the provision of ecosystem services. However, the mixing effects of trees with different identities remain largely understudied. In subtropical China, plantations have been historically dominated by mon...

AimsAboveground litter inputs have been modified by global changes in plantation forests, where understory management is also prevalent, which may alter soil fertility and stand productivity. This study aimed to quantify the specific roles of litter and understory in affecting soil carbon (C) and nitrogen (N) dynamics.MethodsA field experiment was...

Gap formation and closure play important roles in forest succession. Most studies focused on regeneration within gaps, but less is known about the growth dynamics of canopy trees surrounding the gaps (i.e., gap border trees), which limits our understanding of the gap-filling process. In this study, terrestrial laser scanning (TLS) was used to quant...

Background In managed orchards, fertilizer treatments facilitate both high productivity and environmental pollution. Because economic profit takes priority over environmental cost, increasing amounts of chemical nitrogen and phosphorus fertilizer have been used in mature subtropical Torreya grandis orchards. However, given the magnitude of global n...

Arbuscular mycorrhizal fungi (AMF) form a near-ubiquitous mutualistic association with roots to help plants withstand harsh environments, and play a key role in the establishment of coastal beach plant communities. Yet little is known about the structure and composition of AMF communities on coastal beaches of eastern China. In this study, we inves...

Arbuscular mycorrhizal (AM) fungi enhance plant salt tolerance. However, physiological mechanisms of enhanced salt tolerance in leaves and roots of trees rarely have been compared. To reveal the different mechanisms, our study utilized comprehensive analyses of leaves and roots to examine the effects of Funneliformis mosseae on the salinity toleran...

Although photosynthesis (carbohydrate production) decreases under wind load, it is unclear how carbohydrate categories allocation changes. We determined the leaf morphology (specific leaf area (SLA), needle thickness), anatomy (cuticle thickness, epidermal thickness), photosynthesis (effective quantum yield of Photosystem II (Y(II)), carbohydrate (...

Longleaf pine (Pinus palustris Mill.) restoration is an important land management goal throughout the southeastern U.S. On hydric sites within the Atlantic Coastal Plain, restoration may involve site preparation prior to planting to overcome challenges to seedling establishment, such as abundant competition and poor soil drainage. Investment in sit...

Atmospheric nitrogen (N) and acid deposition have become global environmental issues and are likely to alter soil respiration (Rs); the largest CO2 source is from soil to the atmosphere. However, to date, much less attention has been focused on the interactive effects and underlying mechanisms of N and acid deposition on Rs, especially for ecosyste...

Extended abstract-Longleaf pine (Pinus palustris Mill.) restoration is an important land management goal throughout the Southeast. On hydric sites within the Atlantic Coastal Plain, restoration may involve site preparation prior to planting in order to overcome challenges to seedling establishment, such as abundant competition and poor soil drainag...

Background and AimsThe protective effects of arbuscular mycorrhizal fungi (AMF) on salt-stressed crop plants had been well studied. However, the physiological mechanism of AMF in mitigating adverse impact caused by salinity stress in different tissues of woody plants is not clear. Gleditsia sinensis Lam. is a valuable tree species with various pham...

Forest gaps are important small-scale disturbances that initiate forest succession. However, natural regeneration patterns within gaps remain unclear, especially in temperate secondary forests. In this study, three-dimensional graphic systems were established to show the whole regeneration patterns of woody species with different shade tolerance in...

Longleaf pine (Pinus palustris Mill.) forest is a well-known fire-dependent ecosystem. The historical dominance of longleaf pine in the southeast United States has been attributed to its adaptation known as the grass stage, which allows longleaf pine seedlings to survive under a frequent surface fire regime. However, factors affecting post-fire sur...

A predicted impact of a warming climate is an upslope shift of montane plant species. These upslope shifts may be amplified by land-use changes or attenuated by forest recoveries at low elevations where historical disturbances were ceased allowing for plant regrowth. Consequently, species may shift downslope back to low elevations where they had be...

The degree of stoichiometric homeostasis can be indicated by the homeostatic coefficient (H), which reflects the ability of plants to maintain a stable nutrient composition regardless of changes in environmental nutrients. In previous studies, H had been determined primarily in herbs and varied significantly among organs and growth stages. However,...

Background and aims Anthropogenic activities have increased nitrogen (N) and phosphorus (P) inputs to terrestrial ecosystems, which may significantly alter P cycle through accumulation and resorption. Methods We measured the concentrations of four different P fractions (inorganic, nucleic, sugar, and residual P) in both live leaves and senescent l...

Background and aims Nitrogen (N) deposition affects litter decomposition. However, how nutrients, especially deposited N are immobilized and released in decomposing litters with different qualities (C/N and C/P) remains unclear. Methods We conducted a laboratory microcosm experiment with four litter types and a combination of a coniferous and deci...

Key message The gap dynamics in the studied secondary forest were comparable to those of other temperate forests; large openings were filled within 30 years by afforestation; large and medium gaps closed 30–40 years after they formed. Context Gaps have important roles in forest regeneration and plant succession. However, it is difficult to determi...

Previous studies have found that home-field advantage (HFA)appears to be widespread in the decomposition of litter, but few studies have examined HFA in the decomposition of coarse woody debris (CWD)in forest ecosystems. To test the HFA hypothesis for CWD decomposition, we quantified the respiration of CWD (R CWD )for different tree species over a...

The Chinese honey locust tree Gleditsia sinensis Lam. (Fabaceae) is a precious ecological and economic tree species that has wide-ranging usage. However, knowledge regarding seedling cultivation (especially the use of arbuscular mycorrhizal fungi (AMF)) is scarce, which limits the developent of Gleditsia plantations. A pot experiment was carried ou...

Arbuscular mycorrhizal fungi (AMF) play an important role in the establishment and maintenance of plant communities in forest ecosystems. Most previous studies about AMF have been conducted in natural forests, and little attention has been paid to trees in planted forests. This study investigated AMF associated with tree species and the relationshi...

Increases in nitrogen (N) deposition and ultraviolet-B (UV-B) radiation play an important role in global climate change. Because coarse woody debris (CWD) represents a sizeable proportion of total carbon (C) pool in forest ecosystems, understanding the response of CWD decomposition to increased UV-B and N deposition become necessary for evaluating...