1
|
Han Y, Wang B, Sun H. Effects of species mixing on maximum size-density relationships in Chinese fir ( Cunninghamia lanceolata (Lamb.) Hook.)-dominated mixed forests converted from even-aged pure stands. FRONTIERS IN PLANT SCIENCE 2024; 15:1342307. [PMID: 38638356 PMCID: PMC11024540 DOI: 10.3389/fpls.2024.1342307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 03/14/2024] [Indexed: 04/20/2024]
Abstract
Introduction Density management is a key silvicultural tool in management programs that enhances compositional and structural diversity and hence forest growth during the conversion of even-aged pure stands into mixed forests. Methods To determine the optimum stand density, a model of maximum size-density relationships was employed to explore the relationship of the self-thinning trajectory with growth, species mixing, latitude, and site conditions during the transition of even-aged pure Chinese fir stands to Chinese fir-dominated mixed forests using stochastic frontier analysis. Data were obtained from a total of 591 permanent plots located in Fujian, Jiangxi, Zhejiang, and Anhui provinces in southern China. Results The results showed that (1) the slope of the maximum size-density relationship of Chinese fir-dominated mixed forests increased and plateaued over time; (2) the slope of the maximum size-density relationship of Chinese fir-dominated mixed forests did not deviate from Reineke's assumed universal slope of -1.605; and (3) mixing proportion had a positive effect on maximum size-density relationships, and latitude and site conditions had the opposite effect on maximum size-density relationships. Conclusions Our findings will provide valuable guidance for the forest management of areas in which even-aged pure stands are being converted to mixed forests (i.e., when broadleaved tree species are planted after thinning to improve overall stand density and promote stand growth).
Collapse
Affiliation(s)
- Yuanyuan Han
- Research Institute of Subtropical Forestry of Chinese Academy of Forestry, Hangzhou, Zhejiang, China
- Nanjing Forestry University, Nanjing, China
| | - Baichang Wang
- East China Inventory and Planning Institute, National Forestry and Grassland Administration, Hangzhou, China
| | - Honggang Sun
- Research Institute of Subtropical Forestry of Chinese Academy of Forestry, Hangzhou, Zhejiang, China
- Research Institute of Fast-growing Trees, Chinese Academy of Forestry, State Key Laboratory of Efficient Production of Forest Resources, Hangzhou, China
| |
Collapse
|
2
|
Yu K, Chen HYH, Gessler A, Pugh TAM, Searle EB, Allen RB, Pretzsch H, Ciais P, Phillips OL, Brienen RJW, Chu C, Xie S, Ballantyne AP. Forest demography and biomass accumulation rates are associated with transient mean tree size vs. density scaling relations. PNAS NEXUS 2024; 3:pgae008. [PMID: 38390215 PMCID: PMC10883769 DOI: 10.1093/pnasnexus/pgae008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/27/2023] [Indexed: 02/24/2024]
Abstract
Linking individual and stand-level dynamics during forest development reveals a scaling relationship between mean tree size and tree density in forest stands, which integrates forest structure and function. However, the nature of this so-called scaling law and its variation across broad spatial scales remain unquantified, and its linkage with forest demographic processes and carbon dynamics remains elusive. In this study, we develop a theoretical framework and compile a broad-scale dataset of long-term sample forest stands (n = 1,433) from largely undisturbed forests to examine the association of temporal mean tree size vs. density scaling trajectories (slopes) with biomass accumulation rates and the sensitivity of scaling slopes to environmental and demographic drivers. The results empirically demonstrate a large variation of scaling slopes, ranging from -4 to -0.2, across forest stands in tropical, temperate, and boreal forest biomes. Steeper scaling slopes are associated with higher rates of biomass accumulation, resulting from a lower offset of forest growth by biomass loss from mortality. In North America, scaling slopes are positively correlated with forest stand age and rainfall seasonality, thus suggesting a higher rate of biomass accumulation in younger forests with lower rainfall seasonality. These results demonstrate the strong association of the transient mean tree size vs. density scaling trajectories with forest demography and biomass accumulation rates, thus highlighting the potential of leveraging forest structure properties to predict forest demography, carbon fluxes, and dynamics at broad spatial scales.
Collapse
Affiliation(s)
- Kailiang Yu
- High Meadows Environmental Institute, Princeton University, Princeton, NJ 08544, USA
- Department of Ecosystem and Conservation Sciences, WA Franke College of Forestry and Conservation, University of Montana, Missoula, MT 59801, USA
| | - Han Y H Chen
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON P7B 5E1, Canada
| | - Arthur Gessler
- Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf CH-8903, Switzerland
| | - Thomas A M Pugh
- Department of Physical Geography and Ecosystem Science, Lund University, Lund S-223 62, Sweden
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
- Birmingham Institute of Forest Research, University of Birmingham, Birmingham B15 2TT, UK
| | - Eric B Searle
- Faculty of Natural Resources Management, Lakehead University, Thunder Bay, ON P7B 5E1, Canada
| | | | - Hans Pretzsch
- Chair for Forest Growth and Yield Science, Center of Life and Food Sciences Weihenstephan, Technical University of Munich, Freising 85354, Germany
- Sustainable Forest Management Research Institute iuFOR, University Valladolid, Valladolid 47002, Spain
| | - Philippe Ciais
- Le Laboratoire des Sciences du Climat et de l'Environnement, IPSL-LSCECEA/CNRS/UVSQ Saclay, Gif-sur-Yvette 91191, France
| | | | | | - Chengjin Chu
- State Key Laboratory of Biocontrol, School of Ecology, Shenzhen Campus of Sun Yat-sen University, Shenzhen 518000, China
| | - Shubin Xie
- State Key Laboratory of Grassland Agro-Ecosystem, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Ashley P Ballantyne
- Department of Ecosystem and Conservation Sciences, WA Franke College of Forestry and Conservation, University of Montana, Missoula, MT 59801, USA
- Le Laboratoire des Sciences du Climat et de l'Environnement, IPSL-LSCECEA/CNRS/UVSQ Saclay, Gif-sur-Yvette 91191, France
| |
Collapse
|
3
|
Newbery DM, Stoll P. Including tree spatial extension in the evaluation of neighborhood competition effects in Bornean rain forest. Ecol Evol 2021; 11:6195-6222. [PMID: 34141212 PMCID: PMC8207374 DOI: 10.1002/ece3.7452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 01/05/2021] [Indexed: 12/05/2022] Open
Abstract
Classical tree neighborhood models use size variables acting at point distances. In a new approach here, trees were spatially extended as a function of their crown sizes, represented impressionistically as points within crown areas. Extension was accompanied by plasticity in the form of crown removal or relocation under the overlap of taller trees. Root systems were supposedly extended in a similar manner. For the 38 most abundant species in the focal size class (10-<100 cm stem girth) in two 4-ha plots at Danum (Sabah), for periods P1 (1986-1996) and P2 (1996-2007), stem growth rate and tree survival were individually regressed against stem size, and neighborhood conspecific (CON) and heterospecific (HET) basal areas within incremented steps in radius. Model parameters were critically assessed, and statistical robustness in the modeling was set by randomization testing. Classical and extended models differed importantly in their outcomes. Crown extension weakened the relationship of CON effect on growth versus plot species' abundance, showing that models without plasticity overestimated negative density dependence. A significant negative trend of difference in CON effects on growth (P2-P1) versus CON or HET effect on survival in P1 was strongest with crown extension. Model outcomes did not then support an explanation of CON and HET effects being due to (asymmetric) competition for light alone. An alternative hypothesis is that changes in CON effects on small trees, largely incurred by a drought phase (relaxing light limitation) in P2, and following the more shaded (suppressing) conditions in P1, were likely due to species-specific (symmetric) root competition and mycorrhizal processes. The very high variation in neighborhood composition and abundances led to a strong "neighborhood stochasticity" and hence to largely idiosyncratic species' responses. A need to much better understand the roles of rooting structure and processes at the individual tree level was highlighted.
Collapse
Affiliation(s)
| | - Peter Stoll
- Institute of Plant SciencesUniversity of BernBernSwitzerland
- Section of Conservation BiologyDepartment of Environmental SciencesUniversity of BaselBaselSwitzerland
| |
Collapse
|
4
|
Herberich MM, Gayler S, Anand M, Tielbörger K. Biomass–density relationships of plant communities deviate from the self‐thinning rule due to age structure and abiotic stress. OIKOS 2020. [DOI: 10.1111/oik.07073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Maximiliane Marion Herberich
- Inst. for Evolution and Ecology, Dept of Biology, Univ. of Tübingen Auf der Morgenstelle 5 DE‐72076 Tübingen Germany
| | - Sebastian Gayler
- Biogeophysics, Inst. of Soil Science and Land Evaluation, Univ. of Hohenheim Stuttgart Germany
| | - Madhur Anand
- Dept of Environmental Biology, The School of Environmental Sciences, Univ. of Guelph Guelph ON N1G 2W1 Canada
| | - Katja Tielbörger
- Inst. for Evolution and Ecology, Dept of Biology, Univ. of Tübingen Auf der Morgenstelle 5 DE‐72076 Tübingen Germany
| |
Collapse
|
5
|
Dillon KT, Henderson AN, Lodge AG, Hamilton NI, Sloat LL, Enquist BJ, Price CA, Kerkhoff AJ. On the relationships between size and abundance in plants: beyond forest communities. Ecosphere 2019. [DOI: 10.1002/ecs2.2856] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
| | - Amanda N. Henderson
- Department of Biology Kenyon College Gambier Ohio 43022 USA
- Department of Ecology & Evolutionary Biology University of Arizona Tucson Arizona USA
| | - Alexandra G. Lodge
- Department of Biology Kenyon College Gambier Ohio 43022 USA
- Department of Ecosystem Science and Management Texas A&M University College Station Texas 77843 USA
| | | | - Lindsey L. Sloat
- Institute on the Environment University of Minnesota St. Paul Minnesota 55414 USA
| | - Brian J. Enquist
- Department of Ecology & Evolutionary Biology University of Arizona Tucson Arizona USA
| | - Charles A. Price
- School of Plant Biology University of Western Australia Crawley WA 6009 Australia
| | | |
Collapse
|
6
|
Zhang WP, Jia X, Wang GX. Facilitation among plants can accelerate density-dependent mortality and steepen self-thinning lines in stressful environments. OIKOS 2017. [DOI: 10.1111/oik.03983] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wei-Ping Zhang
- Beijing Key Laboratory of Biodiversity and Organic Farming, Key Laboratory of Plant and Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural Univ.; Beijing PR China
| | - Xin Jia
- Yanchi Research Station, School of Soil and Water Conservation, Beijing Forestry Univ., CN-100083; Beijing PR China
| | - Gen-Xuan Wang
- College of Life Sciences, Zhejiang Univ.; Hangzhou PR China
| |
Collapse
|
7
|
Rasmussen CR, Weiner J. Modelling the effect of size-asymmetric competition on size inequality: Simple models with two plants. Ecol Modell 2017. [DOI: 10.1016/j.ecolmodel.2016.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
8
|
Velázquez J, Allen RB, Coomes DA, Eichhorn MP. Asymmetric competition causes multimodal size distributions in spatially structured populations. Proc Biol Sci 2016; 283:rspb.2015.2404. [PMID: 26817778 DOI: 10.1098/rspb.2015.2404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plant sizes within populations often exhibit multimodal distributions, even when all individuals are the same age and have experienced identical conditions. To establish the causes of this, we created an individual-based model simulating the growth of trees in a spatially explicit framework, which was parametrized using data from a long-term study of forest stands in New Zealand. First, we demonstrate that asymmetric resource competition is a necessary condition for the formation of multimodal size distributions within cohorts. By contrast, the legacy of small-scale clustering during recruitment is transient and quickly overwhelmed by density-dependent mortality. Complex multi-layered size distributions are generated when established individuals are restricted in the spatial domain within which they can capture resources. The number of modes reveals the effective number of direct competitors, while the separation and spread of modes are influenced by distances among established individuals. Asymmetric competition within local neighbourhoods can therefore generate a range of complex size distributions within even-aged cohorts.
Collapse
Affiliation(s)
- Jorge Velázquez
- School of Physics and Astronomy, The University of Nottingham, Nottingham NG7 2RD, UK Facultad de Ciencias Físico Matemáticas, Universidad Autónoma de Puebla, Puebla, Pue. 72001, México
| | - Robert B Allen
- Landcare Research, P.O. Box 69, Lincoln 8152, New Zealand
| | - David A Coomes
- Forest Ecology and Conservation Group, Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Markus P Eichhorn
- School of Life Sciences, The University of Nottingham, University Park, Nottingham NG7 2RD, UK
| |
Collapse
|
9
|
Lepik M, Zobel K. Is the positive relationship between species richness and shoot morphological plasticity mediated by ramet density or is there a direct link? Oecologia 2015; 178:867-73. [PMID: 25761447 DOI: 10.1007/s00442-015-3288-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 03/03/2015] [Indexed: 10/23/2022]
Abstract
Little is known about the consequences of phenotypic plasticity in co-existing species for plant community structure. However, it has been proposed that the potential of plants to exhibit plastic responses to light availability could be a key factor determining the capability of individuals to co-exist at small scales. Our previous research demonstrated that morphological plasticity to light was positively related to small-scale species richness in a temperate grassland. However, it remained unclear whether this relationship was solely due to a higher shoot density in plastic assemblages, or whether diversity was directly related to the morphological plasticity of the co-inhabitants. We used two data sets to clarify this relationship: experimentally acquired estimates of plasticity to light availability for 45 herbaceous plant species, and species richness and ramet density data from a 2-year permanent plot study in a semi-natural calcareous grassland. There was little ramet mortality observed in the permanent plot study indicating that the link between plasticity and richness does not operate through reduced mortality in more morphologically plastic assemblages. The local density of ramets explained most of variation in small-scale richness, but there was also a significant direct density-independent effect of mean shoot plasticity on richness, showing that plasticity to light directly enhances the small-scale co-existence of species.
Collapse
Affiliation(s)
- Mari Lepik
- Institute of Ecology and Earth Sciences, University of Tartu, 40 Lai Street, 51005, Tartu, Estonia,
| | | |
Collapse
|
10
|
Individual variability and mortality required for constant final yield in simulated plant populations. THEOR ECOL-NETH 2014. [DOI: 10.1007/s12080-014-0216-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
11
|
Lin Y, Huth F, Berger U, Grimm V. The role of belowground competition and plastic biomass allocation in altering plant mass-density relationships. OIKOS 2013. [DOI: 10.1111/j.1600-0706.2013.00921.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
12
|
Lin Y, Berger U, Grimm V, Huth F, Weiner J. Plant interactions alter the predictions of metabolic scaling theory. PLoS One 2013; 8:e57612. [PMID: 23460884 PMCID: PMC3584043 DOI: 10.1371/journal.pone.0057612] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 01/24/2013] [Indexed: 11/19/2022] Open
Abstract
Metabolic scaling theory (MST) is an attempt to link physiological processes of individual organisms with macroecology. It predicts a power law relationship with an exponent of −4/3 between mean individual biomass and density during density-dependent mortality (self-thinning). Empirical tests have produced variable results, and the validity of MST is intensely debated. MST focuses on organisms’ internal physiological mechanisms but we hypothesize that ecological interactions can be more important in determining plant mass-density relationships induced by density. We employ an individual-based model of plant stand development that includes three elements: a model of individual plant growth based on MST, different modes of local competition (size-symmetric vs. -asymmetric), and different resource levels. Our model is consistent with the observed variation in the slopes of self-thinning trajectories. Slopes were significantly shallower than −4/3 if competition was size-symmetric. We conclude that when the size of survivors is influenced by strong ecological interactions, these can override predictions of MST, whereas when surviving plants are less affected by interactions, individual-level metabolic processes can scale up to the population level. MST, like thermodynamics or biomechanics, sets limits within which organisms can live and function, but there may be stronger limits determined by ecological interactions. In such cases MST will not be predictive.
Collapse
Affiliation(s)
- Yue Lin
- Institute of Forest Growth and Computer Science, Dresden University of Technology, Tharandt, Germany.
| | | | | | | | | |
Collapse
|
13
|
Fibich P, Lepš J. Do biodiversity indices behave as expected from traits of constituent species in simulated scenarios? Ecol Modell 2011. [DOI: 10.1016/j.ecolmodel.2011.04.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
14
|
Zhang WP, Jia X, Bai YY, Wang GX. The difference between above- and below-ground self-thinning lines in forest communities. Ecol Res 2011. [DOI: 10.1007/s11284-011-0843-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
15
|
Zhang Q, Xu L, Tang J, Bai M, Chen X. Arbuscular mycorrhizal mediation of biomass-density relationship of Medicago sativa L. under two water conditions in a field experiment. MYCORRHIZA 2011; 21:269-277. [PMID: 20652365 DOI: 10.1007/s00572-010-0331-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 07/04/2010] [Indexed: 05/29/2023]
Abstract
The biomass-density relationship (whereby the biomass of individual plants decreases as plant density increases) has generally been explained by competition for resources. Arbuscular mycorrhizal fungi (AMF) are able to affect plant interactions by mediating resource utilization, but whether this AMF-mediated interaction will change the biomass-density relationship is unclear. We conducted an experiment to test the hypothesis that AMF will shift the biomass-density relationship by affecting intraspecific competition. Four population densities (10, 100, 1,000, or 10,000 seedlings per square meter) of Medicago sativa L. were planted in field plots. Water application (1,435 or 327.7 mm/year) simulated precipitation in wet areas (sufficient water) and arid areas (insufficient water). The fungicide benomyl was applied to suppress AMF in some plots ("low-AMF" treatment) and not in others ("high-AMF" treatment). The effect of the AMF treatment on the biomass-density relationship depended on water conditions. High AMF enhanced the decrease of individual biomass with increasing density (the biomass-density line had a steeper slope) when water was sufficient but not when water was insufficient. AMF treatment did not affect plant survival rate or population size but did affect absolute competition intensity (ACI). When water was sufficient, ACI was significantly higher in the high-AMF treatment than in the low-AMF treatment, but ACI was unaffected by AMF treatment when water was insufficient. Our results suggest that AMF status did not impact survival rate and population size but did shift the biomass-density relationship via effects on intraspecific competition. This effect of AMF on the biomass-density relationship depended on the availability of water.
Collapse
Affiliation(s)
- Qian Zhang
- Agroecology Institute, College of Life Sciences, Zhejiang University, Zijingang campus, Hangzhou, China
| | | | | | | | | |
Collapse
|
16
|
Schiffers K, Tielbörger K, Tietjen B, Jeltsch F. Root plasticity buffers competition among plants: theory meets experimental data. Ecology 2011; 92:610-20. [PMID: 21608470 DOI: 10.1890/10-1086.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Katja Schiffers
- University of Potsdam, Maulbeerallee 2, 14469 Potsdam, Germany.
| | | | | | | |
Collapse
|
17
|
Jia X, Dai XF, Shen ZX, Zhang JY, Wang GX. Facilitation can maintain clustered spatial pattern of plant populations during density-dependent mortality: insights from a zone-of-influence model. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2010.18674.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Toda M, Takata K, Nishimura N, Yamada M, Miki N, Nakai T, Kodama Y, Uemura S, Watanabe T, Sumida A, Hara T. Simulating seasonal and inter-annual variations in energy and carbon exchanges and forest dynamics using a process-based atmosphere–vegetation dynamics model. Ecol Res 2010. [DOI: 10.1007/s11284-010-0763-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
19
|
Chu CJ, Weiner J, Maestre FT, Wang YS, Morris C, Xiao S, Yuan JL, Du GZ, Wang G. Effects of positive interactions, size symmetry of competition and abiotic stress on self-thinning in simulated plant populations. ANNALS OF BOTANY 2010; 106:647-52. [PMID: 20643802 PMCID: PMC2944970 DOI: 10.1093/aob/mcq145] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Competition drives self-thinning (density-dependent mortality) in crowded plant populations. Facilitative interactions have been shown to affect many processes in plant populations and communities, but their effects on self-thinning trajectories have not been investigated. METHODS Using an individual-based 'zone-of-influence' model, we studied the potential effects of the size symmetry of competition, abiotic stress and facilitation on self-thinning trajectories in plant monocultures. In the model, abiotic stress reduced the growth of all individuals and facilitation ameliorated the effects of stress on interacting individuals. KEY RESULTS Abiotic stress made the log biomass-log density relationship during self-thinning steeper, but this effect was reduced by positive interactions among individuals. Size-asymmetric competition also influenced the self-thinning slope. CONCLUSIONS Although competition drives self-thinning, its course can be affected by abiotic stress, facilitation and competitive symmetry.
Collapse
Affiliation(s)
- Cheng-Jin Chu
- MOE Key Laboratory of Arid and Grassland Ecology at Lanzhou University, Lanzhou, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
May F, Grimm V, Jeltsch F. Reversed effects of grazing on plant diversity: the role of below-ground competition and size symmetry. OIKOS 2009. [DOI: 10.1111/j.1600-0706.2009.17724.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
21
|
Toda M, Yokozawa M, Sumida A, Watanabe T, Hara T. Foliage profiles of individual trees determine competition, self-thinning, biomass and NPP of a Cryptomeria japonica forest stand: A simulation study based on a stand-scale process-based forest model. Ecol Modell 2009. [DOI: 10.1016/j.ecolmodel.2009.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
22
|
Potvin C, Dutilleul P. Neighborhood effects and size-asymmetric competition in a tree plantation varying in diversity. Ecology 2009; 90:321-7. [PMID: 19323214 DOI: 10.1890/08-0353.1] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A plantation of native trees was established in Panama in 2001 to study the relationship between biodiversity and ecosystem functioning. Five years later, mixed-species plots had experienced enhanced tree growth compared with monocultures. Searching for underlying mechanisms, we developed a neighborhood model isolating size and identity effects. We found that the size of neighbors is, by far, the largest source of variation in individual-tree diameter and height. Size-asymmetric competition appears as a structuring factor in the plantation. The relative growth rate of small trees was significantly lower than that of large trees, and their height and basal diameter were most variable. The 50 smallest trees of the plantation suffered a disproportionate amount of death, and the proportion of small trees was highest in monoculture. Increased biomass allocation to branches for trees growing in three-species plots suggests that competition for light might be taking place. Clearly, local neighborhood plays a central role in determining productivity, suggesting that scale needs to be incorporated in the theoretical development and analysis of biodiversity and ecosystem functioning.
Collapse
Affiliation(s)
- Catherine Potvin
- Department of Biology, McGill University, 1205 Dr Penfield, Montreal, Quebec H3A 1B1, Canada.
| | | |
Collapse
|
23
|
Chu CJ, Maestre FT, Xiao S, Weiner J, Wang YS, Duan ZH, Wang G. Balance between facilitation and resource competition determines biomass-density relationships in plant populations. Ecol Lett 2008; 11:1189-1197. [PMID: 18684118 DOI: 10.1111/j.1461-0248.2008.01228.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Cheng-Jin Chu
- MOE Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000, ChinaÁrea de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, SpainNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101-5504, USACold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Fernando T Maestre
- MOE Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000, ChinaÁrea de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, SpainNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101-5504, USACold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Sa Xiao
- MOE Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000, ChinaÁrea de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, SpainNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101-5504, USACold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Jacob Weiner
- MOE Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000, ChinaÁrea de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, SpainNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101-5504, USACold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
| | - You-Shi Wang
- MOE Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000, ChinaÁrea de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, SpainNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101-5504, USACold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Zheng-Hu Duan
- MOE Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000, ChinaÁrea de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, SpainNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101-5504, USACold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Gang Wang
- MOE Key Laboratory of Arid and Grassland Ecology, Lanzhou University, Lanzhou 730000, ChinaÁrea de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, c/Tulipán s/n, 28933 Móstoles, SpainNational Center for Ecological Analysis and Synthesis, Santa Barbara, CA 93101-5504, USACold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
| |
Collapse
|
24
|
The role of size inequality in self-thinning: A pattern-oriented simulation model for arid savannas. Ecol Modell 2008. [DOI: 10.1016/j.ecolmodel.2007.08.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
25
|
Fajardo A, McIntire EJB. Distinguishing Microsite and Competition Processes in Tree Growth Dynamics: An A Priori Spatial Modeling Approach. Am Nat 2007; 169:647-61. [PMID: 17427135 DOI: 10.1086/513492] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Accepted: 12/06/2006] [Indexed: 11/03/2022]
Abstract
Spatially oriented studies have examined the role of competition on plant populations and communities but not the combined effects of microsite heterogeneity and competition. The aim of this study was threefold: first, to apply and test a common geostatistical tool (semivariograms) to disentangle competition and microsite effects; second, to assess the results of this methodology against a generalized early stand development model for tree populations; and third, to examine the role and timing of microsite and competition processes in early population stages. We mapped and measured annual relative growth rates of trees in three different-aged ponderosa pine stands in Patagonia, Chile. We tested the relative support of five a priori semivariogram-based hypotheses and showed that through stand development, many sites followed our expected sequence of semivariogram models. These translated to initial spatially random growth followed by microsite-dominated, mixed microsite and competition, and finally pure competition effects on growth. Our approach will have many and diverse applications wherever processes differ in the type of spatial pattern they exhibit as well as in spatial scale. We emphasize that this methodology works best when there is strong a priori support for the hypotheses being tested but the timing, strength, and occurrence of processes are not known.
Collapse
Affiliation(s)
- Alex Fajardo
- Forest Management Department, College of Forestry and Conservation, University of Montana, Missoula, Montana 59812, USA.
| | | |
Collapse
|
26
|
|
27
|
Muller-Landau HC, Condit RS, Harms KE, Marks CO, Thomas SC, Bunyavejchewin S, Chuyong G, Co L, Davies S, Foster R, Gunatilleke S, Gunatilleke N, Hart T, Hubbell SP, Itoh A, Kassim AR, Kenfack D, LaFrankie JV, Lagunzad D, Lee HS, Losos E, Makana JR, Ohkubo T, Samper C, Sukumar R, Sun IF, Nur Supardi MN, Tan S, Thomas D, Thompson J, Valencia R, Vallejo MI, Muñoz GV, Yamakura T, Zimmerman JK, Dattaraja HS, Esufali S, Hall P, He F, Hernandez C, Kiratiprayoon S, Suresh HS, Wills C, Ashton P. Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models. Ecol Lett 2006; 9:589-602. [PMID: 16643304 DOI: 10.1111/j.1461-0248.2006.00915.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and > 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality.
Collapse
|
28
|
Muller-Landau HC, Condit RS, Chave J, Thomas SC, Bohlman SA, Bunyavejchewin S, Davies S, Foster R, Gunatilleke S, Gunatilleke N, Harms KE, Hart T, Hubbell SP, Itoh A, Kassim AR, LaFrankie JV, Lee HS, Losos E, Makana JR, Ohkubo T, Sukumar R, Sun IF, Nur Supardi MN, Tan S, Thompson J, Valencia R, Muñoz GV, Wills C, Yamakura T, Chuyong G, Dattaraja HS, Esufali S, Hall P, Hernandez C, Kenfack D, Kiratiprayoon S, Suresh HS, Thomas D, Vallejo MI, Ashton P. Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests. Ecol Lett 2006; 9:575-88. [PMID: 16643303 DOI: 10.1111/j.1461-0248.2006.00904.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 old-growth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory's predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it, and were inconsistent with the predictions of metabolic ecology in all forests.
Collapse
|
29
|
Pretzsch H, Schütze G. Crown allometry and growing space efficiency of Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.) in pure and mixed stands. PLANT BIOLOGY (STUTTGART, GERMANY) 2005; 7:628-39. [PMID: 16388466 DOI: 10.1055/s-2005-865965] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In pure and mixed stands of Norway spruce ( Picea abies [L.] Karst.) and European beech ( Fagus sylvatica L.) we have analyzed crown allometry and growing space efficiency at the tree level and have scaled this from tree level to stand level production. Allometry is quantified by the ratio A between the relative growth rates of laterally and vertically oriented tree dimensions. Efficiency parameters, EOC for efficiency in space occupation, EEX for efficiency in space exploitation, and EBI for efficiency in biomass investment, were evaluated, based on quantity and quality of growing space and were measured using crown size and competition index. The evaluation reveals why pure stands of spruce are preferred by foresters, even though the natural vegetation would be dominated by beech. Spruce occupies its share of resources intensively by means of tightly packed pillar-like crowns, whereas beech seizes resources extensively by means of a multi-layered, veil-like canopy. With a given relative biomass increment, beech achieves a 57 % higher increment in crown projection area and a 127 % higher increment in height due to its particular capacity of lateral and vertical expansion. Beech trees are approximately 60 % more efficient in space occupation than spruce trees, however, on average, they are about 70 % less efficient in space exploitation. As a vertical fast growing tree, spruce is efficient in space exploitation under constant conditions, but far more susceptible to disturbances and less well equipped to overcome them when compared with beech. Beech is weaker in terms of space exploitation, while being superior in space occupation, where it encircles competitors and fills gaps after disturbances, which is a successful long-term strategy. A mixture of the two species reduces stand level production by 24 % in comparison to a pure spruce stand, however, when considering enhanced stabilization of the whole stand and risk distribution in the long term, the mixed stand may exceed the production level of pure spruce stands. EEX reflects a strong ontogenetic drift and competition effect that should be considered when scaling from tree to stand level production.
Collapse
Affiliation(s)
- H Pretzsch
- Chair of Forest Yield Science, Faculty of Forest Science and Resource Management, Technical University of Munich, Am Hochanger 13, 85354 Freising-Weihenstephan, Germany.
| | | |
Collapse
|
30
|
Pretzsch H. Species-specific allometric scaling under self-thinning: evidence from long-term plots in forest stands. Oecologia 2005; 146:572-83. [PMID: 16247620 DOI: 10.1007/s00442-005-0126-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Accepted: 12/08/2004] [Indexed: 10/25/2022]
Abstract
Experimental plots covering a 120 years' observation period in unthinned, even-aged pure stands of common beech (Fagus sylvatica), Norway spruce (Picea abies), Scots pine (Pinus sylvestris), and common oak (Quercus Petraea) are used to scrutinize Reineke's (1933) empirically derived stand density rule [see text], N=tree number per unit area, [see text]=mean stem diameter), Yoda's (1963) self-thinning law based on Euclidian geometry ([see text] [see text]=mean biomass per tree), and basic assumptions of West, Brown and Enquist's (1997, 1999) fractal scaling rules ([see text] [see text] w=biomass per tree, d=stem diameter). RMA and OLS regression provides observed allometric exponents, which are tested against the exponents, expected by the considered rules. Hope for a consistent scaling law fades away, as observed exponents significantly correspond with the considered rules only in a minority of cases: (1) exponent r of [see text] varies around Reineke's constant -1.605, but is significantly different from r=-2, supposed by Euclidian or fractal scaling, (2) Exponent c of the self-thinning line [see text] roams roughly about the Euclidian scaling constant -3/2, (3) Exponent a of [see text] tends to follow fractal scaling 8/3. The unique dataset's evaluation displays that (4) scaling exponents and their oscillation are species-specific, (5) Euclidian scaling of one relation and fractal scaling of another are coupled, depending on species. Ecological implications of the results in respect to self-tolerance (common oak>Norway spruce>Scots pine>common beech) and efficiency of space occupation (common beech>Scots pine>Norway spruce>common oak) are stressed and severe consequences for assessing, regulating and scheduling stand density are discussed.
Collapse
Affiliation(s)
- Hans Pretzsch
- Chair of Forest Yield Science, Faculty of Forest Science and Resource Management, Technical University of Munich, Am Hochanger 13, 85354, Freising, Germany.
| |
Collapse
|
31
|
Lepik M, Liira J, Zobel K. High shoot plasticity favours plant coexistence in herbaceous vegetation. Oecologia 2005; 145:465-74. [PMID: 15983752 DOI: 10.1007/s00442-005-0142-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Accepted: 04/22/2005] [Indexed: 10/25/2022]
Abstract
Several theoretical considerations imply that high shoot morphological plasticity could increase competition symmetry and favour plant coexistence. We tested whether mean plasticity across co-occurring species is a key trait for explaining ramet density and species richness in herbaceous vegetation. We used three data sets to test the hypotheses: (a) experimentally achieved estimates of plasticity to light availability for 35 herbaceous species; (b) richness, ramet density and canopy architecture data from 17 herbaceous communities; (c) species richness data from a 5-year permanent-plot study in a calcareous grassland. In herbaceous communities containing species with relatively higher shoot plasticity, ramet density was significantly higher. Consequently, relatively more species were growing per unit area-a greater proportion of the community species pool was represented on 1 m(2). In the permanent plot study species-richness was higher in those 40 x 40 cm quadrats where species with high shoot plasticity prevailed-there was a positive regression of richness on the mean plasticity of species. This relationship was highly significant in five consecutive years. Our results suggest that shoot plasticity to light availability is evidently one of the key traits in processes that alter the density of co-existing plants and, therefore, species diversity in herbaceous communities.
Collapse
Affiliation(s)
- Mari Lepik
- Institute of Botany and Ecology, Tartu University, 40 Lai St, 51005 Tartu, Estonia.
| | | | | |
Collapse
|