DOI: 10.5061/dryad.59zw3r2ff
title: Long-term effects of intercropping on multi-trophic structure and bio-thermodynamic health of mixed Eucalyptus-native tree plantations

description: 1. The intercropping approach of Eucalyptus and native trees has
 been widely recommended, as an ideal replacement for
 monoculture Eucalyptus plantations (EUs), to ameliorate global
 biodiversity loss and mitigate environmental change. However, both
 suitable native tree species and the best intercropping ratio
 between Eucalyptus and native trees have not been determined.
 2. To fill this gap, a four-level intercropping gradient of
 Eucalyptus urophylla planted with eight native tree species was set up
 (i.e., 20%NS, 30%NS, 40%NS, 50%NS), monitored and compared to a
 monoculture E. urophylla plantation (EU) and a randomly mixed plantation
 of nine native tree species (NS) in southern China. 3. The
 results showed that the intercropping ratio of Eucalyptus and native trees
 had a long-term effect on tree layer structure and health status and a
 cascading effect on the thermodynamic health state of soil microbes.
 Shade-tolerant woody species are more suitable for intercropping with
 Eucalyptus. Intercropping plantations with not less than 30% native trees
 were more favorable for long-term survival and growth of both planted
 Eucalyptus and native trees and provided much more favorable conditions
 for the natural immigration of other native trees, which leads to a
 healthy plant community with significantly higher eco-exergy compared to
 EU. The initial mixing ratio between Eucalyptus and high diversity native
 trees affected soil fertility through its long-term effects on the
 biodiversity and bio-thermodynamic state of trees and soil microbes. 4.
 Synthesis and applications. Our results highlight the long-term positive
 effect of the intercropping ratio of Eucalyptus and high diversity native
 trees on multi-trophic biodiversity conservation, bio-thermodynamic health
 development, and soil fertility conservation. In the conversion of
 monoculture Eucalyptus plantations (EU) to multi-species plantations, it
 is recommended to mix more than 30% native tree species that have
 different ecological niches with Eucalyptus.
description: 1. Change of species abundance: Species abundance (Ind/ha) of
 each tree species in the six types of forest plantations from 2006 (1a) to
 2018 (13 a) were given in this file, based on field investigation.
 Detailed field investigation method is available in our paper which will
 be published on Journal of Applied Ecology. The average species abundance
 of each tree was calculated based on three replicated plots for each of
 the six types of forest plantations. The six forest plantations are
 monoculture <em>Eucalyptus urophylla</em> plantation (EU);
 four types of mixed forest plantations of <em>E.
 urophylla</em> and native tree species (20%NS, 30%NS, 40%NS,
 50%NS), and randomly mixed plantation of nine native tree
 species (NS). 2. Tree layer: Plant biomass density
 (t/ha), diameter at breast height (DBH, cm), height (m), crown (cm) and
 mortality (%) for<em> E. urophylla</em> and native trees in
 the six types of mixed forest plantations were given in this file. Three
 repetitive plots were investigated for each type of forest plantation. The
 biomass density of <em>E. urophylla</em> and native trees was
 calculated by Eqn 1 and 2, respectively. Details can be checked out in the
 method section of our paper which will be published on Journal of Applied
 Ecology. The six forest plantations are monoculture <em>Eucalyptus
 urophylla</em> plantation (EU); four types of mixed forest
 plantations of <em>E. urophylla</em> and native tree
 species (20%NS, 30%NS, 40%NS, 50%NS), and randomly mixed plantation of
 nine native tree species (NS). 3. Plant community:
 Eco-exergy (KJ/m2), specific eco-exergy (KJ/g), biomass (t/ha), species
 richness, Shannon-Wiener index, evenness of three plant layers (trees,
 shrubs and herbs) and the plant community as a whole for the six types of
 forest plantations, were given in this file based on field investigation
 done in 2018, 13 years after planting. Three repetitive plots for each
 type of forest plantation, were investigated. Detailed investigation and
 calculation methods can be checked out in the method section of our paper
 which will be published in the Journal of Applied Ecology. The six forest
 plantations are monoculture <em>Eucalyptus
 urophylla</em> plantation (EU); four types of mixed forest
 plantations of <em>E. urophylla</em> and native tree
 species (20%NS, 30%NS, 40%NS, 50%NS), and randomly mixed plantation of
 nine native tree species (NS). 4. Soil fauna:
 Shannon-Wiener, evenness, species richness, abundance (ind/ha), biomass
 (kg/ha), eco-exergy (KJ/m<sup>2</sup>), specific
 eco-exergy(KJ/g) of soil fauna represented here were collected from 0–20
 cm soil layer at each plot during the dry and wet seasons, respectively,
 in 2018, 13 years after planting. Detailed investigation and calculation
 methods can be checked out in the method section in our paper which will
 be published in the Journal of Applied Ecology. The six forest plantations
 are monoculture <em>Eucalyptus urophylla</em> plantation (EU);
 four types of mixed forest plantations of <em>E.
 urophylla</em> and native tree species (20%NS, 30%NS, 40%NS,
 50%NS), and randomly mixed plantation of nine native tree
 species (NS). 5. Soil microbial community: Eco-exergy
 (KJ/m<sup>2</sup>), specific eco-exergy (KJ/g), and soil
 microbe phospholipid fatty acids (PLFAs, ng/g) represented here were
 collected from 0-20 cm soil layer at each plot during the dry and wet
 seasons, respectively, in 2018, 13 years after planting. The groupings of
 soil microbe are actinomycetes, arbuscular mycorrhizal fungi (AFM), fungi,
 general bacteria (GB), gram-negative bacteria (G-), gram-positive bacteria
 (G+). The sum of the above two specific PLFAs was assumed to represent
 total fungal abundance. The ratio of fungal to bacterial PLFAs( G-, G+, GB
 and 15:0, 17:0 ) (F/B) was calculated as an indicator of the microbial
 community structure. The sum of all PLFAs mentioned above was used to
 represent the total PLFAs of the soil microbial community. Detailed
 investigation and calculation methods can be checked out in the method
 section of our paper which will be published in the Journal of Applied
 Ecology. The six forest plantations are monoculture <em>Eucalyptus
 urophylla</em> plantation (EU); four types of mixed forest
 plantations of <em>E. urophylla</em> and native tree
 species (20%NS, 30%NS, 40%NS, 50%NS), and randomly mixed plantation of
 nine native tree species (NS). 6. Soil: SOC (g/kg),
 NO<sup>-</sup><sub>3</sub>-N (mg/kg),
 NH<sup>+</sup><sub>4</sub>-N (g/kg), AP (mg/kg),
 AK (mg/kg) were measured for three soil layers (0–20 cm, 20–40 cm, 40–60
 cm) at each plot during the dry and wet seasons, respectively, in 2018, 13
 years after planting. Detailed investigation and calculation methods can
 be checked out in the method section in our paper which will be published
 in the Journal of Applied Ecology. The six forest plantations are
 monoculture <em>Eucalyptus urophylla</em> plantation (EU);
 four types of mixed forest plantations of <em>E.
 urophylla</em> and native tree species (20%NS, 30%NS, 40%NS,
 50%NS), and randomly mixed plantation of nine native tree
 species (NS). For detailed dataset collection and
 processing information, please check Wang Y, Lin Y, Zhang L, Liu S, Wang
 J, Tian Y, Campbell DE, Lin R, Ren H, Lu H. 2023. Long-term effects of
 intercropping on multi-trophic structure and bio-thermodyanmic health of
 mixed Eucalyptus-native tree plantations. Journal of Applied Ecology
 (JAPPL-2023-00679).
description: Datasets included:   1\) Change of species abundance: * Time: 2016 and
 2018 (1 and 13 years after planting) * Latin name of each tree species *
 Abundance: Number of trees per unit area   2\) Tree layer: * Time: 2018
 (13 years after planting) * Grouping trees as *E. urophylla* and native
 trees * Plant biomass density (biomass per unit area in *E. urophylla* and
 native trees roles, respectively) * Average diameters at breast height for
 *E. urophylla* and native trees * Average heights for *E. urophylla* and
 native trees * Average crown sizes for *E. urophylla* and native trees *
 Mortality rates for *E. urophylla* and native tree   **3) Plant
 community:** * Time: 2018 (13 years after planting) * Grouping plants into
 three layers (trees, shrubs and herbs) and plant community as a whole *
 Eco-exergy indicates the genetic complexity embedded in the biomass of
 each plant community * Specific eco-exergy, indicates the eco-exergy per
 unit biomass for each plant community * Biomass per unit area of each
 plant community * Richness indicates species richness of each plant
 community * Shannon.Wiener indicates Shannon-Wiener index of each plant
 community * Evenness indicates Pielou index of each plant community   4\)
 Soil fauna: * Time: 2018 (13 years after planting) * Season: dry and wet
 seasons * Shannon.Wiener indicates Shannon-Wiener index of soil fauna *
 Evenness indicates Pielou index of soil fauna * Richness indicates species
 richness of soil fauna * Abundance indicates numbers of soil fauna per
 unit area * Biomass per unit area of soil fauna * Eco-exergy indicates the
 genetic complexity embedded in the biomass of soil fauna * Specific
 eco-exergy indicates the community eco-exergy per unit biomass of soil
 fauna   5\) Soil microbial community: * Time: 2018 (13 years after
 planting) * Season: dry and wet season * Actinomycetes PLFA *
 AMF(arbuscular mycorrhizal fungi) PLFA * Fungi PLFA * General bacteria
 PLFA * Gram negative bacteria PLFA * Gram positive bacteria PLFA * F/B
 indicates the ratio of fungal(AMF, Fungi) to bacterial PLFAs (general
 bacteria, gram negative bacteria, gram positive bacteria and 15:0, 17:0 )
 * Total PLFA indicates total PLFAs of the soil microbial community *
 Eco-exergy indicates genetic complexity embedded in the biomass of soil
 fauna community * Specific eco-exergy indicates community eco-exergy per
 unit biomass of soil fauna community   6\) Soil : * Time: 2018 (13 years
 after planting) * Soil layers: 0-20 cm, 20-40 cm, 40-60 cm * SOC indicates
 soil organic carbon contents * NO3--N indicate concentration of nitrate
 nitrogen (NO3--N) * NH4+-N indicates concentration of ammonium nitrogen
 (NH4+-N) * AP indicates soil available potassium contents * AK indicates
 soil available phosphorus contents   \**Stand type: **6 stand types, i.e.,
 a four-level intercropping gradient of *E. urophylla* planted with eight
 native tree species (20%NS, 30%NS, 40%NS, 50%NS) were set up as
 treatments, with a monoculture *E. urophylla *plantation (EU) and a
 randomly mixed plantation of nine native tree species (NS) as controls.
 All six types of plantations were set up by planting one-year-old seedings
 with a 3 m × 2 m spacing on homogeneous degraded hilly land in 2005, after
 it was initially burned in 2004.