MataDIV is a tree diversity experiment that aims to improve our understanding of the functioning of restored forests in the highly-diverse tropical Atlantic forest biome (Mata Atlântica) under climate change, and to provide scientific bases for the design of forest restoration guidelines.
MataDIV was planted on November/December 2019, in the Itatinga research station (University of São Paulo / ESALQ), southern Brazil, in a former Eucalyptus coppice parcel. The experiment focuses on six native species of great restoration and/or silvicultural interest, which display contrasted ecological strategy and are widely distributed in the Mata Atlântica.
The MataDIV experiment is combined with an observational site (MataFLUX, installed in 2020) that measures the water, carbon and energy cycling of a 6-species mixture restoration planting using the Eddy-covariance technique and soil water monitoring. The same 6-species pool is studied in MataDIV and MataFLUX.
The MataDIV/MataFLUX project results from a collaboration between the University of São Paulo / ESALQ (LASTROP - Tropical silviculture Lab) and the Cirad (the French agricultural research and international cooperation organization, Eco&Sols Research unit).

The google Maps image is dated early 2019, during the harvest of the Eucalyptus coppice parcel. The red line indicates the total area of the MataDIV/MataFLUX project (30ha). The squares indicate the 144 plots of MataDIV (colours correspond to different replicated blocks).

Design

MataDIV consists of 144 plots (20 m x 23m, 100 trees), in a randomized split-plot block design. The experiment focuses on six species (but includes "high diversity" 20-species reference plots).
Three variables are manipulated:

• Species richness (six monocultures, four 3-species mixtures, one 6-species mixture and one 20-species mixture "high diversity" reference level). All of the six main species are equally represented at each diversity level ("broken-stick" design). In total 12 different compositions are included.
• Fertilization (no fertilization versus N, P, K, Ca, Mg fertilization)
• Water availability (normal rainfall versus throughfall exclusion). This treatment will be implemented ~1 year after planting.

Fertilization and water availability treatments are not fully crossed. The following combinations are studied: "fertilization and normal rainfall", "fertilization and throughfall exclusion", "no fertilization and normal rainfall". The experiment includes four replicated blocks, with 36 plots per blocks, in a total area of ~8ha.
The studied species are Cariniana estrellensis (CE), Cecropia pachystachya (CP), Guazuma ulmifolia (GU), Hymenaea courbaril (HC), Handroanthus impetigionosus (HI), Syagrus romanzoffiana (SR). Species can be categorised in three functional groups, from acquisitive (pioneer), to conservative (late-successional) species.

Diversity levels (Cariniana estrellensis (CE), Cecropia pachystachya (CP), Guazuma ulmifolia (GU), Hymenaea courbaril (HC), Handroanthus impetigionosus (HI), Syagrus romanzoffiana (SR)).

Codes of the diversity levels and experimental design with the different treatments.

Description of the planting scheme. In each plots, a central area comprising 36 trees was delimited for monitoring.

Site characteristics

location	Itatinga experimental station
former land use	Eucalyptus commercial coppice
altitude	820m
soil type	Deep Ferralsol
area	8ha
no of plots	144
plot size	20m x 23m - 460m²
no of trees planted	14 400
planting date	2019
diversity variables	species richness functional diversity
diversity gradient	1, 3, 6 sp 3 functional groups
size species pool	6 sp + 20 sp in the reference high-diversity plots
species pool	Cariniana estrellensis, Cecropia pachystachya, Guazuma ulmifolia, Hymenaea courbaril, Handroanthus impetigionosus, Syagrus romanzoffiana
contact persons	Joannès Guillemot (tree ecology) Pedro Brancalion (ecological restoration) Agnès Robin (soil ecology)

Research
The MataDIV experiment will be used to conduct research on the biological mechanisms driving biodiversity - Ecosystem functioning relationship, with a particular focus on tree - soil interactions and carbon, water, nutrient and energy cycling.

Extra information

For more information on the MataDIV experiment, send an e-mail to the contact persons or explore the publications:

• Messier C, Bauhus J, Sousa-Silva R, Auge H, Baeten L, Barsoum N, Bruelheide H, Caldwell B, Cavender-Bares J, Dhiedt E, Eisenhauer N, Ganade G, Gravel D, Guillemot J, Hall JS, Hector A, Hérault B, Jactel H, Koricheva J, Kreft H, Mereu S, Muys B, Nock CA, Paquette A, Parker JD, Perring MP, Ponette Q, Potvin C, Reich PB, Scherer-Lorenzen M, Schnabel F, Verheyen K, Weih M, Wollni M, Zemp DC (2021) For the sake of resilience and multifunctionality, let's diversify planted forests! Conservation Letters e12829 - https://doi.org/10.1111/conl.12829

November 2019 (photo: Eder Araujo da Silva)