Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1111/ddi.12956
Licence creative commons licence
Title (Primary) Effects of altitude, land use and microsites on early life performance of a high mountain tree: Insights from an in situ sowing experiment
Author Cáceres, Y.; Schrieber, K.; Lachmuth, S.; Auge, H. ORCID logo ; Argibay, D.; Renison, D.; Hensen, I.
Source Titel Diversity and Distributions
Year 2019
Department BZF; iDiv
Volume 25
Issue 10
Page From 1537
Page To 1550
Language englisch
Data and Software links https://doi.org/10.5061/dryad.7c2g5rn
Supplements https://onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1111%2Fddi.12956&file=ddi12956-sup-0001-Supinfo.docx
Keywords abiotic factors; competition; facilitation; livestock; microsites; Polylepis australis; recruitment; safe sites; seed regeneration; seedlings; environmental gradient; land use; livestock grazing; mountains; restoration; seedling establishment; South America; trees; microhabitat
Abstract

Aim

Understanding the forces that drive range shifts in forest landscapes is imperative for predicting species distributions under anthropogenic climate and land use change. However, empirical studies exploring how these components jointly influence critical early life stages of mountain tree species across environmental gradients are scarce. We used the high mountain tree Polylepis australis as model species to investigate the relative importance of altitude and associated climatic conditions, land use for livestock and microsite characteristics on early life performance.

Location

Córdoba Sierras, central Argentina.

Methods

We set up an extensive in situ sowing experiment with a robust split‐plot design that integrated spatial scales ranging from 0.4 m2 subplots at the microsite level (associated with vegetative and microtopographic structures), to livestock exclosure and enclosure plots of several hectares, to an altitudinal gradient of 1,000 m. Components of early life performance were monitored across two subsequent growing seasons.

Results

Microsite characteristics played a fundamental role in P. australis establishment, whereby interactions with altitude and/or land use suggested alternate mechanisms: facilitation (likely reduced desiccation) dominated at low altitude while at high altitude, abiotic stress (likely intensive frost and radiation) overruled any microsite effects. At mid‐altitude, benefits of competition release prevailed over facilitation and microsite effects gained importance under livestock presence. Inconsistencies between pre‐ and post‐emergence responses illustrated potential trade‐offs between beneficial and detrimental effects of microsite conditions upon performance throughout early life: a favourable location for seeds may abruptly turn adverse for seedlings.

Main conclusions

We unravel how changes in altitude, anthropogenic disturbances and microsite characteristics jointly modulate P. australis performance across stages of early establishment. Such information is fundamental when categorizing specific microhabitats as “safe sites” for tree regeneration especially in mountain environments with high spatio‐temporal heterogeneity.

Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=22017
Cáceres, Y., Schrieber, K., Lachmuth, S., Auge, H., Argibay, D., Renison, D., Hensen, I. (2019):
Effects of altitude, land use and microsites on early life performance of a high mountain tree: Insights from an in situ sowing experiment
Divers. Distrib. 25 (10), 1537 - 1550 10.1111/ddi.12956