TY - JOUR

T1 - Long-term ecological responses of a lowland dipterocarp forest to climate changes and nutrient availability

AU - Prohaska, Ana

AU - Seddon, Alistair W. R.

AU - Rach, Oliver

AU - Smith, Andrew

AU - Sachse, Dirk

AU - Willis, Katherine J.

N1 - Publisher Copyright: New Phytologist© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.

PY - 2023

Y1 - 2023

N2 - Understanding the long-term impact of projected climate change on tropical rainforests is critical given their central role in the Earth's system. Palaeoecological records can provide a valuable perspective on this problem. Here, we examine the effects of past climatic changes on the dominant forest type of Southeast Asia – lowland dipterocarp forest. We use a range of proxies extracted from a 1400-yr-old lacustrine sedimentary sequence from north-eastern Philippines to determine long-term vegetation responses of lowland dipterocarp forest, including its dominant tree group dipterocarps, to changes in precipitation, fire and nutrient availability over time. Our results show a positive relationship between dipterocarp pollen accumulation rates (PARs) and leaf wax hydrogen isotope values, which suggests a negative effect of drier conditions on dipterocarp abundance. Furthermore, we find a positive relationship between dipterocarp PARs and the proxy for phosphorus availability, which suggests phosphorus controls the productivity of these keystone trees on longer time scales. Other pollen taxa show widely varying relationships with the abiotic factors, demonstrating a high diversity of plant functional responses. Our findings provide novel insights into lowland dipterocarp forest responses to changing climatic conditions in the past and highlight potential impacts of future climate change on this globally important ecosystem.

AB - Understanding the long-term impact of projected climate change on tropical rainforests is critical given their central role in the Earth's system. Palaeoecological records can provide a valuable perspective on this problem. Here, we examine the effects of past climatic changes on the dominant forest type of Southeast Asia – lowland dipterocarp forest. We use a range of proxies extracted from a 1400-yr-old lacustrine sedimentary sequence from north-eastern Philippines to determine long-term vegetation responses of lowland dipterocarp forest, including its dominant tree group dipterocarps, to changes in precipitation, fire and nutrient availability over time. Our results show a positive relationship between dipterocarp pollen accumulation rates (PARs) and leaf wax hydrogen isotope values, which suggests a negative effect of drier conditions on dipterocarp abundance. Furthermore, we find a positive relationship between dipterocarp PARs and the proxy for phosphorus availability, which suggests phosphorus controls the productivity of these keystone trees on longer time scales. Other pollen taxa show widely varying relationships with the abiotic factors, demonstrating a high diversity of plant functional responses. Our findings provide novel insights into lowland dipterocarp forest responses to changing climatic conditions in the past and highlight potential impacts of future climate change on this globally important ecosystem.

KW - climate change

KW - El Niño–Southern Oscillation

KW - fire activity

KW - forest productivity

KW - nutrient availability

KW - plant community composition

KW - tropical rainforest

KW - vegetation responses

U2 - 10.1111/nph.19169

DO - 10.1111/nph.19169

M3 - Journal article

C2 - 37604200

AN - SCOPUS:85168567197

VL - 240

SP - 2513

EP - 2529

JO - New Phytologist

JF - New Phytologist

SN - 0028-646X

IS - 6

ER -