Biodiversity Collapse: Climate Change Threatens the Andes & Amazon Forests

The detrimental impacts of climate change are particularly noticeable and documented in forest ecosystems. In particular, the Andean and Amazon Forest ecological zones contribute heavily to carbon storage and biodiversity conservation, so it is crucial to measure and understand their species' richness in response to climate change.

This blog highlights a study by Fadique et al., titled ‘Tree diversity is changing across tropical Andean and Amazonian forests in response to global change,’ published in January 2026 in Nature Ecology & Evolution. The study analyzes data from 406 permanent plots monitored over four decades, with the intent to measure and understand the changing dynamics of the forests, particularly shifts in tree-species richness.  

Why This Matters

• Tree species diversity impacts many characteristics of a forest ecosystem: In response to climate change, a decline in tree species can negatively impact animals that depend on them for habitat and food, accelerating biodiversity loss. As trees change, so do ecosystem functions, which affect the survival of other species and the overall health of the forest.

  
  

• Measuring Carbon Storage: Diversity and abundance of tree species directly influence how much carbon a forest can store. Forests with fewer and/or less diverse trees hold less carbon, which impacts climate mitigation strategies, including carbon offsets.

  
  

• Extreme Weather Patterns: Weather events like droughts and rainfall variability can drive species migration, disrupting ecosystem balance. Studying how species adapt or relocate can help researchers better understand the ecological impacts of climate change and anticipate future forest dynamics.

Focus of the Study

In this study, 406 plots were monitored over different time periods beginning in 1971. These plots span ten Latin American countries and were analyzed to estimate the tree-species richness (the number of different tree species present in each area-specified plot)-- and changes over time.

(a) Map showing the distribution of 406 plots (arrowhead symbols located at plot coordinates) in the six study regions. Symbol color and angle represent richness change in direction, and symbol size is proportional to the magnitude of change for each plot. Black circles represent no change. (b) Richness change (% yr−1) per region expressed as proportional change in relation to the initial census. Tick marks represent individual plots. The shaded area represents the density distribution of the plots. Source linked here.

The researchers also examined potential drivers, including temperature trends, precipitation patterns and seasonality, elevation, and levels of forest fragmentation. They hypothesized that different regions are responding to climate change in distinct ways over time.

It is important to note that the impacts of climate change are not evenly distributed across all ecosystems. Applying these methods to understand and identify the spatial distribution of tree diversity and the factors that influence it helps us understand the Andes and Amazon rainforests specifically. This can inform predictions of future changes in biodiversity patterns as well as establishing effective conservation efforts.

The study aims to answer two questions:

• How is tree species richness changing across the Andes-Amazon area?

• How are changes in richness related to baseline climate, climate change, landscape context, and forest structure?

Results

Several factors influencing changes in tree-species richness showed that higher temperatures, greater precipitation seasonality, and shifts in rainfall patterns were significantly linked to declines in tree species richness.

For example, temperature change observed a “hump-shaped” relationship to richness, decreasing slightly with lower temperatures and decreasing at a faster pace when temperatures warmed faster.

The researchers observed a positive relationship between annual rainfall, abundance change, integrity of landscape, elevation, and identification effort change. Precipitation played a large role in predicating richness change as well, as species richness decline was more abrupt for forests that weren’t as seasonal.

Over the four-decade study period, hotter forests experiencing more pronounced seasonal changes lost more tree species than forests with greater tree density and higher landscape integrity. Additionally, forests undergoing faster warming, typically in the central-eastern and southern Amazon, lost species at a faster rate than forests that don’t experience intense warming.

Connecting to Conservation:

The study findings suggest that forests in less fragmented areas that are surrounded by contiguous forests, are more likely to experience increases in species richness. Conversely, forests that become increasingly isolated tend to show a decline in species richness. This demonstrates the importance of targeted conservation efforts in rainforests, particularly in the Andes-Amazon region.

Precipitation and seasonality (the variability of environmental conditions such as temperature or rainfall) play significant roles in species richness within the Andes-Amazon as well. Higher seasonality shows a relationship with lower species richness, especially in trees experiencing greater seasonal variation.

The results of this study ultimately demonstrate the urgent need to address global warming and climate change, particularly by preserving large forests and ecosystems, especially the Andes and Amazon rainforests.

The Amazon as a Catalyst for Climate Efforts

The impacts of climate change are not uniform across ecosystems, indicating the need for mitigation and conservation strategies to be tailored to the specific conditions of each region. It's no surprise that the Amazon rainforest is home to millions of different plant and animal species: it is crucial for global climate change efforts because it covers almost seven million square kilometers and contains an immense range of biodiversity. It serves as a large carbon sink, storing over 150 billion metric tons of carbon. Its vast size and diversity mean that changes in the Amazon can have major effects on the global climate. The Amazon rainforest serves as a large carbon sink, storing over 150 billion metric tons of carbon.

Take Action

• Asset owners: Ensure that investments are geared towards companies prioritizing the prevention of habitat fragmentation and deforestation.

  
  

• Corporations: Supply chains rely on stable ecosystems, including consistent rainfall and seasonal patterns. Climate change increases the risk of droughts and fires, thus leading to potential supply chain disruptions for many corporations.

  
  

• Lenders: Loans might be negatively impacted by deforestation, declining tree species richness, and other consequences of climate change. It’s important for lenders to be aware of these risks and engage in financially responsible behavior that prioritizes minimizing damage to forests.

Main source: Fadrique, B., Costa, F., Cuesta, F. et al. Tree diversity is changing across tropical Andean and Amazonian forests in response to global change. Nat Ecol Evol 10, 267–280 (2026). https://doi.org/10.1038/s41559-025-02956-5

Cover image: Lingchor on Unsplash.