I have often written about how God has endowed Earth with ample resources and given humans the responsibility to manage those resources for the benefit of all life. New studies show that such stewardship of the world’s forests can help slow global warming, boost the global economy, enhance the world’s ecosystems, and beautify our forests.
In my book Weathering Climate Change, I explained how selective logging could make a major contribution to rectifying climate change while boosting the world economy and substantially enhancing the world’s ecosystems.1 My explanation was based on research studies showing that young trees grow 2–4 times faster than old trees that are approaching death. Selectively harvesting some, but not all, the large old trees in a forest while they are still healthy sequesters their carbon as building material and furniture. On the other hand, permitting all the old trees in a forest to die and decay releases their carbon into the atmosphere. Thus, replacing the logged old trees with seedlings that become young trees greatly increases the amount of carbon dioxide that a forest removes from the atmosphere.
In this manner, well-managed selective logging of forests can make a major contribution to slowing global warming and climate change. It also increases the financial return from logging since healthy old trees deliver the most valuable timber. Forest ecosystems benefit as well. Decreasing the amount of fallen dead and decaying trees makes travel in the forest easier for birds and mammals. Increasing the ratio of young to old trees provides more food for all forest animals.
Measuring Forest Ecosystem Metrics
It is relatively straightforward to measure the comparative lumbering financial returns of different forest management practices. It is also straightforward to determine to what degree different forest management strategies remove greenhouse gases from the atmosphere. The big challenge for forestry researchers is to objectively measure forest ecosystem vitality and functionality.
During the past few decades, ecologists determined forest ecosystem health by measuring species biodiversity (number of species present) in different forest environments. This approach led them to conclude that undisturbed old-growth forests were ecologically healthier than any kind of logged forest since, in most cases, especially in tropical forests, forests disturbed by logging showed a decline in old-growth specialist species.2 In some instances, ecologists also observed a decline in other forest species.3
Recently, a team of 11 environmentalists led by Yadvinder Malhi developed an alternative approach to measuring forest ecosystem health.4 They measured the energetics of birds, mammals, insects, trees, and plants within different forest systems. They augmented these measurements with counts of the number of species, the total biomasses of each species, and the relative dominance of species within the different forest systems.
For their study, Malhi’s team compared four old-growth unlogged forests with five different logged forests and one oil palm plantation in Malaysian Borneo. They collected data from 882 camera sampling locations. At these locations they installed cameras that automatically take photographs when animals pass by. They also captured small mammals at 1,488 different sites, bats at 336 different locations, and counted birds at 508 different places. Malhi and his colleagues complemented their data collection with 14,000 litterfall (dead plant material) measurements, 20,000 measurements of tree diameters, and 2,700 fine root samples.
Forest Ecosystem Energetics
The team’s field observations and measurements revealed that logged forests compared to unlogged forests yielded both greater animal biodiversity and animal biomass and were ecologically more energetic. The difference was not minor. The logged forests showed, on average, a 2.5 times greater increase in total resource consumption by both birds and mammals. In every case the total weight of birds and mammals was higher in a logged forest than in an unlogged forest. Malhi’s team discerned several reasons for this enormous increase.
1. Selective logging of large mature trees creates small gaps in the forest canopy. Such gaps are filled by shrubs, large herbs, and young fast-growing trees that efficiently exploit the increased sunlight falling on the forest floor. These plants possess greater vegetation palatability since they typically invest their energy into capturing light for the photosynthetic manufacture of sugars and starches and tissue growth rather than in chemicals, tough skins and woods, and spines for defenses against herbivores. Gaps in the forest canopy also make forest leaves more accessible for birds and mammals and especially for insects.
2. Malhi’s team observed that insects thrived in logged forests. Therefore, they measured a marked increase in the number and sizes of insect-eating birds in logged compared to unlogged forests. These birds enhanced the health of logged forests by dramatically reducing insect pest pressure, which lowered the tree death rate and furthered tree growth.
3. The team observed a steep drop in biodiversity and biomass in the oil palm plantation. This decline was especially dramatic for birds and mammals. They attributed the primary cause to the much lower canopy height for the oil palm plantation. The lower canopy made it more difficult for animals to hide from and escape predators. The secondary cause was the lack of plant and tree diversity. They agreed with other research teams’ conclusions that deforestation, as opposed to sustainable logging, always degrades biodiversity and ecological health.
Malhi and his colleagues concluded that “conservation of logged forest landscapes has an essential role to play in the protection of global biodiversity and biosphere function.”5 Logged forests, compared to unlogged forests, amplify and diversify ecosystem energetics and improve ecosystem health.
How forests are logged makes a major difference in ecosystem health and in curbing global warming. Clear-cutting leaves large areas where no canopy exists, resulting in lower plant biodiversity, lower photosynthetic activity, and fewer places for animals to hide and rest. Selective harvesting of the mature trees, where these trees are replaced with fast-growing young trees, removes more carbon dioxide from the atmosphere while creating a healthier and more productive ecosystem for both plants and animals.
The environmental researchers explained that wise, economically productive forest management is not enough. Good forest management needs to be combined with effective policing of the logged forests.
Logging requires the construction of roads and trails. These roads and trails make it easier for humans to hunt birds and mammals. Effective policing is needed to reduce hunting pressure to sustainable levels.
Another benefit arises from wise, economically productive sustainable logging and effective regulation of hunting pressure. The forests become more accessible and more attractive for tourists. Many studies show that regular exposure to healthy, attractive forests enhances both human physical and mental health.6
Forests are a reminder of God’s marvelous works of creation—works that bountifully provide for all Earth’s life. As I explained in Improbable Planet, God meticulously created trees in a just-right sequence, just-right diversity, and just-right abundance to perfectly compensate for the Sun’s ongoing brightening.7 If God did not create trees in this manner, all life on Earth would have gone extinct 400 million years ago. Amazingly, God’s creation works in forests over the past 400 million years have culminated in forests today that optimally provide for humanity’s physical, mental, and spiritual well-being. Malhi’s team’s research has shown how we can better fulfill the mandate God gave in Genesis 1:26–30 to Adam and Eve and all their descendants to manage Earth and all its resources for the benefit of all life.
Hugh Ross, Weathering Climate Change: A Fresh Approach (Covina, CA: RTB Press, 2020), 209–211.
Luke Gibson et al., “Primary Forests Are Irreplaceable for Sustaining Tropical Biodiversity,” Nature 478 (October 20, 2011): 378–381, doi:10.1038/nature10425; Edmund W. Basham et al., “Vertical Stratification Patterns of Tropical Forest Vertebrates: A Meta-Analysis,” Biological Reviews, Cambridge Philosophical Society 98, no. 1 (February 2023): 99–114, doi:10.1111/brv.12896.
Zuzana Burivalova, Çağan Hakkı Şekercioğlu, and Lian Pin Koh, “Thresholds of Logging Intensity to Maintain Tropical Forest Biodiversity,” Current Biology 24, no. 16 (August 18, 2014): 1893–1898, doi:10.1016/j.cub.2014.06.065; Basham et al., “Vertical Stratification Patterns.”
Yadvinder Malhi et al., “Logged Tropical Forests Have Amplified and Diverse Ecosystem Energetics,” Nature 612 (December 22, 2022): 707–713, doi:10.1038/s41586-022-05523-1.
Malhi et al., “Logged Tropical Forests,” 712.
Hugh Ross, “Playing in Forests Benefits Children,” Today’s New Reason to Believe (blog), Reasons to Believe, November 23, 2020.
Hugh Ross, Improbable Planet: How Earth Became Humanity’s Home (Grand Rapids, MI: Baker Books, 2016), 183–197.
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